Genesis of Oil and Gas in Sikeshu Sag in the Southern Margin of Junggar Basin

Abstract

Abstract: The oil found in Sikeshu sag in the southern margin of Junggar Basin is the light oil with associated wet gas, but the properties of the oil and gas in different regions are different and there are some disputes about the hydrocarbon sources. The samples of the Middle-Lower Jurassic and Middle-Upper Triassic source rocks obtained from the outcrops in the southern margin are selected. Based on the analysis of rock pyrolysis, choloroform asphalt A, gas chromatography and organic petrology and combined with geochemical analysis of the source rocks, the paper analyzes the geochemical properties of the source rocks of Triassic, Jurassic and Paleogene in Sikeshu sag, determines the organic facies of the source rocks and discusses the genesis and origin of the oil and gas. The study results show that the light oil and gas in Sikeshu sag mainly come from the source rocks of the Lower Jurassic Badaowan Formation, probably from the Middle-Upper Triassic source rocks; the oil in Dushanzi oilfield and the Neogene Xihu anticline mainly comes from Jurassic or Triassic source rocks, partial oil from the source rocks of the Paleogene Anjihaihe Formation.

Key words: Junggar Basin, Sikeshu sag, light oil, source rock, organic facies, hydrocarbon genesis

REN Jiangling, WANG Feiyu, ZHAO Zengyi, ZHANG Yunpei, MI Julei, LIU Cuimin. Genesis of Oil and Gas in Sikeshu Sag in the Southern Margin of Junggar Basin[J]. Xinjiang Petroleum Geology, 2020, 41(zk(English)): 10-15.

References

[1] WANG Xulong,ZHI Dongming,WANG Yutao,et al.Source rock and oil gas geochemistry in Junggar basin [M]. Beijing:Petroleum Industry Press,2013.
[2] CHEN Jianping,WANG Xulong,NI Yunyan,et al.Genetic type and source of natural gas in the southern margin of Junggar basin,NW China[J]. Petroleum Exploration and Development,2019,46(3):461-473.
[3] FAN Guanghua,LI Jianxin.Discussion on oil source in Junggar basin[J]. Xinjiang Petroleum Geology,1985,5(4):11-18.
[4] CHEN Jianping,WANG Xulong,NI Yunyan,et al.The accumulation of natural gas and potential exploration regions in the southern margin of the Junggar basin[J]. Acta Geologica Sinica,2019,93(5):1 002-1 019.
[5] CHEN Jianping,WANG Xulong,DENG Chunping,et al.Geochemical features of source rocks in the southern margin,Junggar basin,northwestern China[J]. Acta Petrolei Sinica,2015,36(7):767-780.
[6] WANG Yutao,JIANG Shaobin.Characteristics of vertical migration of the natural gas and analyses of its origin in the southern margin of Junggar basin[J]. Acta Sedimentologica Sinica,1997,15(2):70-74.
[7] WANG Yutao.Oil and gas resource potential and abundance law on southern periphery of Junggar basin[J]. Petroleum Explorationist,2000,5(1):49-51.
[8] WANG Yutao,JIANG Shaobin.Hydrocarbon generation characteristics and exploration direction in Jurassic of Junggar basin[J]. Xinjiang Petroleum Geology,1995,16(3):222-226.
[9] CHEN Jianping,LIANG Digang,WANG Xulong,et al.The discovery and significance of the crude oils derived from Triassic source rocks in the Junggar basin[J]. Geochimica,2003,32(6):582-590.
[10] JIN Jun,WANG Feiyu,REN Jiangling,et al.Genesis of high-yield oil and gas in Well Gaotan-1 and characteristics of source rocks in Sikeshu sag,Junggar basin[J]. Xinjiang Petroleum Geology,2019,40(2):145-151.
[11] YANG Disheng,XIAO Lixin,YAN Guihua,et al.Structural characteristics and petroleum exploration in Sikeshu sag,southern margin of Junggar basin[J]. Xinjiang Petroleum Geology,2019,40(2):138-144.
[12] LI Jianxin,YANG Bin.Geochemical characteristics of coal-derived oil in the Junggar basin and oil-bearing prospects of the Jurassic coal measures[C]//Xinjiang Petroleum Administration Bereau, Chinese Academy of Resource and Environmental Science. Comprehensive study of petroleum geology in the Junggar basin. Lanzhou:Gansu Science and Technology Press,1992:97-109.
[13] HUI Rongyao,ZHANG Jizhong,MENG Qianxiang.Geochemical characteristics of coal-type oil in southern margin of Junggar basin[J]. Acta Sedimentologica Sinica,1990,8(1):29-36.
[14] PEPPER A J,CORVI P J.Simple kinetic models of petroleum formation. Part I:oil and gas generation from kerogen[J]. Marine and Petroleum Geology,1995,12(3):291-319.
[15] KONG Xiangxing.Oil source of foothill fault-fold structural belt in western part of the southern margin,Junggar basin[J]. Petroleum Exploration and Development,2007,34(4):413-418.
[16] CHENG Changling.Re-cognition of the Jurassic source rocks in Sikeshu sag[J]. Xinjiang Petroleum Geology,2018,39(1):119-124.
[17] KANG Sufang,XIANG Baoli,LIAO Jiande,et al.Organic geochemistry of Triassic source rock in the southern Junggar basin[J]. Journal of Southwest Petroleum University(Seience & Technology Edition),2012,34(2):43-53.
[18] WANG Bin,WU Ming,WANG Xulong,et al.Source rock features and evaluation of Triassic strata in the central Junggar basin[J]. Journal of Southwest Petroleum University(Seience & Technology Edition),2011,33(2):12-20.
[19] GAO Gang,WANG Xulong,LIU Guangdi,et al.Prediction method and of organic carbon abundance of dark color mudstones in the Triassic system of Junggar basin[J]. Geological Journal of China Universities,2012,18(4):745-750.
[20] QI Xuefeng,WU Xiaozhi.Depositional environment of Paleogene Anjihaihe formation in southern margin of Junggar basin and its significance in petroleum geology[J]. Xinjiang Petroleum Geology,2009,30(3):289-292.
[21] ZHOU Chunmei,CHENG Jinhui,Alia AMUTI,et al.Geological age and paleoenvironmental significance of the upper part of middle member of the Anjihaihe formation on southern margin of the Junggar basin,Xinjiang[J]. Journal of Stratigraphy,2012,36(4):723-732.