四川盆地中—上寒武统洗象池群油气成藏模式与勘探前景  

Hydrocarbon accumulation model and exploration prospect of the Xixiangchi Group of Middle-Upper Cambrian in the Sichuan Basin

作　　者：李英强 高键 李双建[1] 郝运轻[1] 林娟华[1] 孙炜[1] 武重阳 马强[1] 王琳霖 LI Yingqiang;GAO Jian;LI Shuangjian;HAO Yunqing;LIN Juanhua;SUN Wei;WU Chongyang;MA Qiang;WANG Linlin(Sinopec Petroleum Exploration and Production Research Institute,Beijing 102206,China)

机构地区：[1]中国石化石油勘探开发研究院

出　　处：《天然气工业》2022年第3期29-40,共12页Natural Gas Industry

基　　金：国家自然科学基金项目“海相深层油气富集机理与关键工程技术基础研究”(编号:U19B6003)。

摘　　要：四川盆地中—上寒武统洗象池群具有良好的天然气勘探潜力,但其勘探程度低,优质储层分布规律不清楚,源—储匹配和成藏条件不落实。为此,利用地震、钻井、露头及薄片等资料,对洗象池群沉积充填、岩相古地理、储层特征及主控因素进行了分析,在解剖典型井的基础上,通过落实烃源岩展布与生烃潜力、油气动态成藏与保存条件,探讨了洗象池群成藏模式及油气勘探前景。研究结果表明:(1)中—上寒武统洗象池群为川中—川北继承性古隆起背景下的碳酸盐岩局限—半局限台地沉积,主要发育颗粒滩相控型、岩溶改造型和裂缝型3类白云岩储层;(2)洗象池群储层岩性为粗晶粒结构的白云岩和针孔状白云岩,储集物性较好,高能相带叠加准同生溶蚀和表生岩溶作用是优质储层形成的主控因素;(3)建立了洗象池群4种成藏模式:以川中威远地区为代表的下生上储、断层垂向输导模式,以川东南平桥1井为代表的新生古储、断层侧向对接输导模式,以川北马深1井为代表的侧生旁储、不整合输导模式,以及川东北宣汉地区多源供烃、断层侧向+垂向联合输导的概念模式。结论认为,川中—川北古隆起周缘与绵阳—长宁古裂陷叠合区、古隆起斜坡背景下的高陡构造变形带是寻找规模天然气藏重点领域;川东高陡构造带源—储对接匹配好的“相对稳定”保存单元是深化天然气勘探的重要领域。The Xixiangchi Group of Middle-Upper Cambrian in the Sichuan Basin has good natural gas exploration potential.However,it is less explored,the distribution laws of its high-quality reservoirs are not understood clearly,and the source-reservoir configuration and hydrocarbon accumulation conditions are not determined.To this end,this paper analyzes the sedimentary filling,lithofacies paleogeography,reservoir characteristics and main controlling factors of Xixiangchi Group by using the data of seismic,drilling,outcrop and thin section.Then,based on the analysis of typical wells,the hydrocarbon accumulation model and exploration prospect of Xixiangchi Group are discussed by investigating the distribution and hydrocarbon generation potential of source rocks and the dynamic hydrocarbon accumulation and preservation conditions.And the following research results are obtained.First,the Xixiangchi Group of Middle-Upper Cambrian is a restricted to semi-restricted carbonate platform deposit under the background of inherited paleouplift in the central-northern Sichuan Basin,where three types of dolomite reservoirs are developed,including grain shoal facies controlled type,karst reconstructed type and fractured type.Second,the reservoir of Xixiangchi Group is lithologically dominated by coarse grained dolomite and pinhole shaped dolomite,and its physical properties are better.High-energy facies belt superimposed with penesyngenetic dissolution and supergene karstification is the main factor controlling the formation of high-quality reservoirs.Third,four hydrocarbon accumulation models are established for the Xixiangchi Group,including lower source rock and upper reservoir and vertical migration along faults represented by Weiyuan area of central Sichuan Basin,young source rocks and old reservoirs and migration through lateral fault contact represented by Well Pingqiao 1 in southeastern Sichuan Basin,lateral source rocks and lateral reservoirs and migration along unconformities represented by Well Mashen 1 in northern Sichuan Ba

关 键 词：四川盆地 中—上寒武统 洗象池群 沉积储层 构造—岩性气藏 成藏模式 勘探领域 

分 类 号：P618.13[天文地球—矿床学]