【摘要】 为了明确四川盆地龙女寺—广安地区中二叠统栖霞组储层特征与主控因素,综合利用岩心、镜下薄片、测井资料、地震预测成果分析了该地区中二叠统栖霞组储层特征,指出了其储集岩类型以残余生屑云岩、中—细晶云岩为主,储集空间中孔隙类型以晶间孔、晶间溶孔为主,溶洞类型以孔隙型溶洞为主、次为裂缝型溶洞。研究结果表明:①其储层物性为低孔—低渗背景下的局部高孔—高渗,主要储层类型为裂缝—孔隙(洞)型,白云岩储层发育受多因素控制,古地貌控制下的台内生屑滩为后期建设性成岩作用的改造提供了宝贵的物质基础;②生屑滩滩体的分布范围大致决定了储层分布范围;③后期白云石化作用和埋藏溶蚀作用是优质白云岩储层形成的决定性因素;④多期构造运动形成的构造裂缝极大地改善了白云岩储层的储渗能力。研究区栖霞组白云岩储层纵向上具有单套厚度薄、多套叠置的特点,横向则分布不连续,展现出较强的非均质性,在MX42、MX107、MX31-X1、GS16井区集中发育。更多还原

【Abstract】 In order to figure out the reservoir characteristics and control factors of the Qixia Formation, Middle Permian in the Longnvsi-Guang’an area, the reservoir characteristics of the Qixia Formation, Middle Permian in the Longnvsi-Guang’an area were analyzed using the core, microscopic thin section, well logging and seismic prediction results comprehensively. It was pointed out the reservoirs are mainly classified into residual bioclastic dolomite and medium-fine crystalline dolomite, the porous reservoir spaces are mainly intercrystalline pore and intercrystalline dissolution pore, and the caves are primarily porous caves and secondarily fractured caves. And the follows research results were obtained. First, its physical properties are local high porosity and high permeability in the setting of low porosity and low permeability, the reservoirs are mainly of fracture-pore(cave) type, the development of dolomite reservoirs is under the control of multiple factors, and the palaeogeomorphology controlled intraplatform bioclastic beach provides the valuable material base for the transformation of constructive diagenesis in the late stage. Second, the distribution range of bioclastic beach bodies determines approximately the distribution range of reservoirs. Third, dolomitization and burial dissolution are the decisive factors for the formation of high-quality dolomite reservoirs. Fourth, the structural fractures resulted from multistage tectonic movement improve the preservation and seepage capacity of dolomite reservoirs. In conclusion, the dolomite reservoir of Qixia Formation in this area is vertically characterized by small thickness of single layer and superposition of multiple layers and laterally by discontinuous distribution and stronger heterogeneity, and it is mainly developed at Well blocks MX42, MX107, MX31-X1 and GS16.更多还原