鄂尔多斯盆地甘泉地区山2段储层特征及其控制因素研究

Study on Reservoir Characteristics and Control Factors of Shan-2 Section in Ganquan Area,Ordos Basin

通过实地地质调查,同时依托区域背景资料,利用相关岩心描述、物性分析、薄片鉴定、扫描电镜及压汞分析等资料,分别从岩石学特征、物性特征、孔隙结构特征三方面对鄂尔多斯盆地甘泉地区山2段储层进行了研究,并从沉积作用、成岩作用方面对其控制因素进行了深入剖析。结果表明:1)辫状河三角洲沉积的山2段储层具成分成熟度与结构成熟度均为中等的岩石学特点,储层孔隙类型以晶间孔和次生溶孔为主,孔喉半径整体偏小,分选中等,孔喉连通性差,晶间孔和次生溶孔是基本油气储集空间,细喉则是基本渗流通道,属于特低孔、致密储集层。2)储层物性受沉积微相和成岩作用双重控制,平面上储层物性受沉积相带的控制,垂向上压实、压溶以及胶结作用对储层是一种破坏,而溶蚀作用对本区山2段储层物性起到建设性的影响。

Acoording to the field geological survey,combined with regional geological data,using relevant core description,core analysis data,thin section identification,scanning electron microscopy and mercury pressure analysis,the reservoir of the Shan-2 section of Ganquan area of Ordos Basin was studied from three aspects:petrological characteristics,physical property characteristics and pore structure characteristics,and its controlling factors were analyzed in depth from the aspects of sedimentation and diagenesis.The results show that:(1)The reservoir of the Shan-2 section sedimented in the braided-river delta has medium petrological characteristics of composition maturity and structural maturity,and the reservoir pore types are mainly intergranular pores and secondary dissolution pores,the overall pore throat radius is small,sorting is different,and the pore-throat connectivity is poor,and the intergranular pores and secondary dissolution pores are the basic oil and gas storage space,and the fine throat is the basic seepage channel,which belongs to ultra-low porous and tight reservoirs.(2)The physical properties of the reservoir are controlled by the dual control of sedimentary microfacies and diagenesis,and the physical properties of the reservoir on the plane are controlled by the sedimentary facies zone,and vertical compaction,compaction and cementation are a kind of damage to the reservoir,while the dissolution effect has a constructive effect on the physical properties of the reservoir in the Shan-2 section in this area.