鄂尔多斯盆地南部地区长7致密油储层特征  

Characteristics of Chang 7 Tight Oil Reservoir in the Southern Ordos Basin

作　　者：屈红军[1] 蒲仁海[1] 曹金舟[2] 郑艳荣[1] 董文武[1] 郭鹏戈 

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]延长油田股份有限公司,陕西延安716000

出　　处：《非常规油气》2015年第1期1-9,共9页Unconventional Oil & Gas

基　　金：国家自然科学基金重大项目;面上项目(41390451;41172101);延长油田股份有限公司科技项目(ycsy2011ky-B-76)联合资助

摘　　要：针对鄂尔多斯盆地南部长7油层组致密油储层开展研究。综合利用铸体薄片、压汞分析、X-衍射全岩和黏土矿物分析、扫描电镜等技术,对工区长7致密储层的岩石学特征、物性特征、微观孔喉特征及有利成岩相等进行综合分析评价。研究表明工区长7储层属特低孔、超低渗致密储层;岩石类型主要为浅灰绿色细粒长石砂岩,填隙物以(铁)方解石为主,绿泥石、伊利石和伊/蒙混层次之,孔隙类型以溶蚀粒间孔、长石溶孔为主,原生粒间孔次之;长7储层毛细管压力曲线特征总体表现为高排驱压力、细歪度,孔喉分选性及连通性较差;平均孔隙度为6.83%,平均渗透率为0.24m D,属小孔、微喉道型储层;长7油层组有利的成岩相类型为长石溶蚀相、绿泥石薄膜胶结原生粒间孔相和高岭石晶间溶孔相。We did research on tight reservoir characteristics in Chang 7 oil-bearing formation. Comprehensive analyses and assessments of the characteristics of lithology, physical property, reservoir micropore and throat characteristics, the fa- vorable diagenetic facies are made in the southern basin area based on techniques of cast thin section, mercury injection a- nalysis, whole rock X-ray diffraction analysis, clay mineral analysis, scanning electron microscope. The study shows that Chang 7 reservoirs are extra low porosity and super low permeability types of tight reservoirs, with the rock types being mainly grayish green fine feldspar sandstone, and the main cement mineral being calcite or ferrocalcite, and chlorite, illite, and illite-smectite mixed-layer followed. The main pore types are intergranular dissolved pore and feldspar dissolved pore, with the secondary pore types being residual primary pore. The characteristics of capillary pressure curves displayed high initial expulsion pressure, fine skewness, which reflecting poor pore throat sorting and poor connectivity in Chang 7 reser- voirs. With low porosity and permeability which are respectly 6. 83% and O. 24 mD in average, Chang 7 oil-bearing forma- tion reservoirs belongs to small pore and micro throat type. The favorable diagenetic facies are feldspar dissolution diagenet- ic facies, Chlorite membrane primary intergranular pore facies and Kaolinite intercrystalline solution pores in Chang 7 oil- bearing formation at the study area.

关 键 词：鄂尔多斯盆地南部 长7油层组 储层特征 致密油 成岩相 长石溶蚀相 

分 类 号：P618.13[天文地球—矿床学]