基于热压生排烃模拟实验的不同类型湖相烃源岩生排烃特征  

Characteristics of hydrocarbon generation and expulsion in different types of lacustrine source rocks based on thermo-compression simulation experiments

作　　者：畅厚鹏 徐建永 徐耀辉 刘岩[1,2] 李威 钟鸣宇[1,2] 李阳 王豫昌 CHANG Houpeng;XU Jianyong;XU Yaohui;LIU Yan;LI Wei;ZHONG Mingyu;LI Yang;WANG Yuchang(Hubei Key Laboratory of Petroleum Geochemistry and Environment,College of Resources and Environment,Yangtze University,Wuhan 430100,China;Key Laboratory of Oil and Gas Resources and Exploration Technology of Ministry of Education(Yangtze University),Wuhan 430100,China;CNOOC Research Institute,Beijing 100010,China)

机构地区：[1]油气地球化学与环境湖北省重点实验室,长江大学资源与环境学院,湖北武汉430100 [2]油气资源与勘探技术教育部重点实验室(长江大学),湖北武汉430100 [3]中海油研究总院有限责任公司,北京100010

出　　处：《天然气地球科学》2024年第12期2240-2252,共13页Natural Gas Geoscience

基　　金：国家自然科学基金项目“渤海湾盆地PETM事件记录和有机质富集—来自藿烷单体烃碳同位素的启示”(编号:42272175)资助。

摘　　要：为了对比分析不同类型有机质丰度烃源岩的生排烃特征,选取3块有机质类型不同且TOC差异较大的烃源岩样品,开展多路分段式热压生排烃模拟实验,总结其在各演化阶段的产物组成变化与排烃效率。结果表明:不同类型烃源岩生排烃模式比较类似,可分为生油阶段和生气阶段(以RO≈1.25%为界),在生油阶段累计排出油产率逐渐升高,残留油率曲线呈先升高后降低的趋势,此阶段烃气产率很低,排烃效率逐渐升高。进入生气阶段大部分油已经排出,累计排出油产率逐渐趋于平稳,残留油率很低,烃气产率迅速升高,此阶段排烃效率很高,最高达90%以上。Ⅰ型烃源岩的总油产率、排出油产率、残留油率、烃气产率及排烃效率均高于Ⅱ型烃源岩;Ⅰ型烃源岩主生油窗(0.65%<RO<1.25%)比Ⅱ型烃源岩(0.65%<RO<0.95%)宽。排出油产率峰值阶段均为0.86%<RO<1.07%,且随着烃源岩热演化程度的增加,I型烃源岩的阶段烃气产率逐渐升高,而Ⅱ型烃源岩阶段烃气产率在RO>1.24%之后不再升高。沉积环境与生源输入的不同是造成不同类型烃源岩生排烃特征差异的重要原因。优质烃源岩烃产率高于中等烃源岩,主生油期也更早,但中等烃源岩生烃早期阶段排油率更高,残留油率更低,导致在生烃早期排烃效率更高,同时TOC转化率也更高,说明较高TOC可能会增加烃源岩的滞油性,反而不利于烃类排出。In order to compare and analyze the hydrocarbon generation and expulsion characteristics of different types and organic matter abundances of source rocks,three source rock samples with different organic matter types and significant TOC differences were selected.Multiple segmented thermo-compression hydrocarbon gen⁃eration and expulsion simulation experiments were conducted to summarize the changes in product composition and expulsion efficiency at each evolution stage.The results show that the hydrocarbon generation and expulsion patterns of different types of source rocks in this article are relatively similar,which can be divided into oil gener⁃ation stage and gas generation stage(with R_(O)≈1.25% as the boundary).During the oil generation stage,the cu⁃mulative oil production rate gradually increases,and the residual oil rate curve shows a trend of increasing and then decreasing.At this stage,hydrocarbon gas yield is very low,and the hydrocarbon expulsion efficiency grad⁃ually increases.Most of the oil has been discharged during the gas generation stage,and the cumulative oil pro⁃duction rate gradually stabilizes.The residual oil rate is very low,and the hydrocarbon gas production rate rapid⁃ly increases.At this stage,efficiency of hydrocarbon expulsion is very high,reaching over 90%.The total oil yield,discharged oil yield,residual oil rate,hydrocarbon gas yield,and expulsion efficiency of Type I source rocks are all higher than those of Type II source rocks;The main oil generation window of Type I source rocks(0.65%<R_(O)<1.25%)is wider than that of Type II source rocks(0.65%<R_(O)<0.95%).The peak stages of oil discharge yield are all 0.86%<R_(O)<1.07%,and as the degree of thermal evolution of the source rock in⁃creases,the stage hydrocarbon gas yield of Type I source rock gradually increases,while the stage hydrocarbon gas yield of Type II source rock no longer increases after R_(O)>1.24%.The difference in sedimentary environ⁃ment and source input is an important reason for the differences

关 键 词：湖相烃源岩 有机质丰度 生排烃特征 排烃效率 多路分段式热压生排烃模拟实验 

分 类 号：TE122.113[石油与天然气工程—油气勘探]