Statistics of Petroleum Exploration in the 

World Outside the United States and Canada 

Through 2001 

Circular 1288 

U.S. Department of the Interior 

U.S. Geological Survey 

 

 

 

 

 

 

 

 

 

 

Statistics of Petroleum Exploration in the 

World Outside the United States and Canada 

Through 2001 

By Emil D. Attanasi, Philip A. Freeman, and Jennifer A. Glovier 

A summary of the geographic location, intensity, productivity, and results 

of petroleum exploration in the world outside the United States and Canada 

through 2001, including maps showing explored and delineated prospective 

areas. This Circular updates and expands the coverage of U.S. Geological 

Survey Circular 1096. 

Circular 1288 

U.S. Department of the Interior 

U.S. Geological Survey 
U.S. Department of the Interior 

Dirk kEmPThornE, Secretary 

U.S. Geological Survey 

mark D. myers, Director 

U.S. Geological Survey, reston, Virginia: 2007 

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Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report. 

Suggested citation: 

Attanasi, E.D., Freeman, P.A., and Glovier, J.A., 2007, Statistics of petroleum exploration in the world outside the 

United States and Canada through 2001: U.S. Geological Survey Circular 1288, 167 p. 

Library of Congress Cataloging-in-Publication Data 

Attanasi, E.D. 

Statistics of petroleum exploration in the world outside the United States and Canada through 2001 / by Emil D. 

Attanasi, Philip A. Freeman, and Jennifer A. Glovier. 

p. cm. (U.S. Geological Survey Circular ; 1288) 

Includes bibliographic references. 

1. Petroleum—Prospecting—Statistics. 2. Oil fields—Statistics. I. Freeman, Philip A. II. Glovier, Jennifer A. III. Title. IV. 

U.S. Geological Survey circular ; 1288. 

TN271.P4R66 2006 

533.2'8—dc22 

2006041703 

iSBn 978–1–411–30900–5 
iii 

Contents 

Abstract ..........................................................................................................................................................1
 

introduction ....................................................................................................................................................1
 

objectives and methods......................................................................................................................1
 

Summary of Findings and Limitations of Study................................................................................2
 

Exploration Process.......................................................................................................................................5
 

oil and Gas Exploration: Concepts and nomenclature ..................................................................5
 

oil and Gas Exploration: institutional Environment.........................................................................7
 

in the United States.....................................................................................................................7
 

outside the United States...........................................................................................................7
 

Exploration of Plays and Sedimentary Basins .................................................................................8
 

Discoveries across Provinces: United States and Study Area ..................................................10
 

measures of Exploration maturity ............................................................................................................12
 

Delineated Prospective Area and Explored Area: Definitions ....................................................14
 

measuring Productivity of Delineated Prospective Areas .........................................................16
 

Tools for Analysis: Graphs.................................................................................................................16
 

Statistics of Exploration and Analysis .....................................................................................................16
 

Exploration Effort.................................................................................................................................16
 

regional Exploration Statistics and Analysis.................................................................................17
 

mexico.........................................................................................................................................18
 

South America............................................................................................................................19
 

Europe..........................................................................................................................................19
 

middle East .................................................................................................................................36
 

Africa............................................................................................................................................36
 

Asia..............................................................................................................................................36
 

Southwestern Pacific................................................................................................................37
 

russia..........................................................................................................................................37
 

Study Area: Summary ...............................................................................................................38
 

Summary and Conclusions.........................................................................................................................38
 

Acknowledgments.......................................................................................................................................39
 

references Cited..........................................................................................................................................39
 

Figures 

[Figures 14–57 follow table 7] 

1.	 Diagram of types of wells leading to additions to reserves in 


discovered fields ...........................................................................................................................6
 

2.	 histogram showing the size-frequency distribution of oil and gas fields 


discovered through 1996 in the Permian Basin, West Texas and eastern 


new mexico, U.S.A. ....................................................................................................................8
 

3.	 Graph showing average sizes of fields discovered in 5-year intervals in 


the Permian Basin between 1920 and 1996 ............................................................................10
 
iv 

4. histograms showing the frequency distribution of cumulative recoverable 

hydrocarbon volumes for 57 onshore provinces of the conterminous 

United States and cumulative recoverable oil volumes for 173 provinces 

of the study area..........................................................................................................................11
 

5. Diagram for identifying and computing delineated prospective area ................................15
 

6. Generalized graphs of the possible profiles of the growth in the cumulative
 

prospective area and the explored area.................................................................................17
 

7. Graph showing that the average price of imported crude oil to U.S. refineries
 

led the annual wildcat drilling rate in the study area from 1968 through 2001 .................18
 

8. Graphs showing historical sequence by year of first discovery in each 


significant petroleum province and magnitude of cumulative recoverable 

oil discoveries through 2001 in each province for six regions ............................................20
 

9–13. Graphs for seven regions and the whole study area showing— 

9.	 Average annual volume of oil discovered offshore and onshore for 


5-year intervals from 1951 though 2000 ..........................................................................26
 

10.	 oil discovery rate per wildcat well for 5-year intervals from 1951 


through 2000........................................................................................................................28
 

11.	 Average annual volume of gas discovered offshore and onshore for
 

5-year intervals from 1951 through 2000.........................................................................30
 

12.	 Growth in delineated prospective area and explored area delineated
 

by wells drilled through 2001............................................................................................32
 

13.	 Cumulative recoverable oil and gas discoveries through 2001 plotted
 

as a function of cumulative delineated prospective area...........................................34
 

14–57. maps, graphs, and tables of data for oil and gas exploration through 2001 in—
 

14.	 Caribbean ............................................................................................................................64
 

15.	 Central America..................................................................................................................66
 

16.	 Suriname, Guyana, and French Guiana..........................................................................68
 

17.	 Chile......................................................................................................................................70
 

18.	 Argentina, Paraguay, Uruguay, and the Falkland islands ...........................................72
 

19.	 Ecuador................................................................................................................................74
 

20.	 Colombia. .............................................................................................................................76
 

21.	 Peru. .....................................................................................................................................78
 

22.	 Venezuela and Trinidad and Tobago ...............................................................................80
 

23.	 Bolivia...................................................................................................................................82
 

24.	 Brazil.....................................................................................................................................84
 

25.	 northern part of Western Europe....................................................................................86
 

26.	 Southern part of Western Europe ...................................................................................90
 

27.	 Eastern Europe ...................................................................................................................94
 

28.	 Turkey and Cyprus ..............................................................................................................98
 

29.	 Arabian Peninsula ............................................................................................................100
 

30.	 Syria, israel, Jordan, Lebanon, Gaza Strip, and the West Bank...............................104
 

31.	 iraq......................................................................................................................................106
 

32.	 iran......................................................................................................................................108
 

33.	 Cote d’ivoire, Ghana, Benin, Guinea-Bissau, Togo, Senegal, The Gambia,
 

Guinea, Sierra Leone, Liberia, and Cape Verde ..........................................................110
 

34.	 Ethiopia, Somalia, Eritrea, kenya, and Djibouti ...........................................................112
 

35.	 Angola.................................................................................................................................114
 
v 

36.	 nigeria................................................................................................................................116
 

37.	 Libya and Tunisia ..............................................................................................................118
 

38.	 Algeria and morocco.......................................................................................................120
 

39.	 Egypt ...................................................................................................................................122
 

40.	 mozambique, Tanzania, Burundi, malawi, and rwanda............................................124
 

41.	 South Africa, namibia, Botswana, Lesotho, Swaziland, Zambia,
 

and Zimbabwe...................................................................................................................126
 

42.	 Gabon, republic of the Congo (Brazzaville), Cameroon, Equatorial Guinea,
 

Democratic republic of the Congo (kinshasa), Central African republic,
 

and Sao Tome and Principe ............................................................................................128
 

43.	 Sudan, Chad, mauritania, niger, Burkina Faso, mali, Uganda, and 


Western Sahara................................................................................................................130
 

44.	 madagascar, Comoros, mauritius, Seychelles, and reunion...................................132
 

45.	 China and mongolia .........................................................................................................134
 

46.	 kazakhstan, Azerbaijan, Turkmenistan, Uzbekistan, Georgia, kyrgyzstan,
 

Tajikistan, and Armenia. ..................................................................................................138
 

47.	 Pakistan and Afghanistan. ..............................................................................................142
 

48.	 india, Bangladesh, Bhutan, maldives, nepal, and Sri Lanka....................................144
 

49.	 Vietnam, Burma, Thailand, Cambodia, and Laos.........................................................146
 

50.	 Japan, South korea, and north korea..........................................................................148
 

51.	 Philippines and Taiwan....................................................................................................150
 

52.	 indonesia............................................................................................................................152
 

53.	 malaysia, Brunei, and Singapore. .................................................................................156
 

54.	 Papua new Guinea, Fiji, new Caledonia, Solomon islands, Vanuatu,
 

French Polynesia, Guam, marshall islands, micronesia, northern mariana
 

islands, and Tonga............................................................................................................158
 

55.	 Australia and East Timor..................................................................................................160
 

56.	 new Zealand .....................................................................................................................162
 

57.	 russia .................................................................................................................................164
 

Tables 

[Tables 5–7 follow references Cited] 

1. Estimated world liquid hydrocarbon and natural gas consumption,
 

production, and reserves for 2002 ..............................................................................................3
 

2.	 number of fields and percentage of fields and discovered oil and gas in
 

each field-size class for the U.S. Permian Basin through 1996 .............................................9
 

3.	 Forty most prolific provinces in the study area and their year of first
 

discovery and cumulative recoverable volumes of oil and gas in their 


petroleum discoveries through 2001 ........................................................................................13
 

4.	 regional distribution in the study area of total and offshore wildcat wells
 

drilled through 2001 and total and offshore estimated cumulative
 

recoverable oil and gas discovered through 2001.................................................................14
 

 
 

vi 

5.	 Wildcat wells by year, 1961–2001, for mexico, the Caribbean, Central and 

South America, Europe, the middle East, Africa, Asia, the southwestern 

Pacific, and russia......................................................................................................................44 

6.	 Year of first discovery and cumulative recoverable oil and gas discovered 

through 2001 in the 173 significant petroleum provinces in the study area......................56 

7.	 regional distribution in the study area of land area, delineated prospective 

area, and explored area through 2001, rate of addition to prospective area, 

1992–2001, and percentages of total prospective area and oil discoveries 

delineated by 1982.......................................................................................................................61 

Conversion Factors, Letter Symbols for Units of Measure, 

and Definitions 

Multiply	 By To obtain 

Length 

foot (ft) 0.3048 meter 

mile (mi) 1.609 kilometer 

Area 

square mile (mi2

)	 2.590 square kilometer 

Volume 

cubic foot (ft3

) 0.02832 cubic meter 

barrel (bbl) 0.1590 cubic meter 

Temperature in degrees Celsius (oC) may be converted to degrees Fahrenheit (oF) as follows: 

oF = (1.8 × oC) + 32 

 

 

Letter Symbols for Units of Definitions 

Measure 

Thousands = 103 

Millions = 106

bbl barrel 

Billions = 109

bbl/mi2 barrels per square mile 

Trillions = 1012 BBO billions of barrels of oil (bbl × 109

) 

BBOE billions of barrels of oil equivalent 

BCF billions of cubic feet (ft3 1 BOE = 1 barrel of crude oil × 109) 

BOE barrel of oil equivalent (42 gallons) 

mi2 = 6,000 cubic feet of square mile 

MMBO millions of barrels of oil (bbl natural gas × 106) 

TCF trillions of cubic feet (ft3 = 1.5 barrels of natural gas × 1012) 

liquids 
 

 

 

Statistics of Petroleum Exploration in the 

World Outside the United States and Canada 

Through 2001 

By Emil D. Attanasi,1 Philip A. Freeman,1 and Jennifer A. Glovier2 

Abstract 

Future oil and gas supplies depend, in part, on the 

reserves that are expected to be added through exploration 

and new discoveries. This Circular presents a summary of the 

statistics and an analysis of petroleum exploration in the world 

outside the United States and Canada (the study area) through 

2001. It updates U.S. Geological Survey Circular 1096 (by 

E.D. Attanasi and D.H. Root, 1993) and expands coverage of 

the statistics to areas where drilling and discovery data have 

recently become available. These new areas include China, 

the formerly Communist countries of Eastern Europe, and the 

countries that once were part of the former Soviet Union in 

Europe and Asia. Data are presented by country but are organized by petroleum provinces delineated by the U.S. Geological Survey World Energy Assessment Team (USGS Digital 

Data Series DDS–60, published in 2000). 

The data and analysis are presented in maps and graphs, 

providing a visual summary of the exploration maturity of 

an area. The maps show the delineated prospective areas and 

explored areas through 2001; explored areas have a drilling 

density that would rule out the occurrence of undetected large 

petroleum accumulations. Graphs summarize the exploration 

yields in terms of cumulative recoverable discovered oil and 

gas by delineated prospective area. 

From 1992 through 2001 in areas outside the United 

States and Canada, the delineated prospective area expanded at 

a rate of about 50,000 square miles per year while the explored 

area grew at the rate of about 11,000 square miles per year. 

The delineated prospective area established by 1970 contains 

about 75 percent of the oil discovered to date in the study area. 

This area is slightly less than 40 percent of the delineated 

prospective area established through 2001. 

Maps and graphs show the extension of the delineated 

prospective area to deepwater areas offshore of Brazil and 

West Africa. From 1991 through 2000, offshore discoveries accounted for 59 percent of the oil and 77 percent of the 

1

U.S. Geological Survey, Reston, VA 20192. 

2

Formerly affiliated with the Department of Geography, University of 

Delaware, Newark, DE 19711. 

gas discovered in the study area. The petroleum industry’s 

decision to incur the greater costs of moving offshore and 

into deeper waters appears to be a response to the absence of 

onshore prospects of comparable quality. Where natural gas 

can be commercially developed and marketed, data show an 

expansion of exploration to target gas-prone areas. 

Introduction 

Objectives and Methods 

Controversy and concern persist about the future supply 

of world oil (Campbell and Laherrère, 1998; Williams, 2003). 

Analysts have come to radically different conclusions based 

on different interpretations of the same data, depending on the 

variables analyzed. One objective of this Circular is to contribute to the analysis of the world oil supply by expanding the 

availability of statistics on oil and gas exploration for all areas 

outside the United States and Canada. The compilation of data 

in this Circular will eliminate the need for costly and timeconsuming replication of effort and will allow researchers and 

decisionmakers access to exploration statistics for planning 

purposes. 

A second objective is to present a visual summary at a 

broad scale of world oil and gas exploration. In particular, 

maps for countries outside the United States and Canada are 

presented to show the historical exploration areas and the 

parts of the exploration areas having a high drilling density. 

Companion graphs summarize the historical exploration yields 

by area searched. Maps and graphs are used to convey visually the exploration maturity of an area. Making the maps and 

graphs required development of a method to characterize a 

common level of exploration maturity across various areas that 

have significantly different drilling densities. 

The statistics of exploration represent one set of indicators that can foreshadow the long-term future of oil-supply 

problems. During the last three decades, the international oil 

market has been influenced by efforts of the Organization of 

Petroleum Exporting Countries (OPEC) to control oil prices 

by restricting production. The oil price variations during that 
 

 

2 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

period have been substantial, and it is evident that such prices 

alone are not reliable indicators of the long-term prospects of 

global oil supply. 

Natural gas development for most areas is tied to local 

demand and the infrastructure to transport gas to international 

markets. On a calorific or British thermal unit (Btu) basis, gas 

costs four times as much as oil to transport. For some areas, 

it is still true that local and international gas demand has been 

insufficient to sustain prices required to justify the building of 

infrastructure and the commercial development of gas. 

This Circular expands and updates U.S. Geological 

Survey (USGS) Circulars 981 and 1096 (Root, Attanasi, and 

Turner, 1987; Attanasi and Root, 1993). It focuses on the 

world outside the United States and Canada (hereinafter called 

the study area) because the United States and Canada have historically accounted for most of the world’s wildcat wells but 

have accounted for a relatively small amount of the total new 

oil and gas discoveries in the last three decades. Circulars 981 

and 1096 did not include data on the Former Soviet Union, 

China, and formerly Communist areas of Eastern Europe. 

The historical data for these and other areas where petroleum 

exploration data were restricted for national security reasons 

will probably remain incomplete, but the early information 

will diminish in importance with the passage of time. Study 

area data on wildcat drilling and field sizes are as of January 

2002 and are from the IHS Energy Group (2002). 

Summary of Findings and Limitations of Study 

As shown by the drilling record and the locations of 

new drilling, the search area for oil and gas has continued to 

expand, but expansion has slowed considerably. Specifically, 

for the decade from 1992 through 2001, the prospective area 

expanded at a rate of about 50,000 square miles per year, and 

the explored area expanded at a rate of about 11,000 square 

miles per year. During the prior decade, the prospective 

area had expanded by 91,000 square miles per year and the 

explored area by 22,000 square miles per year. 

Since 1950, drilling has extended offshore, and through 

2001, offshore discoveries accounted for 20 percent of the 

oil and 28 percent of the gas discovered in the study area. 

In Europe, for example, offshore discoveries accounted for 

about 75 percent of the oil discovered through 2001. All major 

producing regions, with the exception of Russia, have had 

significant offshore drilling, discoveries, and production. The 

petroleum industry’s decision to incur higher costs by moving 

offshore appears to be a response to the absence of onshore 

prospects of comparable quality, although in some countries, 

exploration has moved offshore for political and environmental reasons. Furthermore, since the early 1990s, the expansion of deepwater offshore exploration has been sufficiently 

productive to offset the higher costs in that environment. 

Consumption, production, and reserves for liquid hydrocarbons (oil, condensate, and natural-gas-plant liquids) and 

natural gas are shown in table 1. The data were published 

in the “BP Statistical Review of World Energy 2003” (BP, 

2003). Table 1 highlights the balances between production and 

consumption. For the world, the difference between production and consumption may be explained by a drawdown of 

inventories or by refinery gain (for crude oil). Refinery gain, 

or processing gain, is the increase in crude oil product volumes 

beyond the input crude oil volume that takes place as a result 

of the refining process itself. 

Examination of the balances between liquid hydrocarbon 

production and consumption shows that the three regions of 

North America, Europe and Eurasia, and Asia Pacific consume 

more than they produce. The Western Hemisphere accounts 

for 37 percent of world liquid hydrocarbon consumption, 28 

percent of world liquid hydrocarbon production, and only 14 

percent of world liquid hydrocarbon reserves. The hemispheric 

imbalance for liquid hydrocarbons is expected to increase. 

For natural gas, the regional production and consumption 

balances are closer, but the three regions of North America, 

Europe and Eurasia, and Asia Pacific consume slightly more 

than they produce. International trade of gas is limited by the 

high transportation costs associated with shipping gas overseas. 

During the last decade, natural gas has made rapid 

advances as a commercial resource, but there are still many 

countries and areas where natural gas is not a commercial 

commodity. Where gas is not commercial, there is little incentive to report gas discoveries or to determine the magnitude 

of the discovered gas accurately. This lack of incentive is true 

whether the gas is associated with oil or whether the gas is in a 

nonassociated gas field. Because natural gas has been considered noncommercial for most of the petroleum industry’s 

history, care must be taken when interpreting historical gas 

discovery rates. At this time, there is no obvious way to adjust 

gas estimates to capture the missing or unreported elements. 

The available drilling record outside the United States 

and Canada is incomplete, especially for data prior to 1950. 

In the two earlier editions of this Circular (Root, Attanasi, and 

Turner, 1987; Attanasi and Root, 1993), annual exploratory 

well counts were gleaned from the annual foreign developments issues of the “American Association of Petroleum 

Geologists Bulletin” (“AAPG Bulletin”), which reported data 

by country from 1950 through 1990. In addition, wildcat well 

counts were reported by Petroconsultants S.A., the predecessor of the IHS Energy Group. The exploratory well counts 

from the “AAPG Bulletin” and wildcat well counts reported 

by Petroconsultants S.A. were not very consistent during the 

1950s but were very consistent after 1980. Unfortunately, the 

AAPG discontinued the foreign developments issues in 1990. 

The well data used in this Circular are from the IHS Energy 

Group (2002). For recent drilling in most areas, the IHS 

Energy Group (2002) reports wildcat wells along with other 

exploratory wells. For a few areas, the IHS Energy Group also 

reports some development wells. 

Information used in this Circular includes well location, 

depth, initial classification (such as wildcat, exploration, or 

development), final classification (dry hole or producer), 

spud date, and completion date. In the past, many countries 
 

Table 1. Estimated world liquid hydrocarbon and natural gas consumption, production, and reserves for 2002. 

[For these estimates, liquid hydrocarbon includes crude oil, condensate, and natural-gas-plant liquids. Data are from BP (2003). Region definitions in this 

table differ from those in the rest of this Circular and follow BP (2003). Because of rounding, some regional totals may differ slightly from the sum of the 

component estimates shown. Countries are listed alphabetically within each region] 

Annual Annual Reserves 

 consumption, 2002 production, 2002 at end of 2002 Country Liquid Gas Liquid Gas Liquid Gas 

(106

 bbl/yr) (109 ft/yr) (106 bbl/yr) (109

 ft/yr) (109

 bbl) (1012 ft

) 

North America 

Canada......................................................... 726 2,849 1,051 6,478 6.9 60.1 

Mexico ........................................................ 654 1,486 1,309 1,228 12.6 8.8 

U.S.A. (excludes Puerto Rico).................... 7,193 23,563 2,810 19,334 30.4 183.5 

North America subtotal........................... 8,573 27,898 5,169 27,040 49.9 252.4 

South and Central America 

Argentina..................................................... 129 1,070 292 1,274 2.9 27.0 

Bolivia......................................................... * * * 191 * 24.0 

Brazil........................................................... 675 484 548 321 8.3 8.1 

Chile............................................................ 86 229 * * * * 

Colombia..................................................... 81 215 219 219 1.8 4.5 

Ecuador ....................................................... 48 7 150 * 4.6 * 

Peru ............................................................. 54 14 36 * .3 8.7 

Trinidad and Tobago ................................... * * 57 593 .7 23.5 

Venezuela .................................................... 183 964 1,074 964 77.8 148.0 

Other countries............................................ 419 477 54 74 2.0 6.4 

South and Central America subtotal ....... 1,675 3,459 2,429 3,636 98.6 250.2 

Europe and Eurasia 

Austria......................................................... 98 286 * * * * 

Azerbaijan................................................... 27 279 113 169 7.0 30.0 

Belarus ........................................................ 43 586 * * * * 

Belgium and Luxembourg .......................... 248 522 * * * * 

Bulgaria....................................................... 33 102 * * * * 

Czech Republic ........................................... 64 314 * * * * 

Denmark...................................................... 75 180 135 297 1.3 3.0 

Finland ........................................................ 83 145 * * * * 

France.......................................................... 718 1,511 * * * * 

Germany...................................................... 989 2,916 * 614 * 11.3 

Greece ......................................................... 169 71 * * * * 

Hungary....................................................... 50 420 * * * * 

Iceland......................................................... 7 0 * * * * 

Ireland ......................................................... 66 145 * * * * 

Italy ............................................................. 709 2,245 38 533 .6 8.0 

Kazakhstan.................................................. 47 342 361 434 9.0 65.0 

Lithuania ..................................................... 20 102 * * * * 

Netherlands ................................................. 347 1,387 * 2,114 * 62.0 

Norway........................................................ 76 138 1,215 2,309 10.3 77.3 

Poland ......................................................... 154 395 * 141 * 5.8 

Portugal ....................................................... 113 106 * * * * 

Romania ...................................................... 82 614 47 381 1.0 3.6 

Russia.......................................................... 901 13,711 2,810 19,588 60.0 1,680.0 

Slovakia....................................................... 26 268 * * * * 

Spain ........................................................... 555 734 * * * * 

Sweden........................................................ 115 28 * * * * 

Switzerland ................................................. 97 99 * * * * 

Turkey ......................................................... 236 614 * * * * 

Turkmenistan............................................... 19 466 66 1,761 .5 71.0 

Ukraine........................................................ 95 2,464 * 607 * 39.6 

United Kingdom.......................................... 611 3,336 899 3,639 4.7 24.6 

Uzbekistan................................................... 48 1,850 62 1,899 .6 66.2 

Other countries............................................ 164 469 175 392 2.4 8.4 

Europe and Eurasia subtotal.................... 7,083 36,846 5,921 34,880 97.5 2,155.8 

Introduction  
Table 1. Estimated world liquid hydrocarbon and natural gas consumption, production, and reserves for 2002.—Continued 

Annual Annual Reserves 

Country consumption, 2002 

Liquid Gas 

 production, 2002 

Liquid Gas 

 at end of 2002 

Liquid Gas 

(106

 bbl/yr) (109 ft/yr) (106 bbl/yr) (109

 ft/yr) (109

 bbl) (1012 ft

) 

Middle East 

Bahrain........................................................ * * * 325 * 3.3 

Iran .............................................................. 407 2,397 1,229 2,277 89.7 812.3 

Iraq .............................................................. * * 741 * 112.5 109.8 

Kuwait......................................................... 77 307 683 307 96.5 52.7 

Oman........................................................... * * 329 522 5.5 29.3 

Qatar............................................................ 16 378 276 1,034 15.2 508.5 

Saudi Arabia................................................ 498 1,991 3,168 1,991 261.8 224.7 

Syria ............................................................ * * 210 145 2.5 8.5 

United Arab Emirates ................................. 90 1,387 828 1,624 97.8 212.1 

Yemen ......................................................... * * 173 * 4.0 16.9 

Other countries............................................ 496 801 18 92 .1 1.6 

Middle East subtotal ............................... 1,583 7,261 7,655 8,317 685.6 1,979.7 

Africa 

Algeria......................................................... 82 928 605 2,838 9.2 159.7 

Angola......................................................... * * 330 * 5.4 * 

Cameroon.................................................... * * 26 * .4 * 

Republic of Congo (Brazzaville) ................ * * 94 * 1.5 * 

Egypt........................................................... 201 801 274 801 3.7 58.5 

Equatorial Guinea ...................................... * * 87 * * * 

Gabon.......................................................... * * 108 * 2.5 * 

Libya ........................................................... * * 502 201 29.5 46.4 

Nigeria......................................................... * * 735 625 24.0 124.0 

South Africa ................................................ 183 0 * * * * 

Sudan........................................................... * * 85 * .6 * 

Tunisia......................................................... * * 28 * .3 * 

Other countries............................................ 457 650 22 237 .3 29.5 

Africa subtotal......................................... 922 2,379 2,897 4,702 77.4 418.1 

Asia Pacific 

Australia...................................................... 309 847 266 1,218 3.5 90.0 

Bangladesh.................................................. 26 395 * 395 * 10.6 

Brunei.......................................................... * * 77 406 1.4 13.8 

China........................................................... 1,957 1,063 1,236 1,151 18.3 53.3 

Hong Kong Special Administrative Region 99 85 * * * * 

India ............................................................ 763 995 289 1,003 5.4 26.9 

Indonesia..................................................... 391 1,225 466 2,492 5.0 92.5 

Japan ........................................................... 1,948 2,732 * * * * 

Malaysia...................................................... 179 953 304 1,776 3.0 75.0 

New Zealand ............................................... 53 194 * 222 * * 

Pakistan ....................................................... 131 738 * 738 * 26.4 

Papua New Guinea...................................... * * 17 * .2 12.2 

Philippines................................................... 121 64 * * * * 

Singapore .................................................... 255 64 * * * * 

South Korea................................................. 835 925 * * * * 

Taiwan......................................................... 298 300 * * * * 

Thailand ...................................................... 272 914 72 667 .6 13.3 

Vietnam....................................................... * * 129 * .6 6.8 

Other countries............................................ 173 166 58 582 .8 24.5 

Asia Pacific subtotal................................ 7,810 11,660 2,915 10,650 38.7 445.3 

World total 

World total................................................... 27,648 89,503 26,986 89,224 1,047.7 5,501.5 


*The quantity is not listed separately for an individual country but may be included in the “Other countries” category for the region. 

 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Exploration Process  

considered this drilling information to be important to national 

security and thus restricted the publication of information 

about wells. 

Data describing historical oil discoveries have improved 

since the 1980s, but there is still no standard method used 

internationally to estimate reserves and, therefore, cumulative recoverable oil (reserves plus past production). Field-size 

estimates are not strictly comparable across countries, as each 

country may have a different definition of reserves. There is 

also no evidence that historical estimates of the same field 

are consistent with recent estimates, and so no attempt was 

made to calibrate growth functions or to estimate the potential 

reserve growth in the study area. 

This Circular not only summarizes the basic statistics 

of petroleum exploration and discovery in the world outside 

the United States and Canada, but also presents a unique set 

of analytical techniques to interpret these data. Initially the 

Circular describes background information on the institutional 

context, the practices of modern petroleum exploration, and 

the petroleum discovery process (figs. 1–4, tables 1–5). Following this discussion is an explanation of the unique analytical techniques applied in this study to display and analyze the 

exploration and discovery data at the country and regional 

levels (figs. 5 and 6). The summary results of the analysis of 

exploration and discovery data at the regional level and for 

the entire study area are described (figs. 7–13, tables 6 and 7). 

These results are aggregates of data for individual countries or 

small groups of countries, which are shown as maps, graphs, 

and tables in figures 14 through 57. The concluding section 

of the text discusses the implications of the analysis for future 

discovery and production trends. 

Exploration Process 

The four parts of this section present basic information 

about the petroleum exploration process so that the reader can 

understand and interpret the exploration statistics presented in 

this Circular. In the first part, concepts and nomenclature of 

exploration statistics are discussed. Exploration statistics are 

generated by the firms (economic agents) that are exploring 

for oil and gas, and the data represent their decisions and the 

outcomes of those decisions. When interpreting exploration 

statistics, knowledge of the institutional setting in which the 

firms make decisions is important. Such settings inside and 

outside the United States are briefly described in the second 

part. 

In the third part, characteristics of oil and gas deposits 

are identified that result in the predictability of the petroleum discovery process for petroleum plays. The intensity of 

petroleum exploration in the United States is greater than that 

in any other country in the world. Although U.S. historical 

drilling and discovery data are not complete, they represent the 

most extensive data available in terms of historical, geographical, and geologic breadth for any major producing area in the 

world. In the fourth part, U.S. data are used to illustrate how 

the size distributions of oil and gas accumulations determine 

the regularity and predictability of the discovery process in 

plays, basins, and provinces and across petroleum provinces. 

Oil and Gas Exploration: Concepts and 

Nomenclature 

Exploration is the search for undiscovered oil and gas 

resources that have development and production costs no 

greater than the expected costs associated with producing oil 

and gas from known deposits and adding to reserves in known 

deposits (Adelman, 1970). Exploration is one of several ways 

of adding to oil and gas reserves (defined below). Exploration 

by the petroleum industry includes surveying of surface geology, processing and interpreting newly collected geophysical data, reprocessing and interpreting previously collected 

data, acquiring mineral rights and access, taking subsurface 

samples, and finally drilling exploratory oil and gas wells. 

For this discussion, reserves are defined as the inventory 

of commercially producible oil and gas in known deposits. 

The resources in such deposits should be of such a quality 

and quantity that the resource can be commercially developed 

under market conditions similar to those at the time of 

discovery. 

There are no internationally accepted standards for 

computing reserves. In the United States and Canada, proved 

reserves are defined as estimated quantities of hydrocarbons 

that geologic and engineering data demonstrate with reasonable certainty to be recoverable from identified fields under 

existing economic and operating conditions. In many countries, reserves are thought of as the inventory of oil and gas 

in identified fields. Reserves for these countries represent 

volumes of technically recoverable in-place resources without 

regard to cost or producibility in the near future. The government of Mexico, for example, recently changed the standard 

for reporting reserves by the national oil company (Pemex) 

from a broad definition to the narrow definition of proved 

reserves used in the United States and Canada, thus reducing 

Mexico’s reserves by 53 percent (Williams, 2003). 

For the United States and Canada, the narrow definition 

of proved reserves is necessary because the estimated volumes 

of oil and gas are used in commercial transactions regulated 

by government securities and financial agencies. Estimates of 

proved reserves indicate the short-term sustainability of oil 

and gas production. No more than 10 to 15 percent of proved 

reserves (and often much less) can be extracted annually in 

order to avoid reservoir damage; thus, quantities of proved 

reserves limit annual production to amounts that are much less 

than the known recoverable resources. 

A reservoir is a body of porous, permeable rock that contains a natural accumulation of oil or gas, which is confined 

by impermeable rock or water barriers. A reservoir may be 

called a pool, even though the petroleum exists in the pores 
6 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

of the rock. A field is an area consisting of a single reservoir 

or multiple reservoirs grouped on, or related to, the same 

geologic structure and (or) stratigraphic condition (definition 

from the Energy Information Administration, 2000). Fields are 

discussed in more detail below. 

Wells can be classified into the following categories: (1) 

new field wildcat wells, (2) shallow pool test wells, (3) deep 

pool test wells, (4) extension or outpost test wells, and (5) 

infill development wells. Exploration wells include wildcat 

wells, new pool test wells (shallow or deep pool), and extension wells. The placement of extension wells may be designed 

to delineate the periphery of an identified pool or to target a 

new pool at the periphery of a known accumulation. Historically, an exploration well is classified as a new field wildcat 

well when it is drilled at least 2 miles from any known producing area and targets an undiscovered accumulation (American 

Petroleum Institute, 2002). Risk, or the probability of failure, 

on average, tends to increase from infill development wells to 

exploration wells, to new pool test wells, and then to new field 

wildcat wells. Even infill development wells are not without 

risk; some development wells are drilled that fail to make 

contact with the producing formation. 

Figure 1 is a diagram showing different types of wells 

leading to additions to reserves in discovered fields. In the 

United States during the last two decades, the additions to 

reserves that were derived strictly from new field wildcat 

wells represent a relatively small fraction of annual additions 

to proved reserves. Most of the annual additions to proved 

reserves were the result of drilling the types of wells represented in figure 1. The reserves found may be credited to oil 

and gas fields that were already discovered. For the United 

States, these additions to reserves were recorded and published 

annually as extensions and revisions by the Energy Information Administration (2000) of the U.S. Department of Energy. 

The application of fluid injection programs and well stimulation also added reserves to discovered fields. These procedures 

are designed to increase the flow of hydrocarbons through the 

production wellbore to attain commercially profitable rates of 

production. 

Estimates of sizes of oil and gas fields are commonly 

based on cumulative recoverable petroleum, which is defined 

as the sum of past field production and the most recent estimate of reserves. When additions to proved reserves are credited to a field already discovered, the field size based on the 

estimate of cumulative recoverable petroleum is said to grow. 

Resource analysts describe the hydrocarbon resources that 

are expected to be added to the proved reserves of discovered 

fields as inferred reserves. The change of known hydrocarbon 

resources from the inferred reserve category to the proved 

reserve category typically requires some drilling.

 The amount of growth that will ultimately be credited to 

a new discovery depends on how narrowly the reserve accumulation size estimate is defined. A narrowly defined accumulation size estimate is usually based on the decline function estimate of the reserves for each producing well drilled 

in the field to date. The initial estimate will likely increase 

as the accumulation is developed. Alternatively, if the initial 

accumulation size estimate is based on the technically recoverFigure 1. Diagram of types of wells leading to additions to reserves in discovered fields. The wells (represented by derricks) are as 

follows: (1) shallow pool test well, (2) deep pool test well, (3) infill development well, (4) new pool test well, and (5) extension or outpost 

well. Diagram modified from Drew (1997). In practice, the operator or regulatory body may classify the pools penetrated by well types 

1–5 as a single field or as more than one field. Recognition of the relations among the accumulations can be complicated by the order in 

which the wells are drilled. 
 

 

able value of the in-place volume of oil or gas thought to be 

contained in the geologic structure or stratigraphic trap, it is 

not likely to grow as much as the narrowly defined estimates 

that are tied to production facilities. 

There can be some ambiguity as to whether new reserves 

should be classified as new fields or field growth (see fig. 1). 

As mentioned above, the Energy Information Administration (2000) defined a field as an area consisting of a single 

reservoir or multiple reservoirs related to the same individual 

geologic structural feature and (or) stratigraphic condition. 

In a single field, two or more reservoirs may be separated 

vertically or laterally by impermeable strata. From a practical 

standpoint, the definition of an oil or gas field is not exact. The 

assignment of pools to fields may be for geologic reasons or 

for convenience in regulation, or it may be an artifact of the 

discovery sequence of the pools. Depending on the discovery sequence, the accumulations shown in figure 1 may be 

assigned to a single field or to more than one field. 

Figure 1 shows discrete oil or gas accumulations that are 

considered to be conventional and producible with conventional methods. In contrast, continuous-type oil or gas deposits 

are identified regional accumulations that ordinarily require 

implementation of unconventional production methods and 

theoretically have no hydrocarbon-water contact that provides 

a clear-cut accumulation or pool boundary. Outside the United 

States and Canada, most exploration is focused on discrete oil 

and gas accumulations that can be produced with conventional 

methods. Nonetheless, the in-place hydrocarbon resources 

assessed in continuous accumulations are substantial. 

Exploration expenditures are direct investments made 

by individual firms for the purpose of locating unidentified 

but potentially commercial quantities of oil and gas. From the 

perspective of the firm, exploration begins with a hypothesis 

about the formation of accumulations of hydrocarbons in 

a specific geologic setting. A literature search may then be 

conducted to identify potential geographic locations where 

the hypothesis might be tested. The selection of a target area 

includes a review of available geologic maps, geochemical 

data, and geophysical data. Fieldwork or seismic profiling 

reconnaissance may be required to verify interpretations and to 

collect additional data to identify specific drilling targets. Dur

ing drilling, data are continuously collected and interpreted 

to maximize the probability of locating significant accumulations. After hydrocarbons are encountered by the drill, further 

geologic, engineering, and economic analyses will determine 

the potential for a commercial discovery. 

­

Oil and Gas Exploration: Institutional 

Environment 

In the United States 

In the United States, mineral rights can be owned either 

privately or by the Federal or State governments. Governmentowned mineral rights are typically transferred to the private 

Exploration Process  

sector for exploration and production. In the past, several systems were used to transfer mineral rights to the private sector. 

A comprehensive analysis of these institutional systems with 

respect to economic efficiency and the ability of the government to capture economic rents is beyond the scope of this 

Circular. At present, however, where significant hydrocarbons 

are expected, the method used to transfer oil and gas rights to 

the private sector is the sale of leases through a competitive 

bidding system. 

Private ownership of mineral rights resulted in what 

economists refer to as “market failures” and then in governmental regulations to remedy these failures. If an oil or gas 

pool extends beneath several parcels of land, then there could 

be a number of different property owners with a claim to the 

oil or gas in a common pool. This situation is the common 

property or pool externality. An economic externality is said 

to occur when the welfare of an individual depends directly 

not just on his activities, but also on activities of some other 

economic agent. For example, an economic externality occurs 

when pollution generated upstream affects the welfare of 

downstream water users. 

In the absence of regulation, oil and gas resources were 

subject to the rule of capture. Historically, the owner who first 

discovered the pool would start immediately to drill intensively and to produce the resources. In a reservoir, oil and 

gas flow because of differential reservoir pressures. Thus, by 

drilling and producing quickly, the first producer could drain 

resources from his neighbors. In such a situation, neighbors 

must exploit their parts of the pool as quickly as possible to 

avoid losing resources to the early producer. This situation 

results in extremely rapid exploration and production of the 

resource. The accelerated production reduces the quantity of 

the resource that can ultimately be recovered from the pool. 

Even when oil prices collapse, production does not 

decline because each producer fears having his part of the 

pooled drained by a neighbor. To rectify this situation, government regulators in leading oil-producing States instituted a 

prorationing system that limited production for each well to an 

allowable rate per month and set minimum spacing requirements for wells. 

Outside the United States 

Outside the United States, national governments typically control the ownership of mineral rights. The rights to 

explore a concession area are negotiated with the national 

governments. Although some of the European countries with 

North Sea production follow an auction system, which in some 

ways is similar to the U.S. system, these European countries 

still maintain tight control of resource development. Furthermore, many leading oil- and gas-producing countries outside 

the United States require separate exploration and production 

agreements. For some countries, including those in the Middle 

East, Mexico, and Venezuela, petroleum exploration and 

production are controlled almost entirely by the national oil 
	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

company, and foreign companies (if allowed at all) are used on 

a contract basis. 

For countries that permit foreign participation, exploration concession agreements generally require a commitment to collect data and to drill a specified number of wells 

in exchange for the right to explore. The concession areas 

are sufficiently large so that if a field is found, then the field 

will likely be contained in a single concession. The concession contract typically specifies that all data collected by the 

foreign exploration firm should revert to the government. 

The agreement also specifies what rights, if any, the foreign 

exploration firm might have in the event of a discovery. If a 

discovery is made, then a production concession is negotiated, 

often requiring the foreign exploration firm to share production with the national oil company or to assume the role of 

contract producer with payments taken in kind as a percentage 

of production. 

Each government has a different set of contract provisions and production taxes designed to attain a specific set 

of policy goals. These goals may include the training and 

employment of local workers, the construction of infrastructure, and the provision of social services to the local communities. Moreover, each government typically reserves the right to 

tailor provisions on an individual basis. 

Exploration	of	Plays	and	Sedimentary	Basins

For petroleum exploration within a well-defined sedimentary basin, regularity in the discovery process allows one to 

use the past discovery history to predict the nature and distribution of future discoveries in the basin. The petroleum industry uses the concept of the petroleum play, commonly identified in terms of a geologic formation, as a basis for classifying 

exploration targets (White, 1980; Baker and others, 1984). 

Although in recent years the concept of a petroleum system

has been used to provide a conceptual framework for tracing 

oil and gas migration from its origin to its place of final accumulation (Magoon and Dow, 1994), most exploration geologists still focus on petroleum plays. A play is defined as a set 

of known or postulated oil and (or) gas accumulations sharing 

similar geologic, geographic, and temporal properties, such as 

source rock, migration patterns, timing, trapping mechanism, 

and hydrocarbon type. Typically, a play may contain pools 

related to a specific rock unit that might represent single fields 

or represent parts of fields (Gautier and others, 1996).

In this Circular, field size is measured in terms of fluid 

volumes expressed in barrels of oil or natural gas liquids and 

in cubic feet of gas. On the basis of calorific heating values, 

it is assumed that 1 barrel of oil is equivalent (BOE) to 6,000 

cubic feet of natural gas; that is, 1 BOE = 1 barrel (bbl) of 

crude oil or 6,000 cubic feet (ft3

) of natural gas or 1.5 barrels of natural gas liquids. In addition, a field having at least 

20,000 cubic feet of gas per barrel of crude oil is classified as 

a gas field; otherwise, the field is classified as an oil field.

Most of the conventional hydrocarbon resource discovered in a basin is contained in a small proportion of the 

accumulations, and therefore the observed size-frequency 

distributions of discoveries in most petroleum plays (and 

Figure	2. Histogram showing the size-frequency distribution of oil and gas fields discovered through 1996 in the 

Permian Basin, West Texas and eastern New Mexico, U.S.A. Data are from the Oil and Gas Integrated Field File made 

available by William Monroe, Energy Information Administration, 1998. MMBOE, millions of barrels of oil equivalent  

(106 BOE), where 1 BOE = 1 barrel of crude oil or 6,000 cubic feet of natural gas or 1.5 barrels of natural gas liquids. The 

scale for the field sizes uses unequal intervals defined in powers of 2 to allow all field sizes to fit on the graph.

3,500

NUMBER OF OIL AND GAS FIELDS

3,000

2,500

2,000

1,500

1,000

500

0

<1 1–<2 2–<4 4–<8 8–<16 16–<32 32–<64 64–<128 128–<256 256–<512 512– 2048–

<1024 <4096

FIELD SIZE IN CUMULATIVE RECOVERABLE HYDROCARBON (MMBOE)

1024–

<2048
 

 

 

Table 2. Number of fields and percentage of fields and discovered oil and gas in each field-size class for the U.S. Permian Basin 

through 1996. 

[MMBOE, millions of barrels of oil equivalent. On the basis of calorific heating values, it is assumed that 1 barrel of oil is equivalent to 6,000 cubic feet of 

natural gas; that is, 1 BOE = 1 barrel of crude oil or 6,000 cubic feet of natural gas or 1.5 barrels of natural gas liquids. Volumes of discovered oil and gas 

used to figure the percentage of hydrocarbons in each field-size class are reserves plus past production. Data are from the Oil and Gas Integrated Field File 

made available by William Monroe, Energy Information Administration, 1998. Rounding affects some cumulative percentages] 

Fields Oil and gas 

Field-size class Number Cumulative Percent in size Cumulative (MMBOE) Percentage of fields percentage class percentage 

2,048–4,096 1 0.02 0.02 4.86 4.86 

1,024–2,048 4 .08 .10 12.14 17.01 

512–1,024 14 .28 .38 19.05 36.05 

256–512 27 .54 .92 17.43 53.48 

128–256 35 .70 1.63 11.23 64.71 

64–128 61 1.23 2.85 9.92 74.63 

32–64 91 1.83 4.68 8.01 82.64 

16–32 133 2.67 7.35 5.61 88.25 

8–16 216 4.34 11.69 4.66 92.91 

4–8 267 5.36 17.05 2.85 95.76 

2–4 344 6.91 23.96 1.85 97.61 

1–2 432 8.68 32.64 1.15 98.75 

0.5–1 481 9.66 42.30 .64 99.40 

0.25–0.5 495 9.94 52.24 .33 99.73 

0.125–0.25 483 9.70 61.94 .16 99.89 

0.0625–0.125 451 9.06 71.00 .08 99.97 

<0.0625 1,444 29.00 100.00 .03 100.00 

Total ...................................... 4,979 100.00 --­ 100.00 --­

Exploration Process 9 

petroleum provinces) are highly skewed. Figure 2 shows the 

size-frequency distribution of oil and gas fields discovered in 

the Permian Basin (West Texas and eastern New Mexico, of 

the United States) through 1996. Table 2 shows the percentages 

of discovered hydrocarbons associated with each field-size 

class in the Permian Basin through 1996. The Permian Basin 

is the most prolific oil-producing basin in the onshore conterminous United States. The largest 46 fields (or 0.92 percent of 

the fields) contain more than 53 percent of the hydrocarbons 

discovered by 1996, whereas the 1,444 fields in the smallest 

size class (each containing less than 62,500 BOE) represent 29 

percent of the fields but account for only 0.03 percent of the 

hydrocarbons. 

The shape of the Permian Basin size-frequency distribution is typical of many plays and basins in that most of the 

hydrocarbons are found in a few very large accumulations or 

fields. Exploration drilling success ratios (numbers of successful exploration wells divided by numbers of total exploration 

wells drilled) provide no information about the sizes of future 

discoveries because the (typically) large number of small 

accumulations determines the final success ratios. The largest 

Permian Basin field, containing nearly 2.6 billion barrels of oil 

equivalent (2,600,000,000 BOE or 2.6 BBOE), is at least six 

orders of magnitude larger than the fields in the smallest size 

class. If the interval endpoints on the x axis in figure 2 were not 

in powers of 2 (16–<32, 32–<64), then the size classes for the 

smallest category and the largest category could not have been 

graphed without a scale break in the axis. 

For most fields, the surface expression is related to the 

volume of petroleum in the field. For example, the East Texas 

field in East Texas contains 6 billion barrels of oil (6 BBO) 

and has a surface area of 200 square miles, whereas a field 

containing 1 million barrels of oil (1 MMBO) could have 

a surface expression of 1 square mile (Attanasi and others, 

1981). 

An important consequence of the size distribution is that 

for an area open to drilling, when deposit surface is roughly 

proportional to volume, then with random drilling, the average 

discovery size will decline with equal increments of exploratory drilling. This decline occurs because the larger deposits, 

with the largest surface areas, have a higher probability of 

being found. As they are found early in the discovery process, it will take more wells to identify the remaining smaller 

deposits. Any improvement in exploration efficiency above 

purely random drilling just accelerates discovery of the large 

fields and the decline in the discovery rate. 

Figure 3 shows the progression in the average sizes 

(in barrels of oil equivalent) in fields discovered from 1920 

through 1995 in 5-year intervals in the Permian Basin. The 

regularity of the discovery process allows the expected yields 

of future exploration to be computed with simple analytical 

models. The discovery rate (yield per exploratory well) is 

controlled by the field sizes and the order of discovery. 

Exploration access, distance from market, and technology are factors determining the order in which basins are 

explored. In the early years of the U.S. petroleum industry, 
10	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

search intensity was influenced by the state of production 

technology, the costs of transporting oil to market, and the 

maturity of markets. Some remote prolific basins were not 

explored as early as the less prolific areas closer to market 

areas.

The exploration histories of many sedimentary basins follow predictable patterns. New-field wildcat wells are drilled in 

unproven plays at low but irregular rates, expressed as number 

of wells per year. After a significant discovery is made, there 

is typically an influx of new prospectors similar to the 19th 

century gold rushes; the prospectors create much higher rates 

of drilling. Drilling rates eventually decline as returns deteriorate and exploration in other plays or basins becomes more 

attractive. As other plays in the basin are tested, the process is 

repeated.

Oil and gas production typically exhibits substantial 

economies of scale so that larger fields are typically less 

costly to find and produce than smaller fields. If the industry 

is reasonably efficient in finding the largest and lowest cost 

accumulations early in the discovery process, then the past discovery sequence provides information useful in estimating the 

magnitude and characteristics of the undiscovered resources. 

For countries where field size is narrowly defined (such as the 

sum of only proved reserves plus past production), the true 

discovery sizes will generally increase with field development, 

and such behavior should be taken into account when estimating sizes of recent discoveries.

Discoveries	across	Provinces:	United	States	

and	Study	Area	

In the United States, relatively few petroleum provinces 

contain most of the hydrocarbons discovered to date. Figure 

4A shows the distribution of cumulative recoverable hydrocarbon discoveries (past production and proved reserves of oil, 

gas, and natural gas liquids) in fields discovered through 1998, 

expressed in barrels of oil equivalent for the onshore provinces 

in the conterminous United States. The distribution represents 57 provinces from the conterminous 48 States that were 

delineated and assessed by the U.S. Geological Survey for 

the 1995 National Assessment of United States Oil and Gas 

Resources (Gautier and others, 1996). Of the 57 provinces in 

the conterminous 48 States with the largest discoveries, only 4 

provinces contain 63 percent of the hydrocarbon discovered to 

date, and the top 9 provinces contain more than 80 percent of 

the discovered hydrocarbon (NRG Associates, Inc., 2001). The 

top 9 provinces based on cumulative recoverable hydrocarbon 

discoveries expressed in barrels of oil equivalent are as follows 

(in order of decreasing size): Western Gulf, Permian Basin, 

Anadarko Basin, Louisiana-Mississippi Salt Basins, San Joaquin Basin, Appalachian Basin, Los Angeles Basin, San Juan 

Basin, and Bend Arch-Fort Worth Basin (NRG Associates, 

Inc., 2001).

Large-scale commercial petroleum production began in 

the United States in the middle of the 19th century. By the end 

Figure	3.  Graph showing average sizes of fields discovered in 5-year intervals in the Permian Basin between 1920 and 1996. Data are 

from the Oil and Gas Integrated Field File made available by William Monroe, Energy Information Administration, 1998. MMBOE, millions of barrels of oil equivalent (106 BOE), where 1 BOE = 1 barrel of crude oil or 6,000 cubic feet of natural gas or 1.5 barrels of natural 

gas liquids.

250

200

150

100

AVERAGE DISCOVERY SIZE (MMBOE)

50

0

1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 1996

YEAR
0

10

20

30

NUMBER OF PROVINCES

0

10

20

30

40

50

60

70

NUMBER OF PROVINCES

PROVINCE SIZE IN CUMULATIVE RECOVERABLE HYDROCARBON (BBOE)

PROVINCE SIZE IN CUMULATIVE RECOVERABLE OIL (BBO)

A, Conterminous United States, 1998

B, Study area, 2001

<.5 .5–<1 1–<2 2–<4 4–<8 8–<16 16–<32 32–<64 64–<128

<.5 .5–<1 1–<2 2–<4 4–<8 8–<16 16–<32 32–<64 64–<128 128–<256 256–<512

Figure 4.  Histograms showing the frequency distribution of 

cumulative recoverable hydrocarbon volumes (oil, gas, and 

natural gas liquids in billions of barrels of oil equivalent, BBOE) 

for 57 onshore provinces of the conterminous United States and 

cumulative recoverable oil volumes for 173 provinces of the study 

area, which is the world outside the United States and Canada. In 

both histograms, the unequal intervals for size classes are defined 

in powers of 2 to allow all province sizes to fit on the graph. A, 

Histogram showing the frequency distribution of cumulative 

recoverable hydrocarbon volumes through 1998 for the 57 onshore 

provinces of the conterminous United States having the largest 

discoveries. Data from NRG Associates (2001). B, Histogram 

showing the frequency distribution of cumulative recoverable  

oil volumes (in billions of barrels of oil, BBO) through 2001 for 

the 173 provinces in the study area that have had at least one 

discovery of at least 100 million barrels of oil or 600 billion 

cubic feet of gas. Field data from IHS Energy Group (2002); 

province boundaries from U.S. Geological Survey World Energy 

Assessment Team (2000). In the study area, seven provinces have 

no reported oil discoveries but have gas discoveries of at least 

600 billion cubic feet of gas (which have minor volumes of oil 

associated with the gas).

Exploration Process 11
 

 

12 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

of 1901, petroleum provinces containing more than half the 

recoverable petroleum (oil and gas) resources in the onshore 

provinces of the conterminous 48 States had reported at least 

one discovery of at least 10 million barrels of oil equivalent 

(10 MMBOE) recoverable. By the end of 1920, the provinces 

that contained 94 percent of recoverable oil and gas discovered 

through 1998 had already been explored to such an extent that 

at least one field of 10 MMBOE had been discovered in each 

province. The exploratory drilling through 1920, however, 

represented only a small percentage (less than 5 percent) of 

the total exploratory drilling through 1998. Since 1920, most 

onshore exploratory drilling in the conterminous 48 States has 

been followup drilling in these and other, less prolific provinces (IHS Energy Group, 2001; NRG Associates, Inc., 2001). 

Even for the study area, relatively few provinces account 

for most of the oil discovered to date. The distribution of the 

quantities of known recoverable oil and gas across petroleum 

provinces was studied by assigning fields to petroleum provinces. Estimates of recoverable oil and gas by field are from 

IHS Energy Group (2002). The petroleum province boundaries 

were established by the geologists of the USGS (U.S. Geological Survey World Energy Assessment Team, 2000). The provinces were then classified as significant if they had at least one 

discovery that contained either 100 million barrels of oil (100 

MMBO) or 600 billion cubic feet (600 BCF) of gas. There 

were 173 significant provinces, of which 33 were significant 

for gas only. Figure 4B shows a histogram of the cumulative 

recoverable oil discoveries in these 173 provinces. Table 3 lists 

the 40 most prolific of these provinces arrayed by the volume 

of recoverable oil. 

For areas outside the United States and Canada, the five 

provinces with the largest volumes of cumulative recoverable 

oil discoveries account for 52 percent of the total study area oil 

discovered through 2001 (tables 3 and 4). Similarly, the top 16 

provinces with the largest volumes of cumulative oil discoveries (all having cumulative discoveries of at least 20 billion 

barrels of oil (20 BBO)) account for 81 percent of the total oil 

discovered. Nine provinces have discoveries between 10 and 

20 BBO and could eventually achieve 20 BBO. 

Table 3 identifies the year of the earliest discovery for 

each of the most prolific 40 oil provinces. The provinces that 

were discovered first were not necessarily the most prolific 

provinces. About 23 percent of the oil discovered in the study 

area through 2001 was located in provinces that had at least 

one discovery by 1925. Similarly, 59 percent and 93 percent of 

the oil discovered in the study area through 2001 were located 

in provinces having at least one discovery by 1950 and 1975, 

respectively. 

Empirical studies that describe the exploration and 

discovery process suggest that within a defined area open to 

exploration, the larger fields tend to be discovered early in the 

exploration process, leading to a declining average discovery 

size (Kaufman, 1993). Size distributions of accumulations 

within basins are skewed. Moreover, when the petroleum 

basins and provinces are arrayed by magnitude of discovered 

hydrocarbons, the distribution is also skewed. In other words, 

a small proportion of the provinces accounts for most of the 

discovered petroleum. However, the most prolific basins and 

provinces were not always the earliest explored. Provinces that 

were explored early were accessible, both legally and technologically, to exploration and commercial production. 

Measures of Exploration Maturity 

There is strong interest in measures or indices that 

describe the petroleum exploration maturity of areas. The geographical region of interest may consist of an individual country, groups of countries, or entire continents. Here, exploration 

maturity is defined relative to a density of drilling that, in turn, 

implies an approximate threshold size of an undiscovered 

accumulation. An area is mature relative to a threshold size if 

the drilling is sufficiently dense that there is little chance that 

accumulations at least as large as the threshold size remain 

undetected in the exploration area. 

Petroleum exploration maturity is evaluated by using data 

generated by the exploration process. These data include all 

successful and dry well locations (density of drilling) and the 

locations and magnitudes of discoveries. The well locations 

reflect the industry’s evaluation of the area, and the discovery 

data reflect the exploration outcomes. Although the complete 

set of geologic data used to locate exploration and development wells cannot be replicated by a single entity, the locations of past successful and dry wells are available. 

Gross wildcat or exploration well counts are inadequate 

and misleading measures of exploration maturity in large 

regions. A well drilled near existing wells or production is 

less likely to find new oil than a well drilled further away 

from production. Well location data allow the calculation of 

distances between wells. A minimum distance between wells 

is necessary for an accumulation of a specific size to remain 

undetected. Drilling density and distances between wells convey information about the likelihood of occurrence of undetected target accumulations in the search area. 

For an individual country, oil and gas exploration is generally confined to only a small fraction of the total land area. 

Consider the case of wildcat drilling where wells are sited 

according to a regular grid. If drilling is confined to a fixed 

area, then the probability of having an undetected accumulation declines as drilling density increases; this decline is called 

the crowding-out effect. Alternatively, for a given density of 

drilling, using the definitions given above, the exploration 

for larger accumulations is more advanced (mature) than the 

exploration for small accumulations. The degree of exploration maturity for a confined area is conditional on the distance 

between wells, the target size, and the spatial arrangement of 

wells. 

When the exploration area is fixed, the crowding-out 

effect of wildcat wells together with a rough ordering of 

discoveries by size produces a declining discovery rate. 

However, when exploration expands into frontier areas, the 
Table . Forty most prolific provinces in the study area and their year of first discovery and cumulative 

recoverable volumes of oil and gas in their petroleum discoveries through 2001. 

[Provinces are ranked by the cumulative recoverable volumes of oil in the petroleum discoveries, which are the sum of past 

production and proved reserves of oil, gas, and natural gas liquids. Years and oil and gas volumes are from IHS Energy 

Group (2002); province names and code numbers are from U.S. Geological Survey (USGS) World Energy Assessment 

Team (2000). BBO = billions of barrels (bbl × 109) of oil; TCF = trillions of cubic feet (ft3 × 1012)] 

Rank USGS petroleum province Year of Oil Gas 

name and code number first discovery (BBO) (TCF) 

1 Mesopotamian Foredeep Basin, 2024 1938 326 295 

2 Greater Ghawar Uplift, 2021 1932 147 260 

3 West Siberian Basin, 1174 1953 139 1,531 

4 Zagros Fold Belt, 2030 1905 137 486 

5 Rub Al Khali Basin, 2019 1954 101 212 

6 Volga-Ural Region, 1015 1932 68 100 

7 East Venezuela Basin, 6098 1867 63 173 

8 Maracaibo Basin, 6099 1914 55 53 

9 Niger Delta, 7192 1954 51 194 

10 North Sea Graben, 4025 1966 49 167 

11 Sirte Basin, 2043 1958 45 48 

12 Villahermosa Uplift, 5305 1954 42 51 

13 West-Central Coastal, 7203 1951 26 22 

14 North Caspian Basin, 1016 1898 22 187 

15 South Caspian Basin, 1112 1869 21 71 

16 Trias/Ghadames Basin, 2054 1956 21 41 

17 Bohaiwan Basin, 3127 1961 19 18 

18 Widyan Basin-Interior Platform, 2023 1938 18 15 

19 Songliao Basin, 3144 1959 16 5 

20 Campos Basin, 6035 1974 14 10 

21 Timan-Pechora Basin, 1008 1930 14 42 

22 Central Sumatra Basin, 3808 1939 13 2 

23 Middle Caspian Basin, 1109 1893 12 32 

24 Tampico-Misantla Basin, 5301 1901 12 22 

25 Red Sea Basin, 2071 1907 10 9 

26 Putumayo-Oriente-Maranon Basin, 6041 1963 9 2 

27 Junggar Basin, 3115 1897 8 5 

28 Bombay, 8043 1958 7 28 

29 Baram Delta/Brunei-Sabah Basin, 3701 1910 7 40 

30 Carpathian-Balkanian Basin, 4061 1835 6 8 

31 Interior Homocline-Central Arch, 2020 1989 6 17 

32 Llanos Basin, 6096 1948 5 8 

33 Fahud Salt Basin, 2016 1962 5 11 

34 Illizi Basin, 2056 1956 5 41 

35 Gippsland Basin, 3930 1924 4 11 

36 San Jorge Basin, 6058 1907 4 5 

37 Malay Basin, 3703 1969 4 62 

38 Vestford-Helgeland, 4017 1981 4 37 

39 Kutei Basin, 3817 1897 3 59 

40 Saline-Comalcalco Basin, 5304 1904 3 4 

Measures of Exploration Maturity 1 
14	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

overall discovery rates can be irregular. The exploration area 

may expand because of changes in legal restriction or as a 

result of economic factors or technological breakthroughs. For 

example, offshore deepwater discoveries are now commercial because of recent advances in technology and improved 

economic conditions.

To summarize, the petroleum industry does not site 

exploration wells on a regular grid, and so wells are not evenly 

distributed. Well locations, distances between wells, and the 

arrangement of wells are used to initially delineate the search 

areas, that is, areas where the drilling record shows that firms 

have explored for petroleum. Well locations and the distances 

between wells are also used to determine the degree of maturity of exploration of an exploration area already delineated. 

This determination is accomplished by comparing distances 

between wells to a threshold deposit size so that a pool of a 

larger size will not remain undetected. Wells that are closer 

than the minimum specified distance to preclude the given 

deposit size provide only redundant information.

In the next section, a scheme to standardize the information conveyed by different well densities is explained. The 

scheme also provides the basis for the development of graphical tools and numerical measures that are used to describe the 

location and extent of the area of interest and the maturity of 

exploration of that area. 

Delineated	Prospective	Area	and	Explored	Area:	

Definitions

A country or political entity commonly encompasses 

more than one petroleum province. Locations within an 

individual country or a group of countries are described 

mathematically as a set of grid points in a plane. For ease in 

comparing data in this Circular with data in USGS Circulars 

981 and 1096 (Root, Attanasi, and Turner, 1987; Attanasi and 

Root, 1993), the grid-point spacing used herein has been kept 

the same. The grid points are 2.83 miles apart, and the area 

of each cell having the grid points as corners is 8 square miles. 

Each grid point is identified by a longitude and a latitude 

location. 

The delineated prospective area is described as the set of 

all (grid) points that are reasonably close to wells (producing 

or dry) and that are also inside the area drilled. The scheme for 

choosing the grid points that constitute the delineated prospective area (and for computing the magnitude of the delineated 

prospective area) is based on examination of all non-overlapping triangles (see fig. 5) formed by wells at their vertices. A 

grid point is said to be in the delineated prospective area if it 

is located within a triangle that is small enough to fit inside a 

circle that has a radius of 20 miles. The delineated prospective 

area, in square miles, is computed as the combined (non-overlapping) area of those triangles having a well at each vertex 

and fitting inside a circle with a radius of 20 miles (see fig. 5). 

The delineated prospective areas are then displayed on maps 

as closed polygons.

The 20-mile radius was chosen in USGS Circulars 

981 and 1096 (Root, Attanasi, and Turner, 1987; Attanasi 

and Root, 1993) because it corresponded to a scale that was 

convenient for visual presentation of the area of interest for 

petroleum exploration. The 20-mile radius was also consistent with the precision of the data on the locations of the 

wells and discoveries. When a radius smaller than 20 miles is 

used, numerous gaps (data-poor areas) in the prospective area 

appear, whereas when a larger radius is used, there is a loss of 

resolution in defining the prospective area. 

The computation of the delineated prospective area 

mapped in figures 14–57 used locations of all wildcat, exploration, and development wells, both successful and dry, along 

with the locations of fields. All data except data for wells with 

Table	4. Regional distribution in the study area of total and offshore wildcat wells drilled through 2001 and 

mated cumulative recoverable oil and gas discovered through 2001.

[Data are from IHS Energy Group (2002). BBO, billions of barrels (bbl × 109) of oil; TCF, trillions of cubic feet (ft3 × 1012)]

total and offshore estiRegion Wildcat	

wells

Total

Oil	

(BBO)

Gas

(TCF)

Wildcat	

wells

Offshore

Oil	

(BBO)

Gas	

(TCF)

Mexico ................................... 1,083 57.5 98.3

Caribbean ............................... 515 .4 <.1

Central America ..................... 234 .1 <.1

South America ....................... 16,203 169 423

Europe* .................................. 19,069 75.6 690

Middle East ............................ 3,819 755 2,196

Africa ..................................... 9,794 169 607

Asia ........................................ 13,036 160 1,043

Southwestern Pacific.. ............ 4,740 7.93 209

Russia ..................................... 11,354 235 2,009 

Total study area ................... 79,847 1,630 7,275

*Data for Europe excluding Greenland and Iceland, which have 7 and 0 wildcat wells, respectively.

120

27

64

2,017

4,727

413

2,735

3,979

1,099

57

15,238

32.6

<.1

0

18.8

56.3

103

59

47.6

6.34

2.51

326

21

<.1

0

86.2

338

689

208

406

181

139 

2,068
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Three wells define a circle 

having a radius <20 miles 

Grid points inside 

triangles compose the 

delineated prospective area 

Wells at vertices 

of triangles 

Figure . Diagram for identifying and computing delineated prospective area. To facilitate comparisons 

with Circular 1096 (Attanasi and Root, 1993), the delineated prospective area was calculated the same 

way for this Circular from grid points that were evenly spaced 2.83 miles apart. If three non-colinear wells 

define a circle having a radius less than 20 miles, then the triangle connecting the wells defines the delin

eated prospective area. Grid points that lie within such triangles appear as the delineated prospective area 

on the maps in figures 14–57. Because the grid point symbols in figures 14–57 are too large to be distin

guished separately, the area covered by the grid points appears as a continuous area. 

Measures of Exploration Maturity 1 

­

­

a missing or obviously incorrect location were used because, 

for some areas, most of the wildcat well history, particularly 

prior to 1950, is missing. The dry and producing well locations 

and field locations may represent the only evidence of prior 

exploration. Use of all the data added some redundancy to the 

computations but assured that no area that had been searched 

was excluded because of missing wildcat or exploration wells. 

When exploration begins in a country, the prospective 

area delineated by drilling expands rapidly and then stabilizes 

later as technological barriers stop further drilling or if yields 

to drilling in the new area decline. After the stabilization of 

the delineated prospective area, one might characterize most 

exploratory drilling as followup drilling, which is more intense 

drilling in an already delineated prospective area. The explored 

area is defined as the area consisting of the points in the delineated prospective area that are within 2 miles of a well. 

Suppose that a well is a distance of exactly 2 miles from 

another well and that the area covered by a circle between the 

wells is classified as “explored.” In this situation, the largest 

field that could occur between the wells and in the explored 

area would have a surface area of 3.14 square miles. (The 

circle would have a diameter of 2 miles, and so the radius 

would be 1 mile. The area would then be 3.14 square miles.) 

Expected recovery from pools having that surface area would 

vary with pay thickness and with reservoir properties. For the 

Permian Basin, for example, fields with surface areas of 3.14 

square miles averaged recoverable oil of less than 12 MMBO 

(Attanasi and others, 1981). For the offshore Gulf of Mexico, 

where reservoir properties are better than in the Permian Basin, 

fields with 3.14 square miles of surface expression generally 

averaged less than 24 MMBO (Attanasi and Haynes, 1984). 

According to these data, for areas designated as explored, the 

largest possible undetected accumulations are in the range 

of 12 to 24 MMBO. Although such pool sizes are important 

locally, if overlooked, they will not significantly change the 

outlook for undiscovered resources on a global scale. 

For some provinces, much of the delineated prospective 

area may never become explored area because the delineated 

prospective area was found to be unproductive and not worth 

further evaluation. A single well can potentially condemn a 

large area if the well indicates that the occurrence of commercial discoveries is unlikely (because of problems with the 

timing of hydrocarbon generation, because of a defective trap 

or seal, or because of the lack of reservoir-quality rock). 

The maps for individual countries or groups of countries 

in the study area show the location of the delineated prospective and explored areas (figs. 14–57). On these maps, exploration maturity is conveyed qualitatively as one compares 

visually the extent of prospective and explored areas. Accompanying each map is a graph showing cumulative delineated 

prospective and explored areas, in square miles, plotted against 

the cumulative number of wildcat wells drilled. The interpreta­
 

 

16 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

tion of these graphs is explained below in the section, “Tools 

for Analysis: Graphs.” 

Measuring Productivity of Delineated 

Prospective Areas 

Discovery rates are often calculated as the aggregate 

volume of oil or gas in new discoveries divided by the number 

of exploration wells drilled during a specific time interval. 

Such discovery rates describe yields per unit of exploration. 

For a single play having a fixed boundary, the discovery rate 

declines as progressively smaller accumulations are found. For 

basins containing several plays, if there is a sustained decline 

in discovery rates, then analysts will extrapolate the discovery 

rates to predict future finds, finding costs, and volumes of 

undiscovered recoverable resources. However, if the area of 

interest includes multiple sedimentary basins, then discoveries 

from new areas may offset declining discoveries in old areas, 

and the discovery rate for the entire region may not decline 

during the historical data period. With this situation, extrapolation of discovery rates is not useful. 

The procedure devised for separating the confounding effects of a declining discovery rate in an old area and a 

different, and perhaps increasing, discovery rate in new areas 

required the assignment of discoveries to the grid points in the 

delineated prospective area. Each point in the delineated prospective area was labeled with a prospective area date, which 

is the year that the point became part of the prospective area. 

The volume of oil and gas of each discovery was assigned to 

the grid point in the delineated prospective area that was closest to the field. The prospective area date of a point assigned 

to the volume of a discovery typically precedes the discovery 

date of the field. By attaching volumes of oil and gas to delineated prospective area points and prospective area dates, the 

quality (in terms of petroleum volumes) of the new prospective area can be compared with the quality of the older areas. 

Yields to drilling in old areas can be compared with the yields 

to drilling in new areas, in order to decide whether future drilling should target sites already in the delineated prospective 

area or sites that would open new delineated prospective areas. 

Tools for Analysis: Graphs 

Two types of graphs showing time profiles of selected 

variables were developed to supplement the maps of the 

delineated prospective area and explored area (figs. 14–57). 

A generalized version of the first type of graph is figure 6A, 

which shows the growth of cumulative delineated prospective 

area and explored area, arranged by the year when the areas 

became prospective or explored, versus the cumulative number 

of wildcat wells, which are also ordered by time. Each point in 

the delineated prospective and explored areas carries dates that 

indicate the year in which that location entered the prospective 

area category and the year in which that location entered the 

explored area category. The slope of the graph of cumulative 

delineated prospective area is, in part, determined by the mix 

of wildcat wells targeting sites inside and outside the current 

delineated prospective area. A straight line for cumulative prospective area could indicate a constant fraction of new wildcat 

wells sited inside and outside the current delineated prospective area. An increase in the slope of the graph could indicate 

that more wells were devoted to expanding the prospective 

area. A rollover in the graph (decline in slope) could indicate 

that more wildcat wells were sited in areas that were already 

prospective, thus reducing the amount of prospective area 

added per wildcat well drilled. At the top axis of the graph, 

the closer the 10-year markers are to each other, the smaller 

the number of wildcat wells that were drilled in that decade. A 

decline in the number of wildcat wells drilled could be related 

to market conditions or to changes in political institutions. 

The second type of graph (fig. 6B) shows cumulative 

recoverable oil and gas discoveries as functions of cumulative delineated prospective area, where the increments of 

prospective area are ordered by time. If all areas are equally 

productive (and if followup drilling is assumed to be instantaneous), then the graph of cumulative oil or gas discovered 

versus cumulative delineated prospective area ordered by time 

is a straight line (fig. 6B, curve A). If the earlier delineated 

prospective area is better endowed than the later delineated 

prospective area, then the shape of the graph is concave down 

(fig. 6B, curve B). Alternatively, if the later delineated prospective area is better endowed than earlier delineated prospective area, then the graph is concave up (fig. 6B, curve C). 

Care should be taken when interpreting graphs that show 

later delineated prospective areas as less productive than 

early areas. An apparent decline in the volume of discoveries 

per unit area for recently added areas could be exaggerated 

because of insufficient time for followup drilling required to 

develop resources. However, if sufficient time has elapsed 

without significant discoveries or followup drilling in the later 

delineated prospective area, then the reduced hydrocarbon 

yields in this part of the delineated prospective area probably 

reflect the petroleum endowment accurately. 

When an economic or technological advance occurs, such 

as the movement of Western European petroleum exploration 

to the North Sea or the movement of exploration to highly productive deepwater areas off Brazil and West Africa, the newly 

delineated prospective areas immediately show high yields 

relative to the earlier areas. In graphs for such situations, the 

curve of cumulative oil and gas discoveries plotted as a function of delineated prospective area is concave up. 

Statistics of Exploration and Analysis 

Exploration Effort 

Table 5 presents the annual totals of wildcat wells drilled 

in the study area by country and by region from 1961 through 

2001 (tables 5–7 follow the “References Cited”). The share 
 

A YEAR 

1960 1970 1980 1990 2000 

AREA , IN THOUSANDS OF SQUARE MILES

8 

7 

6 

5 

4 

3 

2 

1 

0 

CUMULATIVE NUMBER OF WILDCAT WELLS 

B YEAR 

1960 1970 1980 1990 2000 

Delineated prospective area 

Explored area 

0 10 20 30 40 50 60 70 80 90 100 

1 

2 

3 

4 

5 

B 

A 

C

OIL, IN BILLIONS OF BARRELS 

0 1 2 3 4 5 6 

0 

DELINEATED PROSPECTIVE AREA, IN THOUSANDS OF SQUARE MILES 

Figure 6. Generalized graphs of the possible profiles of the 

growth in the cumulative prospective area and the explored area. 

A, Profiles showing the growth in cumulative delineated prospective and explored areas plotted against the cumulative number 

of wildcat wells drilled, where both the areas and the wildcat 

wells are ordered by time. The top axis shows 10-year markers; 

the closer the markers are to each other, the fewer the wildcat 

wells that were drilled in that decade. B, Profiles A, B, and C of 

the cumulative oil discovered through 2001 and graphed by the 

year that the field location was classified as part of the delineated 

prospective area. Profile A is straight line and indicates that the 

delineated prospective areas identified by early exploration and 

late exploration are equally productive. Profile B indicates that the 

delineated prospective area identified by early exploration is more 

productive than the delineated prospective area identified by late 

exploration. Profile C indicates that the delineated prospective 

area identified by early exploration is less productive than the 

delineated prospective area identified by late exploration. 

Statistics of Exploration and Analysis 1 

of worldwide wildcat drilling accounted for by wildcat wells 

drilled in the United States and Canada declined from 93 per

cent in 1950 to 66 percent in 2000. The most dramatic reductions in wildcat wells drilled in the United States came in the 

1990s as annual wildcat drilling declined from a high of 9,151 

wells in 1981 to an average of 1,645 wildcat wells per year 

during the period from 1991 through 2000 (American Petroleum Institute, 2003). For the period from 1961 through 2001, 

the data in table 5 show that the share of study area’s wildcat 

wells drilled in Europe declined as the share of the wildcat 

wells drilled in Africa and Asia increased. 

The use of wildcat-well drilling as a measure of exploration effort can be misleading. Many of the wildcat wells 

drilled outside the United States, Canada, and Europe were 

directed at testing new plays, whereas most of the U.S., 

Canadian, and European wildcat wells were drilled in lower 

risk proven plays. Even within the same country, use of 

wildcat-well counts as a measure of exploration effort can be 

misdirected. For well counts to be a meaningful measure of 

exploration effort, the wells should be of roughly equivalent 

costs. Shallow-water offshore wells are typically much less 

costly to drill than deepwater wells, and onshore wells are less 

costly than offshore wells given the same basic subsurface and 

geologic conditions. 

Figure 7 shows that changes in international oil price 

levels led changes in annual wildcat drilling in the study area 

from 1968 through 2001. Changes in the market price of oil 

affect the petroleum industry’s revenues for all fields, its cash 

flow position, and its ability to fund exploration. Price changes 

also create expectations regarding future prices. In an environment of increasing prices, the expectation that such price 

levels can be sustained in the future tends to encourage the 

industry to explore and produce oil in high-cost areas. 

Regional Exploration Statistics and Analysis 

The regional discovery data for the study area are summarized in tables 4 and 6 (tables 5–7 follow the “References 

Cited”) and in figures 8 through 11. Table 4 lists total and 

offshore wildcat wells along with the oil and gas discovered 

by region. Table 6 lists for each region the significant geologic 

provinces and the year of first discovery and cumulative recoverable oil and gas discovered through 2001 for each. Some of 

the 173 significant provinces in the study area have resources 

in two regions, which are apportioned to the appropriate 

region in figures and tables of this Circular (table 6). 

Figure 8 shows for each of the major regions the discovery sequence and the magnitude of the cumulative recoverable 

oil in each significant province. The most prolific provinces 

(defined on the basis of cumulative recoverable oil) are commonly identified early, but they are not generally the first 

found in the discovery history of a region. 

The regional annual discovery rates for oil and gas by 

5-year intervals are shown in figures 9 and 11, respectively, for 

the period from 1951 through 2000. These figures also show 

which portions of total discoveries are onshore and offshore. 

­
1 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

2,500 40 

2,000 

Wildcat 

Price 

T WELLS PER YEAR 

30

1,500 

NUMBER OF WILDCA

20 

1,000 

PRICE, IN DOLLARS PER BARREL

10 

500 

0 0

1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 

YEAR 

Figure . Graph showing that the average price of imported crude oil to U.S. refineries led the 

annual wildcat drilling rate in the study area from 1968 through 2001. Price data are from American 

Petroleum Institute (2003); wildcat well data are from IHS Energy Group (2002). 

The regional oil discovery rates calculated on the basis of oil 

per wildcat well for 5-year intervals from 1951 through 2000 

are presented in figure 10. 

For most areas, gas was not commercial during the period 

from 1951 to 2000, and so the reporting of gas that is discovered with oil and as nonassociated gas is likely to be incomplete and understated. Because wildcat wells typically have no 

predrilling-intent information reported by the data services, in 

countries where gas is a commercial resource, there is no way 

to distinguish the proportion of wells targeting oil prospects 

and those targeting gas prospects. 

The results of the regional computations of the delineated 

prospective areas and explored areas are presented in figures 

12A–G and 13A–G. Table 7 provides a summary of data for 

the 10 regions computed by adding together data from the 

individual countries and country groups (tables 5–7 follow 

the “References Cited”). Although table 5 presents data for 

the Caribbean, Central America, and Mexico, these data are 

included in figures 12 and 13 only in the study area graphs in 

figures 12H and 13H. This analysis of exploration and yield 

data focuses on trends showing exploration maturity; a full 

interpretation of the data should also consider government 

resource development policies, regulations, and the market 

conditions. For example, for some of the countries, when natural gas became a commercially marketable commodity, the 

gas yield curves show the later prospective areas to be better 

endowed than early areas as exploration may have shifted to 

areas prone to discovery of nonassociated gas accumulations. 

The regional delineated prospective area and explored 

area shown in figures 12 and 13 and discussed in the following 

sections on each region are aggregated from the data shown 

in figures 16 through 54. Maps are provided for the Caribbean 

(fig. 14) and Central America (fig. 15), but these areas are not 

discussed as a separate region because the discovered petroleum is very small. No map was made for Mexico because 

although the discovery data for Mexico may be reasonably 

complete, substantial amounts of exploration drilling data are 

missing. Data for each region are derived from figures as follows: South America, figures 16–24; Europe, figures 25–27; 

Middle East, figures 28–32; Africa, figures 33–44; Asia, figures 45–53; southwestern Pacific, figures 54–56; and Russia, 

figure 57. 

In the discussions about the relative richness of prospective area within regions, the prospective area is described in 

terms of an early half and a late half. Suppose there is a region 

where half of the total prospective area that was delineated 

through 2001 became prospective by 1970. Then the early half 

of the prospective area is that part of the prospective area that 

became prospective before January 1970, and the late half of 

the prospective area is that area that became prospective after 

January 1970. 

Mexico 

According to available data, Mexico has five significant 

provinces (table 6). The Villahermosa Uplift accounts for 73 

percent of the oil and 52 percent of the discovered gas in Mexico through 2001. The Tampico-Misantla Basin has discovered 

oil of 11.5 BBO and discovered gas of 21.553 TCF. The two 

provinces together account for 93 percent of the oil and 74 
Statistics of Exploration and Analysis 19 

percent of the gas discovered through 2001. The historical 

well data for Mexico are incomplete. 

South America 

South America accounts for about 10 percent of the oil 

and 6 percent of the gas discovered in the study area (table 4). 

South America has a long history of petroleum exploration 

and discovery. The East Venezuela Basin (fig. 22) and the 

Maracaibo Basin (figs. 20 and 22) each have cumulative 

recoverable oil discoveries in excess of 20 BBO (table 6). 

Along with the Campos Basin (fig. 24), these provinces 

account for 78 percent of the oil discovered through 2001 in 

South America (table 4). Discoveries in the East Venezuela 

and Maracaibo Basins occurred early in the exploration history 

of South America (fig. 8A). For gas, the three most prolific 

provinces—the East Venezuela Basin (fig. 22), Maracaibo 

Basin (figs. 20 and 22), and Santa Cruz-Tarija Basin (figs. 18 

and 23)—accounted for 65 percent of the discovered gas. With 

the exception of gas in the Santa Cruz-Tarija Basin, most of 

this gas was associated with oil discoveries. 

Oil and gas discoveries prior to 1951 account for 50 

percent of the oil and 32 percent of the gas discovered through 

2001. Since 1950, the period from 1956 through 1960 represents the peak 5-year period of annual oil discoveries and oil 

discovered per wildcat well (figs. 9A and 10A). By the last 

period, 1996–2000, more than half of the oil discovered was 

offshore (fig. 9A). For gas, the peak period of annual discoveries was from 1996 through 2000 (fig. 11A), and about onethird of the gas discovered during that period was in offshore 

fields. 

The delineated prospective area for South America doubled between 1974 and the end of 2001, but the oil discovered 

in the prospective area added between 1974 and the end of 

2001 (the late half of the area) amounts to only 16 percent of 

the oil discovered in the area that became prospective before 

1974 (the early half of the prospective area) (figs. 12A and 

13A). Similarly, the gas discovered in the late prospective area 

amounts to only 27 percent of the gas discovered in the early 

prospective area (fig. 13A). By the end of 2001, the explored 

area represented 25 percent of the prospective area (table 7). 

Wildcat drilling declined in the 1990s (table 5), and there was 

a parallel slowdown in the expansion of prospective area. 

Figure 13A shows a slight increase in productivity for 

both oil and gas for the areas added since the mid-1980s. The 

large discoveries in the newly added areas are in the deepwater 

Campos Basin (fig. 24) offshore of Brazil. Commercial exploration and development of these deepwater areas required 

innovations in exploration and production technologies. 

Petrobras, the national oil company of Brazil, led development 

of deeper offshore waters as part of the government’s overall 

energy policy. The maps in figures 14–25 show the 200- and 

1,000-meter (656- and 3,280-foot) bathymetry contours. In 

water deeper than 200 meters, exploration and development 

are substantially more costly than in the adjacent shallow 

areas. 

Europe 

In this Circular, Europe is considered to be continental 

Europe (figs. 25–27), excluding Russia, Greenland, and Iceland. Russia is discussed as a separate region. Greenland has 

seven wildcat wells, and Iceland has none, but their data were 

excluded from the European totals, and maps of these areas 

are not included. 

Some significant provinces have resources in two regions, 

which are apportioned to the appropriate region in figures 

and tables of this Circular (table 6). For example, discoveries 

shown in figure 27 for the European parts of the DnieperDonets Basin and the Azov-Kuban Basin do not include discoveries in the Russian parts of the basins (fig. 57). Similarly, 

discoveries shown in figure 27 for the European part of the 

Aegean do not include discoveries in the Middle East part of 

the Aegean (fig. 28). 

Europe accounts for just less than 5 percent of the oil and 

for 9 percent of the gas discovered in the study area (table 4). 

Oil discoveries date from the mid-1800s (fig. 8B). The North 

Sea Graben (fig. 25) accounts for 65 percent of the cumulative 

recoverable oil and 24 percent of the cumulative recoverable 

gas discovered in Europe through 2001. The four most prolific 

oil provinces—North Sea Graben (fig. 25), CarpathianBalkanian Basin (fig. 27), Vestford-Helgeland (fig. 25), and 

Northwest German Basin (fig. 25)—account for 81 percent of 

the oil. The four most prolific gas provinces—North Sea Graben (fig. 25), Northwest German Basin (fig. 25), Anglo-Dutch 

Basin (fig. 25), and Dnieper-Donets Basin (fig. 27)—account 

for 69 percent of the natural gas. 

Oil and gas discoveries prior to 1951 account for only 8 

percent of the oil and 10 percent of the gas discovered through 

2001. The 5-year period from 1971 through 1975 had the 

highest annual rate of oil discovered and oil per wildcat well 

discovered (figs. 9B and 10B). The 5-year period from 1956 

through 1960 had the highest annual gas discovery rate (fig. 

11B). During that period, Gronnigen, the largest gas field in 

the region, was discovered in the Northwest German Basin. 

Advances in offshore technology and the high oil prices during the 1970s ensured that the North Sea discoveries could be 

commercially developed. 

The delineated prospective area of Europe doubled 

between 1968 and the end of 2001 (fig. 12B). The shapes of 

the oil and gas yield curves shown in figure 13B reflect the 

expansion of the prospective area into the North Sea and the 

offshore area’s richer oil endowment compared to the endowment of onshore areas. The late half of the prospective area, 

principally the North Sea Graben, has more than 3.5 times the 

oil found in the early half of the prospective area. Although 

gas discoveries in the delineated prospective area added 

between 1968 and the end of 2001 amounted to two-thirds 

of the gas discovered in the early half of the prospective 

area, government regulation and market conditions may have 

delayed gas-field development in the late half of the area. 

Text continues on p 36. 
A, Year of first discovery for significant provinces in South America

65 60 55 15 10 

5 

0 

1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 

63.4 BBO 

enezuela Basin East V

TIVE RECOVERABLE OIL (BBO) 54.9 BBO CUMULA

Putumayo-Oriente-Maranon Basin 

Campos Basin 

Maracaibo Basin 

San Jorge Basin 

Neuquen Basin

arija Basin 

Barinas-Apure Basin and Llanos Basin

Talara Basin

Middle Magdelena

Progreso Basin

Santa Cruz-T

Cuyo Basin 

Oran-Olmedo Basin

Ucayali Basin and Reconcavo Basin

Magallanes Basin

Upper Magdelena

Sergipe-Alagoas Basin 

Guyana-Suriname Basin

rough 

Potigar Basin

Tobago T

Cariaco Basin and Santos Basin

YEAR OF FIRST DISCOVERY 

Figure . Graphs showing historical sequence by year of first discovery in each significant petroleum province and magnitude of cumulative recoverable oil discoveries through 2001 in each province for six regions: A, South America; B, Europe; C, Middle East; D, Africa; E, Asia; and F, Russia. Large discoveries require breaks in the vertical axis in parts A, B, C, and F. Some of the significant provinces have oil in two regions, which is apportioned to the appropriate region in this figure. Significant provinces 

plotted have had at least one discovery of at least 100 millio

provinces defined solely on the basis of at least one gas dis600 billion cubic feet of gas are not plotted in this figure but billions of barrels (bbl × 109) of oil. Years of first discovery a

cumulative recoverable oil are from IHS Energy Group (200
B, Year of first discovery for significant provinces in Europe 

50 49 

6 5 4 3 2 1 

0 

1830 1840 1850 1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 

49.1 BBO 

CUMULATIVE RECOVERABLE OIL (BBO)

Carpathian-Balkanian Basin 

North Sea Graben

Northwest German Basin 

North Carpathian Basin 

Pannonian Basin

Dnieper-Donets Basin

Anglo-Paris Basin

Anglo-Dutch Basin

Transylvanian Basin

Bohemia

Adriatic Basin

German-Polish Basin

Pyrenean Foothills-Ebro Basin and Irish Sea

Pripyat Basin

Faeroes-Shetland-Orkney Basin

Ireland-Scotland Platform

Azov-Kuban Basin

Alps 

Po Basin

Sicily

Aquitaine Basin

Iberic Cordillera

Aegean

Tuscany-Latium-Paola 

YEAR OF FIRST DISCOVERY 

Figure . Continued. 
C, Year of first discovery for significant provinces in the Middle East 

350 

150 

100 

50 

0 

1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 

326 BBO 

TIVE RECOVERABLE OIL (BBO)

Zagros Fold Belt

Greater Ghawar Uplift 

Mesopotamian Foredeep Basin 

CUMULA

Rub Al Khali Basin

Widyan Basin-Interior Platform

Euphrates/Mardin 

Levantine Basin

Fahud Salt Basin

Ghaba Salt Basin 

Kura Basin and Qatar Arch

Red Sea Basin

Central Oman Platform

East Flank Oman Sub-basin

Anah Graben

South Oman Salt Basin

YEAR OF FIRST DISCOVERY 

Figure . Continued. 
D, Year of first discovery for significant provinces in Africa 

60 50 

l atsaoCl artneC-tseW

n isaB

l 

a 

a

e 

r

g

m

e

u

n

n

a

e

e

H

S

B

1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 

and

Delta 

Basin 

Niger 

Erg/Ahnet Grand 

Red Sea Basin

Basin Sirte 

TIVE RECOVERABLE OIL (BBO) 40 

Basin 

30 

Trias/Ghadames and Basin 

CUMULA

Illizi 

Basin

20 

Guinea 

Egypt 

of Gulf 

North 

Sud 

and 

and 

10 

Pelagian Basin 

and 

Basin 

Coastal 

Basin 

Basin 

Gharadiq 

Basin 

Delta 

African 

Levantine 

Murzuk 

Nile 

Abu 

South 

0 

YEAR OF FIRST DISCOVERY 

Figure . Continued. 
E, Year of first discovery for significant provinces in Asia 

25 

20 

TIVE RECOVERABLE OIL (BBO) 15 CUMULA10 

5 

0 

n isaBn ogiaS

1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 

Bohaiwan Basin 

Kura Basin and South Caspian Basin

North Caspian Basin 

Central Sumatra Basin

Songliao Basin 

Kutei Basin and Junggar Basin

Baram Delta/Brunei-Sabah Basin

au Basin ung T

Niigata Basin and Assam

errane 

Middle Caspian Basin

olcanic Arc/Accreted T

arakan Basin 

ajik Basin

Bintuni/Sulawati Province 

Northwest Java Basin

Bombay 

Thai Basin 

aiwan Thrust and Fold Belt 

North Sumatra Basin

South Sumatra Basin 

uwei Basin

est Natuna Basin 

East Java Basin 

Fergana Basin

Ordos Basin

Ganges-Brahmaputra Delta

Tarim Basin

North Ustyurt Basin

Malay Basin

Irrawaddy

Japan V

Pamusian T

Afghan-T

Barito Basin

Sichuan Basin and

Amu-Darya Basin

Jiuquan Minle W

Qaidam Basin

Indus 

Greater Sarawak Basin

Nanyang Basin 

Penyu/W

inggehai Basin and Mekong/Cuulong/V Y

Krishna-Godavari and Pearl River Mouth Basin

Thailand Mesozoic Basin Belt

T

Palawan Shelf 

YEAR OF FIRST DISCOVERY 

Figure . Continued. 
F, Year of first discovery for significant provinces in Russia 

140 

120 

1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 

139 BBO 

West Siberian Basin 

Volga-Ural Region 

Azov-Kuban Basin

Middle Caspian Basin

North Sakhalin Basin

Timan-Pechora Basin 

errace 

-Donets Basin 

Angara-Lena T

Dnieper

Yenisey-Khatanga Basin and Nepa-Botuoba Arch 

North Caspian Basin 

Baykit Arch

TIVE RECOVERABLE OIL (BBO) 60 CUMULA40 

20 

0 

YEAR OF FIRST DISCOVERY 

Figure . Continued. 
26	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

0

1

2

3

4

19511956196119661971197619811986199119962001

0

1

2

3

4

5

19511956196119661971197619811986199119962001

0

1

2

3

4

5

6

7

8

9

19511956196119661971197619811986199119962001

0

1

2

3

4

5

19511956196119661971197619811986199119962001

A, South America

B, Europe

D, Africa

E, Asia

YEAR

0

5

10

15

20

25

30

19511956196119661971197619811986199119962001

C, Middle East

YEAR

OIL DISCOVERED (BBO) PER YEAR

EXPLANATION

Offshore

Onshore

Figure	9.  Graphs showing average annual volume of oil 

discovered offshore and onshore for 5-year intervals from 1951 

though 2000 for seven regions and the whole study area: A, 

South America; B, Europe; C, Middle East; D, Africa; E, Asia; F, 

Southwestern Pacific; G, Russia; and H, Study area. The study 

area graph (fig. 9H) includes data for Mexico, Central America, 

and the Caribbean, as well as for the seven regions for which data 

are graphed in figures 9A–G. BBO, billions of barrels of oil (bbl × 

109

). Discovery size estimates are from IHS Energy Group (2002). 
Figure 9. Continued.

0

1

2

0

1

2

3

4

5

6

7

8

9

10

19511956196119661971197619811986199119962001

19511956196119661971197619811986199119962001

0

10

20

30

40

50

60

1951

1956

19611966

19711976

1981

19861991

1996

2001

F, Southwestern Pacific

G, Russia

H, Study area (Note change in vertical scale)

YEAR

OIL DISCOVERED (BBO) PER YEAR

Statistics of Exploration and Analysis 27
28	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

Figure	10.  Graphs showing oil discovery rate per wildcat well 

for 5-year intervals from 1951 through 2000 for seven regions and 

the whole study area: A, South America; B, Europe; C, Middle 

East; D, Africa; E, Asia; F, Southwestern Pacific; G, Russia; and 

H, Study area. The study area graph (fig. 10H) includes data for 

Mexico, Central America, and the Caribbean, as well as for the 

seven regions for which data are graphed in figures 10A–G. 

MMBO, millions of barrels of oil (bbl × 106

). Wildcat well data 

and discovery size estimates are from IHS Energy Group (2002). 

Discovery rates reflect data for all wildcat wells and discoveries 

both onshore and offshore.

0

10

20

A, South America

19511956196119661971197619811986199119962001

0

200

400

600

800

1200

0

10

20

30

40

50

0

10

20

30

40

50

60

C, Middle East (Note change in vertical scale)

D, Africa

E, Asia

YEAR YEAR

OIL DISCOVERED (MMBO) PER WILDCAT WELL

19511956196119661971197619811986199119962001

1951195619611966

1971

1976

198119861991

19962001

1951

1956

1961

19661971

19761981

1986

19911996

2001

1400

0

10

20

B, Europe

19511956196119661971197619811986199119962001
Figure 10. Continued.

Statistics of Exploration and Analysis 29

0

10

20

0

10

30

40

0

10

20

30

40

50

60

H, Study area (Note change in vertical scale)

G, Russia

F, Southwestern Pacific

OIL DISCOVERED (MMBO) PER WILDCAT WELL

19511956196119661971197619811986199119962001

19511956196119661971197619811986199119962001

19511956

1961

1966

1971

19761981

1986

1991

1996

2001

YEAR
30	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

1951

1956196119661971197619811986199119962001

1951

1956196119661971

197619811986199119962001

1951

195619611966197119761981

1986199119962001

1951

1956196119661971

197619811986199119962001

1951

195619611966

19711976

1981

1986199119962001

1951

19561961196619711976198119861991

19962001

A, South America

B, Europe

D, Africa

E, Asia

YEAR

EXPLANATION

Offshore

GAS DISCOVERED (TCF) PER YEAR

Onshore 0

10

20

30

40

0

10

20

30

0

10

20

0

10

20

30

40

50

60

C, Middle East

F, Southwestern Pacific

0

10

20

0

10

20

30

40

50

60

70

80

90

100

110

YEAR

Figure	11.  Graphs showing average annual volume of gas 

discovered offshore and onshore for 5-year intervals from 1951 

through 2000 for seven regions and the whole study area: A,

South America; B, Europe; C, Middle East; D, Africa; E, Asia; F,

Southwestern Pacific; G, Russia; and H, Study area. The study 

area graph (fig. 11H) includes data for Mexico, Central America, 

and the Caribbean, as well as for the seven regions for which data 

are graphed in figures 11A–G. TCF, trillions of cubic feet (ft3

 × 1012).

Discovery size estimates are from IHS Energy Group (2002).
G, Russia

0

100

50

150

200

GAS DISCOVERED (TCF) PER YEAR

1951195619611966

1971

1976

1981

1986

1991

1996

2001

H, Study area (Note change in vertical scale)

YEAR

250

300

1951

195619611966

1971197619811986199119962001

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

Figure 11. Continued.

Statistics of Exploration and Analysis 31
2 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 AREA (THOUSANDS OF SQUARE MILES) 

A, South America 

YEAR
 

1960 1970 1980 1990 2000
 

500
 

400
 

300
 

200
 

100
 

0 

Delineated prospective area 

Explored area 

0 5,000 10,000 15,000 20,000 

C, Middle East 

1960 1970 1980 1990 2000
 

300
 

250
 

200
 

150
 

100
 

50
 

0 

Delineated prospective area 

Explored area 

0 1,000 2,000 3,000 4,000 

CUMULATIVE NUMBER OF WILDCAT WELLS 

B, Europe 

YEAR
 

1960 1970 1980 1990 2000
 

900
 

800
 

700
 

600
 

500
 

400
 

300
 

200
 

100
 

0 

Delineated prospective area 

Explored area 

0 4,000 8,000 12,000 16,000 20,000 

D, Africa
 

1960 1970 1980 1990 2000
 

600
 

500
 

400
 

300
 

200
 

100
 

0 

Delineated prospective area 

Explored area 

0 2,000 4,000 6,000 8,000 10,000 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Figure 12. Graphs showing growth in delineated prospective 


area and explored area delineated by wells drilled through 2001 


for seven regions and the whole study area: A, South America; B,
 

Europe; C, Middle East; D, Africa; E, Asia; F, Southwestern Pacific; 


G, Russia; and H, Study area. The study area graph (fig. 12H) 


includes data for Mexico, Central America, and the Caribbean, 


as well as for the seven regions for which data are graphed in 


figures 12A–G. The regional graphs are at different scales and 


are derived from graphs in figures 16–57. The areas are arranged 


by the year they became prospective or explored, and the wells 

are also ordered by time. At the top axis of the graphs, the closer 

the 10-year markers are to each other, the smaller the number 

of the wildcat wells that were drilled in that decade. Calculation 

of delineated prospective area is explained in the text. Well data 

are from IHS Energy Group (2002). Only wildcat wells that have 

spud or completion dates and that have longitude and latitude 

coordinates are used in the growth calculations for this figure. 
Figure 12. Continued.

E, Asia

Delineated prospective area

Delineated prospective area

Explored area

Explored area

Delineated prospective area

Explored area

Delineated prospective area

Explored area

CUMULATIVE NUMBER OF WILDCAT WELLS

AREA (THOUSANDS OF SQUARE MILES)

1960 1970 1980 1990 2000

YEAR

0

200

400

600

800

1,000

300

200

100

400

500

700

600

20,000 40,000 60,000 80,000

0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

F, Southwestern Pacific

1960 1970 1980 1990 2000

YEAR

0

100

200

300

400

0

0

0

1,000 2,000 3,000 4,000 5,000

H, Study area

1960 1970 1980 1990 2000

G, Russia

1960 1970 1980 1990 2000

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

CUMULATIVE NUMBER OF WILDCAT WELLS

0 2,000 4,000 6,000 8,000 10,000 12,000

Statistics of Exploration and Analysis 33
 

100 

600 

700 

400 

160 

A, South America B, Europe
 

YEAR YEAR
 

1960 1970 1980 1990 2000 1960 1970 1980 1990 2000
 

180
 

Oil 

Gas 

500 80 800

Oil 

Gas 

400 140 60 600

120 

OIL (BBO) OIL (BBO)

300 

GAS (TCF) GAS (TCF)

OIL (BBO) OIL (BBO) 

GAS (TCF) GAS (TCF)

40 

80 

200 

60 

20 200 40 100
 

20
 

0
 0 0 0 

0 100 200 300 400 500 0 100 200 300 400 500 600 700 800 900 

C, Middle East D, Africa 

1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 

800 2,400 200 

100 

Oil 

Gas 

800 

Oil 

Gas 

50 150 200 250 

180 

2,000 160 

140 

1,600 500 120 

400 1,200 100

80 300 

800 60 

200 200 

40 400 

100 20
 

0
 0 0 0 

0 100 300 0 200 300 400 500 600 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

400 

600 

 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

Figure 1. Graphs showing cumulative recoverable oil and gas 

discoveries through 2001 plotted as a function of cumulative 

delineated prospective area for seven regions and the whole 

study area: A, South America; B, Europe; C, Middle East; D, Africa; 

E, Asia; F, Southwestern Pacific; G, Russia; and H, Study area. 

The study area graph (fig. 13H) includes data for Mexico, Central 

America, and the Caribbean, as well as for the seven regions for 

which data are graphed in figures 13A–G. The regional graphs are 

at different scales and are derived from graphs in figures 16–57. 

The oil and gas discoveries are graphed by the year that the field 

location was classified as part of the delineated prospective area, 

and the increments of prospective area are ordered by time. At 

the top axis of the graphs, the closer the 10-year markers are to 

each other, the lower the rate at which prospective area was 

added in that decade. Calculation of delineated prospective area 

is explained in the text. Discovery size estimates are from IHS 

Energy Group (2002). BBO, billions of barrels of oil (bbl × 109

); TCF, 

trillions of cubic feet (ft3

 × 1012). 
E, Asia F, Southwestern Pacific 

YEAR YEAR 

1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 

180 

200 140 Oil 

120 

Gas 150 100 

80 

100 

200 

150 

100 

50 

1,200 9 

Oil 

Gas 

250 

160 8 

1,000 

7 

800 

OIL (BBO) 

6 

GAS (TCF)

OIL (BBO) 5 

600 

4 

GAS (TCF)

60 400 3
 

40
 2 50 200 

20 1
 

0
 0 0 0 

0 200 400 600 800 1,000 0 50 100 150 200 250 300 350 400 

G, Russia H, Study area 

1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 

250 

Oil 

OIL (BBO) 

Gas 

GAS (TCF)

OIL (BBO) 

GAS (TCF) 

100 200 

2,500 1,800 10,000 

Oil 

Gas 

1,600 

2,000 8,000 1,400 

1,200 

1,500 6,000

1,000 

800 

1,000 4,000 

600 

400 500 2,000

200 

0 0 0 0

0 300 400 500 600 700
 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES)
 

Figure 1. Continued. 

Statistics of Exploration and Analysis  
6 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

By the end of 2001, the explored area was 23 percent of the 

delineated prospective area (table 7). 

Middle East 

In this Circular, the Middle East is considered to be 

the Arabian Peninsula, Iran, Iraq, Turkey, Cyprus, Lebanon, 

Jordan, Syria, Israel, Gaza Strip, and West Bank (figs. 28–32). 

Although some significant provinces (Red Sea Basin, Aegean, 

Levantine Basin, South Caspian Basin, Kura Basin, and AmuDarya Basin) have resources both in the Middle East and in 

other regions (table 6), the tables and figures for the Middle 

East include only data for the part of each province in the 

Middle East. 

The Middle East accounts for 46 percent of the oil and 

30 percent of the gas discovered in the study area (table 4). 

The earliest discoveries in the most prolific oil provinces in 

the Middle East were made in the early 1900s (table 6 and fig. 

8C). About 94 percent of the oil discovered in this region is 

contained in four provinces—Mesopotamian Foredeep Basin 

(figs. 29, 31, and 32), Greater Ghawar Uplift (fig. 29), Zagros 

Fold Belt (figs. 28, 30, 31, and 32), and Rub Al Khali Basin 

(figs. 29 and 32). Each of these provinces contains more than 

20 BBO. Similarly, 85 percent of the gas discovered is contained in four provinces—Qatar Arch (figs. 29 and 32), Zagros 

Fold Belt (figs. 28, 30, 31, and 32), Mesopotamian Foredeep 

Basin (figs. 29, 31, and 32), and Greater Ghawar Uplift (fig. 

29). Each of these provinces contains more than 120 trillion 

cubic feet (TCF) of gas. 

Pre-1951 discoveries accounted for 37 percent of the 

oil and 20 percent of the gas discovered through 2001. After 

1950, the peak 5-year period for annual oil discoveries was 

from 1961 through 1965 (fig. 9C). In terms of oil discovered 

per wildcat well, the peak 5-year period after 1950 was from 

1951 through 1955 (fig. 10C). The peak period for annual gas 

discoveries was from 1991 through 1996 (fig. 11C). Nearly all 

the gas reported discovered during that period was offshore. 

The gas discovered in offshore areas was primarily nonassociated gas. 

Figure 12C shows the delineated prospective area of the 

Middle East expanding steadily over time. Half of the delineated prospective area was added between 1976 and the end of 

2001. Through 2001, the late half of the delineated prospective 

area contained only 8 percent of the oil and 22 percent of the 

gas discovered in the early half of the delineated prospective 

area (fig. 13C). The large change in gas is attributable to the 

addition of a giant offshore discovery in Iranian waters. The 

Iranian offshore gas field South Pars appears to be geologically associated with Qatar’s North Field. South Pars became 

prospective in 1991, the year it was reported discovered. 

By the end of 2001, the explored area was only 16 per

cent of the delineated prospective area (table 7). It has been the 

policy of the largest producers in this region, as members of 

the Organization of Petroleum Exporting Countries (OPEC), 

to drill and develop resources in a controlled manner. The 

yields shown in figure 13C for the late delineated prospective 

area likely understate resources actually found. 

­

Africa 

Although some significant provinces (Red Sea Basin, 

Levantine Basin, and Pelagian Basin) have resources both in 

Africa and in other regions (table 6), the tables and figures 

for Africa include only data for the part of each province in 

Africa. The continent of Africa accounts for about 10 percent 

of the discovered oil and 8 percent of the discovered gas in the 

study area (table 4). Most of the large commercial discoveries 

in Africa occurred after World War II (table 6 and fig. 8D). 

Four provinces—Niger Delta (figs. 36 and 42), Sirte Basin 

(fig. 37), West-Central Coastal (figs. 35 and 42), and Trias/ 

Ghadames Basin (figs. 37 and 38)—account for 85 percent 

of the oil discovered in this region. The Niger Delta (figs. 36 

and 42) contains about 194 TCF of gas and is the only African 

province having cumulative gas discoveries larger than 120 

TCF. The Niger Delta accounts for 32 percent of the gas discovered in Africa. Four provinces—Niger Delta (figs. 36 and 

42), Grand Erg/Ahnet Basin (fig. 38), Sirte Basin (fig. 37), and 

Nile Delta Basin (fig. 39)—account for 66 percent of the gas 

discovered through 2001. 

The volumes assigned to pre-1951 discoveries of oil and 

gas are insignificant when compared with total oil and gas 

discovered. The peak 5-year period for annual oil discovered 

was from 1961 through 1965 (fig. 9D), whereas the peak 

5-year period for oil discovered per wildcat well was from 

1956 through 1960 (fig. 10D). The peak 5-year period for 

annual gas discovered was from 1956 through 1960 (fig. 11D). 

According to data used for figure 9D, more than three-fourths 

of the oil discovered during the period from 1996 through 

2000 is offshore. The discoveries are primarily in the deepwater offshore areas of West Africa (figs. 35, 36, and 42). 

Both the annual oil discovery rate and per well discovery rate 

increased dramatically in that period. 

The delineated prospective area doubled in size between 

1971 and the end of 2001 (fig. 12D). The late delineated 

prospective area contains about 30 percent of the oil and 39 

percent of the gas that was in the early area. Figure 12D shows 

the slope of the cumulative growth in delineated prospective 

area slightly increasing during the 1990s. Figure 13D shows 

that the delineated prospective area added during the 1990s 

had a higher petroleum endowment than the areas added during the previous two decades. During the 1990s, the newly 

delineated prospective area consisted primarily of the deepwater areas (deeper than 200 meters) off of West Africa (figs. 

35, 36, and 42). Innovations in exploration and production 

technology allowed the commercial development of those 

resources. By the end of 2001, the explored area was 17 percent of the delineated prospective area (table 7). 

Asia 

In this Circular, Asia is considered to include countries 

of central Asia, China, Mongolia, Southeast Asia, the Indian 

Subcontinent, and the Far East (figs. 45–53) but to exclude 

Russia, which is discussed as a separate region (fig. 57). 

Although some significant provinces (Volga-Ural Region, 
 

North Caspian Basin, Middle Caspian Basin, South Caspian 

Basin, Kura Basin, Amu-Darya Basin, and Bonaparte Gulf 

Basin) have resources both in Asia and in other regions (table 

6), the tables and figures for Asia include only data for the part 

of each province in Asia. 

Asia accounts for 10 percent of the oil and 14 percent 

of the gas discovered to date in the study area (table 4). The 

North Caspian Basin and South Caspian Basin (fig. 46) are the 

only provinces containing at least 20 BBO (table 6). The four 

most prolific provinces for oil are the North and South Caspian 

Basins (fig. 46), Bohaiwan Basin (fig. 45), and Songliao Basin 

(fig. 45). Together these four provinces account for 49 percent 

of the oil discovered in Asia. The Amu-Darya Basin (figs. 46 

and 47) is the only province with total gas discoveries greater 

than 120 TCF. The four provinces having the largest volume 

of discovered gas are the Amu-Darya Basin (figs. 46 and 47), 

North Caspian Basin (fig. 46), Greater Sarawak Basin (figs. 

52 and 53), and South Caspian Basin (fig. 46). Together these 

four account for 46 percent of the gas discovered in the region. 

The recovery size distribution for significant provinces appears 

to be more uniform for Asia than for other regions (fig. 8E). 

Oil and gas in fields discovered prior to 1951 accounted 

for 15 percent of the oil and 2 percent of the gas discovered 

through 2001. After 1950, the 5-year period from 1971 

through 1975 was the peak period for annual oil and annual 

gas discoveries (figs. 9E and 11E), although the period 

from 1956 through 1960 was the peak 5-year period for oil 

discovered per wildcat well (fig. 10E). Between 1960 and the 

end of 2001, about 42 percent of the oil and gas discovered 

was in offshore fields. 

Figure 12E shows the delineated prospective area of Asia 

expanding at a constant rate since 1970. Half the delineated 

prospective area was added between 1979 and the end of 2001. 

Through 2001, oil discoveries in the late half of the prospective area amounted to 25 percent of the oil discovered in the 

early half (fig. 13E). The gas discovered in the late half of the 

prospective area amounted to 35 percent of the gas discovered 

in the early half (fig. 13E). By the end of 2001, the explored 

area accounted for almost 20 percent of the delineated prospective area (table 7). 

Southwestern Pacific 

In this Circular, the southwestern Pacific region is considered to include Australia, New Zealand, East Timor, and 

Papua New Guinea, along with several South Pacific island 

nations (figs. 54–56). Although the Bonaparte Gulf Basin has 

resources both in the southwestern Pacific region and Asia 

(table 6), the tables and figures for the southwestern Pacific 

include only data for the part of the province in the southwestern Pacific. The southwestern Pacific region accounts for 

less than half of 1 percent of the oil and about 3 percent of the 

gas discovered in the study area (table 4). The total amount 

of discovered oil is a modest 7.93 BBO. The total discovered 

natural gas is about 209 TCF, and almost half of the gas is in 

one province, the Northwest Shelf (table 6, fig. 55). 

Statistics of Exploration and Analysis  

Nearly all of the volumes of commercial oil and gas were 

reported discovered after 1950. The peak 5-year period for 

annual oil discoveries and oil discovered per wildcat well was 

from 1966 through 1970 (figs. 9F and 10F), and the peak 5­

year period for annual gas discoveries was from 1971 through 

1975 (fig. 11F). About 80 percent of the oil and 87 percent of 

the gas discovered through 2001 are in offshore fields (table 

4). 

Figure 12F shows that the rate of growth in prospective 

area declined after 1969. Half the delineated prospective area 

was added between 1976 and the end of 2001. Through 2001, 

the discoveries in the late half of the prospective area contained 38 percent of the oil found in the early half and more 

than two times the gas found in the early half. The profile in 

the cumulative gas graph after 1979 (fig. 13F) shows a dramatic rise in gas yields in new additions to prospective area, 

probably indicating a shift in exploration toward gas-prone 

areas. By the end of 2001, the explored area amounted to only 

15 percent of the prospective area (table 7). 

Russia 

Russia accounts for 14 percent of the oil and 28 percent 

of the gas discovered in the study area (table 4). Discovered 

Russian petroleum resources extend into both Europe and 

Asia (fig. 57). Russia shares the Dnieper-Donets Basin and 

the Azov-Kuban Basin (figs. 27 and 57) with Europe and the 

Volga-Ural Region, the North Caspian Basin, and the Middle 

Caspian Basin with Asia (figs. 46 and 57). The tables and figures for Russia include only data for the part of each province 

in Russia. 

The resources in the West Siberian Basin (fig. 57) 

account for 59 percent of the discovered oil in Russia and 76 

percent of the discovered gas (table 4). Moreover, available 

data indicate that the earliest discovery in the West Siberian 

Basin occurred in 1953 (table 6 and fig. 8F). The remoteness and hostile environment that characterize West Siberia 

undoubtedly delayed development of the oil and gas resources. 

Only the West Siberian Basin and the Volga-Ural Region have 

cumulative discoveries greater than 20 BBO, and together they 

account for 88 percent of the oil discovered in Russia. The 

four most prolific gas provinces—West Siberian Basin, South 

Barents Basin, Volga-Ural Region, and North Caspian Basin 

(all shown in fig. 57)—account for 91 percent of Russia’s 

discovered gas. 

Oil and gas in fields discovered prior to 1951 account for 

14 percent of the oil and only 1 percent of the gas discovered. 

Since 1950, the 5-year period with the peak annual oil discovery rate was from 1961 through 1965 (fig. 9G), and the 5-year 

period with the peak discovery rate of oil per wildcat well was 

1956 through 1960 (fig. 10G). The 5-year period from 1966 

through 1970 was the period when the annual gas discovery 

rate peaked (fig. 11G). Although the reported volumes of total 

oil and gas in offshore discoveries are only a small fraction of 

Russia’s total discoveries, the amount of offshore exploration 

effort expended has also been small. 
 

 

 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

Figure 12G shows a slowdown in the expansion of the 

delineated prospective area. Half the delineated prospective 

area was added between 1976 and the end of 2001. Through 

2001, the oil and gas discovered in the late half of the prospective area amounted to only 21 and 23 percent of the oil and 

gas, respectively, discovered in the early half. The explored 

area accounts for about 23 percent of the prospective area 

delineated through 2001 (table 7). The gas profile shown in 

figure 13G indicates a slight increase in yield for gas in areas 

that became prospective during the late 1980s. 

Study Area: Summary 

Table 4 summarizes the study area statistics showing 

cumulative wildcat wells, total oil and gas discoveries, and off

shore wells and oil and gas discoveries. After 1950, the 5-year 

peak annual oil discovery rate was from 1961 through 1965 

(fig. 9H), and the peak oil discovery rate per wildcat well was 

from 1951 through 1955 (fig. 10H). The annual gas discovery 

rate peaked during the 5-year period from 1966 through 1970 

(fig. 11H). In the study area, oil and gas discoveries prior to 

1951 account for 27 percent of the oil and only 9 percent of 

the gas discovered through 2001. Between 1991 and the end 

of 2000, about 59 percent of the oil and 77 percent of the gas 

discovered in the study area were in offshore fields (figs. 9H 

and 11H). 

The delineated prospective and explored areas along 

with cumulative oil and gas profiles were simply added across 

all 10 regions to obtain data for the study area figures, that 

is, figures 12H and 13H. The regional profiles were based 

on profiles at the country or country-group level provided 

in figures 16 through 57. Figure 12H shows how the rate of 

expansion of the delineated prospective area slowed during the 

1990s. Specifically, for the decade from 1992 through 2001 in 

the study area, the prospective area expanded at a rate of about 

50,000 squares miles per year while the explored area grew at 

the rate of about 11,000 square miles per year; in contrast, dur

ing the prior decade, prospective area had expanded at a rate 

of about 91,000 square miles per year while the explored area 

grew at the rate of about 22,000 square miles per year. Half of 

the delineated prospective area was added between 1974 and 

the end of 2001. Through 2001, the late half of the delineated 

prospective area contained 23 percent of the oil and 39 percent 

of the gas found in the early half. Through 2001, the explored 

area accounted for about 20 percent of the delineated prospective area (table 7). 

For prospective areas delineated before 1980, with a 

few exceptions, the growth of cumulative oil and later gas 

increased very rapidly until just prior to 1980. Figure 13H 

shows that the shape of the time profile of cumulative oil 

discoveries per unit area added was constant between 1980 

and the end of 2001, indicating that the newer delineated 

prospective area is at least as productive as the area added dur

ing the 1980s. From 1991 through 2000, offshore discoveries 

accounted for 59 percent of the oil and 77 percent of the gas 

discovered in the study area. 

­

­

­

Table 7 summarizes prospective area, rate of increase per 

wildcat well during the last decade of data, and the relation 

between percentage of total prospective area delineated by 

1982 and percentage of oil discovered through 2001 contained 

in area that became prospective by 1982. Without exception, for each region, the prospective area delineated by 1982 

accounts for a disproportionate amount of the oil discovered 

through 2001. For example, although less than 66 percent of 

Russia’s total prospective area was delineated by 1982, this 

area accounted for 92 percent of the oil discovered by 2001. 

For the entire study area, although the prospective area delineated by 1982 accounted for 68 percent of the prospective area 

delineated through 2001, it contained 92 percent of the study 

area’s oil discovered through 2001. 

Summary and Conclusions 

At a broad scale, this Circular presents a summary of 

available data on oil and gas exploration in each country of the 

study area, which is the world excluding the United States and 

Canada. Exploration effort in terms of wildcat drilling and the 

magnitudes of the discovered oil and gas are presented. The 

maps show the historical exploration areas and the parts of the 

exploration areas having a drilling density that would preclude 

discoveries larger than a threshold volume of oil. The maps 

also indicate the delineated prospective areas that were added 

between 1990 and 2002 beyond the 200- and 1,000-meter 

(656- and 3,280-foot) bathymetric contours, which denote the 

high-cost and high-risk deepwater areas. 

Graphs that summarize exploration yields in terms of 

discovered oil and gas by exploration area are also presented. 

The data in the maps and the associated graphs provide a 

visual summary of the degree of exploration maturity of an 

area. The introductory text summarizes exploration results of 

broad regions, and the country maps and country graphs (figs. 

14–57) provide more detailed information. 

Gas is rapidly becoming a commercial commodity, but 

there are still areas where it is not commercial. For most of the 

world, gas production is still demand limited. Although there 

are local supply shortfalls, no resource-based global supply 

shortfall seems imminent. In fact, it is likely that historical 

discoveries of gas in oil fields and gas in noncommercial gas 

fields have been underreported and, therefore, field size estimates should increase as fields are developed commercially. 

According to economic theory that assumes competitive 

markets, resource prices should provide a signal of impending 

long-run supply difficulties. However, the production restrictions of OPEC produced conditions where international oil 

prices through 2001 did not reflect the marginal costs of production, and the prices varied substantially as the members of 

the cartel complied with or disregarded their production quotas. Such price swings make it extremely risky to enter highcost areas and to explore for and produce high-cost resources. 

In order to predict the timing and potential magnitude of 

oil-supply shortfalls, some analysts (Hubbert, 1967) have used 
References Cited 9 

exploration and discovery data in place of the unreliable price 

and economic signals with some success. However, for such 

analysis to be useful, exploration and discovery data must be 

sufficiently complete and the exploration process must be far 

enough along that the analyst can correctly interpret the trends. 

World production of crude oil has exceeded the reported 

volumes of crude oil in new discoveries since 1980 (Masters 

and others, 1994; Attanasi and Freeman, 2004). In 2001, world 

crude oil production was almost 25 BBO. At the end of 1980, 

proved reserves in the study area were 591 BBO (DeGolyer 

and MacNaughton, 1981), but by the end of 2001, proved 

reserves in the study area were about 1,000 BBO (DeGolyer 

and MacNaughton, 2003). Between 1980 and the end of 

2001, the gap between estimated crude oil in new discoveries and production increased, but the published estimate of 

world crude oil reserves also increased (Attanasi and Freeman, 

2004). Because there are no international standards for computing crude oil reserves, it is difficult to determine whether 

published estimates of reserves are overstated, whether the 

reported estimates of new discoveries are understated, or 

whether the application of improved production technology 

to all fields has incrementally increased the recovery factors 

of in-place resources sufficiently to offset the apparent gap 

between reported oil in new discoveries and production. 

Historically, 81 percent of the oil discovered through 

2001 outside of the United States and Canada is located in 

one of the 16 significant provinces that have at least 20 BBO. 

Another 8 provinces have cumulative recoverable oil discoveries larger than 10 BBO (table 3), but some of these provinces 

are mature. 

The wildcat drilling reported here is extensive. For exploration to add significant quantities to world reserves, provinces 

endowed with oil on the order of 20 BBO in yet-to-be-found 

fields must be identified, explored, and developed. To hold 

such quantities of oil, the province must contain at least a few 

very large accumulations that will likely be found early in the 

exploration process and be sufficiently large to pay for infrastructure and generate intense followup drilling. 

If a partially explored province has not had such a large 

accumulation discovered to date, it is unlikely that additional 

intense exploration will uncover sufficient oil to significantly 

affect oil supply at a global scale. Nonetheless, additional 

discoveries will benefit the individual host countries or the 

companies that drill and produce the oil. The details of the 

individual provinces and country maps indicate how the combination of data on drilling locations, discovery volumes, and 

geologic information can provide an initial reconnaissancetype assessment of undiscovered resources. 

The limitations of this analysis relate to the data and 

methods applied. The absence of a standard procedure to 

compute reserves makes comparisons across countries and 

time periods problematical. If there were a built-in conservative bias, such as those methods required by the U.S. Securities and Exchange Commission (Attanasi and Root, 1994), 

then the changes could be modeled and the estimates could be 

adjusted on the basis of age or development of the discovery. 

Comparisons of reported field sizes over time show years with 

large changes in the estimates attached to certain regions, but 

there is little explanation in the drilling records. 

A second limitation is that the algorithms that computed 

prospective area and explored area were two dimensional. A 

more general approach would have been a three-dimensional 

analysis, perhaps with depth slices. However, the extension 

of the analysis to consider the maps in terms of depth slices 

would probably have little effect on the principal conclusions 

of this study regarding the extent of exploration for oil. For 

many of the provinces in the study area, mobilization and 

demobilization of drilling rigs are so costly that operators have 

a strong incentive to test horizons thought to have commer

cial hydrocarbon potential that lie below and above the target 

horizon. Furthermore, as one drills deeper formations, the 

likelihood of finding oil typically declines. If hydrocarbons 

are found in the deeper formations, they are more likely to be 

nonassociated gas accumulations. Thus, hydrocarbons found 

in the future in untested formations below the exploration 

wells used in this study are not likely to reverse the global 

implications of the study. Examining the data by depth slices 

would provide some new information but would have to be 

interpreted in terms of where the basement rocks lie relative to 

drilling in each province; interpretation of the depth to basement is substantially beyond the scope of this analysis. 

Acknowledgments 

The authors gratefully acknowledge the contributions 

made by the geologists of the U.S. Geological Survey (USGS) 

World Energy Program under the direction of Thomas S. 

Ahlbrandt. The World Energy Program geologists established 

and published the boundaries of the petroleum provinces 

that are used in this Circular. Craig J. Wandrey and Timothy 

R. Klett assisted in retrievals of data from the IHS Energy 

Group’s “International Petroleum Exploration and Production 

Database” (2002). The comments and suggestions made by the 

technical reviewers, Robert C. Milici, Christopher S. Swezey, 

Ione L. Taylor, and James L. Coleman (all of the USGS), 

are also very much appreciated. The authors are especially 

grateful for editorial assistance from Elizabeth Good (USGS) 

and for graphic design support from Lendell Keaton, Patricia 

Packard, and Anna Glover (all of the USGS). 

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Europe, the Middle East, Africa, non-Communist Asia, and 

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resources; Assessment and controversy: New York, Plenum 

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Tables – 

[Figures 14–57 follow table 7] 
Table . Wildcat wells by year, 1961–2001, for Mexico, the Caribbean, Central and South America, Europe, the Middle East, Africa, Asia, the southwestern Pa

[Data are from IHS Energy Group (2002). Some entries in this table differ from similar entries in table 2 of Circular 1096 (Attanasi and Root, 1993) because the well classificatibecause selected data have been re-evaluated. Column denoted “Unkn” means year unknown; these wells are not plotted on graphs in figures 9–57. The computation of the delinin figures 14–57 used locations of all wildcat, exploration, and development wells, both successful and dry, except for wells with a missing or obviously incorrect location] 

Area Pre- 1961 1961 62 6 6 6 66 6 6 69

Mexico1 

0 1 2    6  

Mexico ........................... 355 32 33 19 13 22 32 20 27 28 18 20 16 10 8 4 24 29 

Caribbean2 

Cuba ............................... 216 6 1 0 4 1 0 0 1 0 0 1 2 1 2 4 5 8 

Barbados ........................ 8 0 0 0 0 0 8 2 0 0 1 2 0 0 0 0 0 0 

Dominican Republic ...... Haiti................................ 

22 

8 

3 0 

0 0 

0 0 

0 0 

0 0 

0 0 

2 0 

0 0 

6 0 

1 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 3 

Jamaica........................... 4 0 0 0 0 0 0 0 0 0 1 1 0 1 0 0 0 0 

Puerto Rico..................... 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Lesser Antilles3 .............. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 

Total ........................... 262 9 1 0 4 1 8 4 1 6 3 4 2 2 2 4 5 12 

Central America4 

Guatemala ...................... 9 2 1 0 0 0 0 0 0 0 4 1 1 0 1 2 3 4 

Belize ............................. 11 1 1 1 0 0 0 2 0 0 0 0 5 2 1 4 0 2 

Costa Rica ...................... 19 0 1 2 0 0 0 0 0 0 0 0 0 0 0 1 0 0 

Honduras........................ 6 0 0 1 0 2 4 1 0 1 0 1 3 3 0 1 0 0 

Nicaragua ....................... Panama........................... 

7 

18 

0 1 

0 4 

0 0 

0 0 

0 0 

0 0 

1 0 

2 0 

5 0 

8 0 

3 1 

0 0 

0 0 

3 2 

2 0 

0 0 

2 0 

Total ........................... 70 4 7 4 0 2 4 4 2 6 12 6 9 5 7 10 3 8 

South America 

Guyana ........................... 1 

Suriname ........................ 2 

0 0 

0 0 

0 0 

0 1 

0 1 

0 6 

2 1 

0 5 

0 3 

0 4 

1 1 

0 0 

0 0 

2 0 

3 1 

1 0 

0 0 

French Guiana5 ............... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 

Chile............................... 146 11 18 15 16 14 15 14 17 20 19 18 33 21 29 21 19 6 

Argentina........................ 763 

Paraguay......................... 9 Uruguay.......................... 26 

Falkland Islands ............. 0 

82 

0 0 0 

101 

0 0 0 

54 

0 0 0 

50 

0 0 0 

82 

0 0 0 

76 

0 1 0 

78 

3 0 0 

68 

0 0 0 

59 

0 0 0 

104 

0 0 0 

127 

11 

0 0 

97 

5 0 0 

124 

0 0 0 

93 

0 0 0 

62 

1 0 0 

67 

1 2 

0 

90 

3 0 

0 

Ecuador .......................... 77 2 0 1 1 1 0 3 6 6 12 12 18 8 5 1 1 3 

Colombia........................ 394 33 19 24 23 19 20 18 21 21 19 18 18 18 19 10 15 17 

Peru ................................ 114 15 3 5 0 7 3 7 6 4 12 5 12 14 14 37 11 8 

Venezuela ....................... 2,438 102 88 57 48 52 38 25 27 41 39 49 75 66 90 57 54 48 

Trinidad and Tobago ...... Bolivia............................ 

105 

61 

7 

11 

5 

17 

14 10 

11 11 

13 

9 

3 

13 

3 

14 

8 

13 

6 2 

8 4 

15 

3 

15 

7 

9 

4 

8 

4 

6 

6 

12 

13 

4 

9 

Brazil.............................. 240 48 53 60 47 53 53 69 62 54 50 58 57 59 60 73 86 73 

Total ........................... 4,376 311 304 240 208 251 228 237 233 216 271 318 337 323 324 279 282 261 
Table . Wildcat wells by year, 1961–2001, for Mexico, the Caribbean, Central and South America, Europe, the Middle East, Africa, Asia, the southwestern Pa

Area 192    6   9 90 91 92 9 9 9 96 9 9 1999 

Mexico1—Continued 

Mexico ........................... 13 9 2 6 10 5 6 12 11 23 19 13 7 5 3 3 16 14 

Caribbean2—Continued 

Cuba ............................... 0 0 0 2 3 1 0 3 0 0 2 0 4 1 2 1 3 4 

Barbados ........................ 0 0 8 5 1 0 0 2 3 1 0 0 0 0 0 0 0 0 

Dominican Republic ...... 1 0 0 0 0 0 0 0 0 0 0 0 0 2 2 0 0 0 Haiti................................ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Jamaica........................... 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Puerto Rico..................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Lesser Antilles3 .............. 1 0 0 0 0 0 0 1 2 0 0 0 0 0 0 0 0 0 

Total ........................... 6 0 8 7 4 1 0 6 5 1 2 0 4 3 4 1 3 4 

Central America4—Continued 

Guatemala ...................... 7 3 1 2 0 0 3 2 0 0 0 0 1 1 0 0 4 1 

Belize ............................. 2 2 0 2 0 0 0 0 2 1 0 0 1 0 0 2 0 0 

Costa Rica ...................... 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 

Honduras........................ 0 2 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 

Nicaragua ....................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Panama........................... 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 0 

Total ........................... 9 7 1 4 1 0 3 5 2 1 1 1 2 1 0 2 4 1 

South America—Continued 

Guyana ........................... Suriname ........................ 

2 3 

0 6 

0 0 

0 3 

0 2 

0 0 

0 0 

0 0 

0 0 

1 0 

0 0 

1 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

French Guiana5............... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Chile............................... 15 8 7 1 11 12 7 14 9 5 8 3 2 9 6 1 3 0 

Argentina........................ 66 113 115 137 67 72 74 70 67 73 45 51 83 110 89 79 53 43 

Paraguay......................... 1 0 0 0 1 1 1 1 0 0 0 1 2 2 0 0 0 0 Uruguay.......................... 0 0 0 1 2 2 0 0 0 0 0 0 0 0 0 0 0 0 

Falkland Islands ............. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6 0 Ecuador .......................... 4 9 2 1 4 7 13 7 3 20 5 4 3 5 5 5 5 2 

Colombia........................ 62 24 38 48 45 55 80 52 42 34 26 33 23 12 13 15 14 15 

Peru ................................ 6 15 18 3 2 7 2 3 0 0 3 2 2 4 4 9 10 5 

Venezuela ....................... 155 82 132 149 95 14 38 17 6 7 15 18 21 18 39 30 21 18 

Trinidad and Tobago ...... 9 2 1 2 0 2 3 5 3 5 2 0 7 9 6 3 7 2 

Bolivia............................ 9 4 3 7 1 2 3 7 5 11 12 6 8 7 8 4 7 9 

Brazil.............................. 233 206 193 132 113 109 102 77 70 72 69 74 52 46 62 49 53 54 

Total ........................... 565 469 509 484 343 283 323 253 205 228 185 193 203 222 232 195 179 148 

1Well data for Mexico are known to be incomplete. 2No wildcat wells were reported for The Bahamas and Cayman Islands. 3For this Circular, the Lesser Antilles are Netherlands Antilles, British Virgin Islands, Martinique, Dominica, Grenada, Virgin Islands, Saint Kitts and Nevis, Antigua and Ba

Guadeloupe, Saint Lucia, Saint Vincent and the Grenadines, and Aruba. 

4No wildcat wells were reported for El Salvador. 5French Guiana is listed separately although it is an overseas department of France. 
Table . Wildcat wells b

Area 

United Kingdom............. Norway........................... Germany......................... Denmark......................... 

y year, 

Pre1961 

201 

0 

1,207 

29 

1961–2

1961

8 0 

56 

0 

001, for

62

3 0 

56 

0 

 Mexic

6 

7 0 

25 

0 

o, the C

6 

7 0 

64 

0 

aribbea

6 

28 

0 

38 

0 

n, Centr

66

31 

1 

61 

3 

al and 

6 

41 

5 

35 

2 

South 

6 

36 10 50 

7 

America, 

69

Europe6 

55 13 46 

2 

Europ

0 

30 

7 

37 

3 

e, the M

1 

31 10 33 

2 

iddle E

2 

34 15 29 

0 

ast, Afri



56 13 29 

4 

ca, Asi



74 13 28 

2 

a, the so



86 15 26 

3 

uthwe

6 

67 19 31 

7 

stern Pa

 

78 

7 

33 

5 

Netherlands .................... 128 3 5 2 25 34 9 2 13 32 27 30 24 19 18 21 18 28 

Ireland ............................ 0 0 2 3 0 0 0 0 0 0 0 3 2 3 4 7 5 6 

Sweden........................... 1 0 0 0 0 0 0 1 2 0 0 4 10 13 14 27 6 6 Belgium.......................... Faroe Islands7 ................. 

1 0 

0 0 

2 0 

0 0 

1 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

Svalbard8 ........................ 0 0 0 0 0 0 1 1 0 0 0 1 2 2 2 1 0 1 

Italy ................................ Austria............................ 

713 

76 

82 13 

100 

9 

90 12 

75 11 

48 13 

57 14 

28 

8 

30 

16 

48 

20 

33 

17 

40 

26 

45 

16 

28 

14 

22 

15 

26 

37 

30 

20 

25 

39 

France............................. 807 103 97 101 75 58 30 26 13 25 13 8 10 11 9 10 13 13 

Spain .............................. Portugal.......................... Switzerland .................... 

128 

39 10 

14 

1 2 

17 

1 1 

22 

4 2 

11 

0 2 

15 

0 3 

18 

0 0 

13 

0 0 

16 

0 0 

10 

0 0 

8 0 0 

12 

0 0 

6 0 0 

18 

0 1 

8 3 0 

17 

7 0 

19 

9 0 

16 

1 1 

Malta .............................. 1 0 0 0 0 0 0 0 0 0 0 0 3 1 0 0 0 0 

San Marino..................... 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Romania ......................... 62 4 6 8 8 10 13 11 9 13 9 8 4 9 10 8 6 8 

Ukraine........................... 38 2 3 6 6 4 4 8 3 5 5 2 2 1 3 5 14 11 

Belarus ........................... 0 0 0 0 0 1 0 2 0 0 0 0 2 1 0 1 4 3 

Hungary.......................... Albania........................... 

311 

4 

31 

0 

41 

0 

47 

3 

50 

1 

29 

1 

29 

1 

13 

0 

10 

0 

19 

0 

14 

2 

18 

1 

19 

1 

15 

0 

17 

0 

8 0 

36 

0 

17 

1 

Serbia and Montenegro9 . 

Poland ............................ 

91 27 

17 

5 

10 13 

17 20 

8 

25 

8 

21 

9 

31 

3 

35 

7 

33 

5 

34 

9 

47 

15 46 

17 67 

13 55 

11 23 

22 34 

11 27 

28 14 

Czech Republic .............. Greece ............................ 

9 

11 

2 6 

3 7 

2 5 

2 3 

2 2 

5 0 

2 8 

4 0 

2 0 

3 2 

3 1 

3 1 

7 3 

3 3 

6 0 

6 2 

5 5 

Bulgaria.......................... Lithuania ........................ 

348 

1 

58 

0 

54 

0 

54 

1 

13 

1 

21 

1 

15 

2 

21 

3 

14 

5 

19 

4 

13 

6 

17 

5 

17 

5 

12 

4 

22 

4 

18 

7 

14 

5 

14 

3 

Slovakia.......................... 22 1 3 4 3 8 4 5 2 4 3 2 5 1 0 1 1 0 

Slovenia.......................... 9 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Latvia ............................. 0 0 0 0 1 1 3 6 5 4 2 2 0 0 0 0 0 0 

Moldova ......................... 2 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 

Bosnia and Herzegovina Croatia............................ 

1 

28 

0 1 

0 3 

0 2 

0 3 

0 2 

0 4 

0 5 

0 3 

0 4 

0 4 

0 3 

0 1 

0 

12 

0 6 

0 

5 

0 

0 

0 

5 

Macedonia...................... 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 

Total ........................... 4,306 410 437 437 396 348 345 284 288 365 294 323 340 345 314 398 370 373 
Table . Wildcat wells by year, 1961–2001, for Mexico, the Caribbean, Central and South America, Europe, the Middle East, Africa, Asia, the southwestern Pa

Area 192    6   9 90 91 92 9 9 9 96 9 9 1999 

United Kingdom............. Norway........................... 

Germany......................... Denmark......................... 

83 31 54 

4 

96 26 46 10 

128 

28 44 

5 

124 

23 32 13 

139 

27 39 

3 

86 20 26 

4 

101 

20 20 

3 

110 

14 12 

4 

Europe

161 

24 21 

1 

6—Con

132 

30 16 

3 

tinued 

102 

30 16 

6 

55 19 11 

1 

71 19 

7 0 

64 19 

9 1 

78 22 13 

1 

72 35 10 

6 

53 20 11 

3 

36 14 

6 2 

Netherlands .................... 41 40 33 40 29 26 24 28 35 40 26 20 10 22 24 28 26 13 

Ireland ............................ 4 6 7 6 7 4 4 3 4 1 2 3 2 4 2 3 0 1 

Sweden........................... 14 12 11 15 0 4 11 12 26 12 0 1 0 0 0 0 0 0 

Belgium.......................... Faroe Islands7 ................. 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

Svalbard8 ........................ 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 0 Italy ................................ Austria............................ 

80 21 

54 16 

63 23 

55 12 

94 

9 

76 12 

72 18 

33 

5 

33 12 

45 

5 

33 

7 

25 

5 

21 

6 

28 

9 

28 

9 

23 

14 

27 

5 

16 

5 

France............................. 42 24 36 51 72 27 32 35 25 31 9 4 8 7 6 0 5 0 

Spain .............................. Portugal .......................... Switzerland .................... 

10 

2 3 

19 

3 0 

10 

0 0 

20 

1 0 

17 

0 0 

12 

0 0 

8 3 0 

8 0 1 

4 2 0 

6 0 0 

0 0 0 

3 1 0 

1 0 0 

3 1 0 

1 0 0 

5 0 0 

3 1 0 

4 1 0 

Malta .............................. 2 0 0 1 0 0 0 0 0 0 1 1 0 0 0 0 0 1 San Marino..................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Romania ......................... 4 6 8 2 6 2 2 7 4 4 9 7 8 14 10 18 16 11 

Ukraine........................... 7 8 7 7 3 8 7 4 7 9 9 5 3 4 1 4 3 4 Belarus ........................... 1 4 3 1 1 4 0 2 1 2 2 2 3 9 0 1 0 10 Hungary.......................... Albania........................... 

23 

2 

18 

1 

5 1 

17 

3 

20 

0 

7 3 

3 0 

4 1 

5 0 

4 0 

18 

0 

15 

2 

5 1 

13 

3 

16 

1 

13 

2 

12 

0 

11 

0 

Serbia and Montenegro9 . 

Poland ............................ 

10 31 

12 15 

8 

20 

11 20 

12 18 

10 26 

11 30 

13 37 

3 

35 

7 

15 

5 

17 

6 

10 

7 

15 

7 

55 

7 

40 

7 

37 

10 23 

2 

37 

Czech Republic .............. Greece ............................ 

5 

11 

6 7 

5 7 

5 4 

4 2 

0 3 

1 4 

1 3 

0 1 

2 0 

3 1 

2 0 

2 0 

2 1 

3 0 

2 0 

5 2 

3 0 

Bulgaria.......................... Lithuania ........................ 

10 

4 

19 

4 

14 

6 

16 

3 

23 

4 

19 

5 

18 

6 

10 

2 

8 4 

1 2 

4 1 

6 0 

10 

2 

4 0 

5 0 

0 1 

3 0 

1 0 

Slovakia.......................... 0 1 2 0 0 0 0 0 0 2 1 0 2 2 4 0 1 3 

Slovenia.......................... 1 0 0 1 1 1 0 0 1 3 0 0 0 0 0 0 0 0 

Latvia ............................. 0 0 1 0 0 0 1 2 0 1 0 2 1 0 0 0 0 0 Moldova ......................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Bosnia and Herzegovina Croatia............................ 

0 

11 

0 9 

2 9 

3 

16 

2 

11 

1 2 

0 4 

0 

18 

0 9 

0 1 

0 1 

0 1 

0 8 

0 7 

0 3 

0 5 

0 

4 

0 

0 

Macedonia...................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Total ........................... 511 462 486 502 543 389 403 369 426 375 303 207 212 288 274 286 233 181 

6No wildcat wells were reported for Andorra, Estonia, Finland, Gibraltar, Liechtenstein, Luxembourg, Monaco, or Montenegro. Greenland (which is part of Denmark) has se

has 22 stratigraphic test wells. 

7Faroe Islands are part of Denmark. 8Svalbard is a group of islands in the Arctic Ocean north of and belonging to Norway. 9Data for Serbia and Montenegro are combined in the IHS Energy Group (2002) data. 
Table . Wildcat wells by year, 1961–2001, for Mexico, the Caribbean, Central and South America, Europe, the Middle East, Africa, Asia, the southwestern Pa

Pre- Area 1961 62 6 6 6 66 6 6 69 0 1 2    6  

1961 

Middle East 

Turkey ............................ 93 34 18 11 13 30 31 21 29 12 35 20 24 30 33 42 43 22 

Cyprus............................ 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 Saudi Arabia................... 15 0 0 3 1 2 4 8 7 4 4 7 5 5 6 5 4 3 

Kuwait............................ 11 1 4 12 1 2 5 1 0 0 2 1 2 1 0 0 1 1 

Abu Dhabi10 .................... 4 0 3 0 4 2 4 3 8 8 12 9 1 8 10 5 6 2 

'Ajman10 .......................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dubai10 ........................... 1 0 0 0 2 1 1 0 1 0 0 1 1 0 0 3 5 1 Al Fujayrah10 .................. 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 

Umm al Qaywayn10 ........ 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 2 1 Ra's al Khaymah10 .......... 0 0 0 0 1 0 1 0 0 1 0 1 1 0 0 0 1 1 Sharjah10 ......................... 1 0 0 1 1 1 0 1 0 0 0 1 0 1 1 1 0 0 

Former Neutral Zone11 ... 12 3 7 3 0 1 3 2 0 0 1 0 0 0 0 0 0 0 

Oman.............................. 26 1 2 3 4 1 8 2 3 6 3 11 12 11 3 9 10 8 

Qatar............................... 9 1 5 3 3 1 1 4 3 2 1 2 3 2 0 0 2 1 

Yemen ............................ 0 0 3 0 1 1 0 0 0 0 0 0 0 0 1 0 4 2 

Bahrain........................... 2 1 1 0 0 1 1 0 0 0 0 0 1 1 0 1 0 0 

Syria ............................... 19 1 4 3 0 0 1 0 2 0 0 0 0 0 2 3 13 6 Israel12 ............................ 61 5 4 4 12 10 12 8 9 5 9 7 4 2 1 7 8 17 

Jordan............................. 4 0 0 1 0 0 0 0 0 0 2 5 1 0 1 0 0 0 

Lebanon.......................... 3 1 0 2 0 0 1 0 0 0 0 0 0 0 0 0 0 0 

Iraq ................................. 76 5 0 0 0 0 0 0 0 1 1 2 0 2 3 2 8 3 Iran ................................. 78 12 8 5 7 11 23 21 21 15 13 10 11 21 20 22 22 12 

Total ........................... 415 65 59 51 50 65 96 71 83 56 84 78 66 84 81 100 129 81 
Table . Wildcat wells by year, 1961–2001, for Mexico, the Caribbean, Central and South America, Europe, the Middle East, Africa, Asia, the southwestern Pa

Area 192    6   9 90 91 92 9 9 9 96 9 9 1999 

Middle East—Continued 

Turkey ............................ Cyprus............................ 

Saudi Arabia................... 

32 

0 2 

26 

0 3 

18 

0 2 

24 

0 0 

25 

0 0 

27 

0 0 

34 

0 0 

36 

0 2 

31 

0 4 

27 

0 2 

21 

0 3 

24 

0 3 

21 

0 2 

13 

0 2 

12 

0 1 

11 

0 3 

10 

0 2 

16 

0 2 

Kuwait............................ 0 0 2 1 0 0 1 0 1 0 0 0 0 1 0 0 0 0 

Abu Dhabi10 .................... 8 10 12 9 3 0 1 2 3 1 3 4 2 2 1 0 0 0 

'Ajman10 .......................... 

Dubai10 ........................... 

0 2 

1 0 

0 6 

0 5 

0 1 

0 2 

0 2 

0 1 

0 1 

0 2 

0 1 

0 2 

0 0 

0 0 

0 1 

0 

0 

0 

0 

0 

0 

Al Fujayrah10 .................. 

Umm al Qaywayn10 ........ 

Ra's al Khaymah10 .......... 

Sharjah10 ......................... 

Former Neutral Zone11 ... 

0 1 2 1 1 

0 1 1 2 0 

0 0 2 2 0 

0 0 2 4 0 

0 1 1 0 0 

0 0 0 1 0 

0 0 1 0 0 

0 0 0 0 0 

0 0 0 0 0 

0 0 0 0 0 

0 0 0 1 0 

0 0 1 0 

0 

0 0 0 3 

0 

0 0 0 0 

0 

0 0 0 1 

0 

0 0 0 0 

0 

0 0 1 2 

2 

0 0 0 0 

0 

Oman.............................. 20 18 37 23 32 22 23 18 29 39 18 16 15 13 20 24 15 20 Qatar............................... 2 1 0 0 0 1 6 2 5 3 2 0 2 0 3 3 3 0 

Yemen ............................ 3 1 3 12 16 21 15 16 15 21 38 28 21 20 13 11 9 4 

Bahrain........................... 0 0 0 0 2 0 0 0 0 0 1 1 0 0 0 0 0 0 

Syria ............................... Israel12 ............................ 

3 

15 

1 

10 

5 6 

12 

2 

19 

3 

8 1 

21 

2 

15 

2 

16 

3 

23 

1 

30 

2 

20 

5 

12 

5 

11 

6 

11 

4 

11 

4 

3 

3 

7 

4 

Jordan............................. 1 2 5 1 1 4 5 5 4 3 2 3 6 0 0 0 2 0 Lebanon.......................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Iraq ................................. Iran ................................. 

2 1 

7 0 

1 1 

1 0 

1 0 

2 0 

2 3 

0 1 

0 1 

0 1 

0 3 

1 1 

1 0 

0 2 

0 1 

0 1 

0 2 

1 5 

Total ........................... 96 84 102 96 105 89 116 100 113 123 125 109 90 70 68 68 54 59 

10One of the seven United Arab Emirates.
 11The former Neutral Zone was located between Kuwait and Saudi Arabia.
 12Israel includes data for Gaza Strip and West Bank.
 
Table . Wildcat wells by year, 1961–2001, for Mexico, the Caribbean, Central and South America, Europe, the Middle East, Africa, Asia, the southwestern Pa

Pre- Area 1961 1961 62 6 6 6 66 6 6 69 0 1 2    6  

Africa13 

Cote d’Ivoire .................. 7 1 0 0 0 0 0 0 0 0 0 0 2 1 1 0 0 5 

Ghana ............................. 4 0 0 0 0 0 0 3 0 0 9 1 1 1 1 4 0 1 

Benin .............................. 0 0 0 0 0 0 0 0 1 1 4 0 0 2 0 0 0 0 

Guinea-Bissau................ 1 3 0 0 0 0 0 0 2 3 0 0 0 1 0 0 0 0 

Togo ............................... 0 

Senegal........................... 20 

The Gambia.................... 1 

0 9 1 

0 3 0 

0 0 0 

0 0 0 

0 0 0 

0 2 0 

0 3 0 

0 2 0 

0 3 0 

1 4 0 

0 3 0 

0 

1 

0 

0 

0 

0 

0 

0 

0 

0 

1 

0 

0 

2 

0 

0 

1 

0 

Guinea............................ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 

Sierra Leone................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Liberia............................ 0 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 0 0 

Ethiopia .......................... 17 Somalia .......................... 21 

0 3 

0 2 

1 3 

0 1 

1 3 

0 1 

0 1 

0 

2 

0 

2 

0 

0 

0 

0 

2 

0 

3 

1 

3 

1 

0 

1 

0 

1 

0 

1 

Eritrea............................. 11 0 0 0 0 0 2 0 0 2 2 0 0 3 0 0 0 1 

Kenya ............................. 2 Angola............................ 53 

Nigeria............................ 95 

Libya14 ............................ 143 

Tunisia14 ......................... 64 

1 

10 16 94 

1 

1 4 9 

111 

7 

1 9 

21 

148 

4 

1 4 

32 

134 

5 

0 

16 61 

118 

6 

0 9 

65 63 

6 

1 

15 83 42 

10 

1 

46 35 79 

5 

0 

25 21 76 

3 

0 

13 24 48 

4 

2 

30 54 44 

11 

0 

13 55 31 

13 

0 6 

42 23 

8 

0 

28 49 27 

16 

1 

10 37 47 

7 

2 0 

18 29 

8 

0 6 

29 32 

8 

Algeria............................ 345 

Morocco ......................... 245 

61 17 

57 10 

55 

2 

45 

8 

18 

7 

12 12 

15 11 

14 

5 

30 13 

36 

1 

27 

6 

12 

5 

10 

3 

17 

3 

22 

5 

25 

5 

24 

3 

Egypt .............................. 156 

Mozambique .................. 5 

Tanzania ......................... 3 

10 

1 0 

7 3 1 

12 

0 0 

9 0 0 

8 5 0 

15 

5 0 

10 15 

0 

24 

0 0 

27 

0 0 

37 10 

0 

23 

6 0 

22 

2 0 

16 

0 0 

14 

0 2 

18 

0 0 

37 

0 2 

44 

0 0 

Burundi .......................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

South Africa................... 1 0 0 0 0 8 2 4 3 11 13 18 11 17 2 15 15 11 

Namibia.......................... 1 0 0 0 0 0 0 0 0 0 4 1 0 0 1 0 0 0 Lesotho........................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 

Zambia ........................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Zimbabwe ...................... 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 Gabon............................. 108 8 14 4 1 7 9 10 11 21 12 11 17 13 15 17 14 16 

Congo (Brazzaville) ....... 11 

Cameroon....................... 15 

1 0 

2 0 

2 0 

0 0 

0 1 

0 0 

0 4 

0 0 

1 1 

2 6 

3 2 

6 4 

6 2 

6 3 

4 7 

0 4 

0 

24 

Equatorial Guinea .......... 0 Central African Republic 0 Congo (Kinshasa)........... 2 Sudan.............................. 0 

0 0 0 1 

0 0 0 3 

0 0 0 2 

0 0 1 0 

0 0 3 0 

0 0 0 0 

1 0 0 0 

5 0 0 0 

0 0 0 0 

0 0 0 0 

1 0 1 0 

0 0 6 0 

0 0 4 0 

0 0 0 0 

0 0 4 1 

0 0 2 2 

0 0 1 1 

Chad ............................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 2 4 3 

Mauritania ...................... 0 0 1 1 0 0 0 0 0 2 2 0 1 1 3 0 0 0 

Niger .............................. 0 

Mali................................ 0 

0 0 

6 0 

1 0 

2 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

7 0 

0 0 

0 0 

Uganda ........................... 27 Western Sahara............... 1 

0 9 

0 

15 

0 7 

0 4 

0 3 

0 4 

0 6 

0 0 

0 1 

0 1 

0 0 

0 1 

0 1 

0 0 

0 0 

0 

0 

0 

0 

Madagascar .................... 54 

Mauritius........................ 0 

0 0 

0 0 

1 0 

1 0 

1 0 

0 0 

0 0 

0 0 

0 0 

1 0 

8 0 

1 0 

2 0 

4 0 

1 2 

0 0 

0 0 

Seychelles ...................... 0 

Total ...........................1,413 

0 

247 

0 

256 

0 

274 

0 

248 

0 

266 207 

0 

234 

0 

235 

0 0 

243 235 

0 

256 

0 

206 

0 

166 

0 

200 

0 

214 

0 

170 

0 

212 

0 
Table . Wildcat wells by year, 1961–2001, for Mexico, the Caribbean, Central and South America, Europe, the Middle East, Africa, Asia, the southwestern Pa

Area 192    6   9 90 91 92 9 9 9 96 9 9 1999 

Africa13—Continued 

Cote d’Ivoire .................. 8 1 6 2 0 0 0 0 0 0 0 1 0 0 2 3 5 2 

Ghana ............................. 1 0 0 2 0 1 0 3 1 0 1 0 0 0 0 1 1 0 

Benin .............................. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 

Guinea-Bissau................ 0 0 1 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 

Togo ............................... Senegal........................... The Gambia.................... 

0 1 0 

0 0 0 

0 1 0 

1 0 0 

1 0 0 

0 0 0 

0 1 0 

0 2 0 

0 0 0 

0 0 0 

0 0 0 

0 4 0 

0 0 0 

0 

0 

0 

0 

1 

0 

0 

1 

0 

0 

2 

0 

0 

0 

0 

Guinea............................ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Sierra Leone................... 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Liberia............................ 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Ethiopia .......................... Somalia .......................... 

0 3 

1 0 

1 2 

1 2 

0 0 

2 1 

0 2 

0 0 

1 3 

0 

0 

0 

0 

0 

0 

0 

0 

1 

0 

0 

0 

0 

0 

0 

0 

0 

0 

Eritrea............................. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 1 

Kenya ............................. Angola............................ Nigeria............................ Libya14 ............................ 

Tunisia14 ......................... 

1 

21 29 36 20 

0 

22 26 37 10 

0 9 

16 40 12 

2 

16 15 32 12 

1 

15 18 16 

5 

0 

16 16 17 

12 

3 

17 26 13 

7 

4 

12 26 15 

7 

1 

17 37 11 

6 

0 

20 25 

9 

10 

1 

11 26 21 

13 

1 

10 26 27 

10 

0 9 

13 24 

6 

0 8 

17 15 

14 

0 

13 32 10 

10 

0 

11 22 17 

10 

0 

21 17 15 

11 

0 9 8 8 

5 

Algeria............................ Morocco ......................... 

18 

8 

19 

4 

9 4 

25 

7 

19 

4 

25 

8 

10 

2 

14 

0 

11 

1 

19 

2 

16 

2 

17 

3 

21 

0 

16 

0 

18 

0 

23 

0 

31 

2 

14 

0 

Egypt .............................. Mozambique .................. Tanzania ......................... 

53 

0 2 

41 

0 2 

32 

0 2 

56 

0 2 

56 

1 1 

41 

0 2 

41 

1 0 

33 

0 0 

32 

0 2 

35 

0 1 

34 

0 0 

20 

0 0 

18 

0 0 

23 

0 0 

43 

0 1 

56 

2 1 

56 

0 0 

24 

0 0 

Burundi .......................... 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 

South Africa................... 8 8 13 13 21 15 17 16 21 8 5 3 5 3 0 1 4 0 

Namibia.......................... 0 0 0 0 0 0 0 0 0 1 0 0 1 3 1 0 1 1 Lesotho........................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Zambia ........................... 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 

Zimbabwe ...................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Gabon............................. 16 13 14 12 7 5 16 24 24 32 13 3 4 7 9 14 8 2 

Congo (Brazzaville) ....... Cameroon....................... 

9 8 

4 3 

2 6 

8 4 

4 3 

8 0 

5 2 

3 0 

9 0 

10 

0 

19 

2 

2 1 

1 0 

2 2 

1 1 

3 2 

6 3 

4 2 

Equatorial Guinea .......... Central African Republic . Congo (Kinshasa)........... Sudan.............................. 

4 0 4 

11 

0 0 4 

10 

1 0 5 3 

1 0 1 7 

1 1 1 2 

0 0 0 1 

1 0 3 0 

0 0 1 4 

0 0 1 0 

1 0 0 0 

1 0 0 0 

0 0 0 0 

2 0 1 1 

2 0 0 1 

6 0 1 3 

9 0 0 

11 

6 0 

0 

10 

1 0 

0 

14 

Chad ............................... 0 0 0 3 3 0 0 1 1 1 0 0 2 0 0 0 0 0 

Mauritania ...................... 0 0 1 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 

Niger .............................. Mali................................ 

2 1 

0 0 

0 0 

0 1 

0 0 

0 0 

0 0 

0 0 

2 0 

0 0 

0 0 

0 0 

3 0 

0 0 

0 0 

0 0 

3 0 

0 0 

Uganda ........................... Western Sahara............... 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

Madagascar .................... Mauritius........................ 

0 0 

0 0 

0 0 

4 0 

3 0 

2 0 

0 0 

0 0 

1 0 

1 0 

2 0 

1 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

Seychelles ...................... 0 

Total ........................... 265 

0 

205 

0 

180 

0 

233 

0 

183 

0 

175 

0 

168 

0 

166 

0 

185 

0 

175 

0 

168 

0 

129 

0 

111 

1 

115 

0 

152 

0 

188 

0 

204 

0 

95 

13No wildcat wells were reported for Botswana, Burkina Faso, Cape Verde, Comoros, Djibouti, Malawi, Reunion, Rwanda, Sao Tome and Principe, or Swaziland. 14Wildcat wells from jointly claimed area between Libya and Tunisia are listed under Libya. 
Table . Wildcat wells b

Area 

y year,

Pre1961 

 1961–2

1961

001, for 

62

Mexic

6 

o, the C

6 

aribbea

6 

n, Centr

66

al and 

6 

South 

6 

America,

69

Asia15 

 Europ

0 

e, the M

1 

iddle E

2 

ast, Afri



ca, Asi



a, the so



uthwe

6 

stern Pa

 

China .............................. 69 9 6 5 8 15 27 17 15 8 13 29 20 21 21 31 25 36 

Mongolia........................ Kazakhstan..................... 

1 

42 

0 6 

0 

11 

0 8 

0 7 

0 

14 

0 

20 

0 

18 

0 

36 

0 

28 

0 

15 

0 

15 

0 

14 

0 

21 

0 

25 

0 

44 

0 

25 

0 

29 

Azerbaijan ...................... Turkmenistan.................. 

210 

94 

5 

19 

8 

16 

7 

17 

10 16 

14 40 

17 26 

14 18 

11 40 

11 35 

11 32 

11 21 

11 15 

9 

21 

7 

18 

7 

16 

7 

23 

9 

31 

Uzbekistan...................... 72 11 10 9 9 9 5 16 13 9 11 8 3 11 21 11 5 9 

Georgia........................... Kyrgyzstan ..................... Tajikistan........................ Armenia.......................... 

65 26 

4 0 

0 0 3 0 

4 2 1 0 

5 1 0 0 

1 4 1 0 

4 6 0 0 

4 4 0 0 

2 2 1 0 

5 4 1 0 

10 

6 0 0 

7 1 2 0 

5 1 0 0 

5 1 0 0 

4 3 1 0 

16 

2 1 0 

10 

0 0 0 

3 2 1 0 

9 0 1 0 

Pakistan .......................... 86 2 2 1 3 2 2 2 2 3 1 4 2 4 5 4 2 3 

Afghanistan.................... India ............................... 

3 

23 

0 2 

3 

11 

2 5 

4 8 

0 

12 

0 8 

1 7 

0 

9 

0 

6 

0 

9 

2 

7 

1 

7 

0 

4 

1 

6 

1 

9 

1 

16 

3 

14 

Bangladesh..................... Maldives......................... 

15 

0 

0 0 

2 0 

1 0 

0 0 

1 0 

0 0 

1 0 

0 0 

2 0 

1 0 

0 0 

0 0 

0 0 

0 0 

0 0 

6 1 

3 0 

Nepal .............................. Sri Lanka........................ 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 2 

0 0 

Vietnam .......................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 3 0 0 

Burma............................. 98 4 5 0 1 1 0 0 1 1 1 2 4 2 9 11 12 2 

Thailand16 ....................... 1 0 0 0 0 0 0 0 0 3 0 1 4 3 12 6 15 0 

Cambodia ....................... 0 0 0 0 0 0 0 0 0 0 0 0 1 0 2 0 0 0 Laos................................ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Japan17 ............................ 

South Korea17 ................. 

32 

0 

5 0 

3 0 

5 0 

4 0 

5 0 

4 0 

5 6 

8 1 

6 0 

0 0 

5 0 

8 1 

13 

4 

19 

0 

24 

2 

17 

0 

18 

0 

North Korea.................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 

Philippines...................... Taiwan............................ 

65 18 

9 1 

8 3 

3 2 

12 

4 

0 3 

0 8 

0 7 

0 5 

0 

10 

1 6 

13 

7 

7 3 

10 14 

8 

14 

12 15 

8 8 

12 

8 

Indonesia........................ 435 5 1 8 16 10 7 10 22 29 84 129 112 145 142 128 109 79 

Malaysia16 ....................... 

Brunei............................. 

70 11 

7 1 

5 1 

3 1 

1 0 

0 0 

2 0 

10 

0 

13 

2 

23 

5 

45 

2 

21 

1 

24 

6 

23 

5 

8 1 

20 

9 

3 4 

10 

3 

Total ........................... 1,440 89 102 83 109 136 134 137 188 195 242 282 249 318 340 364 295 279 
Table . Wildcat wells by year, 1961–2001, for Mexico, the Caribbean, Central and South America, Europe, the Middle East, Africa, Asia, the southwestern Pa

Area 192    6   9 90 91 92 9 9 9 96 9 9 1999 

Asia15—Continued 

China .............................. 25 37 51 52 45 38 53 31 35 43 46 51 29 37 44 33 87 38 

Mongolia........................ Kazakhstan..................... 

0 

29 

0 

18 

0 

16 

0 

29 

0 

37 

0 

22 

0 

29 

0 

23 

0 

17 

0 

17 

0 

12 

0 

11 

0 

10 

1 

15 

3 4 

1 0 

1 8 

0 8 

Azerbaijan ...................... Turkmenistan.................. 

10 31 

6 

24 

4 

29 

5 

30 

9 

39 

6 

39 

8 

21 

7 

33 

3 

34 

1 

18 

2 

26 

4 

11 

0 9 

0 3 

4 2 

1 5 

4 5 

4 6 

Uzbekistan...................... 15 17 14 18 8 14 18 11 16 28 14 12 12 11 2 2 13 14 

Georgia........................... Kyrgyzstan ..................... Tajikistan........................ Armenia.......................... 

14 

0 1 0 

10 

4 0 0 

11 

0 1 0 

9 0 1 0 

8 0 2 0 

4 2 0 0 

8 2 0 0 

10 

0 0 0 

5 1 0 0 

7 0 0 0 

3 0 0 0 

2 0 0 0 

0 0 0 0 

2 0 0 0 

0 0 0 0 

0 0 0 0 

0 0 0 2 

0 0 0 0 

Pakistan .......................... 3 10 15 15 12 6 19 18 13 9 16 23 14 22 22 20 23 1 

Afghanistan.................... India ............................... 

0 

10 

2 

23 

1 

33 

0 

34 

0 

42 

0 

46 

0 

43 

0 

61 

0 

86 

0 

90 

3 

77 

0 

53 

0 

43 

0 

40 

0 

54 

0 

28 

0 

40 

0 

13 

Bangladesh..................... Maldives......................... 

2 0 

0 0 

0 0 

0 0 

1 0 

0 0 

4 0 

1 0 

2 0 

0 1 

0 0 

0 0 

0 0 

1 0 

2 0 

1 0 

3 0 

1 0 

Nepal .............................. Sri Lanka........................ 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

1 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

Vietnam .......................... 0 0 0 1 0 0 2 4 5 11 2 13 20 15 16 10 3 1 

Burma............................. 5 6 11 9 8 3 3 4 4 9 9 5 4 7 5 4 4 1 

Thailand16 ....................... 15 25 16 12 2 15 12 2 10 6 9 11 11 4 6 14 7 7 

Cambodia ....................... 0 0 0 0 0 0 0 0 0 0 0 0 4 0 4 0 1 0 Laos................................ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 Japan17 ............................ 

South Korea17 ................. 

9 0 

7 1 

9 0 

11 

0 

12 

0 

7 1 

8 0 

8 3 

6 2 

7 4 

7 0 

7 2 

4 0 

3 0 

6 0 

2 0 

3 1 

3 0 

North Korea.................... 4 0 3 1 0 1 1 2 1 1 0 0 0 0 0 0 0 0 

Philippines...................... Taiwan............................ 

15 

6 

3 7 

1 4 

0 5 

0 3 

3 1 

6 1 

6 1 

3 0 

7 3 

4 2 

3 6 

5 1 

2 1 

4 6 

2 2 

4 4 

2 0 

Indonesia........................ 136 155 120 134 74 54 92 73 80 100 89 80 57 59 71 86 63 53 

Malaysia16 ....................... 

Brunei............................. 

8 5 

4 2 

5 

10 

11 

3 

5 2 

6 2 

7 6 

18 12 

31 

4 

42 

2 

29 

1 

21 

2 

24 

2 

17 

1 

5 1 

13 

5 

7 3 

3 0 

Total ........................... 343 361 354 380 309 270 343 329 358 406 351 317 249 241 261 230 287 155 

15No wildcat wells were reported for Bhutan or Singapore.
 

16Wildcat wells from Malaysia/Thailand Joint Development Area are listed under Malaysia.
 17Wildcat wells from jointly claimed area between Japan and South Korea are listed under Japan.
 
Table . Wildcat wells by year, 1961–2001, for Mexico, the Caribbean, Central and South America, Europe, the Middle East, Africa, Asia, the southwestern Pa

Pre- Area 1961 62 6 6 6 66 6 6 69 0 1 2    6  

1961 

Southwestern Pacific18 

Papua New Guinea......... 53 0 1 1 1 1 0 4 8 3 2 2 1 5 2 3 2 1 Fiji.................................. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 New Caledonia19 ............. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Tonga.............................. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Australia20 ....................... 460 16 65 103 133 142 93 78 70 90 93 58 73 49 42 21 14 15 

East Timor20 ................... 2 2 0 0 0 0 0 0 0 2 4 3 3 0 0 1 0 0 New Zealand .................. 77 3 3 4 10 5 3 4 3 9 10 10 9 2 1 4 6 2 

Total ........................... 592 21 69 108 144 148 96 86 81 104 109 73 86 56 45 29 22 18 

Russia 

Russia............................. 1,392 198 222 254 256 272 240 214 222 263 233 259 208 191 205 245 209 240 

Grand total for study area 

Grand total .................... 14,621 1,386 1,490 1,470 1,428 1,511 1,390 1,291 1,360 1,482 1,501 1,619 1,519 1,500 1,526 1,647 1,509 1,513 
Table . Wildcat wells by year, 1961–2001, for Mexico, the Caribbean, Central and South America, Europe, the Middle East, Africa, Asia, the southwestern Pa

Area 192    6   9 90 91 92 9 9 9 96 9 9 1999 

Southwestern Pacific18—Continued 

Papua New Guinea......... 

Fiji.................................. New Caledonia19.............

1 4 0

1 0 0

5 0 0

3 0 0

2 0 0

2 0 0

30 0

10 16 7 4 2 

0 0 0 0 0 0 0 0 0 0

5 0 0

4 0 0

5 0 0

2 0 0

1 0 0

4 0 0 

Tonga.............................. Australia20....................... 

0 

152 

0 

140 

0 

148 

0 

189 

0 

103 

0 

163 

0 

135 

0 0 0 0 0 

92 118 101 85 83 

0 

92 

0 

108 

0 

108 

0 

121 

0 

123 

0 

76 

East Timor20 ................... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

New Zealand .................. 2 7 16 15 16 9 10 5 6 3 4 7 2 3 6 4 9 4 

Total ........................... 159 148 169 207 121 174 148 107 140 111 93 92 99 115 119 127 133 84 

Russia—Continued 

Russia............................. 303 320 306 353 428 495 514 420 410 307 159 90 90 42 60 57 34 55 

Grand total for study area—Continued 

Grand total ..................... 2,270 2,065 2,117 2,272 2,047 1,881 2,024 1,767 1,855 1,750 1,406 1,151 1,067 1,102 1,173 1,157 1,147 796 

18No wildcat wells were reported for French Polynesia, Guam, Kiribati, Marshall Islands, Micronesia, Nauru, Northern Mariana Islands, Samoa, Solomon Islands, Tuvalu, or 19New Caledonia is listed separately although it is an overseas territory of France.
 20Wildcat wells from the Timor Gap Zone of Cooperation are listed under Australia.
 
 

Table 6. Year of first discovery and cumulative recoverable oil and gas discovered through 2001 in the 173 significant petroleum 

provinces in the study area. 

[Each significant province has at least one field containing 100 million barrels of recoverable oil or 600 billion cubic feet of recoverable gas. Some 

provinces (marked by two asterisks) have resources in more than one region, and the petroleum in each part of the province is apportioned to the correct 

region. Data are from IHS Energy Group (2002). Province names and code numbers are from U.S. Geological Survey (USGS) World Energy Assess

ment Team (2000). The provinces in this table are listed within each region by year of first discovery. The historical sequence by year of first discovery 

in each significant petroleum province is graphed for six regions in figure 8A–F. Province boundaries are mapped and data on oil and gas discoveries in 

significant provinces are given in figures 14–57 for all regions except Mexico. MMBO, millions of barrels (bbl × 106) of oil; BCF, billions of cubic feet 

(ft3 × 109 )] 

Cumulative Cumulative 

Petroleum province name and code (country) 

Year of 

first 

discovery 

recoverable 

oil 

discovered 

through 2001 

recoverable 

gas 

discovered 

through 2001 

(MMBO) (BCF) 

Mexico 

Tampico-Misantla Basin, 5301 .............................................................................................. 1901 11,525 21,553
 

Saline-Comalcalco Basin, 5304............................................................................................. 1904 3,452 3,820
 

Macuspana Basin, 5306 ......................................................................................................... 1905 36 6,245
 

Burgos Basin, 5300................................................................................................................ 1931 32 12,434
 

Villahermosa Uplift, 5305...................................................................................................... 1954 42,085 51,318
 

 Total....................................................................................................................................................................... 57,130 95,370
 

Caribbean (fig. 14) 

Greater Antilles Deformed Belt, 6117 (Cuba)....................................................................... 1881 422 66
 

South America (figs. 8A and 16–24) 

Progreso Basin, 6083 (Ecuador and Peru) ............................................................................. 1863 137 562
 

East Venezuela Basin, 6098 (Venezuela and Trinidad and Tobago)...................................... 1867 63,375 172,767
 

Talara Basin, 6081 (Peru)....................................................................................................... 1869 1,772 2,909
 

San Jorge Basin, 6058 (Argentina) ........................................................................................ 1907 4,015 4,491
 

Maracaibo Basin, 6099 (Colombia and Venezuela)............................................................... 1914 54,878 52,930
 

Middle Magdelena, 6090 (Colombia).................................................................................... 1918 2,479 3,110
 

Neuquen Basin, 6055 (Argentina) ......................................................................................... 1922 3,431 24,868
 

Santa Cruz-Tarija Basin, 6045 (Argentina, Bolivia, and Paraguay) ...................................... 1924 384 49,576
 

Cuyo Basin, 6051 (Argentina) ............................................................................................... 1932 1,396 275
 

Oran-Olmedo Basin, 6046 (Argentina).................................................................................. 1936 139 2,740
 

Reconcavo Basin, 6032 (Brazil) ............................................................................................ 1939 1,667 3,704
 

Ucayali Basin, 6040 (Peru).................................................................................................... 1939 34 3,457
 

Magallanes Basin, 6059 (Argentina and Chile)..................................................................... 1945 1,356 27,963
 

Llanos Basin, 6096 (Colombia and Venezuela)..................................................................... 1948 4,911 7,941
 

Barinas-Apure Basin, 6097 (Venezuela)................................................................................ 1948 1,540 192
 

Upper Magdelena, 6089 (Colombia) ..................................................................................... 1949 1,057 830
 

Sergipe-Alagoas Basin, 6029 (Brazil) ................................................................................... 1957 810 1,973
 

Putumayo-Oriente-Maranon Basin, 6041 (Colombia, Ecuador, and Peru) ........................... 1963 9,131 2,146
 

Guyana-Suriname Basin, 6021 (Suriname) ........................................................................... 1965 154 0
 

Tobago Trough, 6103 (Venezuela and Trinidad and Tobago)................................................ 1971 20 20,614
 

Potigar Basin, 6027 (Brazil) .................................................................................................. 1973 822 1,763
 

Guajira Basin, 6095 (Colombia)............................................................................................ 1973 0 4,695
 

Campos Basin, 6035 (Brazil)................................................................................................. 1974 14,059 9,546
 

Foz do Amazonas Basin, 6022 (Brazil) ................................................................................. 1976 0 885
 

Santos Basin, 6036 (Brazil) ................................................................................................... 1979 343 755
 

Cariaco Basin, 6102 (Venezuela)........................................................................................... 1979 35 1,150
 

Madre dos Dios Basin, 6043 (Bolivia and Peru) ................................................................... 1984 1 12,810
 

Eastern Cordillera Basin, 6092 (Colombia)........................................................................... 1994 60 685
 

 Total....................................................................................................................................................................... 168,006 415,337
 

6 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

­
 

Table 6. Year of first discovery and cumulative recoverable oil and gas discovered through 2001 in the 173 significant petroleum 

provinces in the study area.—Continued 

Cumulative Cumulative 

Petroleum province name and code (country) 

Year of 

first 

discovery 

recoverable 

oil 

discovered 

through 2001 

recoverable 

gas 

discovered 

through 2001 

(MMBO) (BCF) 

Europe (figs. 8B and 25–27) 

Carpathian-Balkanian Basin, 4061 (Bulgaria, Moldova, and Romania) ............................... 1835 5,981 7,560 

North Carpathian Basin, 4047 (Czech Republic, Hungary, Poland, 

Slovakia, and Ukraine) ...................................................................................................... 1850 1,411 22,385 

Northwest German Basin, 4035 (Denmark,* Germany, and Netherlands)............................ 1856 2,283 157,398 

Pannonian Basin, 4048 (Austria, Bosnia and Herzegovina,* Croatia, Hungary, 

Romania, Slovakia, Slovenia, Ukraine, and Serbia and Montenegro) .............................. 1856 1,523 14,692 

Ireland-Scotland Platform, 4026 (Ireland and United Kingdom) .......................................... 1876 18 3,591 

Transylvanian Basin, 4057 (Romania and Ukraine) .............................................................. 1880 1 30,889 

Azov-Kuban Basin,** 1108 (Ukraine) .................................................................................. 1886 22 670 

Po Basin, 4060 (Croatia, Italy, and San Marino*) ................................................................. 1890 320 21,974 

Anglo-Paris Basin, 4040 (France and United Kingdom)....................................................... 1896 841 522 

Bohemia, 4046 (Austria, Czech Republic, Germany, and Slovakia) ..................................... 1913 1,037 5,048 

Tuscany-Latium-Paola, 4062 (Italy) ...................................................................................... 1915 1 1,497 

Adriatic Basin, 4058 (Albania, Croatia, and Italy) ................................................................ 1918 542 1,385 

Anglo-Dutch Basin, 4036 (Netherlands and United Kingdom)............................................. 1919 726 84,541 

German-Polish Basin, 4033 (Germany and Poland).............................................................. 1925 144 15,969 

Alps, 4051 (Croatia, Italy, Macedonia,* and Serbia and Montenegro) ................................. 1933 1,078 6,883 

Dnieper-Donets Basin,** 1009 (Ukraine) ............................................................................. 1936 1,538 68,251 

Irish Sea, 4030 (United Kingdom)......................................................................................... 1939 219 8,479 

Pyrenean Foothills-Ebro Basin, 4044 (France and Spain)..................................................... 1939 118 12,758 

Sicily, 4066 (Italy and Malta*) .............................................................................................. 1940 504 876 

Lusitanian Basin, 4074 (Portugal) ......................................................................................... 1953 0 920 

Aquitaine Basin, 4045 (France) ............................................................................................. 1954 375 27 

Pripyat Basin, 1010 (Belarus) ................................................................................................ 1963 910 255 

North Sea Graben, 4025 (Denmark, Germany, Netherlands, Norway, and 

United Kingdom)............................................................................................................... 1966 49,129 167,015 

Iberic Cordillera, 4083 (Spain) .............................................................................................. 1967 299 178 

Aegean,** 4075 (Greece) ...................................................................................................... 1971 139 142 

Faeroes-Shetland-Orkney Basin, 4019 (United Kingdom).................................................... 1977 1,460 2,279 

Hammerfest-Varanger Basin, 4015 (Norway) ....................................................................... 1981 292 11,755 

Vestford-Helgeland, 4017 (Norway)...................................................................................... 1981 3,717 36,729 

Pelagian Basin,** 2048 (Italy)............................................................................................... 1988 15 0 

 Total....................................................................................................................................................................... 74,643 684,668 

Tables –  
 

Table 6. Year of first discovery and cumulative recoverable oil and gas discovered through 2001 in the 173 significant petroleum 

provinces in the study area.—Continued 

Cumulative Cumulative 

Petroleum province name and code (country) 

Year of 

first 

discovery 

recoverable 

oil 

discovered 

through 2001 

recoverable 

gas 

discovered 

through 2001 

(MMBO) (BCF) 

Middle East (figs. 8C and 28–32) 

Zagros Fold Belt, 2030 (Iran, Iraq, Syria, and Turkey) ......................................................... 1905 137,168 485,666 

Greater Ghawar Uplift, 2021 (Bahrain, Qatar, and Saudi Arabia)......................................... 1932 147,200 259,700 

Widyan Basin-Interior Platform, 2023 (Iraq and Saudi Arabia)............................................ 1938 17,795 14,700 

Mesopotamian Foredeep Basin, 2024 (Iran, Iraq, Kuwait, former 

Kuwait-Saudia Arabia Neutral Zone, and Saudi Arabia).................................................. 1938 326,458 295,452 

Euphrates/Mardin, 2075 (Syria and Turkey).......................................................................... 1940 1,086 2,778 

Rub Al Khali Basin, 2019 (Iran, Oman, Qatar, Saudi Arabia, and 

United Arab Emirates)....................................................................................................... 1954 101,284 212,000
 

Levantine Basin,** 2032 (Israel and Gaza Strip*) ................................................................ 1955 23 3,510
 

South Oman Salt Basin, 2011 (Oman)................................................................................... 1956 2,805 888
 

South Caspian Basin,** 1112 (Iran) ...................................................................................... 1960 0 700
 

Fahud Salt Basin, 2016 (Oman)............................................................................................. 1962 4,661 10,558
 

Ghaba Salt Basin, 2014 (Oman) ............................................................................................ 1964 1,323 19,286
 

Kura Basin,** 1113 (Iran) ..................................................................................................... 1967 1 0
 

Qatar Arch, 2022 (Iran and Qatar)......................................................................................... 1967 2,235 826,000
 

Amu-Darya Basin,** 1154 (Iran) .......................................................................................... 1968 0 13,990
 

Red Sea Basin,** 2071 (Saudi Arabia).................................................................................. 1969 60 1,550
 

Central Oman Platform, 2015 (Oman)................................................................................... 1971 125 7,747
 

East Flank Oman Sub-basin, 2012 (Oman) ........................................................................... 1973 2,334 46
 

Anah Graben, 2089 (Syria).................................................................................................... 1982 456 148
 

Ma'Rib-Al Jawf/Masila Basin, 2004 (Yemen)....................................................................... 1984 1,315 17,887
 

Khleisha Uplift, 2074 (Syria)................................................................................................. 1986 1,680 1,364
 

Aegean,** 4075 (Turkey) ...................................................................................................... 1988 0 90
 

Interior Homocline-Central Arch, 2020 (Saudi Arabia)........................................................ 1989 5,525 17,200
 

Masila-Jeza Basin, 2009 (Yemen).......................................................................................... 1991 1,233 71
 

 Total...................................................................................................................................................................... 754,767 2,191,331
 

Africa (figs. 8D and 33–44) 

Red Sea Basin,** 2071 (Egypt, Eritrea, and Sudan) ............................................................. 1907 10,014 7,230 

Pelagian Basin,** 2048 (Libya and Tunisia) ......................................................................... 1949 2,710 38,144 

West-Central Coastal, 7203 (Angola, Cameroon, Congo (Brazzaville), 

Congo (Kinshasa), Equatorial Guinea, and Gabon) .......................................................... 1951 26,039 21,715
 

Benue, 7136 (Nigeria)............................................................................................................ 1953 5 1,265
 

Mozambique Coastal, 7343 (Mozambique)........................................................................... 1953 0 3,712
 

Grand Erg/Ahnet Basin, 2058 (Algeria) ................................................................................ 1954 608 116,741
 

Niger Delta, 7192 (Cameroon, Equatorial Guinea, and Nigeria) .......................................... 1954 51,130 193,561
 

Trias/Ghadames Basin, 2054 (Algeria, Libya, and Tunisia).................................................. 1956 20,711 41,404
 

Illizi Basin, 2056 (Algeria and Libya) ................................................................................... 1956 4,596 41,212
 

Hamra Basin, 2047 (Libya).................................................................................................... 1957 809 1,635
 

Sirte Basin, 2043 (Libya)....................................................................................................... 1958 44,927 47,777
 

Senegal, 7013 (Guinea-Bissau, Mauritania, and Senegal)..................................................... 1959 340 108
 

Somali, 7255 (Ethiopia and Somalia) .................................................................................... 1959 0 4,401
 

Nile Delta Basin, 2035 (Egypt).............................................................................................. 1966 2 42,775
 

North Egypt Basin, 2039 (Egypt) .......................................................................................... 1966 727 6,396
 

Abu Gharadiq Basin, 2038 (Egypt)........................................................................................ 1968 540 4,540
 

Gulf of Guinea, 7183 (Benin, Cote d’Ivoire, Ghana, Nigeria, and Togo) ............................. 1968 651 3,641
 

South African Coastal, 7363 (South Africa).......................................................................... 1969 119 3,770
 

Tanzania Coastal, 7273 (Tanzania) ........................................................................................ 1974 0 1,765
 

Orange River Coastal, 7303 (Namibia and South Africa) ..................................................... 1974 0 20,815
 

Levantine Basin,** 2032 (Egypt) .......................................................................................... 1975 20 2,736
 

Sud, 7146 (Chad and Sudan) ................................................................................................. 1975 2,564 247
 

Murzuk Basin, 2045 (Libya).................................................................................................. 1978 2,174 433
 

 Total....................................................................................................................................................................... 168,686 606,023
 

 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Table 6. Year of first discovery and cumulative recoverable oil and gas discovered through 2001 in the 173 significant petroleum 

provinces in the study area.—Continued 

Cumulative Cumulative 

Petroleum province name and code (country) 

Year of 

first 

discovery 

recoverable 

oil 

discovered 

through 2001 

recoverable 

gas 

discovered 

through 2001 

(MMBO) (BCF) 

Asia (figs. 8E and 45–53) 

Irrawaddy, 8048 (Burma)....................................................................................................... 1864 798 12,778 

Niigata Basin, 3308 (Japan)................................................................................................... 1867 86 2,670 

Assam, 8034 (India)............................................................................................................... 1867 2,157 5,837 

South Caspian Basin,** 1112 (Azerbaijan and Turkmenistan) ............................................. 1869 21,028 70,645 

Kura Basin,** 1113 (Azerbaijan and Georgia)...................................................................... 1869 524 278 

Japan Volcanic Arc/Accreted Terrane, 3304 (Japan and South Korea) ................................. 1870 120 1,751 

Taiwan Thrust and Fold Belt, 3151 (Taiwan) ........................................................................ 1876 8 1,941 

Sulaiman-Kirthar, 8025 (Pakistan)......................................................................................... 1883 0 16,399 

North Sumatra Basin, 3822 (Indonesia and Malaysia) .......................................................... 1885 736 30,668 

East Java Basin, 3809 (Indonesia) ......................................................................................... 1888 976 6,503 

South Sumatra Basin, 3828 (Indonesia)................................................................................. 1896 2,869 17,986 

Junggar Basin, 3115 (China).................................................................................................. 1897 8,430 4,840 

Kutei Basin, 3817 (Indonesia) ............................................................................................... 1897 3,487 58,666 

North Caspian Basin,** 1016 (Kazakhstan).......................................................................... 1898 21,615 93,628 

Pamusian Tarakan Basin, 3606 (Indonesia)........................................................................... 1900 522 4,243 

Fergana Basin, 1159 (Kyrgyzstan, Tajikistan, and Uzbekistan) ............................................ 1901 781 1,631 

Ordos Basin, 3128 (China) .................................................................................................... 1907 986 14,747 

Baram Delta/Brunei-Sabah Basin, 3701 (Brunei and Malaysia)........................................... 1910 7,142 39,666 

Ganges-Brahmaputra Delta, 8047 (Bangladesh and India) ................................................... 1915 3 18,548 

Tarim Basin, 3154 (China)..................................................................................................... 1918 1,523 16,458 

Afghan-Tajik Basin, 1156 (Afghanistan, Uzbekistan, and Tajikistan) .................................. 1934 155 5,630 

Kanto Basin, 3306 (Japan)..................................................................................................... 1935 0 1,359 

Bintuni/Sulawati Province, 3805 (Indonesia) ........................................................................ 1936 504 19,510 

Barito Basin, 3804 (Indonesia) .............................................................................................. 1937 173 215 

Middle Caspian Basin,** 1109 (Azerbaijan, Kazakhstan, Turkmenistan, and Uzbekistan)........ 1939 5,354 9,426 

Jiuquan Minle Wuwei Basin, 3114 (China)........................................................................... 1939 209 1 

Sichuan Basin, 3142 (China) ................................................................................................. 1939 246 31,915 

Central Sumatra Basin, 3808 (Indonesia) .............................................................................. 1939 13,074 2,109 

Northwest Java Basin, 3824 (Indonesia)................................................................................ 1939 3,434 11,460 

Amu-Darya Basin,** 1154 (Afghanistan, Turkmenistan, and Uzbekistan) .......................... 1953 983 229,851 

Qaidam Basin, 3131 (China).................................................................................................. 1955 541 2,385 

Indus, 8042 (India and Pakistan)............................................................................................ 1957 339 24,067 

Bombay, 8043 (India) ............................................................................................................ 1958 7,325 27,979 

Songliao Basin, 3144 (China)................................................................................................ 1959 15,637 4,722 

Bohaiwan Basin, 3127 (China) .............................................................................................. 1961 19,326 17,527 

Greater Sarawak Basin, 3702 (Indonesia and Malaysia) ....................................................... 1962 900 89,219 

North Ustyurt Basin, 1150 (Kazakhstan and Uzbekistan) ..................................................... 1964 2,589 4,122 

Malay Basin, 3703 (Cambodia, Indonesia, Malaysia, Thailand, and Vietnam) .................... 1969 3,907 62,462 

Nanyang Basin, 3126 (China)................................................................................................ 1971 711 0 

Penyu/West Natuna Basin, 3825 (Indonesia and Malaysia) .................................................. 1972 747 5,081 

Thai Basin, 3507 (Thailand) .................................................................................................. 1973 211 15,228 

Saigon Basin, 3505 (Vietnam) ............................................................................................... 1974 251 6,982 

Yinggehai Basin, 3159 (China and Vietnam) ........................................................................ 1975 19 11,909 

Mekong/Cuulong/Vung Tau Basin, 3503 (Vietnam) ............................................................. 1975 2,064 3,375 

Palawan Shelf, 3605 (Philippines) ......................................................................................... 1976 182 4,575 

Pearl River Mouth Basin, 3130 (China)................................................................................. 1979 1,361 1,584 

Krishna-Godavari, 8045 (India)............................................................................................. 1979 331 3,518 

Thailand Mesozoic Basin Belt, 3508 (Thailand) ................................................................... 1981 256 832 

South Turgay Basin, 1167 (Kazakhstan) ............................................................................... 1984 1,038 743 

South China Continental Shelf Slope, 3181 (China and Vietnam)........................................ 1984 121 1,705 

Sulawesi Accretionary Prism, 3829 (Indonesia).................................................................... 1986 15 3,791 

Volga-Ural Region,** 1015 (Kazakhstan) ............................................................................. 1991 67 837 

Luxi Jiaoliao Uplift, 3124 (China)......................................................................................... 1993 774 154 

Bonaparte Gulf Basin,** 3910 (Indonesia) ........................................................................... 2000 0 1,800 

 Total........................................................................................................................................................................ 156,635 1,025,956 

Tables – 9 
 

Table 6. Year of first discovery and cumulative recoverable oil and gas discovered through 2001 in the 173 significant petroleum 

provinces in the study area.—Continued 

Cumulative Cumulative 

Petroleum province name and code (country) 

Year of 

first 

discovery 

recoverable 

oil 

discovered 

through 2001 

recoverable 

gas 

discovered 

through 2001 

(MMBO) (BCF) 

Southwestern Pacific (figs. 54–56) 

Taranaki Basin, 3031 (New Zealand)..................................................................................... 1867 419 7,096
 

Gippsland Basin, 3930 (Australia)......................................................................................... 1924 4,089 11,097
 

Northwest Shelf, 3948 (Australia) ......................................................................................... 1954 1,806 96,607
 

New Guinea Foreland Basin-Fold Belt, 3966 (Papua New Guinea)...................................... 1956 518 11,310
 

Papuan Basin-Shelf Platform, 3969 (Papua New Guinea)..................................................... 1958 0 2,740
 

Bonaparte Gulf Basin,** 3910 (Australia) ............................................................................ 1964 556 25,492
 

Eromanga Basin, 3924 (Australia)......................................................................................... 1964 301 9,923
 

Browse Basin, 3913 (Australia)............................................................................................. 1971 121 38,751
 

 Total....................................................................................................................................................................... 7,810 203,016
 

Russia (figs. 8F and 57) 

Azov-Kuban Basin,** 1108................................................................................................... 1864 1,929 21,087 

Middle Caspian Basin,** 1109.............................................................................................. 1893 6,727 22,290 

North Sakhalin Basin, 1322 ................................................................................................... 1923 2,128 25,647 

Timan-Pechora Basin, 1008................................................................................................... 1930 13,738 41,474 

Volga-Ural Region,** 1015 ................................................................................................... 1932 67,465 98,681 

West Siberian Basin, 1174 ..................................................................................................... 1953 138,789 1,530,681 

Angara-Lena Terrace, 1209.................................................................................................... 1954 4 9,965 

Lena-Vilyuy Basin, 1214 ....................................................................................................... 1956 0 13,763 

North Caspian Basin,** 1016 ................................................................................................ 1958 47 93,196 

Dnieper-Donets Basin,** 1009.............................................................................................. 1959 21 825 

Yenisey-Khatanga Basin, 1175 .............................................................................................. 1965 4 9,386 

Nepa-Botuoba Arch, 1210 ..................................................................................................... 1965 3,372 27,354 

Baykit Arch, 1207.................................................................................................................. 1974 442 8,424 

South Barents Basin, 1050..................................................................................................... 1983 0 101,208 

Ludlov Saddle, 1059 .............................................................................................................. 1990 0 2,740 

Total ....................................................................................................................................................................... 234,666 2,006,721 

Grand total for significant provinces in the study area*** 

Grand total........................................................................................................................................................... 1,622,765 7,228,488
 

* The significant province extends into this country, but the country lacks discoveries in this province. 

**Some significant provinces have discoveries in more than one region, and the discoveries in each part of the province are apportioned to the correct 

region. These 13 provinces are summarized below: 

– The Levantine Basin and Red Sea Basin are in both the Middle East and Africa. 

– The South Caspian Basin, Kura Basin, and Amu-Darya Basin are in both the Middle East and Asia. 

– The Aegean is in both the Middle East and Europe. 

– The Middle Caspian Basin, North Caspian Basin, and Volga-Ural Region are in both Asia and Russia. 

– The Bonaparte Gulf Basin is in both Asia and the southwestern Pacific. 

– The Azov-Kuban Basin and Dnieper-Donets Basin are in both Russia and Europe. 

– The Pelagian Basin is in both Europe and Africa. 

***The total discoveries in the study area in all provinces are 1,630,000 MMBO and 7,275,000 BCF of gas (table 4); thus, most of the discoveries in the 

study area are in the 173 significant provinces, which contain 1,622,765 MMBO and 7,228,488 BCF of gas. 

60 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
Table . Regional distribution in the study area of land area, delineated prospective area, and explored area through 2001, rate of 

addition to prospective area, 1992–2001, and percentages of total prospective area and oil discoveries delineated by 1982. 

[Drilling data are from IHS Energy Group (2002). Land areas in square miles (mi2) are converted from areas in square kilometers in “The World Factbook 

2001” (U.S. Central Intelligence Agency, 2001)] 

Prospective Explored Rate of addition to Percentage of Percentage of 

Region Land area 

(mi2

) 

area through 

2001 

area through 

2001 

prospective area, 

1992–2001 

total prospective 

area delineated 

oil discoveries in 

area delineated 

(mi2

) (mi2) (mi2/wildcat well) by 192 by 192 

Mexico ............................. 761,602 45,970 9,820 23.2 81.7 95.8 

Caribbean ......................... 88,640 19,358 3,464 66.5 84.9 100.0 

Central America............... 202,232 15,022 1,830 151.6 75.4 100.0 

South America ................. 6,881,714 485,091 123,523 29.7 73.8 90.2 

Europe*............................ 2,260,379 791,839 184,400 18.8 83.4 91.5 

Middle East ...................... 2,317,969 286,061 45,595 62.1 63.4 97.1 

Africa ............................... 11,720,036 578,957 100,749 60.3 72.3 83.1 

Asia .................................. 9,887,100 921,065 179,863 76.8 55.7 81.8 

Southwestern Pacific........ 3,288,873 357,636 54,534 47.7 60.0 75.8 

Russia............................... 6,592,741 627,065 142,661 39.3 65.6 92.4 

Whole study area.......... 44,001,286 4,128,064 846,439 46.7 68.4 92.3 

*Europe does not include data for Greenland or Iceland. 

Tables – 61 
Figures 1–
 

Introduction.—Figures 14–57 show 

delineated prospective area, explored area, 

and known petroleum provinces of the study 

area regions—the Caribbean (fig. 14), Central 

and South America (figs. 15–24), Europe (figs. 

25–27), the Middle East (figs. 28–32), Africa 

(figs. 33–44), Asia (figs. 45–53), the southwestern Pacific (figs. 54–56), and Russia (fig. 57). 

Each figure includes a map, two graphs, and a 

summary of the exploration data. If significant 

provinces occur in the mapped area, then a 

table provides information on each significant 

province. Definitions of terms are provided 

below. 

Maps.—All maps were drawn by using 

ArcView software (version 3.2, created by 

Environmental Systems Research Institute, 

Inc. (ESRI)) and were edited in Adobe Illustrator (version 10). Each map is shown in 

unprojected geographic coordinates, except 

for northern Europe (fig. 25) and Russia (two 

maps in fig. 57). These three maps are shown 

in equidistant conic projection to minimize distortion of distance over the near-polar areas. 

Scales are not provided, as the scale varies 

on unprojected maps. 

Methods for computing and identifying 

delineated prospective areas and explored 

areas are explained in the text and are the 

same methods as those used in Attanasi 

and Root (1993). Recall that the delineated 

prospective area is described as the set of all 

(grid) points that are reasonably close to wells 

(producing or dry) and that are also inside 

the area drilled. Also recall that the explored 

area is defined as the area consisting of the 

points in the delineated prospective area that 

are within 2 miles of a well. The computation 

of delineated prospective area and explored 

area used locations of all wildcat, exploration, 

and development wells, both successful and 

dry, along with the locations of fields. All data 

except data for wells with a missing or obviously incorrect location were used because, 

for some areas, most of the wildcat well 

history, particularly prior to 1950, is missing. 

The dry and producing well locations and field 

locations may represent the only evidence of 

prior exploration. Use of all the data added 

some redundancy to the computations but 

assured that no area that had been searched 

was excluded because of missing wildcat or 

exploration wells. 

Landmass outlines and country boundar

ies are from the “Data & Maps Series Cntry98 

File” (ESRI, 1998). Country names are from 

the “The World Factbook 2001” (U.S. Central 

Intelligence Agency (CIA), 2001). If only part 

of the country is shown, then no delineated 

prospective area was identified in the rest of 

the country. Selected major rivers and lakes 

are from the “ArcWorld 1:3M Rivers and Water 

Bodies Coverage” (ESRI, 1992). 

Generalized bathymetric contour lines 

are shown at 200 and 1,000 meters (656 and 

3,280 feet) below sea level. Contour lines were 

generated from the “ETOPO5 5-Minute-Gridded Elevation Data” (National Geophysical 

Data Center, 1998) by using ESRI’s Arc/Info 

software (version 8.2). ETOPO5 is a raster 

dataset of worldwide land and sea-floor 

elevations at 5-minute spacing. Contour lines 

were then generalized in Arc/Info to smooth 

the lines and to reduce jagged features. 

Petroleum province names, boundaries, 

and code numbers are from the “U.S. Geologi

cal Survey World Petroleum Assessment 2000” 

(U.S. Geological Survey World Energy Assess

ment Team, 2000). Of all the known petroleum 

provinces shown in figures 14–57, 173 are 

classified as significant because, by the end of 

2001, they had at least one field containing 100 

million barrels of crude oil or 600 billion cubic 

feet of gas (table 6). 

Tables of significant petroleum provinces through 2001.—In figures 14–57, tables 

facing the maps provide information on the 

part of each significant province in a country, if there are reported discoveries for that 

significant province in that country. (Table 6 

gives the total cumulative recoverable oil and 

gas volumes in each significant province in 

all the countries it occupies.) Data are from 

the “International Petroleum Exploration and 

Production Database” (IHS Energy Group, 

2002), and the country order in the significant province tables follows the order in that 

database. Within each country, provinces are 

­

­

­
 

listed alphabetically. The tables show year of 

first discovery, oil in large oil fields (containing 

at least 100 million barrels), oil in all oil fields, 

gas in oil fields, gas in gas fields, and gas in all 

fields. A field is classified as either oil or gas 

on the basis of its gas:oil ratio. A field having 

at least 20,000 cubic feet of gas per barrel of 

crude oil is classified as a gas field; otherwise, 

the field is classified as an oil field. 

Graphs.—Two graphs are shown with 

each map in figures 14–57; the two types 

of graphs are described in the text section, 

“Tools for Analysis: Graphs,” and generalized 

graphs are shown in figure 6. The first graph 

shows the growth of cumulative delineated 

prospective area and explored area, arranged 

by the year when the areas became prospective or explored, plotted against the cumulative number of wildcat wells drilled in the 

country or country group through 2001, where 

the wells are also ordered by time. The second graph shows cumulative recoverable oil 

and gas discoveries as functions of cumulative delineated prospective area, where the 

increments of prospective area are ordered 

by time. Dates are shown at the top of each 

graph. Data plotted are from IHS Energy Group 

(2002). 

Only wildcat wells that have spud or 

completion dates and complete data indicating a location within the country or country 

group were used to construct graphs. Thus, 

cumulative wildcat well counts in the graphs 

are typically less than those in table 5, which 

includes wells without dates or coordinates.

 For many wildcat wells drilled before 

1950, data were not available, and, therefore, 

the delineated prospective areas and explored 

areas as of 1950 are underestimated in the 

graphs. Records of followup drilling after 1950 

probably result in an overestimate of the rate 

of increase in the delineated prospective 

area. Nonetheless, the growth in delineated 

prospective area after 1970 is probably real 

and not an artifact of missing data. 

Summaries of exploration data.—Land 

areas from the CIA (2001) in square kilometers 

were converted to square miles for ease in 

comparing this Circular with Circular 1096 

(Attanasi and Root, 1993). Land areas for coun

try groups may not add to the totals shown 

because of rounding. Computation of the 

delineated prospective area and the explored 

area is explained in the text. Wildcat wells and 

cumulative recoverable oil and gas discover

ies through 2001 are from IHS Energy Group 

(2002). Only wildcat wells that have spud or 

completion dates and that have longitude and 

latitude coordinates are used in the calcula

tion of the current rate of growth in delineated 

prospective area per wildcat. The current rate 

is computed as the rate of the expansion in 

the prospective area per wildcat for the last 10 

percent of the wildcat wells drilled in the area. 

The oil richness factor (cumulative oil 

discovered through 2001 divided by the number of square miles in the delineated prospective area) is shown and can be compared with 

the oil richness factors in Attanasi and Root 

(1993). The richness factors tend to be larger 

in areas where exploration has been concentrated in a small part of the prospective area 

(such as the Middle East). 

EXPLANATION FOR MAPS IN FIGURES 1– 

Delineated prospective area 

Explored area 

Petroleum province boundary; province names, 

codes, and boundaries are from U.S. Geological Survey World Energy Assessment Team 

(2000) 

Country boundary from Environmental Systems 

Research Institute (ESRI, 1998); country 

names are from U.S. Central Intelligence 

Agency (2001) 

River from ESRI (1992) 

Bathymetry contour at 200 meters (656 feet) from 

National Geophysical Data Center (1998) 

Bathymetry contour at 1,000 meters (3,280 feet) 

from National Geophysical Data Center (1998) 

UNITS USED IN FIGURES 1– 

BBO billions of barrels of oil (bbl × 109)
 

BCF billions of cubic feet (ft3 × 109)
 

mi2 square miles
 

MMBO millions of barrels of oil (bbl × 106)
 

TCF trillions of cubic feet (ft3 × 1012)
 

Figures 1– 6 

­

­

­
85°W 80°W 75°W 70°W 65°W 

Bahama 

Platform 6119 Greater Antilles 

25°N Deformed Belt 

6117 

THE BAHAMAS 

CUBA 

Yucatan Basin 

6123 DOMINICAN 20°N

CAYMAN ISLANDS REPUBLIC HAITI 

JAMAICA PUERTO RICO 

North Caribbean 

South Nicaraguan Rise Deformed Belt North Nicaraguan Rise 6115 6116 

6114 

15°N 

Venezuelan Basin 

6110 

South Caribbean Deformed 

Belt 

6104 

Figure 1. Map, graphs, and tables of data for oil and gas exploration through 2001 in the Caribbean. Parts of the Caribbean are Cuba, Barbados, The man Islands, Dominican Republic, Haiti, Jamaica, Puerto Rico, and the Lesser Antilles. Bermuda is not shown on the map; it lacks delineated prospectLesser Antilles are considered to include Netherlands Antilles, British Virgin Islands, Martinique, Dominica, Grenada, Virgin Islands, Saint Kitts and NAnguilla, Montserrat, Guadeloupe, Saint Lucia, Saint Vincent and the Grenadines, and Aruba. 
Growth in delineated prospective area and explored area through 2001, graphed by the year the areasbecame prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

300 

20 

AREA (THOUSANDS OF SQUARE MILES)18 16 Delineated prospective area 14 12 10 8 6 Explored area 4 2 

0 

0 100 200 400 500 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provincesthrough 2001, graphed by the year the field locationbecame part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

500 100 400 80

Gas Oil 

OIL (MMBO)300 60

) 

200 40

GAS (BCF

100 20

0 0

0 5 10 15 20 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum province—Year of first discovery and cumulative recoverable 

oil and gas discovered through 2001

Oil in Oil in Gas 

Significant petroleum province 

Year of 

first large fields all fields oi

field

discovery (MMBO) (MMBO) (BC

Cuba: Greater Antilles Deformed

 Belt, 6117.............................................. 1881 143 422 66 

Exploration data 

Country

Cuba ................................ Barbados ......................... 

Bahamas.......................... Bermuda (not shown 

on map) .......................
 

Cayman Islands............... Dominican Republic ....... Haiti................................. Jamaica............................ 

Land area 

(mi2) 

42,803
 

166
 

5,382
 

23 

100 

18,815 10,714 

4,243 

Delineated prospective area through 200

Explored area through 2001 ...................

Wildcat wells through 2001....................Current growth in delineated prospective 

per wildcat (for last 10 percent of wel

Reported discoveries through 2001 of cu

recoverable crude oil and gas in all pr

Oil.................................................Gas................................................

Richness total oil discoveries 

 total delineated prospective ar

( 

Puerto Rico...................... 3,515
 Lesser Antilles ................ 2,909
 

Total......................... 88,670
 

Figure 1. Continued. 
66	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

Figure 15. Map, graphs, and table of data for oil and gas exploration through 2001 in Central America. Countries of Central America

are Guatemala, Belize, Costa Rica, Honduras, Nicaragua, Panama, and El Salvador.

 90°W 85°W 80°W

5°N

10°N

15°N

20°N

Pacific Offshore 

Basin

6088

Columbian Basin

6112

Cayman Trough

6120

Yucatan Basin

6123

Greater Antilles Deformed Belt

6117

Yucatan Platform

5308

Maya Mountains

6125

Cayman Ridge

6121

Middle America

Province

6113

Chiapas Massif-Nuclear 

Central America

6122

Sierra Madre

de Chiapas-Peten

Foldbelt 5310

South Nicaraguan Rise

6115

North Nicaraguan Rise

6114

COSTA RICA

NICARAGUA

HONDURAS

BELIZE

PANAMA

GUATEMALA

EL SALVADOR

Choco Pacific Basin

6087

20°N

15°N

10°N

5°N

90°W 85°W 80°W
 

Growth in delineated prospective area and explored 

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

16 

12 

10 

8 

6 

2 

Delineated prospective area 

Explored area 

AREA (THOUSANDS OF SQUARE MILES) 14 

4 

0 

0 50 100 150 200 250 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

140 20 

16 

14 

OIL (MMBO) 

0 2 4 6 8 10 12 14 16 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Gas 

Oil 

18

120

100 

12 80 

) 

10 

60 8 

GAS (BCF

40 6

4 

20 

2 

0 0

Exploration data 

Country Land area

(mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

15,022 mi2 

1,830 mi2 

Guatemala .............................. 

Belize ..................................... 

Costa Rica .............................. 

Honduras ................................ 

42,042 

8,867 

19,730 

43,278 

Wildcat wells through 2001 .............................................

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 232 wells 

136 mi2

/well 

Nicaragua ............................... 49,998 Oil.......................................................................... 116 MMBO 

Panama................................... 30,193 Gas......................................................................... 17 BCF 

El Salvador............................. 

Total ................................... 

 8,124 

202,232 

Richness total oil discoveries .......... total delineated prospective area ( ) 0.008 MMBO/mi2

Figure 1. Continued. 

Figure 1. Central America 6 
68	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

Figure	16.  Map, graphs, and tables of data for oil and gas exploration through 2001 in Suriname, Guyana, and French Guiana.

60°W 55°W

10°N

East Venezuela Basin

6098

Guyana-Suriname Basin

6021

GUYANA

Foz do Amazonas 

Basin

6022

5°N

SURINAME

FRENCH GUIANA Tacutu Basin

6010 Guyana Shield

6002

0°
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

4 

3 

2 

1 

0 

0 10 20 30 40 50 60 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

OIL (MMBO)

200 

180 

160 

140 

120 

100 

80 

60 

40 

20 

0 

0 1 2 3 4 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum province—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all 

fields

(BCF) 

Suriname: 

Guyana-Suriname Basin, 6021 ................... 1965 153 154 0 0 0
 

Exploration data 

Country Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

3,259 mi2 

613 mi2 

Guyana ................................... 

Suriname ................................ 

French Guiana........................ 

83,000 

63,039 

35,135 

Wildcat wells through 2001 .............................................

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

Reported discoveries through 2001 of cumulative 

58 wells 

140 mi2

/well 

Total ................................... 181,174 recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 154 MMBO 

 Gas......................................................................... 0 

Richness total oil discoveries .......... total delineated prospective area ( ) 0.047 MMBO/mi2

Figure 16. Suriname, Guyana, and French Guiana 69 

Figure 16. Continued. 
70	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

Altiplano Basin

6065 Andean

Province

Moquegua- 6006

Tamaruga Basin

6066

CHILE Salar de Atacama 

Basin

6067

Curico Basin

Central Chile 6068

Forearc Basin

6074

Temuco Basin

6069

Osorno-Llanquihue

Basin

6070

San Jorge 

Basin

Penas Basin 6058

6073

Deseado-Falklands

Province

6009

Magallanes

Madre de Basin

Dios Basin 6059

6072

Diego Ramirez 

Basin

6071

80°W 70°W 60°W 50°W

20°S

30°S

40°S

50°S

Figure	17.  Map, graphs, and tables of data for oil and gas exploration through 2001 in Chile.
Growth in delineated prospective area and explored 

area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

16 

14 

12 

10 

8 

6 

4 

2 

0 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

0 100 200 300 400 500 600 700 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 1990

1960 1970 1980 2000

400 12 

10 

300 

8 

200 6 

4 

100 

2 

0 0 

Oil 

Gas 

OIL (MMBO)

) (TCFGAS 

0 5 10 15 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum province—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in 

all 

fields 

(BCF) 

Chile: 

Magallanes Basin, 6059.............................. 1945 0 373 1,429 8,366 9,795
 

Exploration data 

Country Land area

(mi2

)	 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

14,384 mi2
 

4,871 mi2
 

Chile....................................... 292,259
 Wildcat wells through 2001 .............................................

Current growth in delineated prospective area 

 633 wells


per wildcat (for last 10 percent of wells) ..................... 3 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 373 MMBO 

 Gas......................................................................... 9.836 TCF 

Richness total oil discoveries .......... ( total delineated prospective area ) 0.026 MMBO/mi2

Figure 1. Chile 1 

Figure 1. Continued. 
80°W 70°W 60°W 50°W

20°S

Santa Cruz-Tarija 


Basin
 Andean Province 6045
 6006 

PARAGUAY 

Brazilian 

Oran-Olmedo
 Shield 

Bolsones Basin Basin
 6004 

6048 6046
 

Mascasin Basin Familina 

Chaco Basin 6050 Province Parana Basin 6047 6007 6020 

Bermejo Basin 30°S 6049 

Cuyo Basin 

6051 

URUGUAY ARGENTINA Neuquen Basin Pelotas Basin 

6055 Salado Basin Mercedes Basin 6037 

6052 6054 

Laboulaye-Macachin Basin 

6053 

40°S Nirihuau Basin 

6056 Colorado Basin 

6057 Canadon Asfalto 

6008 

Magallanes Basin San Jorge Basin 

6059 6058 

East Patagonia 


Basin
 

6061
 

DeseadoFalklands 

Falklands Plateau Province 

6060 6009 

50°S

FALKLAND ISLANDS 

Malvinas Basin Burdwood Bank-North Scotia Ridge 6063 6064 

Figure 1. Map, graphs, and tables of data for oil and gas exploration through 2001 in Argentina, Paraguay, Uruguay, and the Falkland 

Islands. 

2 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

140 

120 

100 

80 

60 

40 

Delineated prospective area 

Explored area 

AREA (THOUSANDS OF SQUARE MILES)

20 

0 

0 1,000 2,000 3,000 4,000 5,000 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location 

became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

12 100

80 

OIL (BBO)

60 

4 

Oil 

Gas 

10 

8 

) 

6 

40 

GAS (TCF

20 2

0 0 

0 20 40 60 80 100 120 140 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Year of 

Significant petroleum province first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in 

all 

fields 

(BCF) 

Argentina: 

Cuyo Basin, 6051........................................ 1932 987 1,396 246 29 275 

Magallanes Basin, 6059 .............................. 1949 192 983 7,585 10,583 18,168 

Neuquen Basin, 6055.................................. 1922 1,858 3,431 5,813 19,055 24,868 

Oran-Olmedo Basin, 6046 .......................... 1936 0 139 212 2,528 2,740 

San Jorge Basin, 6058................................. 1907 2,422 4,015 4,393 98 4,491 

Santa Cruz-Tarija Basin, 6045 .................... 1926 0 50 17 12,727 12,744 

Total ............................................................................. 5,459 10,014 18,266 45,020 63,286 

Paraguay: 

Santa Cruz-Tarija Basin, 6045 .................... 1959 0 0 0 15 15 

Exploration data 

Country Land area

(mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

124,099 mi2 

37,406 mi2 

Argentina................................ 

Paraguay................................. 

Uruguay.................................. 

Falkland Islands ..................... 

Total ................................... 

1,068,297 

157,046 

68,039 

 4,700 

1,298,082 

Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 

3,994 wells 

17 mi2

/well 

10.015 BBO 

 Gas......................................................................... 63.676 TCF 

Richness total oil discoveries .......... total delineated prospective area ( ) 0.081 MMBO/mi2

Figure 1. Argentina, Paraguay, Uruguay, and the Falkland Islands  

Figure 1. Continued. 
 

80°W 75°W

Choco Pacific Basin 

6087 

Borbon Basin Cauca Basin 

6085 6086 

0°

Manabi Basin 

6084 

ECUADOR 

Progreso Basin 

6083 West-Central 

Cordillera 

6106 

Talara Basin 

6081 Lancones Basin 

6082 Putumayo-Oriente-Maranon
 

Basin
 

6041
 

Santiago Basin 

6038 

5°S

Andean Province 

6006 

Figure 19. Map, graphs, and tables of data for oil and gas exploration through 2001 in Ecuador. 

 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

25 

20 

15 

10 

5 

0 

0 100 200 300

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

OIL (BBO)

) 

Gas 

GAS (TCF

8 5 

4 

6 

3 

4 

2 

2 

1 

0 0 

0 5 10 15 20 25 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Ecuador: 

Progreso Basin, 6083 .................................. 1918 120 133 189 320 509 

Putumayo-Oriente-Maranon 

Basin, 6041 ............................................. 1967 5,715 7,551 1,637 0 1,637 

Total.......................................................................... 5,835 7,684 1,826 320 2,146 

Exploration data 

Country 

Land area

(mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

20,835 mi2
 

3,709 mi2
 

Ecuador .................................. 109,483
 Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

293 wells 


per wildcat (for last 10 percent of wells) ..................... 67 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 7.684 BBO 

 Gas......................................................................... 2.146 TCF 

Richness total oil discoveries .......... total delineated prospective area ( ) 0.369 MMBO/mi2

Figure 19. Ecuador  

Figure 19. Continued. 
80°W 75°W 70°W

South Caribbean Deformed Belt Guajira Basin 6104 6095 

Sierra Nevada de Santa Marta 

6105 

Cesar Basin 

6094 

Choco Pacific Basin Perija-Venezuela-Coastal Ranges 10°N 6087 6093 

Maracaibo Basin 

6099 

Eastern Cordillera Basin 

6092 

Lower Magdelena Barinas-Apure Basin 

6091 6097 

Middle Magdelena 

Pacific Offshore Basin 6090 

6088 

West-Central
 

Cordillera
 Guyana Shield

6106 6002 

5°N

Llanos Basin 

6096 

COLOMBIA 

Upper Magdelena 

6089 

Putumayo-Oriente-Maranon Basin 

6041 

0°

Cauca Basin 

6086 

Solimoes Basin 

6011 

Figure 20. Map, graphs, and tables of data for oil and gas exploration through 2001 in Colombia. 

6 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

100 

80 

60 

40 

20 

0 

0 200 400 600 800 1,000 1,200 1,400 1,600 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

OIL (BBO)

Gas 

) GAS (TCF

10 40 

8 

30 

6 

20 

4 

10 

2 

0 0 

0 10 20 30 40 50 60 70 80 90 100 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in 

all 

fields 

(BCF) 

Colombia: 

Eastern Cordillera Basin, 6092 ................... 1994 0 60 685 0 685 

Guajira Basin, 6095 .................................... 1973 0 0 0 4,695 4,695 

Llanos Basin, 6096...................................... 1948 3,057 3,678 4,149 3,755 7,904 

Maracaibo Basin, 6099 ............................... 1920 410 472 559 355 914 

Middle Magdelena, 6090 ............................ 1918 1,983 2,479 2,908 202 3,110 

Putumayo-Oriente-Maranon Basin, 6041 ... 1963 292 445 387 0 387 

Upper Magdelena, 6089.............................. 1949 292 1,057 499 331 830

Total ............................................................................. 6,034 8,191 9,187 9,338 18,525 

Exploration data 

Country 

Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

82,941 mi2 

14,398 mi2 

Colombia................................ 439,734 Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

1,513 wells 

per wildcat (for last 10 percent of wells) ..................... 15 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 8.27 BBO 

 Gas......................................................................... 20.408 TCF 

Richness total oil discoveries .......... total delineated prospective area ( ) 0.100 MMBO/mi2

Figure 20. Colombia  

Figure 20. Continued. 
78	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

80°W 75°W 70°W

0°

5°S

10°S

15°S

Progreso

Basin

6083 Santiago Basin

West- 6038

Central

Cordillera

6106 Putumayo-OrienteMaranon Basin

6041

Lancones

Basin Solimoes Basin

6082 6011 Huallaga Basin

6039

Talara 

Basin

6081

Acre Basin

6042 Sechura

Basin

6080

Trujillo Basin

6079 Ucayali

Basin

Salaverry Basin 6040

6078

PERU Madre dos 

Dios Basin

Lima Basin 6043

6077

Andean Province

Pisco Basin 6006

6076

Altiplano

Basin

6065

Moquegua-Tamaruga Basin

6066

Figure	21.   Map, graphs, and tables of data for oil and gas exploration through 2001 in Peru.
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

20 

15 

10 

5 

0 

0 100 200 300 400

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated rospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

OIL (BBO)

) 

Gas 

GAS (TCF

3 20 

15 

2 

10 

1 

5 

0 0 

0 5 10 15 20 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in 

all 

fields 

(BCF) 

Peru: 

Madre dos Dios Basin, 6043....................... 1984 0 0 0 12,800 12,800 

Progreso Basin, 6083 .................................. 1863 0 4 0 53 53 

Putumayo-Oriente-Maranon Basin, 6041 ... 1971 535 1,135 122 0 122 

Talara Basin, 6081....................................... 1869 1,505 1,772 2,833 76 2,909 

Ucayali Basin, 6040.................................... 1939 0 34 0 3,457 3,457 

Total.......................................................................... 2,040 2,945 2,955 16,386 19,341 

Exploration data 

Country 

Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

17,825 mi2 

3,302 mi2 

Peru ........................................ 496,224 Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

395 wells 

per wildcat (for last 10 percent of wells) ..................... 101 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 2.945 BBO 

 Gas......................................................................... 19.346 TCF 

Richness total oil discoveries .......... total delineated prospective area ( ) 0.165 MMBO/mi2

Figure 21. Peru 9 

Figure 21. Continued. 
70°W 65°W 60°W

Neogene Volcanic 


Belt
 15°N 6108
 

Lesser Antilles 

Deformed Belt 

6107 

Cariaco Basin 

South Caribbean Deformed Belt 6102 

6104 

Tobago Trough
 

6103
 

TOBAGO 

Bonaire Basin 

6101 

Falcon Basin 

6100 

Perija-Venezuela-Coastal Ranges 10°N 6093 

East Venezuela
 

Basin
 

6098
 

TRINIDAD 

Barinas-Apure Basin 

6097 

Maracaibo Basin 

6099 VENEZUELA

5°N

Guyana Shield 

Llanos Basin 6002 

6096 

0°

Figure 22. Map, graphs, and tables of data for oil and gas exploration through 2001 in Venezuela and Trinidad and Tobago. 

0 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored 

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

100
 

80 

60 

40 

Delineated prospective area 

Explored area 

AREA (THOUSANDS OF SQUARE MILES)

20 

0 

0 1,000 2,000 3,000 4,000 5,000 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

became part of the delineated prospective area 

YEAR
 

1960 1970 1980 1990 2000
 

140 300

250 

200 

Oil 

OIL (BBO)

Gas 

120 

100 

80 

) 

150 

60 

GAS (TCF

100 

40 

50 20 

0 0

0 10 20 30 40 50 60 70 80 90 100 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Year of 

Significant petroleum province first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Venezuela: 

Barinas-Apure Basin, 6097......................... 1948 953 1,540 71 121 192 


Cariaco Basin, 6102.................................... 1979 0 35 150 1,000 1,150 


East Venezuela Basin, 6098 ........................ 1913 55,525 59,686 122,833 16,236 139,069 


Llanos Basin, 6096...................................... 1983 1,233 1,233 37 0 37 


Maracaibo Basin, 6099 ............................... 1914 53,306 54,406 51,180 836 52,016 


Tobago Trough, 6103.................................. 1979 0 20 0 16,209 16,209
 

Total ............................................................................. 111,017 116,920 174,271 34,402 208,673
 

Trinidad and Tobago: 

East Venezuela Basin, 6098 ........................ 1867 2,800 3,689 5,906 27,792 33,698 


Tobago Trough, 6103.................................. 1971 0 0 0 4,405 4,405
 

Total ............................................................................. 2,800 3,689 5,906 32,197 38,103
 

Exploration data 

Country 

Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

84,754 mi2 

30,163 mi2 

Venezuela ............................... 

Trinidad and Tobago .............. 

Total ................................... 

352,143 

 1,980 

354,123 

Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

Reported discoveries through 2001 of cumulative 

5,087 wells 

15 mi2

/well 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 120.799 BBO 

 Gas......................................................................... 247.496 TCF 

Richness total oil discoveries .......... total delineated prospective area ( ) 1.425 MMBO/mi2

Figure 22. Venezuela and Trinidad and Tobago 1 

Figure 22. Continued. 
 

70°W 65°W 60°W

10°S

Madre dos 

Dios Basin 

6043 

BOLIVIA 

15°S

Beni Basin Brazilian 

6044 Shield 

6003 

Parecis 

Province Altiplano 6014 Basin 

6065 

Santa CruzTarija Basin 

6045 Andean 

Province 

6006 

20°S

Figure 2. Map, graphs, and tables of data for oil and gas exploration through 2001 in Bolivia. 

2 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES)

Delineated prospective area 

Explored area 

30 

20 

10 

0 

0 100 200 300 400 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

OIL (MMBO)

) 

Gas 

GAS (TCF

400 50 

40 

300 

30 

200 

20 

100 

10 

0 0 

0 10 20 30 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Bolivia: 

Madre dos Dios Basin, 6043....................... 1991 0 1 10 0 10 


Santa Cruz-Tarija Basin, 6045 .................... 1924 0 334 1,868 34,949 36,817 


Total ............................................................................. 0 335 1,878 34,949 36,827
 

Exploration data 

Country 

Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

24,858 mi2 

4,089 mi2 

Bolivia.................................... 424,162 Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

378 wells 

per wildcat (for last 10 percent of wells) ..................... 41 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 336 MMBO 

 Gas......................................................................... 36.827 TCF 

Richness total oil discoveries .......... ( ) total delineated prospective area 

0.014 MMBO/mi2

Figure 2. Bolivia  

Figure 2. Continued. 
70°W 60°W 50°W 40°W

Foz do Amazonas Basin 

6022 

Tacutu 

Santana Basin 

Platform 6010 Barreieinas 

6023 Basin 

6025 San Luis 

Basin Caera 

Putumayo- 6024 Basin 

Oriente- Guyana Shield 0° Amazonas Basin 6026 

Maranon 6002 6012 Potigar 

Basin Basin 

6041 Solimoes 6027 

Basin 

6011 

Parnaiba Araripe 

Basin Province 

Sucunduri 6016 6019 

Pernambuco Province Jatoba Basin 

Acre 6013 BRAZIL Basin 6028 

Basin 6030 Diamantina 6042 

Province 10°S

6018 

Xingu 

Madre dos Dios Province 

Basin 6015 6043 Sao SergipeFrancisco Alagoas Brazilian Tucano Ucayali Basin Shield Basin Basin Basin 6029 

6003 Brazilian 6017 6031 6040 Brazilian Bahia 

Shield Shield Sul 

6005 6004 Reconcavo Basin 

Basin 6033 

Santa Cruz-Tarija Basin 6032 

6045 

Parana Basin 20°S

6020 Parecis Province 

6014 

Espirito 

Santo Basin 

6034 

Santos Basin Campos 

6036 Basin 

6035 

30°S

Pelotas Basin 

6037 

Figure 2. Map, graphs, and tables of data for oil and gas exploration through 2001 in Brazil. 

 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

120 

100 

80 

60 

40 

20 

0 

0 1,000 2,000 3,000 4,000 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Gas 

) 

OIL (BBO)

(TCFGAS 

Oil 

20 25 

20 

15 

15 

10 

10 

5 

5 

0 0 

0 10 20 30 40 50 60 70 80 90 100 110 120 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in 

all 

fields 

(BCF) 

Brazil: 

Campos Basin, 6035 ................................... 1974 12,897 14,059 9,339 207 9,546 

Foz do Amazonas Basin, 6022.................... 1976 0 0 0 885 885 

Potigar Basin, 6027..................................... 1973 320 822 806 957 1,763 

Reconcavo Basin, 6032............................... 1939 1,100 1,667 2,557 1,147 3,704 

Santos Basin, 6036...................................... 1979 150 343 232 523 755 

Sergipe-Alagoas Basin, 6029...................... 1957 330 810 1,506 467 1,973

Total ............................................................................. 14,797 17,701 14,440 4,186 18,626 

Exploration data 

Country 

Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

112,136 mi2 

24,972 mi2 

Brazil...................................... 3,286,473 Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

3,695 wells 

per wildcat (for last 10 percent of wells) ..................... 54 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 18.192 BBO 

 Gas......................................................................... 22.422 TCF 

Richness total oil discoveries .......... total delineated prospective area ( ) 0.162 MMBO/mi2

Figure 2. Brazil  

Figure 2. Continued. 
30°W 20°W 10°W 0° 10°E 20°E 30°E 40°E 

Troms-Bjornoya Basin 

70°N 4014 

Hammerfest-Varanger Basin 

4015 

Barents Continental Slope 

4013 

Central Barents 

Platform 

4012 

Kola Monocline-Finnmark Platform 

1051 

4 

Vestford-Helgeland 

4017 

Faeroes-Shetland- North Sea Graben Baltic Shield-Norwegian Caledonides Orkney Basin 4025 4016 

4019 10 

60°N 3 

9 

Northwest 

German Basin 

4035 

 Midland Valley-Forth HordaApproaches Basin Norwegian4027 11 Danish Basin 

Mid-North 4023 Baltic 

Sea High 2 Depression 4028 4021 

Fennoscandian Irish Sea Border-Danish-Polish 4030 Margin Southwest 

Ireland- 6 4022 German Basin 8 4039 Scotland 

Platform German-Polish 

50°N 4026 Basin 

4033 Munsterland 

1 Basin Bohemia 

7 4038 4046 

London- Rhine Graben Molasse Basin 

Brabant Armoricia 4055 4049 5 Platform 4041 Anglo-Paris Basin 

4037 Anglo-Dutch 4040 

Basin Trans-graben 4036 4053 Alps 4051 

EXPLANATION 

1 Belgium 3 Faroe Islands 5 Germany 7 Luxembourg 9 Norway 11 United Kingdom 

2 Denmark 4 Finland 6 Ireland 8 Netherlands 10 Sweden 

Figure 2. Maps, graphs, and tables of data for oil and gas exploration through 2001 in the northern part of Western Europe. For this 

figure, the parts mapped are the United Kingdom, Norway, Germany, Denmark, Netherlands, Ireland, Sweden, Belgium, Faroe Islands, 

Finland, Luxembourg, and Svalbard. The Faroe Islands are a self-governing overseas administrative division of Denmark. Svalbard 

(a territory of Norway) is a group of islands in the Arctic Ocean; see the separate small map. Data for Greenland and Iceland are not 

mapped and are not included in the exploration data; they had no discoveries through 2001. 

6 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
Figure 25. Northern Part of Western Europe 87

Map of oil and gas exploration through 

2001 in Svalbard.

Svalbard High 4011

Svalbard

10 ̊E 20 ̊E 30 ̊E

80 ̊N

Growth in delineated prospective area and explored 

 area through 2001, graphed by the year the areas

 became prospective or explored

YEAR

1960 1970 1980 1990 2000

AREA (THOUSANDS OF SQUARE MILES)

Delineated prospective area

Explored area

CUMULATIVE NUMBER OF WILDCAT WELLS

350

300

250

200

150

100

50

0

0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000

Figure 25.  Continued.

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area

YEAR

1960 1970 1980 1990 2000

Oil

OIL (BBO)

)

Gas

GAS (TCF

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES)

60 600

50 500

40 400

30 300

20 200

10 100

0 0

0 50 100 150 200 250 300 350
 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Oil in Oil in Gas in Gas in Year of large all oil gas Significant petroleum province first fields fields fields fields discovery (MMBO) (MMBO) (BCF) (BCF) 

United Kingdom: 

Anglo-Dutch Basin, 4036 .......................... 1919 0 78 19 53,776 

Anglo-Paris Basin, 4040 ............................ 1896 490 544 217 178 

Faeroes-Shetland-Orkney Basin, 4019....... 1977 1,241 1,460 879 1,400 

Ireland-Scotland Platform, 4026................ 1876 0 0 0 80 

Irish Sea, 4030............................................ 1939 0 219 390 8,089 

North Sea Graben, 4025............................. 1969 20,145 25,146 28,315 23,694 

Total ............................................................................. 21,876 27,447 29,820 87,217 

Norway: 

Hammerfest-Varanger Basin, 4015 ............. 1981 0 292 190 11,565 

North Sea Graben, 4025.............................. 1968 18,793 21,926 29,143 73,000 

Vestford-Helgeland, 4017 ........................... 1981 3,325 3,717 8,953 27,776 

Total ............................................................................. 22,118 25,935 38,286 112,341 

Germany: 

Bohemia, 4046 ............................................ 1930 0 1 0 322 

German-Polish Basin, 4033 ........................ 1925 0 24 38 8,732 

North Sea Graben, 4025.............................. 1974 0 0 0 450 

Northwest German Basin, 4035.................. 1856 911 2,029 1,311 34,525 

Total ............................................................................. 911 2,054 1,349 44,029 

Denmark: 

North Sea Graben, 4025.............................. 1966 1,672 1,916 2,574 5,185 

Netherlands: 

Anglo-Dutch Basin, 4036 ........................... 1952 120 648 613 30,133 

North Sea Graben, 4025.............................. 1968 0 141 620 4,035 

Northwest German Basin, 4035.................. 1943 253 254 400 121,162 

Total ............................................................................. 373 1,043 1,633 155,330 

Ireland: 

Ireland-Scotland Platform, 4026................. 1971 0 18 16 3,495 

Gas in

all

fields

(BCF) 

53,795 

395 

2,279 

80 

8,479 

52,009 

117,037 

11,755 

102,143 

36,729 

150,627 

322 

8,770 

450 

35,836 

45,378 

7,759 

30,746 

4,655 

121,562 

156,963 

3,511 

Figure 2. Continued. 

 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
Exploration data 

Country 

United Kingdom.....................
 

Norway...................................
 

Germany.................................
 

Denmark.................................
 

Netherlands ............................
 

Ireland ....................................
 

Sweden...................................
 

Belgium..................................
 

Faroe Islands ..........................
 

Land area

(mi2

) 

94,525 

125,181 

137,846 

16,639 

16,033 

27,135 

173,731 

11,780 

540 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 

 Gas......................................................................... 

Richness total oil discoveries .......... ( ) total delineated prospective area 

310,575 mi2 

79,074 mi2 

7,551 wells 

19 mi2

/well 

58.72 BBO 

484.757 TCF 

0.189 MMBO/mi2

Finland ...................................
 130,127 

Luxembourg...........................
 998 

Svalbard .................................
 23,957 

Total ...................................
 758,494 

Figure 2. Continued. 

Figure 2. Northern Part of Western Europe 9 
10°W 5°W 0°

Anglo-Paris Basin 

4040 

50°N

Armoricia 

4041 

Spanish Trough- FRANCE 

Cantabrian Zone Aquitaine 

4070 Basin 

4045 Massif Central 45°N Pyrenean Foothills-Ebro Basin 4043 

4044 

ANDORRA 

Galician 

Basin 

4073 Tajo-Duero 

Basin PORTUGAL 4082 

Iberian Iberic Cordillera 

Massif 4083 

4072 SPAIN 

40°N

Lusitanian 

Basin Betic Zone 4074 4078 

Andalucia 

Alentejo- 4088 

Guadalquivir 

Basin 

4077 Rif Basin 

2072 

GIBRALTAR 

35°N

Figure 26. Map, graphs, and tables of data for oil and gas exploration through 2001 in the southern part of Western Europe. For this fig

ure, the parts mapped are Italy, Austria, France, Spain, Portugal, Switzerland, Andorra, Liechtenstein, Malta, Monaco, San Marino, and 

Gibraltar (an overseas territory of the United Kingdom). 

90 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

5°E

London-Brabant 

Platform 

4037 

Tr

Jura 

4052 

Bresse 

Depressio

4054 

Li

Provence Ba

4068 

Corsic

Sardinian 

406

­
5°E 10°E 15°E 20°E

North Carpathian 
 Rhine Graben
 

Basin
 4055
 London-Brabant 4047
 

Platform 

4037 50°N

Bohemia Southwest 

4046 German Basin 

4039 

Transgraben Molasse Basin Jura 4053 4049 4052 AUSTRIA 

Pannonian Basin 

SWITZERLAND 4048 

LIECHTENSTEIN Po Basin

ITALY 4060

Alps Bresse 4051 45°N

Depression 

4054 

MONACO 

Lion-Camargue SAN MARINO 

4056 

Tuscany- Provence Basin Adriatic Basin 

Latium- 4068 4058 

Paola 

4062 

40°N

Tyrrhenian Basin Apulia Platform Corsican- 4069 4059 Sardinian Basins 

4067 

Sicily 

4066 

MALTA 

Pelagian Basin 35°N

2048 

Figure 26. Continued. 

3

Figure 26. Southern Part of Western Europe 91 

entral 

RA 
92 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

250 

200 

150 

100 

50 

0 

0 1,000 2,000 3,000 4,000 5,000 6,000 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

OIL (BBO)

Gas 

) GAS (TCF

4 60 

50 

3 

40 

2 30 

20 

1 

10 

0 0 

0 50 100 150 200 250 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Figure 26. Continued.
 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Italy: 

Adriatic Basin, 4058 ................................... 1980 0 39 0 225 225 

Alps, 4051................................................... 1933 750 1,077 1,078 5,790 6,868 

Pelagian Basin, 2048................................... 1988 0 15 0 0 0 

Po Basin, 4060............................................ 1890 250 320 120 21,111 21,231 

Sicily, 4066 ................................................. 1940 335 504 85 791 876 

Tuscany-Latium-Paola, 4062...................... 1915 0 1 0 1,497 1,497

Total.............................................................................. 1,335 1,956 1,283 29,414 30,697 

Austria: 

Bohemia, 4046............................................ 1930 545 803 1,782 1,313 3,095 

Pannonian Basin, 4048 ............................... 1982 0 0 0 1 1

Total ............................................................................. 545 803 1,782 1,314 3,096 

France: 

Anglo-Paris Basin, 4040............................. 1954 0 297 7 120 127 

Aquitaine Basin, 4045 ................................ 1954 220 375 27 0 27 

Pyrenean Foothills-Ebro Basin, 4044......... 1939 0 118 80 12,153 12,233 

Total ............................................................................. 220 790 114 12,273 12,387 

Spain: 

Iberic Cordillera, 4083................................ 1967 160 299 92 86 178 

Pyrenean Foothills-Ebro Basin, 4044 ......... 1980 0 0 0 525 525 

Total ............................................................................. 160 299 92 611 703 

Portugal: 

Lusitanian Basin, 4074 ............................... 1953 0 0 0 920 920 

Exploration data 

Country 

Italy ........................................
 

Austria....................................
 

France.....................................
 

Spain ......................................
 

Portugal..................................
 

Switzerland ............................
 

Andorra ..................................
 

Liechtenstein..........................
 

Malta ......................................
 

Land area

(mi2

) 

116,305 

32,378 

211,208 

194,897 

35,672 

15,942 

181 

62 

122 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 

 Gas......................................................................... 

Richness total oil discoveries .......... ( total delineated prospective area ) 

224,886 mi2 

45,596 mi2 

5,892 wells 

10 mi2

/well 

3.969 BBO 

49.1 TCF 

0.018 MMBO/mi2

Monaco ..................................
 1 

San Marino.............................
 24 

Gibraltar .................................
 3 

Total ...................................
 606,793 

Figure 26. Southern Part of Western Europe 9 

Figure 26. Continued. 
94	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

Figure	27.	 Map, graphs, and tables of data for oil and gas exploration through 2001 in Eastern Europe. For this figure, the parts mapped 

are Romania, Ukraine, Belarus, Hungary, Albania, Serbia and Montenegro, Croatia, Poland, Czech Republic, Greece, Bulgaria, Slovakia, 

Slovenia, Moldova, Lithuania, Latvia, Bosnia and Herzegovina, Estonia, and Macedonia.

30° 40°

60°

50°

40°

20°E 30°E 40°E

Baltic Shield-Norwegian 

Caledonides

4016

60°N

Fennoscandian BorderDanish-Polish Margin

4022

Baltic Depression 

4021

Russian Craton Margin 1011

Belorussian-Voronezh High Poles Saddle 1012 1004

Pripyat Basin 1010 GermanPolish Dnieper-Donets Basin 1009

Basin 4033

Donbass

Foldbelt North Carpathian 1014 Basin 50°N

Bohemia 4047

4046

Ukrainian Shield

1013

North Crimea Basin Pannonian Basin 1105 4048

Azov-Kuban Transylvania 4057 Basin

1108

Crimea High 

1104 Po Basin Alps 4051 Dobrogean Orogen 4063

4060 Dobrogea Foreland West Black Sea Basin 1103

Adriatic Basin 4064

4058

Thrace/Samsun 40°N

Apulia Platform 2085

Aegean Carpathian-Balkanian 4059 4075 Basin Dinaric

Alps 4061

4071

Mediterranean Basin

2070 Crete 4076

7

10

11

2

15

6

18 20

13 9

16

19

5

3 17

14

4 1 12

8

EXPLANATION 

1 Albania 5 Croatia 9 Hungary 13 Moldova 17 Serbia

2 Belarus 6 Czech Republic 10 Latvia 14 Montenegro 18 Slovakia

3 Bosnia and Herzegovina 7 Estonia 11 Lithuania 15 Poland 19 Slovenia

4 Bulgaria 8 Greece 12 Macedonia 16 Romania 20 Ukraine
Figure 2. Eastern Europe 9 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

300
 

250 

Delineated prospective area 

200 

Explored area 

AREA (THOUSANDS OF SQUARE MILES) 150
 

100
 

50
 

0 

0 1,000 2,000 3,000 4,000 5,000 6,000 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

became part of the delineated prospective area 

YEAR
 

1960 1970 1980 1990 2000
 

14
 200
 

Oil 

150 

Gas 

OIL (BBO)

12
 

10
 

8
 

) 

100
 

6
 

GAS (TCF

4
 

50 

2
 

0 0

0 100 200 300
 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Figure 2. Continued.
 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Oil in Oil in Gas in Gas in Year of large all oil gas Significant petroleum province first fields fields fields fields discovery (MMBO) (MMBO) (BCF) (BCF) 

Romania: 

Carpathian-Balkanian Basin, 4061 ............. 1835 2,575 5,932 4,052 3,307 

Pannonian Basin, 4048................................ 1956 129 389 215 297 

Transylvanian Basin, 4057.......................... 1880 0 1 0 30,877 

Total ........................................................................... 2,704 6,322 4,267 34,481 

Ukraine: 

Azov-Kuban Basin, 1108............................ 1886 0 22 8 662 

Dnieper-Donets Basin, 1009....................... 1936 885 1,538 4,472 63,779 

North Carpathian Basin, 4047..................... 1860 702 1,264 3,172 11,704 

Pannonian Basin, 4048 ............................... 1960 0 0 0 2 

Transylvanian Basin, 4057.......................... 1962 0 0 0 12 

Total ........................................................................... 1,587 2,824 7,652 76,159 

Belarus: 

Pripyat Basin, 1010..................................... 1963 248 910 255 0 

Hungary: 

North Carpathian Basin, 4047..................... 1937 0 11 5 1 

Pannonian Basin, 4048................................ 1936 391 752 3,874 5,727 

Total ........................................................................... 391 763 3,879 5,728 

Albania: 

Adriatic Basin, 4058 ................................... 1918 203 503 860 300 

Serbia: 

Alps, 4051................................................... 1977 0 1 5 5 

Pannonian Basin, 4048................................ 1949 0 376 622 806 

Total ........................................................................... 0 377 627 811 

Croatia: 

Adriatic Basin, 4058 ................................... 1983 0 5 0 0 

Alps, 4051................................................... 1979 0 0 0 5 

Pannonian Basin, 4048................................ 1856 391 817 948 2,092 

Po Basin, 4060 ............................................ 1977 0 0 0 743 

Total ........................................................................... 391 822 948 2,840 

Poland: 

German-Polish Basin, 4033 ........................ 1961 0 120 428 6,771 

North Carpathian Basin, 4047..................... 1853 0 136 96 7,019 

Total ........................................................................... 0 256 524 13,790 

Czech Republic: 

Bohemia, 4046 ............................................ 1920 0 178 374 155 

North Carpathian Basin, 4047 .................... 1908 0 0 0 77 

Total ........................................................................... 0 178 374 232 

Greece: 

Aegean, 4075 .............................................. 1971 120 139 90 52 

Bulgaria: 

Carpathian-Balkanian Basin, 4061 ............. 1949 0 46 43 158 

Slovakia: 

Bohemia, 4046 ............................................ 1913 0 55 163 939 

North Carpathian Basin, 4047..................... 1850 0 0 0 311 

Pannonian Basin, 4048................................ 1958 0 0 0 53 

Total ........................................................................... 0 55 163 1,303 

Slovenia: 

Pannonian Basin, 4048................................ 1942 0 6 23 32 

Moldova: 

Carpathian-Balkanian Basin, 4061 ............. 1957 0 3 0 0 

Gas in

all

fields

(BCF) 

7,359 

512 

30,877 

38,748 

670 

68,251 

14,876 

2 

 12

83,811 

255 

6 

9,601 

9,607 

1,160 

10 

1,428 

1,438 

0 

5 

3,040 

 743

3,788 

7,199 

7,115 

14,314 

529 

 77

606 

142 

201 

1,102 

311 

 53

1,466 

55 

0 

Figure 2. Continued. 

96 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
Exploration data 

Country 

Romania ................................. 

Ukraine................................... 

Belarus ................................... 

Hungary.................................. 

Albania................................... 

Serbia and Montenegro* ........ 

Croatia.................................... 

Poland .................................... 

Czech Republic ...................... 

Land area

(mi2

) 

91,699 

233,089 

80,154 

35,919 

11,100 

39,517 

21,831 

120,728 

30,450 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 

 Gas......................................................................... 

Richness total oil discoveries .......... 0.050 MMBO/mi2

 ( ) total delineated prospective area 

256,378 mi2 

59,730 mi2 

5,153 wells 

20 mi2

/well 

12.898 BBO 

155.707 TCF 

Greece .................................... 50,942 

Bulgaria.................................. 42,822 

Slovakia.................................. 18,859 

Slovenia.................................. 7,820 

Moldova ................................. 13,067 

Lithuania ................................ 25,174 

Latvia ..................................... 24,938 

Bosnia and Herzegovina ........ 19,741 

Estonia.................................... 17,462 

Macedonia.............................. 9,781 

Total ................................... 

*Montenegro became independent 

895,093 

on June 3, 2006, and is shown separately on the map in figure 27. The data for Serbia and Montenegro are com

bined in the tables because they were combined in IHS Energy Group (2002). 

Figure 2. Continued. 

Figure 2. Eastern Europe 9 

­
30°E 35°E 40°E 

Black Sea Deep-Water Basin Black Sea 1102 

Continental Slope 

1107 

Black Sea 

Continental 

Slope 

1107 

Thrace/Samsun 

2085 Lesser Caucasus 

2081 

40°N Tuz/Corum 

2083 

Kardiff/Menders Zagros Massif 

Thrust Zone 

Aegean 2084 2031 

4075 TURKEY 

Euphrates/ 

Mardin 

2075 

Adana/Sivas Haleb 

2079 2076 

35°N CYPRUS 

Crete
 

4076
 

Figure 2. Map, graphs, and tables of data for oil and gas exploration through 2001 in Turkey and Cyprus. 
Growth in delineated prospective area and explored 

area through 2001, graphed by the year the areasbecame prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

35 

AREA (THOUSANDS OF SQUARE MILES) 30 Delineated prospective area 10 Explored area 25 20 15 5 

0 

0 200 400 600 800 1,000 1,200 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provincesthrough 2001, graphed by the year the field locationbecame part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

1,000 

Oil 

OIL (MMBO) Gas 

1,200 1,000 

800 600 400 200 

0 

800 600 

) 

400 

GAS (BCF

200 0 

0 5 10 15 20 25 30 35 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recovera

oil and gas discovered through 2001

Oil in Oil in Ga

Year of large all 

Significant petroleum province first fields fields fi

discovery (MMBO) (MMBO) (B

Turkey: 

Aegean, 4075 ......................................... 1988 0 0 Euphrates/Mardin, 2075......................... 1958 0 284 1Zagros Fold Belt, 2030 .......................... 1945 185 565 

Total ................................................................ 185 849 1

Exploration data 

Delineated prospective area through 200

Land area

Country Explored area through 2001...................

(mi 2) Wildcat wells through 2001 ...................

Turkey .............................. 301,382 Current growth in delineated prospectivCyprus.............................. 3,571 per wildcat (for last 10 percent of wel

Total ............................. 304,954
 Reported discoveries through 2001 of cu

recoverable crude oil and gas in all pr

Oil................................................Gas...............................................

Richness total oil discoveries 

( total delineated prospective a

Figure 2. Continued. 
100	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

Figure	29.  Map, graphs, and tables of data for oil and gas exploration through 2001 in the Arabian Peninsula. For this figure, the 

parts mapped are Saudi Arabia, Kuwait, United Arab Emirates, 

Oman, Qatar, Yemen, and Bahrain. Outlines of the seven individual 

emirates of the United Arab Emirates (UAE) are not shown on the 

map, but significant provinces are listed for six of them; the seven 

are Abu Dhabi, Dubai, Sharjah, Ra's al Khaymah, Umm al Qaywayn, 'Ajman, and Al Fujayrah. The former Kuwait-Saudi Arabia 

Neutral Zone contains resources according to the IHS Energy 

Group (2002), and so it is listed in the significant provinces table, 

but it is not mapped because it is not mentioned in “The World 

Factbook 2001” (CIA, 2001).

40°E 50°E

30°N

20°N

10°N

North Harrah 

Volcanics 

2027

Sinai

Basin

2033

Jafr-Tabuk Basin 

2026

South Harrah 

Volcanics 

2034

Arabian Shield 

2101

Arabian

Shield

2101

Yemen Volcanic 

Basin (North) 

2001

Hays

Structural

Belt

2003

Yemen Volcanic 

Basin (South) 

2002 Mukalla Rift Basin 

2005

Ma'Rib-Al Jawf/ 

Masila Basin 

2004

Red Sea 

Basin

2071

Hail-Ga'Ara

Arch

2025

Rutbah

Uplift

2028

Widyan BasinInterior Platform 

2023

Mesopotamian

Foredeep Basin 

2024

Interior HomoclineCentral Arch

2020

Rub Al Khali Basin

2019

Shabwah Basin 

2006

Somali

Deep Sea 

7263

Sharmah Rift Basin 

2007

Masila-Jeza

Basin

2009

Greater Ghawar 

Uplift

2021

Qatar Arch

2022

Gulf of Oman 

Basin 2018

Mirbat

Precambrian

Basement

2102 East Flank 

Oman

Sub-basin

2012

Masirah

Trough 

2008

Ghudun-Khasfeh

Flank Province 

2010

South Oman Salt Basin 

2011

Huqf-Haushi

Uplift

2013

Ghaba Salt Basin 

2014

Fahud Salt Basin 

2016

Central Oman Platform 

2015

Oman

Mountains

2017

Wadi-Surhan 

Basin

2029

QATAR

KUWAIT

BAHRAIN

OMAN YEMEN

UNITED

ARAB

EMIRATES

SAUDI ARABIA
Figure 29. Arabian Peninsula 101 

Growth in delineated prospective area and explored 

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

160
 

140 

Delineated prospective area 

120 

100 

80 

60 

40 

Explored area 

20 

AREA (THOUSANDS OF SQUARE MILES)

0 

0 200 400 600 800 1,000 1,200 1,400 1,600
 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

became part of the delineated prospective area 

YEAR
 

1960 1970 1980 1990 2000
 

600
 1,400

Oil 

Gas 

OIL (BBO)

1,200 500
 

1,000 

400
 

800 

) 

300
 

600 

GAS (TCF

200
 

400 

100
 200 

0 0
 

0 20 40 60 80 100 120 140 160
 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Figure 29. Continued. 
 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Oil in Oil in Gas in Gas in Year of large all oil gas Significant petroleum province first fields fields fields fields discovery (MMBO) (MMBO) (BCF) (BCF) 

Gas in

all

fields

(BCF) 

Saudi Arabia: 

Greater Ghawar Uplift, 2021 ...................... 1938 140,850 140,850 233,000 3,400 236,400 

Interior Homocline-Central Arch, 2020...... 1989 5,500 5,525 11,150 6,050 17,200 

Mesopotamian Foredeep Basin, 2024......... 1940 118,800 118,891 66,493 0 66,493 

Red Sea Basin, 2071 ................................... 1969 0 60 0 1,550 1,550 

Rub Al Khali Basin, 2019........................... 1967 15,950 15,987 26,500 6,000 32,500 

Widyan Basin-Interior Platform, 2023........ 1957 15,914 15,980 8,990 3,000 11,990 

Total .......................................................................... 297,014 297,293 346,133 20,000 366,133 

Kuwait: 

Mesopotamian Foredeep Basin, 2024......... 1938 85,198 85,248 60,135 0 60,135 

UAE - Abu Dhabi: 

Rub Al Khali Basin, 2019........................... 1954 70,105 71,728 137,595 5,415 143,010 

UAE - Dubai: 

Rub Al Khali Basin, 2019........................... 1966 4,060 4,130 2,460 4,000 6,460 

UAE - Sharjah: 

Rub Al Khali Basin, 2019........................... 1972 110 110 900 5,900 6,800 

UAE - Ra's al Khaymah: 

Rub Al Khali Basin, 2019........................... 1972 0 56 500 135 635 

UAE - Umm al Qaywayn: 

Rub Al Khali Basin, 2019........................... 1976 0 0 0 100 100 

UAE - 'Ajman: 

Rub Al Khali Basin, 2019........................... 1983 0 0 0 1 1 

Former Kuwait-Saudi Arabia 

Neutral Zone: 

Mesopotamian Foredeep Basin, 2024......... 1953 12,375 12,560 12,470 0 12,470 

Oman: 

Central Oman Platform, 2015 ..................... 1971 0 125 120 7,627 7,747 

East Flank Oman Sub-basin, 2012.............. 1973 1,351 2,334 46 0 46 

Fahud Salt Basin, 2016 ............................... 1962 4,460 4,661 6,500 4,058 10,558 

Ghaba Salt Basin, 2014............................... 1964 601 1,323 2,460 16,826 19,286 

Rub Al Khali Basin, 2019........................... 1969 719 1,063 1,060 1,714 2,774 

South Oman Salt Basin, 2011 ..................... 1956 1,626 2,805 858 30 888

Total .......................................................................... 8,757 12,311 11,044 30,255 41,299 

Qatar: 

Greater Ghawar Uplift, 2021 ...................... 1940 5,300 5,300 10,800 0 10,800 

Qatar Arch, 2022......................................... 1971 815 835 1,000 350,000 351,000 

Rub Al Khali Basin, 2019........................... 1960 4,187 4,327 10,907 0 10,907

Total .......................................................................... 10,302 10,462 22,707 350,000 372,707 

Yemen: 

Ma'Rib-Al Jawf/Masila Basin, 2004........... 1984 1,146 1,315 6,301 11,586 17,887 

Masila-Jeza Basin, 2009 ............................. 1991 854 1,233 6 65 71

Total ........................................................................... 2,000 2,548 6,307 11,651 17,958 

Bahrain: 

Greater Ghawar Uplift, 2021 ...................... 1932 1,050 1,050 12,500 0 12,500 

Figure 29. Continued. 

102 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
Exploration data 

Country Land area

(mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

148,008 mi2 

23,425 mi2 

Saudi Arabia........................... 756,981 Wildcat wells through 2001 ............................................. 1,512 wells 

Kuwait.................................... 6,880 Current growth in delineated prospective area 

United Arab Emirates ............ 32,000 per wildcat (for last 10 percent of wells) ..................... 66 mi2

/well 

Oman...................................... 82,031 Reported discoveries through 2001 of cumulative 

Qatar....................................... 4,416 recoverable crude oil and gas in all provinces: 

Yemen .................................... 203,849 Oil.......................................................................... 497.533 BBO 

Bahrain................................... 239 Gas......................................................................... 1,041.381 TCF 

Total ................................... 1,086,397 Richness total oil discoveries .......... total delineated prospective area ( ) 3.362 MMBO/mi2

Figure 29. Continued. 

Figure 29. Arabian Peninsula 10 
35°E 40°E

Zagros Fold Belt 

2030 

Adana/Sivas 

2079 

Euphrates/Mardin 

2075 

Haleb 

2076 

Khleisha 

Uplift 

Beirut 2074 

2078 35°N

Palmyra 

Zone 

2077 Anah Graben 

LEBANON 2089 

Levantine SYRIA Widyan Basin-Interior Basin Platform 2032 2023 

Wadi-Surhan Basin 

WEST 2029 

BANK North Harrah 

Volcanics 

GAZA 2027 

STRIP 

JORDAN 

ISRAEL 

30°N

Sinai Basin Jafr-Tabuk 

2033 Basin 

2026 

Figure 0. Map, graphs, and tables of data for oil and gas exploration through 2001 in Syria, Israel, Jordan, Lebanon, Gaza Strip, and 

the West Bank. 

10 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
Growth in delineated prospective area and explored 

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

40 

30 

20 

10 

0 

0 100 200 300 400 500 600 700 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

Gas 

OIL (BBO)

) GAS (TCF

6 12 

5 10 

4 8 

3 6 

2 4 

1 2 

0 0 

0 10 20 30 40 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Syria: 

Anah Graben, 2089 ..................................... 1982 351 456 148 0 148 


Euphrates/Mardin, 2075.............................. 1940 365 802 1,421 1,212 2,633 


Khleisha Uplift, 2074.................................. 1986 1,022 1,680 1,364 0 1,364 


Zagros Fold Belt, 2030 ............................... 1956 2,099 2,206 912 74 986 


Total ............................................................................. 3,837 5,144 3,845 1,286 5,131 


Israel: 

Levantine Basin, 2032................................. 1955 0 23 0 3,510 3,510 


 

Exploration data 

Country 

Syria ................................ 

Israel................................ 

Jordan.............................. 

Lebanon........................... 

Gaza Strip........................ 

West Bank ....................... 

Total............................ 

Land area

(mi2

) 

71,498
 

8,019
 

35,637
 

4,015
 

139
 

 2,263
 

121,571
 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 

 Gas......................................................................... 

Richness total oil discoveries .......... ( ) total delineated prospective area 

33,118 mi2 

5,169 mi2 

679 wells 

22 mi2

/well 

5.326 BBO 

9.057 TCF 

0.161 MMBO/mi2

Figure 0. Syria, Israel, Jordan, Lebanon, Gaza Strip, and the West Bank 10 

Figure 0. Continued. 
 

40°E 45°E

Zagros Fold Belt 

2030 

Euphrates/ 

Mardin 

2075 

Khleisha Uplift 

2074 

35°N

Zagros Thrust Zone 

2031 

Wadi-Surhan 

Basin 

2029 Anah Graben 

2089 Mesopotamian Foredeep 

Basin 

2024 

Rutbah Uplift 

2028 IRAQ 

Widyan Basin-Interior 

Platform 

2023 

Hail-Ga'Ara Arch 

2025 

30°N

Figure 1. Map, graphs, and tables of data for oil and gas exploration through 2001 in Iraq. 

106 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

20 

15 

10 

5 

0 

0 50 100 150

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

OIL (BBO)

Gas 

) GAS (TCF

140 140 

120 120 

100 100 

80 80 

60 60 

40 40 

20 20 

0 0 

0 5 10 15 20 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Iraq: 

Mesopotamian Foredeep Basin, 2024......... 1949 87,985 88,875 58,645 3,300 61,945 


Widyan Basin-Interior Platform, 2023........ 1938 1,695 1,815 210 2,500 2,710 


Zagros Fold Belt, 2030 ............................... 1905 30,199 31,015 30,697 9,100 39,797 


Total ............................................................................. 119,879 121,705 89,552 14,900 104,452 


Exploration data 

Land area Delineated prospective area through 2001....................... 18,647 mi2 

Country (mi2

) Explored area through 2001............................................. 2,894 mi2 

Iraq ......................................... 168,754 Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

147 wells 

per wildcat (for last 10 percent of wells) ..................... 124 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 121.705 BBO 

 Gas......................................................................... 104.452 TCF 

Richness ( total oil discoveries ) .......... total delineated prospective area 

6.527 MMBO/mi2

Figure 1. Iraq 10 

Figure 1. Continued. 
50°E 60°E

Kura Basin 

40°N 1113 

Amu-Darya Basin Araks 1154 2080 South Caspian Basin 

1112 Lesser Caucasus Kopet-Dag Foldbelt 

2081 1155 

Alborz Fold Belt Central Iranian Basins 

2094 2091 Zagros Fold 

Belt 

2030 

IRAN 

Central Iranian 

Microcontinents 

2092 Mesopotamian Zagros Thrust 

Foredeep Basin Zone Lut Block and Baluchistan 

2024 2031 Depression 8022 

2093 

30°N

Qatar 

Arch 

2022 Makran 

8021 

Rub Al Khali 

Basin 

2019 

Figure 2. Map, graphs, and tables of data for oil and gas exploration through 2001 in Iran. 

10 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

60 

50 

40 

30 

20 

10 

0 

0 100 200 300 400 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

OIL (BBO)

) GAS (TCF

Gas 

140 1,200 

120 1,000 

100 

800 

80 

600 

60 

400 

40 

200 20 

0 0 

0 10 20 30 40 50 60 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Iran: 

Amu-Darya Basin, 1154 ............................. 1968 0 0 0 13,990 13,990 

Kura Basin, 1113 ........................................ 1967 0 1 0 0 0 

Mesopotamian Foredeep Basin, 2024......... 1960 20,566 20,884 23,559 70,850 94,409 

Qatar Arch, 2022......................................... 1967 0 1,400 0 475,000 475,000 

Rub Al Khali Basin, 2019........................... 1965 3,883 3,883 6,768 2,045 8,813 

South Caspian Basin, 1112 ......................... 1960 0 0 0 700 700 

Zagros Fold Belt, 2030 ............................... 1908 100,729 103,382 264,050 180,543 444,593 

Total .......................................................................... 125,178 129,550 294,377 743,128 1,037,505 

Exploration data 

Country 

Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

52,639 mi2 

6,277 mi2 

Iran ......................................... 636,293 Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

384 wells 

per wildcat (for last 10 percent of wells) ..................... 253 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 129.561 BBO 

 Gas......................................................................... 1,038.260 TCF 

Richness ( total oil discoveries ) .......... total delineated prospective area 

2.461 MMBO/mi2

Figure 2. Iran 109 

Figure 2. Continued. 
15°W 10°W 5°W 0° 15°N 10°N 5°N 

oltaV 

Gulf of Guinea

7183

7114

GHANA

ogo, Senegal, T

est African Shield

COTE

7021

D’IVOIRE

W

Taoudeni Basin

7035

LIBERIA

THE

GAMBIA

GUINEA

SIERRA

LEONE

Senegal

7013

SENEGAL

Baffa

7105

est W

African

Coastal

7173

erde (not mapped).

GUINEABISSAU

		33.Figure Map, graphs, and tables of data for oil and gas exploration through 2001 in Cote d’Ivoire, Ghana, Benin, Guinea-Bissau, T

Leone, Liberia, and Cape V
Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areasbecame prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

12 10 

Delineated prospective area 

8 

Explored area 

AREA (THOUSANDS OF SQUARE MILES) 6 4 2 

0 

0 50 100 150 200 250 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

through 2001, graphed by the year the field location became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

700
 3 

Gas Oil 

600 500 

2 

O) B400 M(MOIL 300 

GAS (TCF) 

1
 

200
 100 

0 0
 

0 2 4 6 8
 10 12 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable 

oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas 

o

fie

(BC

Cote d’Ivoire: Gulf of Guinea, 7183 ...................... Ghana: 

1972 350 472 63

Gulf of Guinea, 7183 ...................... 1970 0 100 24Benin:Gulf of Guinea, 7183 ...................... 1968 0 41 8Guinea-Bissau: Senegal, 7013.................................. Togo: Gulf of Guinea, 7183 ...................... 

1967 1970 

0 0 

10 

3 

Senegal: Senegal, 7013.................................. 1959 0 0 

Exploration data 

Country 

Cote d’Ivoire .................... Ghana ............................... 

Benin................................ 

Guinea-Bissau.................. Togo ................................. Senegal............................. The Gambia...................... Guinea.............................. Sierra Leone..................... 

Land area

(mi 2) 

124,502
 

92,100
 43,483
 13,946
 21,925
75,749
 

4,363


94,925
 27,699


Delineated prospective area through 200

Explored area through 2001....................

Wildcat wells through 2001 ....................Current growth in delineated prospective 

per wildcat (for last 10 percent of well

Reported discoveries through 2001 of cu

recoverable crude oil and gas in all pro

Oil.................................................

Gas................................................

Richness total oil discoveries 

( 

 total delineated prospective a

Liberia.............................. 43,000
Cape Verde (not shown 

on map) ......................... 1,557 

Total............................ 543,249
 

Figure . Continued. 
 

35°E 40°E 45°E 50°E

South Red 

Sea Shield 

7091 

ERITREA Red Sea Basin 

2071 15°N

Amhara Plateau 

7161 

DJIBOUTI 

10°N

Sud 

7146 ETHIOPIA SOMALIA 

Somali 

Deep Sea 

7263 

5°N

Somali 

7255 

KENYA 

0°

East African Rift 

7246 

Tanzania Coastal 

7273 

Figure . Map, graphs, and tables of data for oil and gas exploration through 2001 in Ethiopia, Somalia, Eritrea, Kenya, and Djibouti. 

112 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area

6 

5 

4 

3 

2 

1 

0 

0 20 40 60 80 100 120 140 160 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable gas discoveries in all provinces

 through 2001, graphed by the year the field location

became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000

Gas 

5 

4 

3 

) 

2 

GAS (TCF

1 

0 

0 1 2 3 4 5 6 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in 

all 

fields 

(BCF) 

Ethiopia: 

Somali, 7255 ............................................... 1973 0 0 0 2,401 2,401 

Somalia: 

Somali, 7255............................................... 1959 0 0 0 2,000 2,000 

Eritrea: 

Red Sea Basin, 2071................................... 1970 0 0 0 5 5 

 

Exploration data 

Country 

Ethiopia.................................. 

Somalia .................................. 

Eritrea..................................... 

Kenya ..................................... 

Djibouti .................................. 

Total ................................... 

Land area

(mi2

) 

435,184
 

246,200
 

46,842
 

224,961
 

 8,494
 

961,681
 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 

 Gas......................................................................... 

5,680 mi2 

682 mi2 

146 wells 

17 mi2

/well 

0 

4.406 TCF 

Figure . Ethiopia, Somalia, Eritrea, Kenya, and Djibouti 11 

Figure . Continued. 
 

15°E 20°E

5°S

Zaire 

7225 

West Zaire 

Precambrian Belt 

7211 

East Zaire 

Precambrian Belt 

7231 

10°S

West-Central 

Coastal 

7203 

ANGOLA 

Luffillian 

Arch 

7291 

Etosha 

7285 

15°S

Damer Belt 

7311 

Figure . Map, graphs, and tables of data for oil and gas exploration through 2001 in Angola. 

11 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

30 

AREA (THOUSANDS OF SQUARE MILES) 25 

Delineated prospective area 

20 

15 

10 

Explored area 

5 

0 0 100 200 300 400 500 600 700 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

20 20 

15 15 

OIL (BBO)

) 

10 Gas 10 

GAS (TCF

Oil 5 5 

0 0 

0 5 10 15 20 25 30 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum province—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Angola: 

West-Central Coastal, 7203......................... 1955 14,307 16,977 14,300 1,336 15,636 


Exploration data 

Country 

Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

28,581 mi2 

6,144 mi2 

Angola.................................... 481,351 Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

601 wells 

per wildcat (for last 10 percent of wells) ..................... 89 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 16.977 BBO 

 Gas......................................................................... 15.636 TCF 

Richness ( total oil discoveries ) .......... total delineated prospective area 

0.594 MMBO/mi2

Figure . Angola 11 

Figure . Continued. 
5°E 10°E

Iullemmeden 

7055 

Chad 

7066 

Nigerian Massive 

7121 

NIGERIA 

10°N

Benue 

7136 

Gulf of Guinea 

7183 

West Zaire 

Precambrian Belt 

7211 

5°N

Niger Delta 

7192 

Figure 6. Map, graphs, and tables of data for oil and gas exploration through 2001 in Nigeria. 

116 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

60
 

Delineated prospective area 

40 

30 

20 

Explored area 

AREA (THOUSANDS OF SQUARE MILES)

50 

10 

0 

0 200 400 600 800 1,000 1,200 1,400 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

became part of the delineated prospective area 

YEAR
 

1960 1970 1980 1990 2000
 

50 250

Oil 

150 

OIL (BBO)

Gas 

40 200

30 

) 

20 100

GAS (TCF

10 50

0 0

0 10 20 30 40 50 60 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in 

all 

fields 

(BCF) 

Nigeria: 

Benue, 7136 ................................................ 1953 0 5 35 1,230 1,265 

Gulf of Guinea, 7183 .................................. 1981 0 35 10 1,000 1,010 

Niger Delta, 7192........................................ 1954 40,174 49,369 128,272 56,877 185,149 

Total ............................................................................. 40,174 49,409 128,317 59,107 187,424 

Exploration data 

Country 

Land area

(mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

51,649 mi2 

14,567 mi2 

Nigeria.................................... 356,667
 Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

1,279 wells 

per wildcat (for last 10 percent of wells) ..................... 81 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 49.409 BBO 

 Gas......................................................................... 187.424 TCF 

Richness total oil discoveries .......... ( ) total delineated prospective area 0.957 MMBO/mi2

Figure 6. Nigeria 11 

Figure 6. Continued. 
10°E 15°E 20°E 25°E

Tellian Foredeep 

2052 

Tellian 

Uplift 

2050 Sicily 

4066 

Atlas 

Uplift 

35°N 2053 Pelagian 

Basin 

2048 Cyrenacia Uplift 

2040 

Nefusn Uplift 

2049 

TUNISIA 

Trias/ 

Ghadames 

Basin Hamra Basin 

2054 Cyrenacia Basin 2047 

2041 

30°N

Illizi Basin Fezzan Uplift 

2056 2046 

LIBYA 

Sirte Basin 

2043 

25°N

Murzuk Basin 

2045 

Thiemboka Uplift 

2057 

Erdis Kufra 

7075 

Nubian Uplift 

2044 

20°N

Figure . Map, graphs, and tables of data for oil and gas exploration through 2001 in Libya and Tunisia. 

11 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

200 

150 

100 

50 

0 

0 500 1,000 1,500 2,000 2,500 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

OIL (BBO)

Gas 

) GAS (TCF

60 100 

50 80 

40 

60 

30 

40 

20 

20 

10 

0 0 

0 50 100 150 200 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in 

all 

fields 

(BCF) 

Libya: 

Hamra Basin, 2047 ..................................... 1957 150 809 121 1,514 1,635 

Illizi Basin, 2056 ........................................ 1964 213 213 3,340 1,600 4,940 

Murzuk Basin, 2045 ................................... 1978 1,805 2,174 433 0 433 

Pelagian Basin, 2048 .................................. 1959 1,585 1,840 12,831 22,295 35,126 

Sirte Basin, 2043 ........................................ 1958 40,919 44,927 31,867 15,910 47,777 

Trias/Ghadames Basin, 2054...................... 1961 0 254 170 45 215 

Total ......................................................................... 44,672 50,217 48,762 41,364 90,126 

Tunisia: 

Pelagian Basin, 2048................................... 1949 350 870 880 2,138 3,018 

Trias/Ghadames Basin, 2054 ...................... 1964 750 848 1,354 253 1,607 

Total ......................................................................... 1,100 1,718 2,234 2,391 4,625 

Exploration data 

Country 

Land area

 (mi2

) Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

190,467 mi2 

27,801 mi2 

Libya ...................................... 679,359 Wildcat wells through 2001 ............................................. 2,233 wells 

Tunisia.................................... 63,170 Current growth in delineated prospective area 

Total ............................... 742,529 per wildcat (for last 10 percent of wells) ..................... 66 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 51.960 BBO 

 Gas......................................................................... 94.807 TCF 

Richness ( total oil discoveries ) .......... total delineated prospective area 

0.273 MMBO/mi2

Figure . Libya and Tunisia 119 

Figure . Continued. 
10°W 0° 10°E

Tellian Foredeep 

2052 

40°N

Guercif Basin Tellian Uplift 2069 2050 Rif Basin 

2072 

Atlas Basin 

2062 Atlas Uplift 

2053 

Hauts Basin Essaouni Basin 2051 

2064 MOROCCO Trias/Ghadames 

Basin 

2054 

Grand Erg/Ahnet Basin 

2058 Ougarta Uplift 30°N 2061 

Tindouf Basin Reggane Basin
 

2067 2060
 

Illizi Basin 

2056 Murzuk 

Reguibate Uplift Basin 

2068 2045 

Thiemboka Uplift 

ALGERIA 2057

Hoggar 

7041 

Aaiun-Tarfaya 


Basin
 

2066
 

20°N

Taoudeni Basin 

7035 Chad 

7066 

Iullemmeden 

7055 

Figure . Map, graphs, and tables of data for oil and gas exploration through 2001 in Algeria and Morocco. 

120 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored 

area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

150 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

100 

50 

Explored area 

0 

0 500 1,000 1,500 2,000 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

25 250 

Oil 20 200 

Gas 

OIL (BBO)15 150 

) 

10 100 

GAS (TCF

5 50 

0 0 

0 50 100 150 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in 

all 

fields 

(BCF) 

Algeria: 

Grand Erg/Ahnet Basin, 2058..................... 1954 325 608 566 116,175 116,741 

Illizi Basin, 2056......................................... 1956 3,270 4,383 16,335 19,937 36,272 

Trias/Ghadames Basin, 2054 ...................... 1956 17,917 19,609 23,985 15,597 39,582 

Total ............................................................................. 21,512 24,600 40,886 151,709 192,595 

Exploration data 

Country 

Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

140,790 mi2 

20,219 mi2 

Algeria.................................... 

Morocco ................................. 

Total ................................... 

919,591 

 172,413 

1,092,004 

Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

Reported discoveries through 2001 of cumulative 

1,711 wells 

96 mi2

/well 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 24.688 BBO 

 Gas......................................................................... 193.52 TCF 

Richness( total oil discoveries ) ....... total delineated prospective area 

0.175 MMBO/mi2

Figure . Algeria and Morocco 121 

Figure . Continued. 
25°E 30°E 35°E

Cyrenacia Uplift 

2040 Nile Delta 

Basin 

2035 Levantine Basin 

2032 

North Egypt Basin 

2039 

30°N

Sinai Basin 

2033 

Arabian 

Shield Abu Gharadiq 2101 

Basin Syrian Arch 

2038 2036 

Arabian 

Cyrenacia Shield 

Basin 2101 

2041 

EGYPT 

25°N

Erdis Kufra Red Sea 

7075 Basin 

2071 

Upper Egypt Basin 

2037 

North Red 

Sea Shield 

2073 

Figure 9. Map, graphs, and tables of data for oil and gas exploration through 2001 in Egypt. 

122 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

70 

60 

50 

40 

30 

20 

10 

0 

0 200 400 600 800 1,000 1,200 1,400 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

OIL (BBO)

) GAS (TCF

Gas 

12 70 

60 10 

50 

8 

40 

6 

30 

4 

20 

2 10 

0 0 

0 10 20 30 40 50 60 70 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Egypt: 

Abu Gharadiq Basin, 2038.......................... 1968 114 540 1,632 2,908 4,540 

Levantine Basin, 2032................................. 1975 0 20 13 2,723 2,736 

Nile Delta Basin, 2035................................ 1966 0 2 0 42,775 42,775 

North Egypt Basin, 2039............................. 1966 0 727 912 5,484 6,396 

Red Sea Basin, 2071 ................................... 1907 8,502 10,014 5,270 1,105 6,375 

Total ............................................................................. 8,616 11,303 7,827 54,995 62,822 

Exploration data 

Country 

Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

61,775 mi2 

11,688 mi2 

Egypt...................................... 386,660 Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

1,386 wells 

per wildcat (for last 10 percent of wells) ..................... 36 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 11.425 BBO 

 Gas......................................................................... 62.827 TCF 

Richness total oil discoveries ) .......... total delineated prospective area ( 0.185 MMBO/mi2 

Figure 9. Egypt 12 

Figure 9. Continued. 
124	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

25°E 30°E 35°E 40°E 45°E

5°S

10°S

15°S

20°S

25°S

RWANDA

BURUNDI

TANZANIA

Tanzania Coastal

East African Rift 7273

7246

MALAWI

MOZAMBIQUE

East Kalahari 

Precambrian

Belt

7331

Kalahari

7325 Mozambique

Coastal

7343

Figure	40.  Map, graphs, and tables of data for oil and gas exploration through 2001 in Mozambique, Tanzania, Burundi, Malawi, and 

Rwanda.
 

Growth in delineated prospective area and explored 

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

6 

5 

4 

3 

2 

1 

0 

0 10 20 30 40 50 60 70 80 90 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable gas discoveries in all provinces

 through 2001, graphed by the year the field location

became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

) 

Gas 

GAS (TCF

6 

5 

4 

3 

2 

1 

0 

1 2 3 4 5 6 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Mozambique: 

Mozambique Coastal, 7343 ........................ 1953 0 0 0 3,712 3,712 

Tanzania: 

Tanzania Coastal, 7273 ............................... 1974 0 0 0 1,765 1,765 

Exploration data 

Country 

Mozambique .......................... 

Tanzania ................................. 

Burundi .................................. 

Malawi ................................... 

Rwanda .................................. 

Total ................................... 

Land area

(mi2

) 

309,494
 

364,898
 

10,745
 

45,745
 

10,169
 

741,052
 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 

 Gas......................................................................... 

5,237 mi2 

815 mi2 

86 wells 

183 mi2

/well 

0 

5.477 TCF 

Figure 0. Mozambique, Tanzania, Burundi, Malawi, and Rwanda 12 

Figure 0. Continued. 
126	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

15°E 20°E 25°E 30°E

15°S

20°S

25°S

30°S

35°S

East African Rift 

Luffillian Arch 7246

7291

West Zaire 

Precambrian Belt

7211 ZAMBIA

Etosha

7285

East Kalahari 

Precambrian

NAMIBIA Belt

7331

ZIMBABWE

Kalahari

Damer Belt 7325

Orange 7311

River BOTSWANA Coastal

7303 Mozambique Coastal

7343

LESOTHO

Karoo

7355 SOUTH

AFRICA

SWAZILAND

South African Coastal

7363

Figure	41.  Map, graphs, and tables of data for oil and gas exploration through 2001 in South Africa, Namibia, Botswana, Lesotho, 

Swaziland, Zambia, and Zimbabwe.
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

20 

15 

10 

5 

0 

0 100 200 300 400

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Gas 

OIL (MMBO)

) 

Oil 

GAS (TCF

150 25 

20 

100 

15 

10 

50 

5 

0 0 

0 5 10 15 20 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in 

all 

fields 

(BCF) 

South Africa: 

Orange River Coastal, 7303 ........................ 1987 0 0 0 815 815 

South African Coastal, 7363....................... 1969 0 119 368 3,402 3,770 

Total ............................................................................. 0 119 368 4,217 4,585 

Namibia: 

Orange River Coastal, 7303 ........................ 1974 0 0 0 20,000 20,000 

Exploration data 

Country 

South Africa........................... 

Namibia.................................. 

Botswana................................ 

Lesotho................................... 

Swaziland............................... 

Zambia ................................... 

Zimbabwe .............................. 

Total ................................... 

Land area

(mi2

) 

471,008 

318,694 

231,803 

11,720 

6,704 

290,585 

 150,803 

1,481,317 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 

 Gas......................................................................... 

Richness total oil discoveries .......... ( total delineated prospective area ) 

19,784 mi2 

3,152 mi2 

345 wells 

22 mi2

/well 

119 MMBO 

24.585 TCF 

0.006 MMBO/mi2

Figure 1. South Africa, Namibia, and Neighboring Countries 12 

Figure 1. Continued. 
 

10°E 15°E 20°E 25°E 30°E

Chad 

7066 

10°N

Sud 

7146 

East African 

Rift 

7246 

Benue CAMEROON CENTRAL AFRICAN 7136 REPUBLIC West Zaire 

5°N Precambrian Belt 

7211 

EQUATORIAL GUINEA 

Niger 

Delta East Zaire 

7192 Precambrian Belt CONGO 7231 (KINSHASA) 

0° GABON 

Zaire 

CONGO 7225 

(BRAZZAVILLE) 

5°S

SAO TOME AND 

PRINCIPE 

10°S

West-Central 

Coastal 

7203 Etosha Luffillian
 

7285 Arch
 

7291
 

Figure 2. Map, graphs, and tables of data for oil and gas exploration through 2001 in Gabon, Republic of the Congo (Brazzaville), Cam

eroon, Equatorial Guinea, Democratic Republic of the Congo (Kinshasa), Central African Republic, and Sao Tome and Principe. 

12 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

­
 

Growth in delineated prospective area and explored 

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

50
 

Delineated prospective area 

Explored area 

AREA (THOUSANDS OF SQUARE MILES) 40 

30 

20 

10 

0 

0 200 400 600 800 1,000 1,200 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000
 

12 20

Oil 

OIL (BBO)

Gas 

10

15 

8 

) 

6 10 

GAS (TCF

4 

5 

2 

0 0

0 10 20 30 40 50 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Year of 

Significant petroleum province first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Gabon: 

West-Central Coastal, 7203......................... 1951 2,596 4,549 1,500 246 1,746 


Republic of the Congo (Brazzaville): 

West-Central Coastal, 7203......................... 1957 2,722 3,414 2,362 775 3,137 


Cameroon: 

Niger Delta, 7192........................................ 1967 445 1,276 1,620 1,674 3,294 


West-Central Coastal, 7203......................... 1954 0 19 43 1,029 1,072
 

Total ............................................................................. 445 1,295 1,663 2,703 4,366 

Equatorial Guinea: 

Niger Delta, 7192........................................ 1984 350 485 178 4,940 5,118 

West-Central Coastal, 7203......................... 1999 650 724 31 0 31

Total ............................................................................. 1,000 1,209 209 4,940 5,149
 

Democratic Republic of the 

Congo (Kinshasa): 

West-Central Coastal, 7203......................... 1964 135 356 93 0 93 


Exploration data 

Country Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

44,866 mi2 

10,527 mi2 

Gabon..................................... 103,346 Wildcat wells through 2001 ............................................. 1,079 wells 

Congo (Brazzaville) ............... 132,046 Current growth in delineated prospective area 

Cameroon............................... 183,568 per wildcat (for last 10 percent of wells) ..................... 42 mi2

/well 

Central African Republic ....... 240,534 Reported discoveries through 2001 of cumulative 

Congo (Kinshasa)................... 905,564 recoverable crude oil and gas in all provinces: 

Equatorial Guinea .................. 10,831 Oil.......................................................................... 10.823 BBO 

Sao Tome and Principe .......... 386 Gas......................................................................... 14.491 TCF 

Total ................................... 1,576,275 Richness total oil discoveries ....... ( ) total delineated prospective area 

0.241 MMBO/mi2

Figure 2. Gabon, Republic of the Congo (Brazzaville), and Neighboring Countries 129 

Figure 2. Continued. 
15°W 0° 15°E 30°E

15°N

0°

North 

S

Kh

Upper Egypt 

Basin

2037

SUDAN

Erdis

estern Nubian 

Shield

7151

7246

Kufra

7075

W

East African Rift

Nubian

Uplift

2044

CHAD

Murzuk

Basin

2045

Chad

7066

Thiemboka

 Uplift

2057

NIGER

Iullemmeden

7055

Hoggar

7041

BURKINA

ASOF

MALI

aoudeni 

Basin

7035

T

2067

est African 

Tindouf Basin

Shield

7021

ANIA

W

Reguibate

Uplift

2068

WESTERNSAHARA

MAURIT

Senegal

7013

-Aaiun

arfaya T

Basin2066

Figure 43. exploration  gasand oil for  dataof tables  andgraphs, Map,  Sudan, in 2001  through Burkina  ,Niger Mauritania,  Chad, 

a

 Uganda, Mali, Faso, 
Significant petroleum provinces—Year of first discovery and cumulative recoverable 

oil and gas discovered through 2001 

Oil in Oil in Gas 

Year of large all oi

Significant petroleum province first fields fields field

discovery (MMBO) (MMBO) (BC

Sudan: Red Sea Basin, 2071 .............................. 1963 0 0 0 Sud, 7146 ............................................... 1979 785 1,511 207 

Total.............................................................. 785 1,511 207 

Chad: Sud, 7146 ............................................... 1975 900 1,053 40 Mauritania: Senegal, 7013......................................... 2001 330 330 0 

Exploration data 

Land area Delineated prospective area through 200

Country (mi2) Explored area through 2001....................

Wildcat wells through 2001 ....................

Sudan................................ 967,494
 Current growth in delineated prospective Chad ................................. 495,753
 per wildcat (for last 10 percent of wel

Mauritania........................ 397,954
 Reported discoveries through 2001 of cuNiger ................................ 489,189 recoverable crude oil and gas in all proBurkina Faso .................... 105,869
 Oil.................................................Mali.................................. 478,764
 Gas................................................Uganda ............................. 91,135
 Richness total oil discoveries 

Western Sahara................. 102,703 ( 

 total delineated prospective a

Total.............................. 3,128,861 

Growth in delineated prospective area and explored 

area through 2001, graphed by the year the areasbecame prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

15 

AREA (THOUSANDS OF SQUARE MILES) 10 5 Delineated prospective area Explored area 

0 

0 100 200 300 400 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

through 2001, graphed by the year the field locationbecame part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

4 2 

3 2 

Gas 

Oil 

0 

0 5 

OIL (BBO)

) 

1

GAS (TCF

1 

0 

10 15 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Figure . Continued. 
132	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

45°E 50°E 55°E 60°E

5°S

10°S

15°S

20°S

25°S

SEYCHELLES

COMOROS Seychelles

7417

Morondava

7373

MADAGASCAR

Madagascar REUNION MAURITIUS 7381

Figure	44.  Map, graphs, and table of data for oil and gas exploration through 2001 in Madagascar, Comoros, Mauritius, Seychelles, and 

Reunion (an overseas department of France).
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

4 

3 

AREA (THOUSANDS OF SQUARE MILES)

Delineated prospective area 

2 

1 

Explored area 

0 

0 20 40 60 80 100 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

80 

60 

Gas 

Oil 

10 100

8

OIL (MMBO) 6 

GAS (BCF) 

4 40 

2 20 

0 

0 1 2 3 4 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Exploration data 

Country Land area

(mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

3,701 mi2 

535 mi2 

Madagascar ............................ 226,656 Wildcat wells through 2001 ............................................. 95 wells 

Comoros................................. 838 Current growth in delineated prospective area 

Mauritius................................ 718 per wildcat (for last 10 percent of wells) ..................... 71 mi2

/well 

Seychelles .............................. 176 Reported discoveries through 2001 of cumulative 

Reunion.................................. 972 recoverable crude oil and gas in all provinces: 

Total ................................... 229,360 Oil.......................................................................... 9 MMBO 

 Gas......................................................................... 83 BCF 

Richness total oil discoveries .......... ( ) total delineated prospective area 0.002 MMBO/mi2

Figure . Madagascar, Comoros, Mauritius, Seychelles, and Reunion 1 

Figure . Continued. 
70°E 80°E 90°E 100°E

Great Lake Uplift Great Lake Basin 3209 Baikal-Patom 3208 Folded Region 

50°N 1230 

Zaysan Basin Altay-Sayan 1170 Folded Region Mongol-Okhotsk 

Alakol Basin 1219 Folded Region 

1169 3202 

MONGOLIA Karamay Thrust Belt 

3116 Bogdashan Fold Belt 

East Ili Basin 3105 

1164 Junggar Basin 

3115 

Tian Shan Foldbelt Turpan Basin 1158 3156 Alashan Yinshan Altunshan Fold Fold Belt 

40°N Belt 

Kumukulig 3101 3102 

Basin Qilianshan 

Kunlunshan 3117 Fold Belt Qaidam Basin Fold Belt Tarim Basin 3134 Jiuquan Minle 3131 3118 3154 Wuwei Basin 

3114 

Qiangtang Terrane Songpan Ganzi Fold Belt 

3133 3143 Qabdu Basin 

Qiangtang Tanggula Basin 3137 

3132 CHINA Longmenshan 

Dabashan Fold Belt 

3168 

Qiangtang 

Cuoqing Lunpola Basin Terrane Lhasa Xichang 30°N 3108 3133 Terrane Yunnan Himalayan 3122 Fold Belt 8002 Lhasa Basin 

3157 3121 

Chuxiong 

Basin 

3107 Sulongshan 

Fold Belt 

3148 

Lanping Simao 

Basin Truong 3119 

20°N Son Fold 

Thailand Tenasserim- Belt 

Mesozoic Shan 3510 

Basin Belt 8006 

3508 

Figure . Map, graphs, and tables of data for oil and gas exploration through 2001 in China and Mongolia. 

1 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

Ulan Bat

Basin 

3210 

Gobi 

Basin 

3204 

Ordos B

3128 

Qinling Dabieshan 

Fold Belt 

3135 

Yunnan 

Guizhou Hub

Fold Belt 

3161 

Yinggehai 

Basin 

3159 
110°E 120°E 130°E

50°N

40°N

30°N

20°N

Mohe Basin Heilongjiang Basin 3165 Sikhote-Alin

3164 Folded Region

Ulan Bator Middle Amur 1224

Ushumun Basin Temtsag Basin Basin 3210 Hailar Basin 1227 3138 3207

Nyalga Basin Yinshan Da and Xiao 

3205 Hingganling Uplift

3160

Yitong Graben Khanka Basin 3169

1226

Songliao Basin Gobi

3144 Basin Suifun

3204 Basin

Erlian Uplift 3166 Zhangguangcailing 1225

Uplift Erlian Basin 3110 3162

Taihangshan Yanshan Fold Belt Yinshan Da and Xiao 

3149 Hingganling Uplift

Ordos Basin 3160

3128 Korean

Craton

Shanxi 3405

Plateau

3140 Bohaiwan

Basin

3127 Luxi Subei Yellow 

Jiaoliao Sea Basin

Uplift 3147

Nanyang Basin 3124

Qinling Dabieshan Taikang Hefei 3126 Fold Belt Basin

3135 3150

East China 

Jianghan Sea Basin

Basin Sichuan 3109

3112 Basin Jiangnan South 3142 Jiangsu Fold Belt South China 3113 Yunnan Fold Belt

Guizhou Hubei 3146

Fold Belt

3161 Sanshui Basin

3139

Nanpanjiang Depression

3125 Leidong Shiwan Dashan Basin Basin

3141 Pearl River Mouth Basin 3120 Yinggehai 3130

Basin Beibuwan Basin

3159 3103

South China Continental Shelf Slope

3181

Xisha Trough

3158

Qiongdongnan Basin

3136

Choybalsan

Basin

3203

Figure 45.  Continued.

E

ngmenshan

shan Fold Belt

3168

Truong

Son Fold 

Belt

3510

Chuxiong

Basin

3107

chang

unnan 

d Belt

3157

Alashan Yinshan 

Fold Belt

3101

Baikal-Patom

Folded Region

1230

 Minle 

Basin

4

MONGOLIA
 

Growth in delineated prospective area and explored 

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

350
 

300 

Delineated prospective area 250 

Explored area 

AREA (THOUSANDS OF SQUARE MILES) 200 

150 

100 

50 

0 

0 500 1,000 1,500 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR
 

1960 1970 1980 1990 2000
 

60 120

100 Oil 

80 

OIL (BBO)

Gas 

50 

40 

) 

30 60 

GAS (TCF

20 40

10 20

0 0

0 5 0 100 150 200 250 300 350 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

China: 

Bohaiwan Basin, 3127 ................................ 1961 13,988 19,326 10,091 7,436 17,527 


Jiuquan Minle Wuwei Basin, 3114 ............. 1939 160 209 1 0 1 


Junggar Basin, 3115.................................... 1897 7,915 8,430 2,500 2,340 4,840 


Luxi Jiaoliao Uplift, 3124........................... 1993 650 774 154 0 154 


Nanyang Basin, 3126 .................................. 1971 600 711 0 0 0 


Ordos Basin, 3128....................................... 1907 640 986 111 14,636 14,747 


Pearl River Mouth Basin, 3130................... 1979 635 1,361 524 1,060 1,584 


Qaidam Basin, 3131.................................... 1955 300 541 229 2,156 2,385 


Sichuan Basin, 3142.................................... 1939 0 246 263 31,652 31,915 


Songliao Basin, 3144 .................................. 1959 14,380 15,637 2,817 1,905 4,722 


South China Continental Shelf
 

Slope, 3181 ............................................. 1984 0 121 205 0 205 


Tarim Basin, 3154....................................... 1918 332 1,523 2,409 14,049 16,458 


Yinggehai Basin, 3159................................ 1983 0 0 0 10,810 10,810
 

Total....................................................................... 39,600 49,865 19,304 86,044 105,348 


16 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

Figure . Continued. 
 

Exploration data 

Country Land area

(mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

307,184 mi2
 

65,488 mi2
 

China............................... 3,705,390
 Wildcat wells through 2001 ............................................. 1,394 wells 

Mongolia ......................... 604,247 Current growth in delineated prospective area 

Total ............................ 4,309,637 per wildcat (for last 10 percent of wells) ..................... 135 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 52.763 BBO 

 Gas......................................................................... 110.696 TCF 

Richness total oil discoveries ....... ( ) total delineated prospective area 

0.172 MMBO/mi2

Figure . Continued. 

Figure . China and Mongolia 1 
40°E 50°E 60°E 

Volga-Ural Region Ural-Novaya 1015 Zemlya Foldbelt Mugodzhary-South 1017 Emba 

1018 

North Caspian 50°N Basin Central Kaza

1016 Folded Re

South Turgay 1168 Basin 

Turgay Depression 1167 

1166 

Great Caucasus 

Foldbelt 

1110 

Ch

Mangyshlak- East Aral North Ustyurt East Aral Slope 

GEORGIA Ustyurt Foldbelt Basin Basin 1178 

1152 1151 1150 

Middle UZBEKISTAN 

Syr-Darya 

Basin Caspian Basin 

1177 

1109 

ARMENIA Karabogaz-Karakum High 

1153 

40°N

Araks 

2080 TAJ

AZERBAIJAN 

Lesser South Caspian 

Caucasus Basin 

2081 1112 Afghan-T

Kura TURKMENISTAN Basin Basin Kopet-Dag Foldbelt Amu-Darya Basin 1156 1113 1155 1154 

Figure 6. Map, graphs, and tables of data for oil and gas exploration through 2001 in Kazakhstan, Azerbaijan, Turkmenistan, Uzbekistan, Georgia, KyArmenia. 
Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

180 

AREA (THOUSANDS OF SQUARE MILES)160 140 120 Delineated prospective area 100 80 60 40 Explored area 20 

0 

0 500 1,000 1,500 2,000 2,500 3,000 3,500 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

OIL (BBO) Gas 

60 50 40 30 20 10 

0 

600 500 400 

) 

300 

(TCFGAS 

200 100 0 

0 20 40 60 80 100 120 140 160 180 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Figure 6. Continued. 
Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Oil in Oil in Gas in Gas in Gas in Year of large all oil gas all Significant petroleum province first fields fields fields fields fields discovery (MMBO) (MMBO) (BCF) (BCF) (BCF) 

Kazakhstan: 

Middle Caspian Basin, 1109 .................. 1961 4,761 5,211 3,980 3,546 7,526 

North Caspian Basin, 1016 .................... 1898 18,565 21,615 39,961 53,667 93,628 

North Ustyurt Basin, 1150 ..................... 1964 2,408 2,588 1,864 1,892 3,756 

South Turgay Basin, 1167...................... 1984 667 1,038 725 18 743 

Volga-Ural Region, 1015 ....................... 1991 0 67 835 2 837 

Total ................................................................... 26,401 30,519 47,365 59,125 106,490 

Azerbaijan: 

Kura Basin, 1113 ................................... 1873 0 155 17 0 17 

Middle Caspian Basin, 1109 .................. 1939 128 143 249 47 296 

South Caspian Basin, 1112 .................... 1869 16,310 17,072 14,642 35,038 49,680 

Total ................................................................... 16,438 17,370 14,908 35,085 49,993 

Turkmenistan: 

Amu-Darya Basin, 1154 ........................ 1959 0 81 360 135,945 136,305 

Middle Caspian Basin, 1109 .................. 1973 0 0 0 4 4 

South Caspian Basin, 1112 .................... 1933 3,421 3,956 11,017 9,948 20,965 

Total ................................................................... 3,421 4,037 11,377 145,897 157,274 

Uzbekistan: 

Afghan-Tajik Basin, 1156 ...................... 1934 0 97 21 4,937 4,958 

Amu-Darya Basin, 1154 ........................ 1953 400 790 5,938 82,609 88,547 

Fergana Basin, 1159............................... 1931 180 513 233 231 464 

Middle Caspian Basin, 1109 .................. 1964 0 0 0 1,600 1,600 

North Ustyurt Basin, 1150 ..................... 1968 0 1 0 366 366 

Total ................................................................... 580 1,401 6,192 89,743 95,935 

Georgia: 

Kura Basin, 1113 ................................... 1869 223 369 198 63 261 

Kyrgyzstan: 

Fergana Basin, 1159............................... 1901 104 229 866 7 873 

Tajikistan: 

Afghan-Tajik Basin, 1156 ...................... 1949 0 51 76 174 250 

Fergana Basin, 1159............................... 1908 0 39 49 245 294 

Total ................................................................... 0 90 125 419 544 

Figure 6. Continued. 
Exploration data

Country

Kazakhstan.......................Azerbaijan........................Turkmenistan...................Uzbekistan........................Georgia.............................Kyrgyzstan.......................Tajikistan..........................Armenia............................

Total............................

Land area 

(mi2)

1,049,151

33,436

188,456172,741

26,91176,64155,251

.. . 11,506

1,614,093

Delineated.prospective.area.through.2001.................... 168,262.mi2

Explored.area.through.2001.......................................... 32,179.mi2Wildcat.wells.through.2001.......................................... 3,237.wells

Current.growth.in.delineated.prospective.area..

per.wildcat.(for.last.10.percent.of.wells).................. 104.mi2/well

Reported.discoveries.through.2001.of.cumulative..

recoverable.crude.oil.and.gas.in.all.provinces:

. Oil....................................................................... 54.065.BBO

.Gas...................................................................... 416.610.TCF

Richness. total.oil.discoveries . .......... 0.321.MMBO/mi2 ( ) .................total.delineated.prospective.area

Figure 46. Continued.
 

65°E 70°E 75°E

40°N

Qiangtang 

Amu-Darya Terrane 

Basin 3133 

1154 

Kopet-Dag Afghan-Tajik Foldbelt 

Basin 1155 1156 

Himalayan 

35°N AFGHANISTAN 8002 

Central Central 

Iranian Afghanistan 

Basins 8023 Southeast 

2091 Afghanistan 

8001 Afghan 

8024 

Kohat-Potwar 

Baluchistan 8026 

8022 Sulaiman-Kirthar 

8025 

30°N

PAKISTAN 

Indus Lut Block and 8042 Depression 

2093 

Makran 

8021 

25°N

Bombay 

8043 

Figure . Map, graphs, and tables of data for oil and gas exploration through 2001 in Pakistan and Afghanistan. 

12 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

40 

30 

20 

10 

0 

0 100 200 300 400 500 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location 

became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Gas 

OIL (MMBO)

) 

Oil 

GAS (TCF

1,000 50 

900 

800 40 

700 

600 30 

500 

400 20 

300 

200 10 

100 

0 0 

0 10 20 30 40 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Year of 

Significant petroleum province first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Pakistan: 

Indus, 8042.................................................. 1957 0 299 328 23,580 23,908 


Sulaiman-Kirthar, 8025............................... 1883 0 0 0 16,399 16,399 


Total .......................................................................... 0 299 328 39,979 40,307 


Afghanistan: 

Afghan-Tajik Basin, 1156........................... 1960 0 7 10 412 422 


Amu-Darya Basin, 1154 ............................. 1959 0 112 100 4,899 4,999 


Total .......................................................................... 0 119 110 5,311 5,421 


Exploration data 

Country Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

35,953 mi2 

5,534 mi2 

Pakistan ........................... 310,402 Wildcat wells through 2001 ............................................. 442 wells 

Afghanistan..................... 250,000 Current growth in delineated prospective area 

Total ............................ 560,402 per wildcat (for last 10 percent of wells) ..................... 115 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 768 MMBO 

 Gas......................................................................... 47.988 TCF 

Richness total oil discoveries ....... ( ) total delineated prospective area 0.021 MMBO/mi2

Figure . Pakistan and Afghanistan 1 

Figure . Continued. 
70°E 80°E 90°E

Kohat-Potwar
 

8026
 

Himalayan
 

8002
 

BHUTAN 

30°N

Indus NEPAL 8042 

Himalayan INDIA Foreland 

8028 Damodar Assam 

8032 8034 

Chindwara 

8030 

Bombay 

8043 

North 

Burma Satpura­ 8035 Brahmani Indian Shield 8031 8003 Ganges- 20°N Brahmaputra Delta 

8047 

Pranhita-Godavari 

8033 Mahanadi 

8046 IndoBurman 

8005 

Krishna-Godavari 

8045 BANGLADESH 

Lakshadweep
 

8062
 

Cauvery Irrawaddy 

8044 8048 

10°N

Sri Konkan North Sumatra

Lanka 8063 SRI Basin

8004 3822 LANKA Maldives
 

8061
 

MALDIVES 

0°

Figure . Map, graphs, and tables of data for oil and gas exploration through 2001 in India, Bangladesh, Bhutan, Maldives, Nepal, and 

Sri Lanka. 

1 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

80 

70 

60 

50 

40 

30 

20 

10 

0 

0 200 400 600 800 1,000 1,200 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

Gas 

OIL (BBO)

) GAS (TCF

11 70 

10 

60 

9 

8 50 

7 

40 6 

5 30 

4 

20 3 

2 10 

1 

0 0 

0 10 20 30 40 50 60 70 80 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

India: 

Assam, 8034................................................ 1867 1,717 2,157 5,286 551 5,837 


Bombay, 8043 ............................................. 1958 6,075 7,325 15,081 12,898 27,979 


Ganges-Brahmaputra Delta, 8047............... 1915 0 1 0 843 843 


Indus, 8042.................................................. 1967 0 40 0 159 159 


Krishna-Godavari, 8045.............................. 1979 223 331 427 3,091 3,518 


Total .......................................................................... 8,015 9,854 20,794 17,542 38,336 


Bangladesh: 

Ganges-Brahmaputra Delta, 8047............... 1923 0 2 0 17,705 17,705 


Exploration data 

Country Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

71,557 mi2 

14,577 mi2 

India ................................ 1,269,340 Wildcat wells through 2001 ............................................. 1,163 wells 

Bangladesh...................... 55,598 Current growth in delineated prospective area 

Bhutan ............................. 18,147 per wildcat (for last 10 percent of wells) ..................... 67 mi2

/well 

Maldives.......................... 116 Reported discoveries through 2001 of cumulative 

Nepal............................... 54,363 recoverable crude oil and gas in all provinces: 

Sri Lanka......................... 25,332 Oil.......................................................................... 9.923 BBO 

Total ............................ 1,422,896 Gas......................................................................... 57.126 TCF 

Richness total oil discoveries .......... ( ) total delineated prospective area 0.139 MMBO/mi2

Figure . India, Bangladesh, Bhutan, Maldives, Nepal, and Sri Lanka 1 

Figure . Continued. 
95°E 100°E 105°E 110°E

Himalayan 

8002 

Assam 

8034 

Sulongshan South China 25°N North Fold Belt Fold Belt Lanping Shiwan Burma 3148 3146 Simao Dashan 8035 Basin Basin 

3119 3141 

Tenasserim- South China Shan Continental 8006 Shelf Slope 

VIETNAM 3181 

BURMA LAOS 

20°N

Truong Son 

Fold Belt 

3510 

GangesBrahmaputra 

Delta 

8047 

Khorat Platform 

3502 

Indo- 15°N

Burman THAILAND 

8005 Yinggehai Tonle 

Thailand Basin Sap-Phnom Mesozoic 3159 Penh Basin 

Basin Belt 3509 

3508 

CAMBODIA 

Central Irrawaddy Vietnam 8048 Basin 

3501 

10°N Saigon
 

Thai Basin
 

Basin 3505
 

Malay 3507 

Peninsula Panjang/
 

3704 Cardomomes
 

Basin
 

North 3504 

Sumatra Malay Mekong Cuulong/ Basin Basin Vung Tau Basin 3822 3703 3503 

Figure 9. Map, graphs, and tables of data for oil and gas exploration through 2001 in Vietnam, Burma, Thailand, Cambodia, and Laos. 

16 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 
 

Growth in delineated prospective area and explored area 

through 2001, graphed by the year the areas became 

prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

MILES) SQUARE 

Delineated prospective area 

OF (THOUSANDS AREA 

Explored area 

60 

50 

40 

30 

20 

10 

0 

0 100 200 300 400 500 600 700 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces 

through 2001, graphed by the year the field location became 

part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

OIL (BBO)

Gas 

) GAS (TCF

4 60 

50 

3 

40 

2 30 

20 

1 

10 

0 

0 10 20 30 40 50 60 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Year of 

Significant petroleum province first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Vietnam: 

Malay Basin, 3703 ...................................... 1994 

Mekong/Cuulong/Vung Tau 

Basin, 3503 ............................................. 1975 

Saigon Basin, 3505 ..................................... 1974 

South China Continental Shelf 

0 

1,710 

111 

82 

2,064 

251 

395 

2,255 

1,110 

1,675 

1,120 

5,872 

2,070 

3,375 

6,982 

Slope, 3181 ............................................. 1991 

Yinggehai Basin, 3159................................ 1975 

Total....................................................................... 

Burma: 

0 

 0 

1,821 

0 

 19 

2,416 

0 

 0 

3,760 

1,500 

1,099 

11,266 

1,500 


1,099 


15,026 


Irrawaddy, 8048 .......................................... 1864 

Thailand: 

649 798 1,226 11,552 12,778 


Malay Basin, 3703 ...................................... 1973 

Thai Basin, 3507 ......................................... 1973 

0 

0 

27 

211 

117 

1,218 

10,347 

14,010 

10,464 


15,228 


Thailand Mesozoic Basin Belt, 3508.......... 1981 240 256 812 20 832 


Total....................................................................... 

Cambodia: 

240 494 2,147 24,377 26,524 


Malay Basin, 3703 ...................................... 1994 0 1 0 75 75 


Exploration data 

Country Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

56,096 mi2 

9,274 mi2 

Vietnam ........................... 

Burma.............................. 

Thailand .......................... 

127,243 

261,969 

198,456 

Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

670 wells 

169 mi2

/well 

Cambodia ........................ 69,900 Reported discoveries through 2001 of cumulative 

Laos................................. 91,429 recoverable crude oil and gas in all provinces: 

Total ............................ 748,997 Oil.......................................................................... 3.794 BBO 

 Gas......................................................................... 56.316 TCF 

Richness total oil discoveries ....... ( ) total delineated prospective area 0.068 MMBO/mi2

Figure 9. Vietnam, Burma, Thailand, Cambodia, and Laos 1 

Figure 9. Continued. 
148	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

125°E 130°E 135°E 140°E

Aniva

Basin

1327

45°N

Ishikari

Hidaka Basin Gensan Basin 3303 Tokachi Basin 3401 3314

Korea Bay Korean Sea of Japan Basin Continental Backarc Basin 3404 NORTH Shelf 3312

3406

40°N KOREA

Akita Korean Niigata Basin Basin Craton 3308 3301 3405 Tottori 

Basin

SOUTH 3315

Huksan

Platform KOREA

Tsushima 3403 Basin Japan Volcanic 3316 Arc/Accreted Terrane

35°N 3304

JAPAN Joban

Basin

Gyeongsang Basin 3305

3402 Honshu

Ridge Kanto

Sinzi Uplift Sagara 3302 Basin

3313 Basin 3306

3311

Miyazaki

Okinawa Basin

Trough 3307

30°N 3309

Ryukyu East China Volcanic Sea Basin Arc 3109

3310

25°N

Figure	50.  Map, graphs, and tables of data for oil and gas exploration through 2001 in Japan, South Korea, and North Korea.
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

14 

12 

10 

8 

6 

4 

2 

0 

0 100 200 300 400 500 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

OIL (MMBO)

Gas 

) GAS (TCF

300 8 

7 

6 

200 

5 

4 

3 

100 

2 

1 

0 0 

0 2 4 6 8 10 12 14 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Year of 

Significant petroleum province first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Japan: 

Japan Volcanic Arc/Accreted 

Terrane, 3304 .......................................... 1870 0 120 87 1,564 1,651 


Kanto Basin, 3306....................................... 1935 0 0 0 1,359 1,359 


Niigata Basin, 3308..................................... 1867 0 86 297 2,373 2,670 


Total....................................................................... 0 206 384 5,296 5,680 


South Korea: 

Japan Volcanic Arc/Accreted 

Terrane, 3304 .......................................... 1987 0 0 0 100 100 

Exploration data 

Country 

Land area

(mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

12,818 mi2 

3,403 mi2 

Japan ...................................... 

South Korea............................ 

North Korea............................ 

Total ................................... 

145,882
 

38,023
 

46,541
 

230,446
 

Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

402 wells 

33 mi2

/well 

 Oil.......................................................................... 261 MMBO 

 Gas......................................................................... 6.057 TCF 

Richness total oil discoveries ....... ( total delineated prospective area ) 0.020 MMBO/mi2

Figure 0. Japan, South Korea, and North Korea 19 

Figure 0. Continued. 
150	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

115°E 120°E 125°E 130°E

East China Sea Basin Okinawa

3109 Trough

3309

Taiwan Thrust 

and Fold Belt Ryukyu 25°N

3151 Volcanic Arc

3310

TAIWAN

Taiwan 

Melange Taixinan Belt Basin 3152 3153

20°N

Bijianan Cagayan

Basin Basin

3180 3602

Philippine

Accretionary

Prism

3607

PHILIPPINES

Zambalez/Central 15°N Luzon Basin Bicol Shelf 

South China 3837 Basin

Continental 3601

Shelf Slope Palawan

3181 Shelf Reed Bank 3605 Basin Philippine

3609 Magmatic Arc

South China 3608

Ocean Basin

3167

Visayan 10°N 3612

Sulu Sea Basin

3611

Sulu Arch

Baram Delta/ 3610

Brunei-Sabah

Basin Cotabato

3701 Basin

3603 5°N

Figure	51.  Map, graphs, and tables of data for oil and gas exploration through 2001 in the Philippines and Taiwan.
 

Growth in delineated prospective area and explored 

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

40
 

Delineated prospective area 

20 

Explored area 

AREA (THOUSANDS OF SQUARE MILES)

30 

10 

0 

0 100 200 300 400 500 600
 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

became part of the delineated prospective area 

YEAR
 

1960 1970 1980 1990 2000
 

200 8 

OIL (MMBO)

5 

Gas 

Oil 

7 

6 

) 

100 4 

3 

GAS (TCF

2 

1 

0 0 

0 10 20 30 40 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES)
 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in 

all 

fields 

(BCF) 

Philippines: 

Palawan Shelf, 3605.................................... 1976 0 182 36 4,539 4,575 

Taiwan: 

Taiwan Thrust and Fold Belt, 3151............. 1876 0 8 0 1,941 1,941 

Exploration data 

Country 

Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

30,553 mi2 

5,045 mi2 

Philippines.............................. 

Taiwan.................................... 

Total ................................... 

115,830 

13,892 

129,722 

Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 

Reported discoveries through 2001 of cumulative 

526 wells 

55 mi2

/well 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 193 MMBO 

 Gas......................................................................... 7.341 TCF 

Richness total oil discoveries .............. ( total delineated prospective area ) 0.006 MMBO/mi2

Figure 1. Philippines and Taiwan 11 

Figure 1. Continued. 
100°E 110°E

10°N

Malay Saigon

North Sumatra Basin Basin 

Basin 3703 3505 Ketuneau/Sintang 3822 Greater Terrane 

Penyu/West Sarawak 3816

Natuna Basin Basin 

3825 3702 

Rajang-Crocker

Central Accretionary

Sumatra Prism 

Basin East Natuna 3705 

3808 Basin 

3810 

Sumatra/Java Sunda Platform

3835 Fore-Arc Basins INDONESIA 

3832 0° South Sumatra 


Basin
 

3828 Melawi Sumatra/Java 

Magmatic Arc Basin Barito

3818 Basin 3833 

3804 

Sumatra/Java Northwest Meratus Accretionary Java Basin East High Prism 3824 Java 3819 3831 Basin 

3809 

Bali 

Basin 10°S

3802 

Figure 2. Map, graphs, and tables of data for oil and gas exploration through 2001 in Indonesia. 

S

12 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

120°E

Pamusian

Tarakan 

Basin

3606

Go

Kutei 

Basin

3817

South

Makassar

Basin 

3827 

Flores 

Basin 

3811 

P
120°E 130°E 140°E

10°N

0°

10°S

Pamusian

Tarakan 

Basin

3606

Halmahera

Platform

3814

Sulawesi Bintuni/Sulawati Gorontalo Magmatic Arc Northern Irian Jaya Province Basin 3830 Halmahera Waropen Basin 3805 3812 Basin 3823

3813

Sulawesi

Kutei Accretionary New Guinea 

Basin Prism Mobile Belt

3817 3829 3967

North

Banda

Basin

3821

South

Makassar Java/ South Banda Weber Basin Banda Sea Basin Basin 3827 3815 Arafura Basin- 3826

3836 Irian Jaya

3801 Flores

Basin

3811 Bone Basin Merauke

3806 Platform

3820

Papuan BasinShelf Platform

Banda Arc 3969

3803

Sumba

Province Bonaparte 3834 Gulf Basin

3910

Figure 52.  Continued.

ntang

Meratus

High

3819

Bali

Basin

3802

Figure 52. Indonesia 153
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area 

200 

180 

160 

140 

120 

100 

80 

60 

40 

20 

0 

0 1,000 2,000 3,000 4,000 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

 became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Oil 

Gas 

OIL (BBO)

) GAS (TCF

30 250 

200 

20 

150 

100 

10 

50 

0 0 

0 20 40 60 80 100 120 140 160 180 200 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

Indonesia: 

Barito Basin, 3804 ...................................... 1937 143 173 210 5 215 

Bintuni/Sulawati Province, 3805 ................ 1936 195 504 248 19,262 19,510 

Bonaparte Gulf Basin, 3910........................ 2000 0 0 0 1,800 1,800 

Central Sumatra Basin, 3808 ...................... 1939 10,989 13,074 1,416 693 2,109 

East Java Basin, 3809.................................. 1888 380 976 1,667 4,836 6,503 

Greater Sarawak Basin, 3702...................... 1970 0 20 25 46,395 46,420 

Kutei Basin, 3817........................................ 1897 2,417 3,487 10,121 48,545 58,666 

Malay Basin, 3703 ...................................... 1982 0 45 0 930 930 

North Sumatra Basin, 3822......................... 1885 292 736 1,968 28,695 30,663 

Northwest Java Basin, 3824........................ 1939 1,652 3,434 5,043 6,417 11,460 

Pamusian Tarakan Basin, 3606 ................... 1900 350 522 814 3,429 4,243 

Penyu/West Natuna Basin, 3825................. 1972 320 678 1,628 3,420 5,048 

South Sumatra Basin, 3828......................... 1896 1,069 2,869 5,113 12,873 17,986 

Sulawesi Accretionary Prism, 3829............ 1986 0 15 0 3,791 3,791 

Total........................................................................... 17,807 26,533 28,253 181,091 209,344 

1 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

Figure 2. Continued. 
Exploration data 

Country 

Land area

(mi2

)	 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

179,462 mi2
 

34,465 mi2
 

Indonesia......................... 741,097
 Wildcat wells through 2001 ............................................. 3,608 wells


Current growth in delineated prospective area 

per wildcat (for last 10 percent of wells) ..................... 36 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 26.675 BBO 

 Gas......................................................................... 211.433 TCF 

Richness total oil discoveries ....... ( ) total delineated prospective area 

0.149 MMBO/mi2

Figure 2. Continued. 

Figure 2. Indonesia 1 
100°E 105°E 110°E 115°E 10°N 5°N0° Malay Basin 

3703 

Baram 

Delta/Brunei- Sabah Basin Greater Sarawak 3701 North Basin Sumatra 3702 BRUNEI Basin East 3822 Malay Peninsula Natuna 3704 Basin Penyu/West 3810 Natuna Basin MALAYSIA 3825 

Rajang-Crocker 

Accretionary Prism SINGAPORE 

3705 

Ketuneau/Sintang Terrane 3816 S

JDA Figure	53.  Map, graphs, and tables of data for oil and gas exploration through 2001 in Malaysia, Brunei, and Singapore. In the table of significant pro

Malaysia-Thailand Joint Development Area (JDA) are included with discoveries in the Malay Basin of Malaysia.
Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areasbecame prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

70 60 

Delineated prospective area 50 

40 

Explored area 

AREA (THOUSANDS OF SQUARE MILES) 30 20 10 

0 

0 100 200 300 400 500 600 700 800 900 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

12 

Oil Gas 10 

8 6 

150 100 

)

) 

(BBOOIL 

GAS (TCF

4 50 2 0 0 

0 10 20 30 40 50 60 70 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recoverable 

oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas 

oi

field

(BC

Malaysia: Baram Delta/Brunei-Sabah 

Basin, 3701 ........................................ 1910 2,449 3,292 8,4

Greater Sarawak Basin, 3702................. 1962 342 880 1,9Malay Basin, 3703 (includes JDA) ........ 1969 2,384 3,752 12,6North Sumatra Basin, 3822.................... 1989 0 0 Penyu/West Natuna Basin, 3825............ 1973 0 69 

Total............................................................. 5,175 7,993 23,0

Brunei: 

Baram Delta/Brunei-Sabah 

Basin, 3701 ........................................ 1914 3,416 3,850 19,6

Exploration data

Country 

Land area

(mi 2)

Delineated prospective area through 200

Explored area through 2001...................

Wildcat wells through 2001 ....................

Malaysia........................... 127,317
 Current growth in delineated prospective Brunei............................... 2,228 per wildcat (for last 10 percent of wel

Singapore ......................... 250 Reported discoveries through 2001 of cu

Total.......................... 129,794 recoverable crude oil and gas in all pr

Oil.................................................

Gas................................................

Richness total oil discoveries 

( 

total delineated prospective ar

Figure . Continued. 
  

pr

co

territory delineated  For   overseas Tonga.  have   and  (an   areas  Islands, Caledonia  theseSix   Fiji,Guinea, Tonga.  New of Northern Mariana and Micronesia,  Islands,  NewPapua  Islands,  Mariana  Tuvalu. in 2001 Northern hall   and   through  Mars  Micronesia,   exploration  Nauru, Kiribati, Guam, gas  Polynesia,  exploration:  andIslands,  oil data for  the map: French  Marshall of Guam, petroleum of lack  tables limits  they  the  andgraphs, Polynesia, although  outside the map,  French are Map,  but  on anuatu, 54.V   labeled Figure Islands, discoveries are 

New 

A

3

L

170°E

NAURU

TU

3018

Java Rise

Basin

3028

VANUA

New Caledonia

East Ontong 

3014

Vanikoro 

Malakula/Aoba/

Banks Basin

3938

NEW

CALEDONIA

160°E

Russell Basin

SOLOMON

ISLANDS

3016

Indispensable

Reef

3015

Shorland

Solomon

Basin

3004

Islands

3005

Cape V

Basin

3964

Bellona Plateau

3002

ogel 

New Guinea 

Mobile Belt

3967

150°E

New Ireland Basin

3968

South Bismarck Volcanic Arc3971

3969

GUINEA

Papuan Basin-Shelf 

Platform

New Guinea 

PAPUA NEW

Fold Belt

3966

140°E

Foreland BasinArafura Basin-Irian Jaya

Carpentaria

Basin

Sepik-Ramu Basin

3917

3801

3970

Merauke Platform

3820

130°E

0°

10°S20°S
Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areasbecame prospective or explored 

YEAR	 

1960 1970 1980 1990 2000 

15 

Delineated prospective area 

10 

5 

Explored area 

AREA (THOUSANDS OF SQUARE MILES)

0 

0 50 100 150 200 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

through 2001, graphed by the year the field location	

became part of the delineated prospective area	 

YEAR	 

1960 1970	 1980 1990 2000 

600 500 

Gas 

Oil 

) GAS (TCF

15 

400 10

O)BM(M300 OIL 

200 5100 

0 0 5
 10 15 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES)
 

Significant petroleum provinces—Year of first discovery and cumulative recoverab

oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large	 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

G

fi

(B

Papua New Guinea: New Guinea Foreland Basin-Fold 

Belt, 3966............................................... 1956 270 518 1,9

Papuan Basin-Shelf Platform, 3969........... 1958 0 0 

Total.................................................................. 270 518 1,9

Exploration data 

Country 

Papua New Guinea........... 

Fiji.................................... 

New Caledonia................. 

Solomon Islands............... 

Vanuatu ............................ 

French Polynesia*............ Guam*.............................. Marshall Islands*............. Micronesia*...................... 

Land area 

(mi2)	 

178,703
 

7,054
 7,359
 

10,985
 

4,710
 

1,609
 

212
 

70
 

271 

Delineated prospective area through 20

Explored area through 2001..................

Wildcat wells through 2001 ..................

Current growth in delineated prospectiv

per wildcat (for last 10 percent of we

Reported discoveries through 2001 of c

recoverable crude oil and gas in all p

Oil...............................................

Gas..............................................

Richness total oil discoveries 

( 

 total delineated prospective 

Northern Mariana 

Islands* ........................ 184
 

Tonga*.............................. 289
 

Total .......................... 

*Not shown on map. 

211,446


Figure .	 Continued. 
110°E 120°E 130°E 140°E 150°E 

Money Shoal Basin 

3941 

Banda Arc EAST TIMOR Pine Creek Bonaparte Gulf Basin Australian 10°S 3803 Geosyncline 3910 TIMOR GAP Arafura Basin 3954 3905 Carpentaria Laura Basin Browse Basin Basin 3937 3913 Coen-Yambo Block 3917 

McArthur Basin 3920 Victoria River Basin 

3945 Hodgkin

3962 Daly River Basin 

3921 Halls Creek Province Kimberley 3933 Drummon

Basin Pilbara Block 

3935 Wiso 3953 Georgina Canning Basin Basin 

Basin Paterson Province 3914 3963 Mt. Isa Block 

3929 3951 3942 

20°S Birrindudu Tennant Creek 

Northwest Galilee Basin Basin and Arunta Block Block Shelf 3926 Tanami Block 3904 3961 3948 Gascoyne Block 3909 

3927 Eromanga 

Carnarvon Basin Basin 3916 AUSTRALIA Ngalia Basin Amadeus Basin 

3924 

3947 3903 

Musgrave Block 

3944 Bangemall and 

Nabberu Basins Stuart Shelf Officer Basin 

3906 3957 3949 

Albany-Fraser Darling Basin Surat New 30°S Province Eucla Basin Gawler 3922 Basin Englan

3902 3925 Block 3958 Fold Be

3928 3946 

Yilgarn Block Lacklan 3974 Fold Belt 

3936 

Murray Basin 

Perth Basin Bremer Basin 3943 

3952 3912 

Great Australian Adelaide and Gipp

Bight Basin Kanmantoo Fold Belts 

3931 3901 Bass 

40°S 39

Otway Basin 

3950 

Bassia

Rocky Cape Block/Dundas Trough 390

3956 

Tasmania Basin 

3960 

Figure . Map, graphs, and tables of data for oil and gas exploration through 2001 in Australia and East Timor. The countries shared the Timor Ga
Growth in delineated prospective area and explored area through 2001, graphed by the year the areasbecame prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

350 300 Delineated prospective area 

Explored area 

AREA (THOUSANDS OF SQUARE MILES) 250 200 150 100 50 

0 

0 1,000 2,000 3,000 4,000 5,000 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

through 2001, graphed by the year the field location became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

8 250 7 

200 

6 Oil 

5 

Gas 

OIL (BBO)150 

) 

4 

100 3 GAS (TCF

2 

50 

1 0 0 

0 50 100 150 200 250 300 350 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum provinces—Year of first discovery and cumulative recove

oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Ga

fie

(B

Australia: Bonaparte Gulf Basin, 3910................ 1964 230 447 Browse Basin, 3913 ............................ 1971 0 121 Eromanga Basin, 3924........................ 1964 0 301 1Gippsland Basin, 3930........................ 1924 3,776 4,089 2Northwest Shelf, 3948 ........................ 1954 964 1,806 1

Total ................................................................ 4,970 6,764 5

Timor Gap Zone of Cooperation: 

Bonaparte Gulf Basin, 3910................ 1974 0 109 

Exploration data 

Delineated prospective area through 

Land area

Country Explored area through 2001............

(mi 2) Wildcat wells through 2001 ............

Australia.......................... 2,967,896 Current growth in delineated prospeEast Timor....................... 5,794
 per wildcat (for last 10 percent of 

Total ............................ 2,973,690
 Reported discoveries through 2001 

recoverable crude oil and gas in a

Oil.........................................Gas........................................

Richness total oil discoverie

( total delineated prospectiv

Figure . Continued. 
162	 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001

165°E 170°E 175°E

35°S

Northland

Basin Waikato Basin

3023 3029

Taranaki Basin Challenger 3031 Plateau

3918

Wanganui Basin

3030 40°S

New Zealand East 

Coast Basin

3020

NEW

ZEALAND

Chatham Rise

3972

New Zealand 

Orogenic Belt 45°S 3021

Hikurani Trough

3008

Great South Basin Solander-Waiau Basin 3007 3025

50°S

Figure	56.  Map, graphs, and tables of data for oil and gas exploration through 2001 in New Zealand.
 

Growth in delineated prospective area and explored

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

AREA (THOUSANDS OF SQUARE MILES) 

Delineated prospective area 

Explored area

16 

14 

12 

10 

8 

6 

4 

2 

0 

0 100 200 300 400 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

Gas 

O)B

) 

M(M

Oil 

OIL 

GAS (TCF

500 8 

7 

400 

6 

5 300 

4 

200 3 

2 

100 

1 

0 0 

0 2 4 6 8 10 12 14 16 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum province—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in

all

fields

(BCF) 

New Zealand: 

Taranaki Basin, 3031................................... 1867 200 419 552 6,544 7,096 


Exploration data 

Country 

Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

15,313 mi2 

2,286 mi2 

New Zealand .......................... 103,737 Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

323 wells 

per wildcat (for last 10 percent of wells) ..................... 48 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 419 MMBO 

 Gas......................................................................... 7.536 TCF 

Richness total oil discoveries ) ....... ( total delineated prospective area 

0.027 MMBO/mi2

Figure 6. New Zealand 16 

Figure 6. Continued. 
0° 10°E 20°E 30°E 40°E 50°E 60°E 70°E 80°E 70°N

North Barents Basin Admiralty Arch 

1060 1061 

Central Barents Platform Kola Monocline4012 Novaya Finnmark Platform 

Zemlya 1051 South Monocline 

Barents 1062 

Basin 

1050 Timan-Pechora 

Basin 

1008 

Ludlov Saddle 

1059 RUSSIA 

in Asia 

Timan 

High Baltic Shield-Norwegian 1007 

Caledonides 

4016 60°N

Mezen Basin 

1006 

Ural­ Volga-Ural Novaya Region Zemlya 1015 

Kotelnich Foldbelt 

Arch 1017 

Baltic 1005 

Depression Moscow Basin 4021 1003 

RUSSIA 

Belorussian- in Europe Voronezh High 

1004 

50°N

DnieperDonets Basin 

1009 North Caspian 

Basin 

1016 

Donbass Foldbelt 

1014 

AzovKuban 

Basin 

1108 

Great Caucasus Foldbelt Middle Caspian 

1110 Basin 

1109 

Figure . Maps, graphs, and tables of data for oil and gas exploration through 2001 in Russia. Separate maps show exploration in the 

part of Russia in Europe and the part of Russia in Asia. The graphs and data tables in this figure show data for all of Russia. 

16 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

Russia in Europe (the map of Russia in Asia is on p. 166–167) 
 

Growth in delineated prospective area and explored 

 area through 2001, graphed by the year the areas

 became prospective or explored 

YEAR 

1960 1970 1980 1990 2000 

700 

600 

Delineated prospective area 

Explored area 

AREA (THOUSANDS OF SQUARE MILES) 500 

400 

300 

200 

100 

0 

0 2,000 4,000 6,000 8,000 10,000 12,000 

CUMULATIVE NUMBER OF WILDCAT WELLS 

Cumulative recoverable oil and gas discoveries in all provinces

 through 2001, graphed by the year the field location

became part of the delineated prospective area 

YEAR 

1960 1970 1980 1990 2000 

250 

Oil 

Gas 

2,500 

200 2,000 

150 1,500 

OIL (BBO)

) 

100 1,000 

GAS (TCF

50 500 

0 0 

0 100 200 300 400 500 600 700 

DELINEATED PROSPECTIVE AREA (THOUSANDS OF SQUARE MILES) 

Significant petroleum province 

Year of 

first 

discovery 

Oil in 

large 

fields 

(MMBO) 

Oil in 

all 

fields 

(MMBO) 

Gas in 

oil 

fields 

(BCF) 

Gas in 

gas 

fields 

(BCF) 

Gas in 

all 

fields 

(BCF) 

Russia: 

Angara-Lena Terrace, 1209......................... 1954 0 4 0 9,965 9,965 

Azov-Kuban Basin, 1108............................ 1864 1,068 1,929 4,770 16,317 21,087 

Baykit Arch, 1207....................................... 1974 365 442 3,211 5,213 8,424 

Dnieper-Donets Basin, 1009....................... 1959 0 21 8 817 825 

Lena-Vilyuy Basin, 1214 ............................ 1956 0 0 0 13,763 13,763 

Ludlov Saddle, 1059 ................................... 1990 0 0 0 2,740 2,740 

Middle Caspian Basin, 1109 ....................... 1893 4,933 6,727 6,840 15,450 22,290 

Nepa-Botuoba Arch, 1210 .......................... 1965 2,946 3,372 15,410 11,944 27,354 

North Caspian Basin, 1016 ......................... 1958 0 47 20 93,176 93,196 

North Sakhalin Basin, 1322 ........................ 1923 1,376 2,128 8,701 16,946 25,647 

South Barents Basin, 1050.......................... 1983 0 0 0 101,208 101,208 

Timan-Pechora Basin, 1008........................ 1930 9,943 13,738 6,849 34,625 41,474 

Volga-Ural Region, 1015 ............................ 1932 52,388 67,465 22,919 75,762 98,681 

West Siberian Basin, 1174 .......................... 1953 124,984 138,789 149,610 1,381,071 1,530,681 

Yenisey-Khatanga Basin, 1175 ................... 1965 0 4 0 9,386 9,386 

Total .......................................................................... 198,003 234,666 218,338 1,788,383 2,006,721 

Exploration data 

Country 

Land area

 (mi2

) 

Delineated prospective area through 2001....................... 

Explored area through 2001............................................. 

627,065 mi2 

142,661 mi2 

Russia..................................... 6,592,741 Wildcat wells through 2001 ............................................. 

Current growth in delineated prospective area 

10,738 wells 

per wildcat (for last 10 percent of wells) ..................... 42 mi2

/well 

Reported discoveries through 2001 of cumulative 

recoverable crude oil and gas in all provinces: 

 Oil.......................................................................... 236.533 BBO 

 Gas......................................................................... 2,015.312 TCF 

Richness ( total oil discoveries ) .......... total delineated prospective area 

0.377 MMBO/mi2

Figure . Russia 16 

Significant petroleum provinces—Year of first discovery and cumulative recoverable oil and gas discovered through 2001 

Figure . Continued. 
Russia in Asia 

60°N 50°E 70°N 60°E 70°E 80°E 90°E 100°E 110°E

Severnaya Zemlya High 

1072 

RUSSIA 

in Europe Arctic Ocean 

Taimyr-Kara Slope 

1117 High 50°E 1176 

Khatanga 

Saddle Yenisey- 1201 Khatanga Basin 

1175 

Anabar-Olenek 

High Ural-Novaya 1202 Zemlya Foldbelt Turukhan- 1017 

Norilsk 

60°E Folded Zone 

1204 TurukhanIgarka Uplift Kempendiay RUSSIA Turgay 1205 Region 

Depression in Asia 1212 

1166 NepaBotuoba 

Tunguska Arch 

50°N West Baykit Siberian Basin 1210 

Arch Basin 1203 

1207 

1174 

70°E Kuznetsk 

Basin Cis-Sayan Cis-Patom 1171 Basin 

Foredeep 1208 Central Kazakhstan North Minusa 1211 

Folded Region Basin 

1168 1172 

Altay-Sayan South Minusa Baikal-Patom 

Folded Region Basin Folded Region 

1219 1173 1230 

Angara-Lena 

Terrace 

1209 

40°N Mongol-Okhotsk 

Folded Region 

3202 

80°E

Figure . Continued. 

1

166 Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001 

120°E 130°E

A

U

Laptev Shelf 

1218 

Anabar Basin 

1200 

LenaVilyuy 

Basin 

1214 

Aldan Up

1215 

Aldan 

1

Upp

Ushumun B

Basin
 

3138
 

ZeyaBureya 

Basin 

1222 

Yinshan Da 


and Xiao 


Hingganling
 

Uplift
 

3160
 
Russia in Asia—Continued 

120°E 130°E 140°E 150°E 160°E 170°E 180° 70°N 170°W 60°N

Novosibirsk Wrangel- Basin Herald Anadyr Basin Anzhu 1256
 Uplift 1300
 Uplift 1260
 1255 South

Laptev Shelf Chukchi-Hope Blagoveshchensk Basin Gangut 1218 Basin 1254 High 170°W
 1261
 1301
 Anabar Basin
 

1200
 

Ayon Basin
 Koryak­ 1253
 Verkhoyan- Kamchatka Khatyrka Basin Chukotka Folded Penzhina Basin Foldbelt 1302
 

Region 1303
 1304


1250 East Kamchatka Uplift
 

Kinkil Basin 1313
 

1305
 

Koni- Olyutor Basin 180°

Tayganos 1314
 

Uplift Lena- Zyryanka Basin Gizhigin Basin 1308
 

Vilyuy 1251 1307 Central Kamchatka Group of Basins
 

Basin 1312


Moma Basin 1214
 West Kamchatka Basin 

1252
 1311
 

East Kamchatka 50°N North Okhotsk Basin Group of Basins 1315
 Aldan Uplift 1309 Tinro 


1215
 Basin
 

North 1310
 

Sakhalin
 170°E Kuril-Kamchatka Basin

Slope 1322
 Central Okhotsk 1316
 Aldan Shield High 1216
 1319
 Bureya-Dunbey Deryugin Basin
 

Region 1321
 

Upper Zeya Ushumun 1220
 Basin Basin East Sakhalin Uplift 1217
 3138
 1323
 

Onekotan Basin
 Sikhote-Alin 1317
 Folded Region
 

1224
 South Okhotsk Tatar Zeya- Basin

Bureya Strait

1320
 Basin Basin Terpeniya Bay Basin 1222 1328
 West Sakhalin Uplift 1324 40°N Yinshan Da 1325
 South Kuril Basin and Xiao Middle Upper Aniva Basin Hingganling 1318
 Bureya Amur 1327
 Uplift Japan Volcanic Arc/Accreted Terrane 160°E
 Basin Basin 

3160 1223 1227 3304
 

Figure . Continued. 

h

2

Figure . Russia 16 

110°E

tic Ocean 

Slope 

1117 

lenek 

Kempendiay 

Region
 

1212
 

pa

uoba
 

ch
 

10
 

Cis-Patom 

Foredeep 

1211
 

atom 

egion 


 

Attanasi and others—Statistics of Petroleum Exploration in the World Outside the United States and Canada Through 2001—Circular 1288 

Printed on recycled paper