吴旗地区薛岔区块延长组长6砂岩储层成岩作用研究  

Diagenesis of Chang6 Reservoir in Xuecha Block of Wuqi Area

作　　者：曹斌风[1,2] 孙卫[1] 

机构地区：[1]西北大学大陆动力学国家重点实验室,西北大学地质学系,陕西西安710069 [2]中国石油大学地球科学学院,北京102249

出　　处：《天然气地球科学》2011年第6期951-960,共10页Natural Gas Geoscience

基　　金：国家科技支撑计划基金项目(编号:2007BAB17B00);西北大学创新性实验计划项目(编号:2009041)联合资助

摘　　要：为评价与预测鄂尔多斯盆地吴旗地区薛岔区块长6低孔—超低渗透砂岩储层,进行油藏精细描述和高效开发,通过铸体薄片、扫描电镜、X-射线衍射、电子探针、碳氧同位素和镜煤反射率方法研究储层成岩作用机理,揭示时空上成岩—物性演化规律。结果表明:目前长6储层主要处于晚成岩阶段的A期—B期;主要成岩作用类型有压实作用、胶结作用、交代作用、裂缝作用及烃类侵位作用;压实作用强烈是导致该储层早期孔隙丧失的根本原因;晚成岩阶段铁方解石胶结作用是造成储层物性非均质性严重的主要因素;溶蚀作用、绿泥石衬里、破裂作用及烃类侵位作用对储层物性起建设性作用;储层孔隙类型主要有残余粒间孔、长石溶孔和岩屑溶孔,次为微孔隙及裂缝孔隙;喉道细小,分选较差,孔喉连通性差;储层微观孔隙结构非均质性严重。同时,分析储层成岩演化序列和孔隙演化史。In order to evaluate and forecast the Chang6 reservoir of low porosity and super-low permeability sandstone in Xuecha block of Wuqi area in Ordos basin,describe the reservoir subtly and develop it effectively,this paper studies the reservoir diagenetic mechanism and reveals the diagenesis-physical property evolutionary law based on the data analysis of casting lamella,scan electron microscope,X-ray diffraction,electron probe,oxygen and carbon stable isotope and vitrinite reflectance.The results show that the Chang6 reservoir is now in the late diagenetic phase A to B;main diagenesis include compaction,cementation,metasomatosis,cataclasis and hydrocarbon emplacement;the intense compaction is the radical contributor to the pore beravement in early phase and the ferroan calcite cementation in the late diagenetic phase induces the severe heterogeneity of physical property;dissolution,grain-coating chlorite,cataclasis and hydrocarbon emplacement work on physical property constructively;pore types of Chang6 reservoir mainly include primary remained intergranular pore,feldspar dissolved pore and lithic dissolved pore,secondly micropore and fracture pore;the reservoir is characterized by fine throat,worse sorting,worse connectivity;the heterogeneity of the micro-pore structure is intense.Meanwhile,reservoir diagenetic evolutionary sequence and the history of porosity evolution are analysed.

关 键 词：超低渗透砂岩储层 长6储层 成岩作用 演化序列 微观孔隙结构 孔隙演化 

分 类 号：TE122.2[石油与天然气工程—油气勘探]