World Petroleum Resources Project

Assessment of Undiscovered Oil and Gas Resources of the Central Burma Basin and 

the Irrawaddy–Andaman and Indo-Burman Geologic Provinces, Myanmar

The Irrawaddy–Andaman and Indo-Burman Geologic Provinces were recently assessed for undiscovered technically recoverable 

oil, natural gas, and natural gas liquids resources as part of the U.S. Geological Survey’s (USGS) World Oil and Gas Assessment. Using a 

geology-based assessment methodology, the USGS estimated mean volumes of 2.3 billion barrels of oil, 79.6 trillion cubic feet of gas, and 

2.1 billion barrels of natrual gas liquids.

Geologic

Provinces

EXPLANATION

Irrawaddy–Andaman

 Geologic Province

Indo-Burman Geologic

 Province

Irrawaddy–Andaman AU

Cenozoic AU

Central Burma Basin AU

GULF

OF

 THAILAND 

INDIAN

OCEAN

ANDAMAN

SEA 

BAY OF BENGAL

0 100 200 MILES

0 200 KILOMETERS 100

CHINA

INDIA

MYANMAR

THAILAND

LAOS

BANGLADESH

NEPAL BHUTAN

86° 88° 90° 92° 94° 96° 98° 100° 102°

28°

26°

24°

22°

20°

18°

16°

14°

12°

10°

8°

6°

INDIA

CHINA

MALAYSIA

Figure 1. Assessed areas of Myanmar were defined as three

composite assessment units (AU) (outlined in black). These are 

the Central Burma Basin AU (80480101), Irrawaddy–Andaman AU 

(80480102), and Cenozoic AU (80050101).

Introduction

The U.S. Geological Survey (USGS) World Petroleum 

Resources Project assesses the potential for undiscovered, technically recoverable oil and natural gas resources of the world, 

exclusive of the United States. As a part of this program, the USGS 

recently completed an assessment of the onshore and offshore areas 

of the Central Burma Basin and the Irrawaddy–Andaman and IndoBurman Geologic Provinces (fig. 1). This assessment was based on 

data from oil and gas exploration and production wells, production 

data, and published geologic reports. Only conventional oil and gas 

resources were assessed.

U.S. Department of the Interior

U.S. Geological Survey

Central Burma Basin Assessment Unit 

The Central Burma Basin assessment unit (AU) encompasses 

an area of 242,000 km2

 in the Central Burma Basin and includes 

source, reservoir, and seal rocks predominately of Eocene to Miocene age, although Upper Cretaceous and Paleocene source rocks 

also may contribute to the AU. The basin is an Eocene back arc 

basin formed by oblique collision of oceanic and continental plates 

and filled with sediments of a restricted marine environment overlain 

by sediments of a southward-prograding delta and alluvial system. 

Compression and folding developed anticlines and faulted anticlines 

intermittently from Oligocene to present (U.S. Geological Survey 

Fact Sheet 2012–3107

August 2012
World Energy Assessment Team, 2000). Traps are primarily anticlines and stratigraphic traps including pinchouts. Eleven oil and 

nine gas fields greater than the minimum assessed size of 5 million 

barrels of oil equivalent (MMBOE) (grown or maximum expected 

recovery) have been discovered in the Central Burma Basin AU 

(IHS Energy, 2010).

Irrawaddy–Andaman Assessment Unit 

The Irrawaddy–Andaman AU includes an area of 226,000 km2

and includes source, reservoir, and seal rocks primarily of Eocene 

to Miocene age. It is the southward extension of the Central Burma 

Basin with a similar geologic setting and tectonic history; however, 

the effects of compression caused by plate collision are less 

evident, whereas the oblique or strike-slip component becomes 

more dominant. The features distinguishing the Irrawaddy–

Andaman AU from the Central Burma Basin AU are that the 

source and reservoir rocks were deposited in a predominately 

deltaic and marine environment, and source rocks are more gas 

prone. Source rock burial depths become greater to the south, 

and cracking of oil to gas because of greater depths of burial may 

contribute to this AU being more gas prone. Traps are primarily 

anticlines, alluvial channels, deltaic features, and carbonate reefs 

and pinnacles (Wandrey, 2006). Twenty-two gas fields greater 

than the minimum assessed size of 5 MMBOE (grown) have been 

discovered (IHS Energy, 2010).

Cenozoic Assessment Unit 

The Cenozoic AU encompasses an area of 71,000 km2 and 

includes source, reservoir, and seal rocks primarily of Eocene to 

Pliocene age. The AU includes the Rahkine Basin and occupies 

the eastern abyssal plain of the Bay of Bengal and part of the 

accretionary wedge created by oblique subduction of the Indian 

Plate beneath the Burmese Plate. Source rocks are postulated to be 

middle to late Eocene shales. Reservoirs are Oligocene-Miocene 

thick sheet sandstones and turbidites sourced by the Bengal fan, 

Miocene-Pliocene turbidites, and aggraded lower-slope channel 

sandstones sourced by the younger Rahkine-Yoma fan. Three 

gas fields greater than the minimum assessed size of 5 MMBOE 

(grown) have been discovered (IHS Energy, 2010).

Resource Summary

The USGS geology-based assessment of the undiscovered 

technically recoverable oil, natural gas, and natural gas liquids 

resources in the Central Burma Basin and the Irrawaddy–Andaman 

and Indo-Burman Geologic Provinces resulted in estimated undiscovered mean volumes of 2.3 billion barrels of oil, 79.6 trillion 

cubic feet of gas, and 2.1 billion barrels of natrual gas liquids.

References Cited 

IHS Energy, 2010, International petroleum exploration and production database [current through December 2010]: Available from 

IHS Energy, 15 Inverness Way East, Englewood, CO 80112.

U.S. Geological Survey World Energy Assessment Team, 2000, 

U.S. Geological Survey World Petroleum Assessment 2000―

Description and results: U.S. Geological Survey Digital Data 

Series DDS-60, 4 CD ROMS.

Wandrey, C.J., 2006, Eocene to Miocene composite total petroleum system, Irrawaddy–Andaman and North Burma Geologic 

Provinces, Myanmar, chap. E in Wandrey, C.J., ed., Petroleum 

systems and related geologic studies in Region 8, South Asia: 

U.S. geological Survey Bulletin 2208-E, 26 p.

For Additional Information 

Assessment results are available at the USGS Central Energy 

Resources Science Center website: http://energy.cr.usgs.gov/

oilgas/ or contact Craig J. Wandrey, the assessing geologist 

(cwandrey@usgs.gov).

Central Burma Basin and the Irrawadddy–Andaman 

and Indo-Burman Geologic Provinces Assessment 

Team 

Craig J. Wandrey, Christopher J. Schenk, Timothy R. Klett, 

Michael E. Brownfield, Ronald R. Charpentier, Troy A. Cook, 

Richard M. Pollastro, and Marilyn E. Tennyson. 

Total petroleum systems

(TPS)

and assessment units (AU) 

Field

 type 

Largest

expected

mean

 field size 

Total undiscovered resources

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

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

Irrawaddy–Andaman Geologic Province, Eocene to Miocene TPS

Central Burma Basin AU

Oil 84

Gas 411

Irrawaddy–Andaman AU

Oil 44

Gas 2,201

Indo-Burman Geologic Province, Eocene to Pliocene TPS

Cenozoic AU

Oil 31 148

Gas 6,351 30,862

Total conventional

 resources

1,049 1,732 2,822 1,808 2,501 4,157 6,804 4,340 67 112 185 117

4,786 7,988 13,072 8,332 126 213 349 222

198 372 680 397 256 568 1,156 619 7 15 32 17

17,693 33,163 60,715 35,309 470 884 1,624 941

40 88 175 95 37 122 348 1 3 10 4

12,008 28,366 58,386 316 753 1,579 823

1,287 2,192 3,677 2,300 37,281 74,364 140,481 79,610 987 1,980 3,779 2,124

[MMBO, million barrels of oil; BCFG, billion cubic feet of gas; MMBNGL, million barrels of natural gas liquids. Results shown are fully risked estimates. For 

gas fields, all liquids are included under the NGL (natural gas liquids) category. Undiscovered gas resources are the sum of nonassociated and associated 

gas. F95 represents a 95-percent chanceof at least the amount tabulated. Other fractiles are defined similarly. Fractiles are additive under the assumption 

is in MMBO; largest expected gas field is in BCFG. TPS, total petroleum system; AU, assessment unit. Gray shading indicates not appllicable] 

Table 1. Myanmar assessment results for undiscovered oil and gas resources of the Central Burma Basin and the Irrawaddy–Andaman 

and Indo-Burman Geologic Provinces, Myanmar.