U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2011–3050

 June 2011 

World Petroleum Resources Project

Assessment of Undiscovered Oil and Gas Resources of the 

West Siberian Basin Province, Russia, 2010

Printed on recycled paper

Introduction

The U.S. Geological Survey (USGS) recently assessed the 

undiscovered oil and gas resources of the West Siberian Basin 

Province in Russia as part of a program to estimate petroleum 

resources for priority basins around the world. This province is 

the largest petroleum basin in the world for petroleum volume, 

with an areal extent of about 2.2 million square kilometers 

(fig. 1). It is a large rift-sag feature (fig. 2) bounded to the west

by the Ural fold belt; to the north by the Novaya Zemlya fold 

belt and North Siberian Sill; to the south by the Turgay Depression and Altay–Sayan fold belt; and to the east by the Yenisey 

Ridge, Turukhan–Igarka uplift, Yenisey–Khatanga Basin, and

Taimyr High (fig. 1). The West Siberian Basin Province has total

discovered recoverable oil and gas volume of more than 360 billion barrels of oil equivalent (Ulmishek, 2003). Exploration has 

led to the discovery of tens of giant oil and gas fields, including

the Urengoy gas field with more than 350 trillion cubic feet of

gas reserves and Samotlar oil field with reserves of nearly 28

billion barrels of oil (Ulmishek, 2003). This report summarizes 

the results of a recently completed reassessment of the undiscovered oil and gas potential of the entire province that had 

been assessed previously in 2000 (Ulmishek, 2000). The total 

petroleum systems (TPS) and assessment units (AU) defined

by the USGS for the assessment in 2000 were adopted for this 

assessment.

Total Petroleum Systems and Assessment Units

Two TPSs, the Northern West Siberian Mesozoic Composite 

TPS and the Southern West Siberian Mesozoic Composite TPS, 

were defined for the West Siberian Basin Province (fig. 1 and table

1); each was defined to include strata of Jurassic and Cretaceous age.

In the Northern West Siberian Mesozoic Composite TPS, several rock

units might be potential source rocks; however, the true source of 

the gas resources remains uncertain (Ulmishek, 2003). More than 70 

fields have been discovered in this TPS, most of which are gas fields.

In the Southern West Siberian Mesozoic Composite TPS, primary

source rocks include the Upper Jurassic Bazhenov Formation, Toarcian Togur Formation, and Aalenian Radom Bed. More than 450

fields have been discovered, most of which are oil fields. Thirty-eight

of these oil fields are considered giants [larger than 500 million barrels of oil (MMBO)].

Three AUs were defined within the West Siberian Basin Province (fig. 1). The Northern West Siberian Onshore Gas AU includes

primarily Cretaceous sandstone reservoirs in structural traps. The 

_ Omsk

Novosibirsk

KARA SEA

Central Kazakhstan

Folded Region

65°

60°

55°

40° 50° 60° 70° 80°

Yenisey-Khatanga

Basin

Taimyr

High

North Siberian Sill

Arctic Circle

NORTHERN 

WEST

SIBERIAN 

ONSHORE GAS AU

 

SOUTH KARA SEA

OFFSHORE AU

SOUTHERN 

WEST

SIBERIAN 

RESERVOIRS AU

 

Ob Inlet

Yamal

Pen.

Gydan Pen.

BARENTS SEA

A

A’

Altay-Sayan

fold belt

Yenisey Ridge

Turukhan-lgarka Uplift

Tunguska

Basin

Novaya Zemlya fold belt

Timan-Pechora

Basin

Ural

fold belt

Turgay

Depression

Yenisey River

River

River

Irtysh

Ob

EXPLANATION

Oil field centerpoint 

Gas field centerpoint 

0 620 KILOMETERS

0 385 MILES

Figure 1. West Siberian Basin Province (red line), Russia. Three 

assessment units (AU) were defined in this study: Northern West Siberian 

Onshore Gas AU, South Kara Sea Offshore AU, and Southern West Siberian 

Reservoirs AU. Blue line represents the boundary between the Northern 

West Siberian Mesozoic Composite total petroleum system (TPS) and the 

Southern West Siberian Mesozoic Composite TPS.

The U.S. Geological Survey, using a geology-based 

assessment methodology, estimated mean volumes of 

technically recoverable, conventional, undiscovered 

petroleum resources at 8 billion barrels of crude oil, 670 

trillion cubic feet of natural gas, and 21 billion barrels of 

natural gas liquids for the West Siberian Basin Province.

South Kara Sea Offshore AU, considered to be the offshore geologic

extension of the Northern West Siberian Onshore Gas AU, includes 

similar traps and reservoirs. The Southern West Siberian Reservoirs 

AU also includes primarily Cretaceous sandstone reservoirs in structural traps. Each AU was evaluated in its entirety for undiscovered, 

technically recoverable, oil and gas resources.
Figure 2. Line of cross section A-A’ in the West Siberian Basin Province, 

Russia; location of section shown in figure 1. TPS, total petroleum system; 

AU, assessment unit; J1-2, Lower to Middle Jurassic; J3

, Upper Jurassic; K1b, 

Berrasian; K1

v, Valanginian; K1g, Hauterivian; K1br, Barremian; K1a, Aptian; 

K1

al, Albian; K2c, Cenomanian; K2t, Turonian; Pg1, Paleogene; Pg2-3, EoceneOligocene; Q, Quaternary. B.S.L., below sea level. From Ulmishek (2000).

Assessment Results

The results of the quantitative 

assessment of undiscovered, technically 

recoverable, conventional oil and gas 

resources in the West Siberian Basin 

Province are listed in table 1. The total

estimated means for undiscovered conventional oil and gas resources are 8,000

million barrels of oil (MMBO), 670,144

billion cubic feet of natural gas (BCFG),

and 20,836 million barrels of natural gas

liquids (MMBNGL). Of these volumes, 

the Northern West Siberian Onshore Gas 

AU accounts for 1,601 MMBO, 40,663

BCFG, and 1,181 MMBNGL; the South

Kara Sea Offshore AU accounts for

2,507 MMBO, 622,222 BCFG, and 19,479 MMBNGL;

and the Southern West Siberian Reservoirs AU accounts 

for 3,892 MMBO, 7,259 BCFG, and 176 MMBNGL. The

large estimate for undiscovered gas in the South Kara Sea

AU reflects the exploration immaturity compared to the

Northern West Siberian Onshore Gas and Southern West 

Siberian Reservoirs AUs.

References Cited

Ulmishek, G.F., 2000, West Siberia Basin—Geologic

Province 1174, in U.S. Geological Survey World Energy 

Assessment Team, U.S. Geological Survey World Petroleum Assessment 2000—description and results: U.S.

Geological Survey Digital Data Series DDS–60, four 

CD–ROM set, Disk 1.

Ulmishek, G.F., 2003, Petroleum geology and resources

of the West Siberian Basin, Russia: U.S. Geological

Survey Bulletin 2201–G, 49 p.

For Further Information

Publications detailing the geology and the methodology for the 

West Siberian Basin Province and assessment results are available at 

the USGS Central Energy Resources Science Center web site, http://

energy.cr.usgs.gov/oilgas/.

West Siberian Basin Province Assessment Team

T.R. Klett (tklett@usgs.gov), Christopher J. Schenk, Kenneth J. Bird,

Michael E. Brownfield, Ronald R. Charpentier, Troy A. Cook, Donald L. Gautier, David W. Houseknecht, Thomas E. Moore, Mark J.

Pawlewicz, Janet K. Pitman, Richard M. Pollastro, and Marilyn E.

Tennyson.

EXPLANATION

Sandstones and shales Hydrocarbon pool

Quaternary sediments

Fault

Mainly sandstones Pre-Jurassic rocks

Mainly shales

Major unconformity

0

1.0

2.0

3.0

4.0

KM, B.S.L.

Pg2-3

K t-Pg 2 1

K1br-K1al 

Kc2 K a-Kc 1 2

K b-K1g 1 J3

J1-2

Kb1

K v-K1br 1

A A'

Approximate Location

of TPS and AU Boundary

0 100 KILOMETERS

0 60 MILES

Q

Total petroleum systems 

(TPS) 

and assessment units (AU)

AU

probability

Field

 type 

Largest

expected

field size 

Total undiscovered resources

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

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

Northern West Siberian Mesozoic Composite TPS

Northern West Siberian 

Onshore Gas AU 1.00

Oil 431 309 1,252 4,070 1,601 1,724 7,367 24,644 9,527 35 152 513 197

Gas 5,560 8,669 26,154 70,336 31,136 269 825 2,241 984

South Kara Sea Offshore AU 1.00

Oil 712 572 2,053 6,023 2,507 3,183 12,064 36,779 14,933 64 248 763 308

Gas 189,354 154,681 513,304 1,372,510 607,289 4,799 16,000 44,090 19,171

Total conventional 

resources 8,000 670,144 20,836

[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 accumulations, all liquids are

included as NGL (natural gas liquids). Undiscovered gas resources are the sum of nonassociated and associated gas. F95 represents a 95 percent chance of at least the amount tabulated; other

fractiles are defined similarly. AU probability is the chance of at least one accumulation of minimum size within the AU. Largest expected oil field size in MMBO; largest expected gas field size in

BCFG. TPS, total petroleum system; AU, assessment unit. Gray shading indicates not applicable; oil field sizes in MMBO; gas field sizes in BCFG] 

Table 1. Assessment results for technically recoverable, conventional, undiscovered oil and gas resources of the West Siberian Basin Province, Russia, 2010.

Southern West Siberian

Reservoirs AU 1.00

Oil 175 1.911 3,634 6,780 3,892 2,220 4,452 8,557 4,790 50 102 199 110

Gas 634 941 2,222 4,851 2,469 24 59 133 66

Southern West Siberian Mesozoic Composite TPS