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The hydrocarbon generation and expulsion features of source rocks and tight oil potential of the second member of the Qiketai Formation, Shengbei area in the Turpan–Hami Basin, NW China
Author(s) -
Feng Yue,
Huang Zhilong,
Wang Enze,
Zhang Hua,
Li Tianjun,
Liang Yu
Publication year - 2021
Publication title -
geological journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.721
H-Index - 54
eISSN - 1099-1034
pISSN - 0072-1050
DOI - 10.1002/gj.3963
Subject(s) - source rock , kerogen , hydrocarbon , geology , structural basin , geochemistry , mineralogy , tight oil , total organic carbon , oil shale , chemistry , geomorphology , paleontology , environmental chemistry , organic chemistry
Significant progress in tight oil exploration has been reported in the second member of the Qiketai Formation (J 2 q 2 ) in the Shengbei area of the Turpan–Hami Basin. Geochemical analyses were conducted to assess the quality of the J 2 q 2 source rocks. The improved hydrocarbon generation potential method was utilized to quantify the hydrocarbon generation and expulsion features of the source rocks. The results showed that J 2 q 2 source rocks were deposited in a reduced lacustrine setting with a high palaeoproductivity. The J 2 q 2 source rocks are widely distributed (approximately 1,000 km 2 ) and have a thickness that varies from 50 to 130 m. Moreover, they can be identified as a set of high‐quality source rocks (thermally mature rocks with R o values >0.5%, consisting mainly of types I and II kerogen and possessing an average total organic carbon content of 2.68%). The oil–source correlation results reveal that the source of crude oil in the studied area is J 2 q 2 . The improved hydrocarbon generation potential method is established for different kerogen types to limit the influence of the kerogen type on the calculation. The hydrocarbon expulsion threshold of the type I model is located at R o = 0.6%. The type II kerogen rocks have different characteristics, and the hydrocarbon expulsion threshold is located at R o = 0.62%. The maximum hydrocarbon generation and expulsion intensities are 700 × 10 4 t/km 2 and 400 × 10 4 t/km 2 , respectively. The hydrocarbon generation and expulsion amount of the J 2 q 2 source rocks are 21.4 × 10 8 t and 12.3 × 10 8 t, respectively. The tight oil potential of the J 2 q 2 tight oil in the Shengbei area is 4.09 × 10 8 t. The SB10 and SB6 well areas are favourable J 2 q 2 tight oil exploration areas in the Shengbei area. The SB10 well area has the highest hydrocarbon generation and expulsion intensities in the study area and is the best tight oil exploration target.