川西地区雷口坡组四段天然气成藏过程分析  

Analysis of gas accumulation process of the fourth member of Leikoupo Formation,Western Sichuan Basin

作　　者：陈智远[1,2] 孟宪武[2] 沈开元 张晓文 宋晓波[2] CHEN Zhiyuan;MENG Xianwu;SHEN Kaiyuan;ZHANG Xiaowen;SONG Xiaobo(Post-doctoral Research Station,Southwest Petroleum Branch,SINOPEC,Chengdu,Sichuan 610041,China;Research Institute of Petroleum Exploration and Production,Southwest Petroleum Branch,SINOPEC,Chengdu,Sichuan 610041,China;Well Testing Company,Xibu Drilling and Exploration Engineering Company,Karamay,Xinjiang 834000,China)

机构地区：[1]中国石化西南油气分公司博士后科研工作站,四川成都610041 [2]中国石化西南油气分公司勘探开发研究院,四川成都610041 [3]中国石油西部钻探工程有限公司试油公司,新疆克拉玛依834000

出　　处：《东北石油大学学报》2021年第3期1-9,I0001,共10页Journal of Northeast Petroleum University

基　　金：中国石油化工股份有限公司“十条龙”项目(P16093)。

摘　　要：基于川西地区构造演化,利用区域基础地质资料和流体包裹体等分析测试数据,恢复川西地区雷口坡组四段埋藏—热演化史,明确天然气成藏过程。结果表明:研究区主要发育两类包裹体,即含烃盐水包裹体和盐水包裹体,盐水包裹体较为常见,显微镜下可见气烃和极少量的液态烃包裹体;盐水包裹体均一温度分布在80~200℃之间,表现为双峰型特征,峰温分别为130~140和160~170℃;天然气主成藏期有两期,第一主成藏期主要为早侏罗世晚期—中侏罗世中晚期,第二主成藏期主要为中—晚中新世。天然气成藏过程为上二叠统烃源岩在晚三叠世(印支末期)进入生油高峰期,形成古油藏;至晚三叠世—中侏罗世,古油藏裂解成气;中—晚侏罗世(燕山早期),雷口坡组烃源岩进入生气高峰期,进一步补充气源,在川西地区正向构造中形成天然气藏。受喜山期构造挤压抬升的影响,雷口坡组内部继续发育小断层,至中—晚中新世,古气藏发生调整并最终定型。该结果为川西地区雷口坡组天然气勘探提供指导。Based on the tectonic evolution of Western Sichuan Basin,the burial-thermal evolution history of T 2 l 4 is restored,and the process of natural gas accumulation is clarified by using regional basic geological data and fluid inclusion analysis test data.The results show that there are two types of inclusions(including hydrocarbon bearing brine inclusions and brine inclusions).Under the microscope,brine inclusions are more common.Gas hydrocarbon and a small amount of liquid hydrocarbon inclusions can be seen in T 2 l 4.The homogenization temperature of inclusions is mainly distributed between 80-200℃,with bimodal characteristics.The peak temperatures are 130-140 and 160-170℃,respectively.It shows that there are two stages of main gas accumulation in T 2 l 4,the first stage of main gas accumulation is mainly from the late of Early Jurassic to the middle-late of Middle Jurassic,and the second stage of main gas accumulation is mainly from the Middle-Late Miocene.The natural gas accumulation process is as follows:the Upper Permian source rock entered the peak period of oil generation in the Late Triassic(the end of Indosinian)and formed the paleo oil reservoir;the paleo oil reservoir cracked into gas from Late Triassic to Middle Jurassic,and the source rock of Leikoupo Formation entered the peak period of gas generation in the Middle-Late Jurassic(the early of Yanshan)to further supplement gas source,forming natural gas reservoir in the positive structure of Western Sichuan Basin.Due to the influence of tectonic compression and uplift since Himalayan,small faults continue to develop in Leikoupo Formation,and in the Middle-Late Miocene,the paleo gas reservoir was adjusted and finally finalized.The results provide guidance for natural gas exploration of Leikoupo Formation in Western Sichuan Basin.

关 键 词：包裹体特征 埋藏—热演化史 成藏过程 均一温度 雷口坡组四段 川西地区 

分 类 号：TE122.11[石油与天然气工程—油气勘探]