岩相构型对致密砂岩优质储层的控制作用——以川西坳陷须二段为例  

The controlling effect of lithofacies architecture on high quality tight sandstone reservoirs:A case study of second member of the Upper Triassic of Xujiahe Formation,western Sichuan Depression,China

作　　者：印森林[1] 陈恭洋[1] 张玲[2] 罗迎春[1] 汪超平[3] 刘甜甜[3] 

机构地区：[1]长江大学录井技术与工程研究院,湖北荆州434023 [2]中国石化西南油气分公司勘探开发研究院,四川成都610041 [3]长江大学地球科学学院,湖北武汉430100

出　　处：《天然气地球科学》2016年第7期1179-1189,共11页Natural Gas Geoscience

基　　金：国家自然科学基金项目(编号:41502126);长江大学青年基金项目(编号:2015cqn55);中国石油大学(北京)油气资源与探测国家重点实验室开放基金项目(编号:PRP/open-1510)联合资助

摘　　要：针对致密砂岩优质储层的沉积成因机制及其分布模式不完善的情况,拟探讨不同岩相构型叠置样式对致密砂岩优质储层的控制作用。利用野外露头、地震资料、样品分析化验资料、测井资料及生产测试资料,结合砂体结构分析法、沉积岩相分析法及岩相组合成因分析法等开展岩相构型控制下致密砂岩优质储层的分布模式研究。研究表明:1不同岩相构型揭示了不同的沉积环境。须家河组二段典型的岩相构型样式有5种,其与沉积亚相具有较好的对应关系。2岩相构型对储层质量具有重要的控制作用。取样分析揭示了块状层理细—粉砂岩孔隙度均值小于交错层理粉砂岩孔隙度均值,其中块状层理细—粉砂岩储层(河道主体)顶部孔隙度比底部及侧翼要高,交错层理粉砂岩储层(废弃河道)则表现为中心及底部孔隙度值高,其侧翼及其顶部孔隙度低。3岩相构型对含气性的控制作用明显。分层系数越高,含气性高产的可能性就越大,分层系数越低,水层的可能性越大。相变带及裂缝发育带是控制含气性的2个关键因素,相变带和裂缝发育带的耦合则是形成高产井气藏的必要条件。Deposition mechanism and distribution patterns of high quality tight sandstone reservoirs are not fully understood yet,so this study intends to discuss the controlling effect of stacking patterns of different lithofacies architectures on high quality tight sandstone reservoirs.By using outcrops,seismic data,physical property and logging and test data,the distribution patterns of high quality tight sandstone reservoirs controlled by lithofacies architecture have been investigated with sand body structure analysis,sedimentary lithofacies analysis,genesis analysis of lithofacies and lithofacies combinations methods.The research indicates：（1）Different lithofacies architectures suggest different depositional environments.There are 5 typical lithofacies architectures in the 2^（nd） member of Xujiahe Formation,which correspond well with sedimentary subfacies.（2）The quality of reservoir is strongly controlled by lithofacies architecture.The analysis of samples shows that the average porosity of fine siltstone with massive bedding is lower than that of siltstone with crossing bedding,and the porosity of the top of fine siltstone reservoir with massive bedding（main part of channel）is higher than that ofits bottom and flank;whilefor siltstone reservoirs with crossing bedding,the center and bottom part have higher porosity than the flank and top（abandoned channel）.（3）Lithofacies architecture has strong control over gas-bearing property.The higher the lamination factor,the higher the possibility of high gas productivity.The lower the lamination factor,the higher the possibility of water-bearing layer.Facies change zone and fracture developing zone are two key factors affecting gas bearing property,and the coupling offacieschange zone and fracture developing zone is the necessary condition for high production gas wells.

关 键 词：岩相构型 须家河组 致密砂岩气 优质储层 川西坳陷 

分 类 号：TE122.21[石油与天然气工程—油气勘探]