断层封闭性演化地球化学评价方法及其控藏作用——以准噶尔盆地西北缘红车断裂带为例  

A geochemical evaluation method of fault sealing evolution and its controlling effect on hydrocarbon accumulation:A case study of the Hongche fault zone in the northwest margin of the Junggar Basin

作　　者：李勇[1,2,3] 罗力元 王剑[4] 刘向君 马万云[4] 陈世加[1,2,3] 何清波[3] LI Yong;LUO Liyuan;WANG Jian;LIU Xiangjun;MA Wanyun;CHEN Shijia;HE Qingbo(State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation//Southwest Petroleum University,Chengdu,Sichuan 610500,China;Sichuan Provincial Key Laboratory of Gas Geology,Chengdu,Sichuan 610500,China;School of Geoscience and Technology,Southwest Petroleum University,Chengdu,Sichuan 610500,China;Research Institute of Experiment and Testing,PetroChina Xinjiang Oilfield Company,Karamay,Xinjiang 834000,China)

机构地区：[1]油气藏地质及开发工程全国重点实验室·西南石油大学 [2]天然气地质四川省重点实验室 [3]西南石油大学地球科学与技术学院 [4]中国石油新疆油田公司实验检测研究院

出　　处：《天然气工业》2023年第8期12-25,共14页Natural Gas Industry

基　　金：国家科技重大专项“准噶尔盆地火山岩大型气田成藏过程与富集规律”(编号:2016ZX05007003-007);中国石油—西南石油大学创新联合体科技合作项目“鄂尔多斯盆地海陆过渡相页岩气规模建产开发关键技术研究”(编号:2020CX030000)、“四川盆地侏罗系湖相页岩油地质理论技术研究与有利区评价”(编号:2020CX050000)。

摘　　要：断层封闭性评价对油气成藏研究具有重要的指导意义,但是断层封闭性演化和油气动态成藏有机结合的研究却较少。为此,以准噶尔盆地西北缘红车断裂带为例,利用烃源岩生物标志化合物、生烃热模拟产物特征、原油色谱色质、碳同位素、轻烃等地球化学实验分析技术,建立了断层封闭性演化地球化学评价方法,揭示了不同地质历史时期断层封闭性差异演化对油气运聚成藏的控制作用。研究结果表明:①红车断裂带断层侧向封闭性控制了断层上/下盘原油性质差异。②晚三叠世—早侏罗世,断层侧向对油气不封闭,下二叠统风城组烃源岩成熟阶段原油运移至上盘石炭系遭受生物降解形成高密度重质油;晚侏罗世—早白垩世,断层侧向对油封闭,对气不封闭,风城组高成熟原油和中二叠统下乌尔禾组成熟原油在下盘聚集成藏。③不同地质历史时期断层对不同流体封闭性差异是红车断裂带油藏伴生气普遍为干气的主要原因。④断层封闭性演化可以划分为开启、弱封闭、中封闭、强封闭4个演化阶段,分别控制了油气散失、上盘油藏遭受生物降解、下盘油藏聚集天然气散失、晚期干气捕获4个成藏过程,前3个阶段导致成熟—高成熟阶段天然气散失,晚期强封闭阶段干气大规模聚集,形成了重质油、中质油、轻质油、干气并存的油气分布复杂现象。结论认为,建立的断裂封闭性动态演化历程的地球化学评价方法,对复杂地区多源多期油气勘探开发具有重要的指导意义。Evaluation on fault sealing evolution is of guiding significance to hydrocarbon accumulation research,but there are few researches on the organic combination of fault sealing evolution and dynamic hydrocarbon accumulation.Taking the Hongche fault zone in the northwest margin of the Junggar Basin as an example,this paper establishes a geochemical evaluation method of fault sealing evolution by means of the geochemical test and analysis technologies such as biomarker of source rocks,characteristics of hydrocarbon generation thermal simulation products,chromatography and mass spectroscopy of crude oil,carbon isotopes,and light hydrocarbons.In addition,the controlling effect of the differential evolution of fault sealing in different geological periods on hydrocarbon migration and accumulation is revealed.The following research results are obtained.First,the lateral sealing of the fault in the Hongche fault zone controls the difference of crude oil properties between the upper and the lower block of the fault.Second,in the Late Triassic to the Early Jurassic,the fault didn't provide lateral sealing to oil and gas,so mature crude oil migrated from the source rock of Lower Permian Fengcheng Formation to the Carboniferous in the upper block,where it was biodegraded to high-density heavy oil.In the Late Jurassic to the Early Cretaceous,the fault sealed oil laterally instead of gas,so the highly mature oil of Fengcheng Formation and the mature oil of Middle Permian Lower Wuerhe Formation accumulated in the lower block.Third,the main reason why the associated gas in the reservoir of Hongche fault zone is generally dry gas is that the sealing of faults to different fluids is different in different geological periods.Fourth,the evolution of fault sealing can be divided into four stages:opening,weak sealing,medium sealing and strong sealing,which respectively control the four accumulation processes of oil and gas loss,oil reservoir biodegradation at the upper block,oil reservoir accumulation and natural gas loss at the lower

关 键 词：断层封闭性 地球化学评价 控藏作用 准噶尔盆地 红车断裂带 

分 类 号：P618.13[天文地球—矿床学]