Skip to Main Content
GEOREF RECORD

Organic petrology of peak oil maturity Triassic Yanchang Formation lacustrine mudrocks, Ordos Basin, China

Paul C. Hackley, Zhang Lixia and Tongwei Zhang
Organic petrology of peak oil maturity Triassic Yanchang Formation lacustrine mudrocks, Ordos Basin, China
Interpretation (Tulsa) (May 2017) 5 (2): SF211-SF223

Abstract

An organic petrology evaluation and a determination of solid bitumen reflectance BR (sub o) were completed for organic-rich Triassic Yanchang Formation mudrocks (n = 15) from the Ordos Basin, north-central China, as part of a larger investigation of "shale gas" resources. These data were integrated with information from Rock-Eval programmed pyrolysis to show that the samples are in the peak oil window of thermal maturity and that organic matter is dominated by solid bitumen with minor amounts of type III kerogen (vitrinite and inertinite) from vascular land plants. Describing a "kerogen type" for these rocks based strictly on parameters determined from programmed pyrolysis is misleading because the original organic matter has converted to hydrocarbons (present as solid bitumen), a large proportion of which may have been expelled into adjacent reservoir facies. However, based on the comparison with immature-early mature lacustrine mudrock (Garden Gulch Member of Green River Formation) and marine shale (Boquillas Formation), we suggest that the original organic matter in the organic-rich samples examined for our study may have been type I/II kerogen with hydrogen index values of >700 mg HC/g TOC.


ISSN: 2324-8858
EISSN: 2324-8866
Serial Title: Interpretation (Tulsa)
Serial Volume: 5
Serial Issue: 2
Title: Organic petrology of peak oil maturity Triassic Yanchang Formation lacustrine mudrocks, Ordos Basin, China
Affiliation: U. S. Geological Survey, Reston, VA, United States
Pages: SF211-SF223
Published: 201705
Text Language: English
Publisher: Society of Exploration Geophysicists, Tulsa, OK, United States
References: 59
Accession Number: 2017-051941
Categories: Sedimentary petrologyEconomic geology, geology of energy sources
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 table, sketch map
N33°00'00" - N39°00'00", E103°00'00" - E114°00'00"
Secondary Affiliation: Shaanxi Yanchang Petroleum Company, Research Institute, CHN, ChinaUniversity of Texas at Austin, Bureau of Economic Geology, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by Society of Exploration Geophysicists, Tulsa, OK, United States
Update Code: 201728
Program Name: USGSOPNon-USGS publications with USGS authors
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal