鄂尔多斯盆地延安地区山2段储层特征及其主控因素

Reservoir characteristics and main controlling factors of P1s2 member in Yan′an Area, Ordos Basin

琚惠姣 孙 卫 杨希濮 韩宗元

西北大学大陆动力学教育部重点实验室，陕西 西安 710069 中海油研究总院，北京 100027 胜利石油管理局石油开发中心，山东 东营 257000

MOE Key Laboratory of Continental Dynamics, Northwest University, Xi′an 710069, China Research Institute, CNOOC, Beijing 100027, China Petroleum Development Center, Shengli Petroleum Administration Bureau, SINOPEC, Dongying 257000, China

采用储层物性分析、扫描电镜、铸体薄片及高压压汞等实验技术，对鄂尔多斯盆地延安地区山2段储层岩心样品进行分析、测试，研究其储层基本特征，分析有利储层发育的主控因素。研究表明，鄂尔多斯盆地延安地区山2段储层属特低孔、低渗储层，但局部发育有物性相对较好的有利储层，其孔隙度在6.2%～13.2％，渗透率在（0.1～45）×10-3 μm2。有利储层的形成和分布主要受沉积微相和成岩作用的影响与控制。其中，水下分流河道和河口坝沉积微相控制了有利储层的分布范围，硅质胶结作用和溶蚀作用则促进了储层原生孔隙的保存和次生孔隙的形成。综合分析表明，有利储层主要发育在Y120、Y121、Y127、Y161、Y162、Y169及YQ2等井区的水下分流河道和河口坝砂体中。

On the basis of the laboratory techniques of reservoir property analysis, SEM, cast thin section, high pressure mercury penetration, the core samples of P1s2 reservoir in Yan′an Area, Ordos Basin are analyzed. This paper discusses the basic reservoir characteristics and describes the major controlling factors of reservoir development. Study results show that P1s2  reservoir in Yan′an Area belongs to especially low porosity and low permeability reservoir and the reservoir with good physical property developed partially. The porosity is 6.2%-13.2% in partial area and the permeability is 0.1-45 md. The formation and distribution of favorable reservoir are controlled mainly by sedimentary microfacies and diagenesis. The underwater distributary channel and mouth bar sedimentary microfacies control the distribution of favorable reservoir. Strong siliceous cementation and denudation promote the preservation of primary pore of reservoir and the formation of secondary pore. The comprehensive analysis result shows that the favorable reservoirs developed mainly in the sand body of underwater distributary channel and mouth bar in the well areas of Y120, Y121, Y127, Y161, Y162, Y169 and YQ2.