四川盆地东部复兴地区侏罗系东岳庙段页岩热演化史及油气地质意义  

Thermal evolution history of the Jurassic Dongyuemiao shale in the Fuxing area of eastern Sichuan Basin and its petroleum geological significance

作　　者：包汉勇[1] 张莉[2] 舒逸 杨锐[3] 余慧 BAO Hanyong;ZHANG Li;SHU Yi;YANG Rui;YU Hui(Oil and Gas Production Capacity Building Management Center,Sinopec Jianghan Oilfield Company,Chongqing 408107,China;Exploration and Production Research Institute,Sinopec Jianghan Oilfield Company,Wuhan,Hubei 430070,China;MOE Key Laboratory of Tectonics and Petroleum Resources,China University of Geosciences-Wuhan,Wuhan,Hubei 430074,China)

机构地区：[1]中国石化江汉油田分公司油气产能建设管理中心 [2]中国石化江汉油田分公司勘探开发研究院 [3]中国地质大学(武汉)构造与油气资源教育部重点实验室

出　　处：《天然气工业》2025年第1期68-79,共12页Natural Gas Industry

基　　金：国家自然科学基金面上项目“构造抬升-降温阶段海相深层页岩气赋存状态动态演化过程”(编号:42172157);中国石化股份有限公司科研项目“川东地区重点层系页岩气成藏条件与评价技术研究”(编号:P23077)。

摘　　要：页岩热演化史与油气生成过程、微观孔隙的形成演化以及油气的富集成藏密切相关,是准确评价页岩油气资源潜力、揭示成藏富集规律的关键参数。为了准确评价四川盆地东部复兴地区侏罗系东岳庙段页岩热演化史、含油气特征及其与海相页岩气的差异,结合研究区典型井地质、测井及地球化学资料,利用BasinMod软件模拟了东岳庙段页岩的埋藏史、热演化史和生烃史,探讨了页岩热演化与油气生成、孔隙演化、成藏富集之间的关系。研究结果表明:(1)研究区东岳庙段页岩在侏罗纪中期进入生烃门限,侏罗纪中晚期达到主生油高峰,并存在两个生烃高峰,分别为侏罗纪末期和白垩纪中期;(2)第一个生烃高峰期以生油为主,持续时间长且生烃速率较快,第二个生烃高峰期以生成凝析油和湿气为主,持续时间较短且生烃强度较低;(3)东岳庙段页岩的平均累计生油强度为9.5×10^(8)t/km^(2),平均累计生气强度为2.5×10^(8)m^(3)/km^(2);(4)东岳庙段页岩孔隙演化过程可分为4个阶段,分别为早期压实减孔阶段、液态烃滞留堵孔阶段、热裂解有机孔形成阶段和热裂解生湿气阶段;(5)压实作用和液态烃滞留堵孔是导致页岩原生孔隙快速减少的主要原因,有机质(主要为固体沥青)与黏土混杂堆积形成的有机黏土复合体是东岳庙段页岩重要的储集空间。结论认为:(1)不同构造部位的埋藏史、热演化史和生烃史影响了页岩油气的生成、排放与滞留,决定了现今页岩油气的含量差异,抬升剥蚀厚度较小且保存条件较好的地区,具有较高的油气滞留量,值得高度关注;(2)成果认识坚定了川东地区陆相页岩油气勘探开发信心,为其他类似地质情况的探区提供了有益借鉴。The thermal evolution history of shale is closely related to hydrocarbon generation process,micropore formation and evolution,and hydrocarbon accumulation and enrichment,and it is a key parameter for accurately evaluating the resource potential of shale oil and gas and understanding its accumulation and enrichment patterns.In order to accurately evaluate the thermal evolution history and hydrocarbon-bearing characteristics of the Jurassic Dongyuemiao Member shale in the Fuxing area of eastern Sichuan Basin and its difference from marine shale gas,the burial history,thermal evolution history and hydrocarbon generation history of the Dongyuemiao Member shale were simulated by using the BasinMod software,based on the geological,logging and geochemical data of some typical wells in the study area.In addition,the relationships of shale thermal evolution with hydrocarbon generation,pore evolution,and hydrocarbon accumulation and enrichment were discussed.The following results are obtained.First,the Dongyuemiao Member shale in the study area reached the hydrocarbon generation threshold in the middle Jurassic period and entered the main oil generation peak in the middle to late Jurassic,with two distinct hydrocarbon generation peaks occurring at the end of the Jurassic and in the middle Cretaceous,respectively.Second,the first hydrocarbon generation peak is primarily characterized by oil generation,with a long duration and high hydrocarbon generation rate,while the second peak is dominated by the generation of condensate oil and wet gas,with a short duration and low hydrocarbon generation intensity.Third,the average cumulative oil generation 88 intensity of the Dongyuemiao Member shale is 9.5×10^(8) t/km^(2),and the average cumulative gas generation intensity is 2.5×10^(8)^(3)/km^(2).Fourth,the pore evolution process in the Dongyuemiao Member shale can be divided into four stages:early compaction and pore reduction,liquid hydrocarbon retention causing pore blockage,organic pore formation by thermal cracking,and wet gas

关 键 词：四川盆地 复兴地区 东岳庙段 生烃能力 热演化史 页岩油气 地质意义 

分 类 号：TE122[石油与天然气工程—油气勘探]