U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2014–3047

August 2014

National and Global Petroleum Assessment

Assessment of Unconventional Oil and Gas Resources in 

Northeast Mexico, 2014

Introduction

The U.S. Geological Survey (USGS), in cooperation with 

the U.S. Department of State, quantitatively assessed the potential for unconventional oil and gas resources within the Sabinas 

Basin, Burgos Basin, and Tampico-Misantla Basin provinces of 

northeast Mexico (fig. 1). Resources of the Veracruz Basin were 

not quantitatively assessed due to a lack of reservoir information. Unconventional resources include shale gas, shale oil, tight 

gas, tight oil, and coalbed gas. Undiscovered conventional oil 

and gas resources were assessed in Mexico in 2012 (Schenk and 

others, 2012).

The USGS assessment methodology consists of a wellperformance approach (Charpentier and Cook, 2011) that 

recognizes the geologic variability within assessed reservoirs. 

For assessments outside of the United States, the USGS assesses 

shale-gas or shale-oil reservoirs that (1) have greater than 

2 weight percent total organic carbon; (2) are within the proper 

thermal maturity window for oil or gas generation; (3) have 

greater than 15 meters (m) of organic-rich shale; and (4) contain 

Type I or II organic matter (Charpentier and Cook, 2011). Areas 

that do not meet these criteria are unlikely to have significant 

resource potential without major technological improvements or 

price increases. When applied to any given shale-oil or shalegas reservoir, these specific USGS criteria might significantly 

reduce the potential resource area compared to maps made 

with greater than 1 percent total organic carbon (TOC). For 

example, the area of potential reservoir of the Pimienta Shale in 

the Tampico-Misantla Basin with greater than 2 weight percent 

TOC is only about 21 percent of the total area of thermally 

mature Pimienta Shale.

An important part of the geologic phase of this study was 

a formal USGS–PEMEX (Petroleos Mexicanos) Workshop on 

Unconventional Resources convened in Mexico City in June 

2012, during which the geology and current exploration results 

from within the various shale-oil and shale-gas assessment units 

of northeast Mexico were discussed in detail. Several maps 

with geologic data (as outlined above) that were critical to the 

USGS assessment were supplied by PEMEX. These maps were 

combined to produce areas within the Sabinas, Burgos, and 

Tampico-Misantla Basins that were then considered for quantitative USGS assessment using the criteria outlined above.

The input data for each unconventional assessment unit is 

shown in table 1.

Resource Summary

The USGS quantitatively assessed unconventional oil and 

gas resources in 11 assessment units within 3 geologic provinces (table 2). For unconventional oil resources, the mean total 

is 776 million barrels of oil (MMBO), with a range of 353–

1,365 MMBO; for unconventional gas, the mean total is 23,474 

billion cubic feet (BCFG), with a range of 7,431–44,630 BCFG; 

and a mean total of 883 million barrels of natural gas liquids 

(MMBNGL), with a range of 278–1,690 MMBNGL.

Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 0.78 billion barrels of 

unconventional oil, 23.5 trillion cubic feet of unconventional gas, and 0.88 billion barrels of natural gas liquids in the Sabinas 

Basin, Burgos Basin, and Tampico-Misantla Basin provinces of northeast Mexico.

102° 100° 98° 96° 94° 92°

32°

30°

28°

26°

24°

22°

20°

18°

16°

GULF 

OF 

MEXICO

PACIFIC OCEAN

UNITED STATES

MEXICO

Tampico-Misantla 

Basin Province

Veracruz Basin

Province

Burgos Basin

Province

Sabinas Basin

Province

UNITED STATES

Area of

figure

PACIFIC

OCEAN

GULF OF

MEXICO

ATLANTIC

OCEAN

MEXICO

Assessed provinces

Unassessed province

EXPLANATION

0 10050 150 200 MILES

0 100 15050 200 KILOMETERS

Figure 1. Map showing locations of the Sabinas Basin, Burgos 

Basin, and Tampico-Misantla Basin provinces assessed in this 

study.
Of the mean unconventional oil total of 776 MMBO, about 

82 percent is in the Tampico-Misantla Basin. Within the basin, 

55 percent (426 MMBO) is estimated to be in the Agua Nueva 

Shale Oil Assessment Unit (AU), and 27 percent (212 MMBO) 

is in the Pimienta Shale Oil AU. The Agua Nueva Shale Oil 

AU in the Burgos Basin contains the remaining 18 percent 

(138 MMBO).

For the mean unconventional gas total of 23,474 BCFG, 

about 66 percent (15,591 BCFG) is estimated to be in the 

Burgos Basin; 25 percent (5,822 BCFG) is in the Sabinas Basin; 

and 9 percent (2,061 BCFG) is in the Tampico-Misantla Basin.

For Further Information

Supporting studies of the geologic models and the 

methodology used in the assessment of northeast Mexican 

unconventional resources are in progress. Assessment results 

are available at the USGS Energy Resources Program website, 

http://energy.usgs.gov/oilgas/. 

References Cited

Charpentier, R.R., and Cook, T.A., 2011, USGS methodology 

for assessing continuous petroleum resources: U.S. Geological 

Survey Open-File Report 2011–1167, 75 p., http://pubs.usgs.

gov/of/2011/1167/. 

Schenk, C.J., Charpentier, R.R., Cook, T.A., Klett, T.R., Pitman, 

J.K., Pollastro, R.M., and Weaver, J.N., 2012, Assessment of 

undiscovered conventional oil and gas resources of Mexico, 

Guatemala, and Belize, 2012: U.S. Geological Survey Fact 

Sheet 2012–3069, 4 p., http://pubs.usgs.gov/fs/2012/3069/. 

Northeast Mexico Assessment Team

Christopher J. Schenk, Ronald R. Charpentier, 

Timothy R. Klett, Marilyn E. Tennyson, Stephanie Gaswirth, 

Michael E. Brownfield, Mark J. Pawlewicz, and Jean N. Weaver.

Austin Chalk

Boquillas/Eagle Ford Formation

Buda Limestone

Exposure of Boquillas/Eagle Ford Formation on south bank of Langtry Creek in Pump Canyon, Val Verde County Texas.

Photograph taken by Michael Lewan, August 19, 2010.
Assessment input data

Burgos Basin

Rio Escondido Basin Olmos Coalbed Gas AU 53000281

Burgos Basin

La Casita Shale Gas AU 53000361

Minimum Mode Maximum Calculated mean Minimum Mode Maximum Calculated mean

Potential production area of AU (acres) 10,000 250,000 750,000 336,667 100,000 828,000 2,500,000 1,142,667

Average drainage area of wells (acres) 40 80 160 93 80 120 160 120

Percent of AU untested 100 100 100 100 100 100 100 100

Success ratios (%) 50 70 90 70 40 60 80 60

Average EUR (MMBO, oil; BCFG, gas) 0.03 0.2 1 0.24 0.3 0.6 0.9 0.61

Burgos Basin

Agua Nueva Shale Oil AU 53000461

Burgos Basin

Agua Nueva Shale Gas AU 53000462

Minimum Mode Maximum Calculated mean Minimum Mode Maximum Calculated mean

Potential production area of AU (acres) 100,000 704,000 1,100,000 634,667 100,000 2,259,000 3,530,000 1,963,000

Average drainage area of wells (acres) 160 280 400 280 80 120 160 120

Percent of AU untested 100 100 100 100 100 100 100 100

Success ratios (%) 50 70 90 70 50 70 90 70

Average EUR (MMBO, oil; BCFG, gas) 0.04 0.08 0.2 0.086 0.4 0.8 1.2 0.813

Burgos Basin

Wilcox-Lobo Tight Gas AU 53000561

Sabinas Basin

La Casita Shale Gas AU 53230161

Minimum Mode Maximum Calculated mean Minimum Mode Maximum Calculated mean

Potential production area of AU (acres) 10,000 550,000 700,000 420,000 94,000 565,000 1,882,000 847,000

Average drainage area of wells (acres) 40 110 180 110 80 120 160 120

Percent of AU untested 100 100 100 100 100 100 100 100

Success ratios (%) 50 70 90 70 10 50 90 50

Average EUR (MMBO, oil; BCFG, gas) 0.25 0.6 1.5 0.645 0.3 0.6 0.9 0.610

Sabinas Basin

Agua Nueva Shale Gas AU 53230261

Tampico-Misantla Basin

Pimienta Shale Oil AU 53010261

Minimum Mode Maximum Calculated mean Minimum Mode Maximum Calculated mean

Potential production area of AU (acres) 100,000 704,000 2,400,000 1,068,000 100,000 695,000 2,100,000 965,000

Average drainage area of wells (acres) 80 120 160 120 140 240 300 227

Percent of AU untested 100 100 100 100 100 100 100 100

Success ratios (%) 10 50 90 50 40 60 80 60

Average EUR (MMBO, oil; BCFG, gas) 0.4 0.8 1.2 0.813 0.03 0.08 0.14 0.082

Tampico-Misantla Basin

Pimienta Shale Gas AU 53010262

Tampico-Misantla Basin

Agua Nueva Shale Oil AU 53010361

Minimum Mode Maximum Calculated mean Minimum Mode Maximum Calculated mean

Potential production area of AU (acres) 10,000 33,000 100,000 47,667 1,052,000 2,104,000 2,735,000 1,963,667

Average drainage area of wells (acres) 80 120 160 120 160 280 400 280

Percent of AU untested 100 100 100 100 100 100 100 100

Success ratios (%) 40 60 80 60 50 70 90 70

Average EUR (MMBO, oil; BCFG, gas) 0.3 0.6 0.9 0.610 0.04 0.08 0.2 0.086

Tampico-Misantla Basin

Agua Nueva Shale Gas AU 53010362

Minimum Mode Maximum Calculated mean

Potential production area of AU (acres) 10,000 128,000 368,000 168,667

Average drainage area of wells (acres) 80 120 160 120

Percent of AU untested 100 100 100 100

Success ratios (%) 50 70 90 70

Average EUR (MMBO, oil; BCFG, gas) 0.4 0.8 1.2 0.813

Table 1. Key assessment input data for unconventional assessment units in northeast Mexico.

[EUR (estimated ultimate recovery per well), well drainage area, and success ratios are from U.S. shale-gas, shale-oil, tight-gas, and coalbed gas 

analogs. MMBO, million barrels of oil; BCFG, billion cubic feet of gas; AU, assessment unit, %, percent. The average EUR input is the minimum, 

median, maximum, and calculated mean.]
ISSN 2327-6916 (print)

ISSN 2327-6932 (online)

http://dx.doi.org/10.3133/fs20143047

Total Petroleum Systems 

(TPS) 

and Assessment Units (AU)

AU 

Probability

Field 

Type

Total Undiscovered Resources

Oil (MMBO) Gas (BCFG) NGL (MMBNGL)

F95 F50 F5 Mean F95 F50 F5 Mean F95 F50 F5 Mean

BURGOS BASIN

Olmos Coalbed Gas TPS

Rio Escondido Basin Olmos Coalbed 

Gas AU 53000281 1.0 Gas 125 479 1,544 612 0 0 0 0

Upper Jurassic La Casita TPS

La Casita Shale Gas AU 53000361 1.0 Gas 1,148 3,253 6,730 3,516 69 195 407 211

Turonian Agua Nueva TPS

Agua Nueva Shale Oil AU 53000461 1.0 Oil 52 129 251 138 96 252 533 275 2 5 11 6

Agua Nueva Shale Gas AU 53000462 1.0 Gas 3,211 9,320 15,982 9,403 127 368 654 376

Paleogene TPS

Wilcox-Lobo Tight Gas AU 53000561 1.0 Gas 535 1,675 3,431 1,785 5 16 36 18

SABINAS BASIN

Upper Jurassic La Casita TPS

La Casita Shale Gas AU 53230161 1.0 Gas 577 1,899 4,687 2,172 17 56 144 65

Turonian Agua Nueva TPS

Agua Nueva Shale Gas AU 53230261 1.0 Gas 941 3,189 7,922 3,650 37 127 321 146

TAMPICO-MISANTLA BASIN

Upper Jurassic Pimienta TPS

Pimienta Shale Oil AU 

53010261 1.0 Oil 69 194 412 212 82 232 498 254 2 7 15 8

Pimienta Shale Gas AU 53010262 1.0 Gas 58 136 272 147 2 4 8 4

Turonian Agua Nueva TPS

Agua Nueva Shale Oil AU 53010361 1.0 Oil 232 402 702 426 406 789 1,502 852 7 16 32 17

Agua Nueva Shale Gas AU 53010362 1.0 Gas 252 754 1,529 808 10 30 62 32

VERACRUZ BASIN

Turonian Maltrata TPS

Maltrata Shale Oil AU 

53020261 Oil Not quantitatively assessed

Maltrata Shale Gas AU 53020262 Gas Not quantitatively assessed

Total unconventional

 resources 353 725 1,365 776 7,431 21,978 44,630 23,474 278 824 1,690 883

Table 2. Northeast Mexico unconventional oil and gas resource assessment results.

[MMBO, million barrels of oil. BCFG, billion cubic feet of gas; MMBNGL, million barrels of natural gas liquids; TPS, total petroleum system; AU, assessment 

unit. Results shown are fully risked estimates. For gas fields, all liquids are included under the NGL (natural gas liquids) category. F95 represents a 95 percent 

chance of at least the amount tabulated. Other fractiles are defined similarly. Shading indicates not applicable.]