准噶尔盆地南缘下组合煤系烃源岩生烃模拟及高探1井油气源研究

Hydrocarbon generation simulation of coaly source rocks in the Lower combination on the southern margin of Junggar Basin and indications for oil and gas sources of well Gaotan 1

于淼 高岗 靳军 马万云 何丹 向宝力 樊柯廷 刘苗

YU Miao GAO Gang JIN Jun MA Wanyun HE Dan XIANG Baoli FAN Keting LIU Miao

中国石油大学 地球科学学院, 北京 102249 油气资源与探测国家重点实验室, 北京 102249 新疆砾岩油藏实验室, 新疆 克拉玛依 834000 砾岩油气藏勘探开发重点实验室, 新疆 克拉玛依 834000 中国石油 新疆油田分公司 实验检测研究院, 新疆 克拉玛依 834000

College of Geosciences, China University of Petroleum (Beijing), Beijing 102249, China State Key Laboratory of Petroleum Resources and Prospecting, Beijing 102249, China Xinjiang Conglomerate Reservoir Laboratory, Karamay, Xinjiang 834000, China Key Laboratory of Exploration and Development of Conglomerate Reservoirs, Karamay, Xinjiang 834000, China Research Institute of Experimental Testing, Xinjiang Oilfield Company, PetroChina, Karamay, Xinjiang 834000, China

随着准噶尔盆地勘探的不断深入，准南下组合日益成为油气勘探的重点，但目前针对下组合烃源岩生烃演化特征尚未进行系统性研究，不同岩性煤系烃源岩生烃能力和生油气量如何等尚未进行系统性实验分析。最近获得高产的高泉背斜高探1井油气与哪种岩性煤系源岩关系最为密切等都值得进一步讨论。通过对侏罗系煤岩、碳质泥岩和泥岩进行密闭容器高压釜加水热模拟实验，对3种岩性煤系烃源岩生烃特征及油气源对比进行了研究。碳质泥岩和泥岩具有较高的生油潜力，碳质泥岩是侏罗系煤成油的主要贡献者，且角质体可能是碳质泥岩主要生油母质。煤岩在更高演化阶段较碳质泥岩和泥岩具有更高的生气潜力，且主要为干酪根降解气。模拟气体随演化程度升高均不同程度出现碳同位素分馏效应，即随成熟度增加气体稳定碳同位素先变轻后变重，且δ13C1分馏效应较δ13C2明显。结合模拟实验进一步对高探1井油气源进行了分析，认为高探1井下白垩统清水河组原油主要为侏罗系碳质泥岩生成的较高成熟度原油，而3种岩性煤系烃源岩对天然气均有贡献。

With the deepened exploration progress in the Junggar Basin, the lower assemblage has increasingly become the focus for oil and gas exploration. However, systematic research has not been achieved on the hydrocarbon generation characteristics of the lower assemblage source rocks, and systematic experimental analysis has not been carried out on the hydrocarbon generation potential and oil and gas generation capacity of coaly source rocks with different lithology. Oil and gas have highly yielded in the well of Gaotan 1 in the Gaoquan anticline, and which lithology of coaly source rocks have the closest relationship with it is worth for a further discussion. Sealed vessel autoclave hydrous simulation of Jurassic coaly rock, carbonaceous mudstone and mudstone was carried out in this study, results show that carbonaceous mudstone and mudstone have high oil generation potential. Carbonaceous mudstone is the main contributor of Jurassic coal formed oil, and cutinite may be the main oil source in carbonaceous mudstone. Coaly rock has higher gas generation potential than carbonaceous mudstone and mudstone in higher evolution stage, mainly generating kerogen cracking gas. The carbon isotopic fractionation of simulated gas appears in vary degrees with the increase of evolution, that is, with the increase of maturity, the stable carbon isotope of gas first becomes lighter and then becomes heavier, and the δ13C1 fractionation is more obvious than that of δ13C2. Combined with simulation experiments, the oil and gas source of well Gaotan 1 was further analyzed. It was then concluded that the crude oil of Cretaceous Qingshuihe Formation in well Gaotan 1 is mainly high-mature crude oil generated by Jurassic carbonaceous mudstone, and the three lithologic coaly source rocks contributed to natural gas.

中石油新疆油田分公司对外协作项目 2020-C4006

https://doi.org/10.11781/sysydz202204687