National and Global Petroleum Assessment

Assessment of Undiscovered Continuous Oil and Gas Resources of 

Upper Cretaceous Shales in the Songliao Basin of China, 2017

Introduction

The U.S. Geological Survey (USGS) quantitatively assessed 

the potential for continuous (unconventional) oil resources within 

organic-rich lacustrine shale of the Upper Cretaceous Qingshankou 

and Nenjiang Formations of the Songliao Basin. The Songliao Basin 

is the most productive oil-bearing nonmarine basin in China, mainly 

from the super-giant, conventional Daqing Oil Field (fig. 1). This field, 

discovered in 1959, produces oil from high-quality sandstone reservoirs in large anticlinal traps, sourced by adjacent lacustrine shale of 

the Qingshankou Formation (Lee, 1986; Li, 1995). Daqing Oil Field 

has produced over 12 billion barrels of oil, but production has declined 

in recent years. In light of this decline in conventional oil production, 

Cao and others (2017) and Liu and others (2017) analyzed the shale-oil 

potential of the Qingshankou. These authors noted that operators have 

completed preliminary exploration and tests, but there has been no 

reported shale-oil production in the Songliao Basin.

Geologic Background

The Qingshankou and Nenjiang Formations were deposited during 

a postrift sag basin phase characterized by strong subsidence that followed an Early Cretaceous rift phase in this continental retro-arc basin 

(Feng and others, 2010; Wang and others, 2016). The Qingshankou 

was deposited from 92.0 to 86.2 mega-annum (Ma) (Wang and others, 

2016). Its organic-rich first (lowest) member is 60–135 meters (m) 

thick, covering an area of 87,000 square kilometers (km2) (representing 

the maximum extent of the Upper Cretaceous lacustrine system), and 

present total organic carbon (TOC) content is typically 3–4 weight percent up to a maximum of 7.5 weight percent (Feng and others, 2010). 

Liu and others (2017) indicate several areas near the basin center where 

TOC exceeds 5 weight percent. The Nenjiang was deposited from 84.5 

to 79.1 Ma (Wang and others, 2016). Its organic-rich first and second 

members have a composite thickness of 200–400 m, cover an area of 

20,000 km2, and contain TOC values of 1–3 weight percent (Feng and 

others, 2010). The Qingshankou and Nenjiang both contain Type I 

kerogen and are mainly within the oil window with vitrinite reflectance 

values in the center of the Songliao Basin exceeding 1.1 percent for 

the Qingshankou, decreasing below 0.5 percent near the basin margins 

(Feng and others, 2010; Liu and others, 2017). The depth to the 

Qingshankou source-rock interval exceeds 1 kilometer over a large 

area of the basin, with a maximum depth of about 2,650 m, whereas 

the Nenjiang source rocks are 0–1,900 m deep (Li, 1995; Pan and 

others, 2010). The brittle mineral content of the Qingshankou exceeds 

40 percent (relative mineral abundance) (Cao and others, 2017). Its clay 

content averages 55 percent (Liu and others, 2017), much higher than 

producing shale-oil reservoirs in the United States, raising concerns that 

it might not be amenable to effective hydraulic fracturing. 

Assessment Units

Within the Upper Cretaceous Total Petroleum System, we defined 

two assessment units (AUs): the Qingshankou Formation Shale Oil AU 

and the Nenjiang Formation Shale Oil AU (fig. 1). Burial history modeling suggests that these units were buried sufficiently by Late Cretaceous 

sediments to generate oil beginning in the latest Cretaceous (Liu and others, 2017). The Qingshankou, being several hundred meters deeper than 

Figure 1. Map showing the location of the Songliao Basin and the 

Qingshankou Formation Shale Oil and Nenjiang Formation Shale Oil 

Assessment Units (AUs).

HARBIN

Qiqihar

CHANGCHUN

MONGOLIA

CHINA

NORTH

KOREA

RUSSIA RUSSIA

SEA

OF

JAPAN

YELLOW

SEA

120° E 125° E 130° E

50° N

45° N

Map

area MNG

CHN

PRK

KOR

JPN

RUS

Base map from U.S. Department of the Interior

National Park Service

EXPLANATION

Qingshankou Formation Shale Oil AU

Songliao Basin boundary

Nenjiang Formation Shale Oil AU

Daqing

Oil Field

0 100 200 KILOMETERS

0 100 200 MILES

U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2018–3014

May 2018

Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered, technically recoverable resources 

of 3.3 billion barrels of oil and 887 billion cubic feet of gas in shale reservoirs of the Upper Cretaceous Qingshankou and Nenjiang Formations in 

the Songliao Basin of northeastern China.
Total petroleum system and

assessment units (AUs)

AU 

probability

Accumulation 

type

Total undiscovered resources

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

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

Upper Cretaceous Total Petroleum System

Qingshankou Formation Shale Oil AU 1.0 Oil 470 1,853 4,734 2,131 107 464 1,380 569 2 11 36 14

Nenjiang Formation Shale Oil AU 1.0 Oil 250 1,018 2,735 1,192 57 254 790 318 1 6 21 8

Total undiscovered continuous resources 720 2,871 7,469 3,323 164 718 2,170 887 3 17 57 22

Table 2. Results for two continuous assessment units in the Songliao Basin, China.

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

risked estimates. For gas accumulations, all liquids are included in the NGL category. F95 represents a 95-percent chance of at least the amount tabulated; other fractiles 

are defined similarly. Fractiles are additive under the assumption of perfect positive correlation. Shading indicates not applicable]

Assessment input data—

Continuous AUs

Qingshankou Formation Shale Oil AU Nenjiang Formation Shale Oil AU

Minimum Mode Maximum Calculated 

mean Minimum Mode Maximum Calculated mean

Potential production area of AU (acres) 2,000 7,000,000 16,300,000 7,767,333 2,000 4,000,000 10,000,000 4,667,333

Average drainage area of well (acres) 40 80 120 80 40 80 120 80

Success ratio (%) 10 50 90 50 10 40 90 46.7

Average EUR (MMBO) 0.02 0.04 0.1 0.043 0.02 0.04 0.1 0.043

AU probability 1.0 1.0

Table 1. Key input data for two continuous assessment units in the Songliao Basin, China.

[AU, assessment unit; %, percent; EUR, estimated ultimate recovery per well; MMBO, million barrels of oil. Well-drainage area, success ratio, and EUR are from U.S. 

shale-oil analogs. The average EUR input is the minimum, median, maximum, and calculated mean. Shading indicates not applicable]

References Cited

Cao H.R., Zou Y.-R., Lei Y., Xi D., Wan X.Q., and Peng P.A., 2017, 

Shale oil assessment for the Songliao Basin, northeastern China, using 

oil generation−sorption method: Energy Fuels, v. 31, p. 4826−4842. 

[Also available at https://doi.org/10.1021/acs.energyfuels.7b00098.]

Feng Z.Q., Jia C.Z., Xie X.N., Zhang S., Feng Z.H., and Cross, T.A., 

2010, Tectonostratigraphic units and stratigraphic sequences of the 

nonmarine Songliao basin, northeast China: Basin Research, v. 22, 

no. 1, p. 79–95. [Also available at https://doi.org/10.1111/

j.1365-2117.2009.00445.x.]

Lee K.Y., 1986, Petroleum geology of the Songliao basin, Northeast 

China: U.S. Geological Survey Open-File Report 86–502, 19 p. 

Li D.S., 1995, Hydrocarbon habitat in the Songliao Rift Basin, China, 

in Lambiase, J.J., ed., 1995, Hydrocarbon habitat in rift basins: 

Bath, United Kingdom, The Geological Society, London, Special 

Publication No. 80, p. 317–329.

Undiscovered Resources Summary

The USGS quantitatively assessed the Qingshankou Formation 

Shale Oil AU and the Nenjiang Formation Shale Oil AU within the 

Upper Cretaceous Total Petroleum System in the Songliao Basin, 

northeast China (table 2). The mean total for continuous oil resources 

is 3,323 million barrels of oil (MMBO), or 3.3 billion barrels of oil, 

the Nenjiang, has greater thermal maturity, but neither was buried deeply 

enough to become overmature. The thermal and burial conditions in the 

Songliao Basin were nearly optimal for oil generation. The Qingshankou 

Formation Shale Oil AU corresponds to areas where the thermal maturity 

of the Qingshankou has achieved vitrinite reflectance above 0.6 percent, 

according to Liu and others (2017). The areal extent of the Nenjiang 

Formation Shale Oil AU is patterned after the Qingshankou Formation 

Shale Oil AU, truncated to exclude areas where the thickness of the 

Nenjiang is less than 100 m based on Feng and others (2010). 

Continuous oil and gas accumulations in the United States were 

used as analogs in this assessment. Table 1 lists the principal input data 

used for the assessment.

with an F95–F5 range from 720 to 7,469 MMBO. The mean total for 

continuous gas resources is 887 billion cubic feet (BCFG) with an 

F95–F5 range from 164 to 2,170 BCFG. The mean total for natural gas 

liquids is 22 million barrels of natural gas liquids (MMBNGL) with an 

F95–F5 range from 3 to 57 MMBNGL. These estimates are for undiscovered, technically recoverable resources of oil, gas, and natural gas 

liquids and do not reflect economically recoverable resources.

Liu C.L., Wang Z.L., Guo Z.Q., Hong W.Y., Dun C., Zhang X., Li 

B., and Wu L.Q., 2017, Enrichment and distribution of shale oil in 

the Cretaceous Qingshankou Formation, Songliao Basin, northeast 

China: Marine and Petroleum Geology, v. 86, p. 751–770. [Also 

available at https://doi.org/10.1016/j.marpetgeo.2017.06.034.]

Pan S.X., Wang T.Q., Wei P.S., Wang J.G., Liu C.Y., and Liang 

S.J., 2010, Accumulation and exploration prospects of shale oil 

and gas in Songliao Basin, eastern China: American Association of Petroleum Geologists, Search and Discovery Article No. 

10272, December 29, 2010, 8 p., accessed August 21, 2017, at 

http://www.searchanddiscovery.com/documents/2010/10272pan/.

Wang P.-J., Mattern, F., Didenko, N.A., Zhu D.-F., Singer, B., and 

Sun X.-M., 2016, Tectonics and cycle system of the Cretaceous 

Songliao Basin—An inverted active continental margin basin: 

Earth-Science Reviews, v. 159, p. 82–102. [Also available at 

https://doi.org/10.1016/j.earscirev.2016.05.004.]

Songliao Basin Assessment Team

Christopher J. Potter, Christopher J. Schenk, Janet K. Pitman, Timothy R. Klett, Marilyn E. Tennyson, Stephanie B. Gaswirth, Heidi M. 

Leathers-Miller, Thomas M. Finn, Michael E. Brownfield, Tracey J. Mercier, Kristen R. Marra, Cheryl A. Woodall

For More Information

Assessment results are also available at the USGS Energy Resources Program website at https://energy.usgs.gov.

ISSN 2327-6916 (print) ISSN 2327-6932 (online) https://doi.org/10.3133/fs20183014

Banner satellite image from Google, 2018