远源致密砂岩气成藏主控因素及成藏概率定量评价——以四川盆地西南部中侏罗统沙溪庙组气藏为例  

Major controlling factors and quantitative probability evaluation of hydrocarbon accumulation in distal tight sandstone gas reservoirs:A case study on the gas reservoir of Middle Jurassic Shaximiao Formation in the southwestern Sichuan Basin

作　　者：吕雪莹 李小刚 王小娟[2] 杨田 陈双玲[2] 潘珂[2] 杨鑫[1] 朱德宇 杜璐露 LYU Xueying;LI Xiaogang;WANG Xiaojuan;YANG Tian;CHEN Shuangling;PAN Ke;YANG Xin;ZHU Deyu;DU Lulu(School of Petroleum Engineering,Chongqing University of Science&Technology,Chongqing 401331,China;Exploration and Development Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610051,China;Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu,Sichuan 610059,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation//Chengdu University of Technology,Chengdu,Sichuan 610059,China)

机构地区：[1]重庆科技大学石油与天然气工程学院 [2]中国石油西南油气田公司勘探开发研究院 [3]成都理工大学沉积地质研究院 [4]油气藏地质及开发工程全国重点实验室·成都理工大学

出　　处：《天然气工业》2024年第6期12-22,共11页Natural Gas Industry

基　　金：重庆市教育委员会科学技术研究项目“不同源储接触关系下油气充注机理研究”(编号:KJQN202001516);自然资源部沉积盆地与油气资源重点实验室开放基金项目“强改造作用下页岩气保存机制研究:以雪峰山沅麻盆地下寒武统牛蹄塘组为例”(编号:cdcgs2022006)。

摘　　要：四川盆地西南部(以下简称川西南部地区)中侏罗统沙溪庙组致密砂岩气藏属于远源次生气藏,不同构造天然气富集差异性大,成藏主控因素不清。为此,基于远源致密砂岩气成藏条件分析,对比了川西南部地区沙溪庙组7个含气构造的成藏差异性,明确了成藏主控因素,在综合考虑控制致密砂岩气成藏差异性的各类地质因素的基础上,建立了远源致密砂岩气成藏概率的定量评价方法,并预测了天府气田简阳区块沙溪庙组天然气储量丰度。研究结果表明:(1)川西南部地区沙溪庙组主要发育构造—岩性气藏,天然气均源自下伏上三叠统须家河组煤系烃源岩,不同含气构造在天然气组分、储层特征、输导保存条件等方面存在明显差异;(2)烃源岩排烃能力奠定了物质基础,断—盖配置决定了天然气富集层系,断—储耦合控制着天然气聚集效率,储层品质决定了天然气富集规模;(3)烃源岩排烃能力指数、源—储距离指数、储层物性指数、储层厚度指数、断—盖耦合类型指数及断—储配置类型指数可作为评价致密砂岩气成藏概率指标,提出的远源致密砂岩气成藏概率指数(HAI)可用于该地区远源致密砂岩气地质储量预测。结论认为,HAI与储量丰度具有很好的正相关关系,并预测了天府气田简阳区块的HAI值为0.53,沙溪庙组气藏的储量丰度为1.32×10^(8)m^(3)/km^(2),提出的天然气成藏定量评价方法准确度较高,为川西南部地区沙溪庙组天然气勘探开发指明了方向。The tight sandstone reservoir of the Middle Jurassic Shaximiao Formation in the southwestern Sichuan Basin is a distal secondary gas reservoir.There are significant differences in natural gas enrichment among different gas bearing structures,however,the main controlling factors of hydrocarbon accumulation have not been figured out.Therefore,the hydrocarbon accumulation conditions of distal tight sandstone gas reservoirs were firstly analyzed.And then,7 gas bearing structures of the Shaximiao Formation in the southwestern Sichuan Basin were compared in terms of the differences in hydrocarbon accumulation,and the major controlling factors of hydrocarbon accumulation were clarified.Finally,a method for quantitatively evaluating the accumulation probability of distal tight sandstone gas was established by comprehensively considering various geological factors that control the differences in tight sandstone gas accumulation.On this basis,the abundance of natural gas reserves in Shaximiao Formation of Jianyang Block in the Tianfu Gas Field were predicted.And the following research results are obtained.First,the Shaximiao Formation gas reservoir in the southwestern Sichuan Basin is mainly a structural-lithological gas reservoir,with natural gas sourced from the underlying coal measure source rocks of Upper Triassic Xujiahe Formation.Different gas bearing structures are greatly different in natural gas composition,reservoir characteristics,and migration and preservation conditions.Second,the hydrocarbon expulsion ability of source rocks lays the material foundation,faultcaprock configuration determines the natural gas enriched layers,fault-reservoir coupling controls the natural gas accumulation efficiency,and reservoir quality determines the natural gas enrichment scale.Third,hydrocarbon expulsion capacity index of source rock,sourcereservoir distance index,reservoir physical property index,reservoir thickness index,fault-cap coupling type index,and fault-reservoir configuration type index can be taken as the evaluation

关 键 词：远源致密砂岩气 成藏主控因素 成藏概率指数 中侏罗统 沙溪庙组 四川盆地西南部 有利勘探区 

分 类 号：TE122.1[石油与天然气工程—油气勘探]