鄂尔多斯盆地东部山西组2段致密砂岩储层特征  

Characteristics of tight sandstone reservoirs of the second member of Shanxi Formation in eastern Ordos Basin

作　　者：王永骁 付斯一 张成弓[1] 范萍[2] WANG Yongxiao;FU Siyi;ZHANG Chenggong;FAN Ping(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China;Research Institute of Exploration and Development,PetroChina Changqing Oilfield Company,Xi’an 710018,China)

机构地区：[1]油气藏地质及开发工程国家重点实验室(成都理工大学),成都610059 [2]中国石油长庆油田分公司勘探开发研究院,西安710018

出　　处：《岩性油气藏》2021年第6期12-20,共9页Lithologic Reservoirs

基　　金：“十三五”国家科技重大专项“鄂尔多斯盆地大型低渗透岩性地层油气藏开发”(编号:2016ZX05050005);国家科技重大专项“鄂尔多斯盆地西部上古生界沉积体系及储层展布规律”(编号:2016ZX05050-001)联合资助。

摘　　要：鄂尔多斯盆地东部山西组2段是主力产气层位,埋深浅,但物性较差。为明确低孔低渗成因并预测储层有利区,在岩心观察的基础上,用薄片镜下鉴定、扫描电镜、压汞等实验手段结合成岩相分析,结果表明:山2段致密砂岩储层的岩石类型主要为中—细粒岩屑石英砂岩和石英砂岩,储集空间以粒间孔为主,为低孔低渗储层。其主要成因:①沉积砂岩中含有部分塑性颗粒和岩屑,受压易变形,降低了物性;②多种类型的胶结物充填了大量孔隙,加剧物性变差;③含煤的酸性沉积环境不利于原生孔隙的保存;④后期较弱的溶蚀作用无法改善储层物性。研究认为乌拉庙—榆林—清涧地和府谷—佳县—吴堡地区为储层相对有利区。该成果可对鄂尔多斯盆地东部致密砂岩气勘探部署提供依据。The second member of Shanxi Formation in eastern Ordos Basin is a key gas producing zone,with shal‐low buried depth but poor physical properties.In order to clarify the genesis of low porosity and low permeability and predict the favorable areas of reservoirs,based on the drilling core observations,the experimental methods such as identification under thin slice microscope,scanning electron microscope,mercury intrusion were used.The results show that the tight sandstone reservoirs of the second member of Shanxi Formation are mainly medium fine-grained lithic quartz sandstone and quartz sandstone,and the reservoir space is dominated by intergranular pores.The main causes of low porosity and low permeability:(1)There are some plastic particles and debris in the sedimentary strata,which are easy to deform under pressure and reduce physical properties.(2)Multiple ce‐mentation produces many types of cements,filling a large number of pores and aggravating the deterioration of physical properties.(3)The acidic sedimentary environment containing coal is not conducive to the preservation of primary pores.(4)The weak dissolution in later stage cannot improve the physical properties of the reservoir.Combined with the analysis of the plane distribution characteristics of diagenetic facies,it is considered that the Wulamiao-Yulin-Qingjiandi and Fugu-Jiaxian-Wubao areas are relatively favorable reservoir areas.The research results can provide re ference for the exploration and deployment of tight sandstone gas in eastern Ordos Basin.

关 键 词：致密砂岩 储层特征 成岩相 山西组 鄂尔多斯盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]