鄂尔多斯盆地东部梅塔区长2油层储层特征研究

Study on the Reservoir Characteristics of Chang-2 Reservoir in Meita Exploration Block,Eastern Ordos Basin

梅塔区长2油层砂体横向变化快、连通性差,造成储层空间展布复杂且非均质性强,储层的储集性能受多种因素影响,开发难度较大。针对这一现状,通过露头、岩心、测井及多种分析测试资料,对该区长2油层组沉积相、储层砂岩的物质成分、物性特征及成岩作用进行研究,详细探讨了影响储层物性的主要因素。研究表明:研究区长2砂岩储层孔隙类型以粒间孔为主,占总孔隙的73.6%;储层孔隙度一般多在10.0%~18.0%,平均孔隙度为13.7%;平均渗透率为2.9mD。成岩作用对砂岩储层物性的影响既有建设性也有破坏性。压实作用,碳酸盐、黏土矿物的胶结作用是破坏储层孔隙度、降低渗透率的主要因素;溶蚀作用易产生溶蚀孔隙,改善储层的物性。研究成果为该区长2油层的开发提供了充足的理论依据。

Sand body of Chang-2 reservoir in Meita exploration block varies fast horizontally and connected poor, leading to the complex spatial distribution of reservoirs and strong heterogeneity. Reservoir performance is affected by many factors, and the development is difficulty. In view of this situation, through outcrops, cores, well logging and analysis test data, of Chang-2 deposition phase, storage layer of sandstone material composition, physical characteristics and diagenesis are studied, a detailed discussion of the main factors affect the properties of the reservoir. Research showed that： Chang-2 sandstones reservoir pore types in intergranular pore, accounted for 73.6% of total porosity, reservoir porosity is general in 10.0% to 18.0%, average porosity is 13.7%, and the average permeability is 2.9mD. The effect of diagenesis on the physical properties of sandstone reservoir is not only constructive and destructive. The cementation of carbonate and clay minerals is the main factor to destroy the reservoir porosity and decrease the permeability. The research results provide sufficient theoretical basis for development of Chang-2 reservoir.