富有机质页岩中烃类动态运移对页岩气富集成藏的制约——以四川盆地龙马溪组为例  

Constraints of hydrocarbon migration in Longmaxi shale in Sichuan Basin on shale gas accumulation

作　　者：王佳[1,2] 谭先锋[2] 田景春[1] 罗超[3] 冉天 陈青[2] 李霞[2] 曾春林 Wang Jia;Tan Xianleng;Tian Jingchun;Luo Chao;Ran Tian;Chen Qing;Li Xia;Zeng Chunlin(Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, Sichuan 610059,China;School of Petroleum, Engineering, Chongqing University of Science ＆ Technology, Chongqing 401331,China;Exploration and Development Research Institute of Southwest Oil and Gas Field Company, PetroChina, Chengdu, Sichuan 610051,China;Chongqing Institute of Geology and Mineral Resources, Chongqing 400042,China)

机构地区：[1]成都理工大学沉积地质研究院,成都610059 [2]重庆科技学院石油与天然气工程学院,重庆401331 [3]中国石油西南油气田分公司勘探开发研究院,成都610051 [4]重庆地质矿产研究院,重庆400042

出　　处：《石油实验地质》2017年第6期755-762,769,共9页Petroleum Geology & Experiment

基　　金：国家自然科学基金项目(No.41402118;41202043);重庆市教委科学研究技术项目(KJ1601340)资助

摘　　要：页岩气作为一种典型的连续性油气藏,其形成和富集均发生在页岩中,因此页岩中天然气的形成、运移、聚集等过程是页岩气有效富集成藏的关键。以钻井及露头剖面为基础,采用有机地球化学分析、X射线衍射、扫描电镜等实验手段相结合,发现四川盆地龙马溪组页岩具有优异的地球化学参数和储层微观特征。以PY1井埋藏史为例,结合盆地区域构造演化史及龙马溪组页岩中有机质热演化史特征,通过与Barnett页岩对比发现,四川盆地龙马溪组页岩埋深相对较深,且后期构造运动导致其保存条件处于一个相对"开放"的状态,不利于页岩中游离气的赋存;同时龙马溪组页岩干酪根类型以Ⅰ或Ⅱ型干酪根为主,页岩在前期热演化过程中形成的烃类主要以石油的形式大范围排出页岩,仅晚期形成的过成熟气和滞留的油裂解气未脱离页岩系统,这在一定程度上制约了页岩气的有效富集成藏。A shale gas reservoir is typically a continuous hydrocarbon reservoir,and its lormation and enrichment cannot be separated from the shale. The generation,migration and accumulation ol natural gas are the key factors lor the ellective accumulation ol shale gas in shale. The Longmaxi shale in Sichuan Basin has excellent geochemical parameters and reservoir characteristics as indicated by organic geochemical analysis, X-ray diffraction and scanning electron microscopy and on drilling and outcrop data. We studied the tectonic evolution ol well PY1 in Sichuan Basin and the thermal evolution history ol organic matter in the Longmaxi shale. Compared to the Barnett shale,the Long- maxi shale was buried deeper,and was preserved in an open state due to tectonic activity,which was unlavorable lor lree gas accumulation. Kerogen in the Longmaxi shale belongs to types I and II. The early lormed hydrocarbons discharged out ol the shale in the lorm ol oil,and only the late l＇ ormed,overmature gas and secondary gas （lrom oil cracking） remained in the shale system, restricting the effective accumulation ol shale gas to some extent.

关 键 词：有机质 生烃演化 页岩气 龙马溪组 四川盆地 

分 类 号：TE132.2[石油与天然气工程—油气勘探]