吐哈盆地巴喀西山窑组致密砂岩储层特征及主控因素

为揭示巴喀西山窑组致密砂岩储层的发育规律和主控因素,根据岩石薄片、铸体薄片、扫描电镜及物性资料分析,研究了储层的岩石学特征、孔渗特征、成岩作用类型、孔隙结构及孔隙类型。结果表明:该区储层主要以中砂岩为主,粗砂岩和细砂岩次之;储集空间主要是粒内溶蚀孔、粒间溶孔、残余粒间孔隙、微孔隙和微裂缝,属于典型的低孔低渗致密砂岩储层。在此基础上,综合分析了致密储层与成岩作用的关系认为:压实作用和胶结作用导致储层致密化,溶蚀作用是储层次生孔隙发育的主要因素;西山窑组未充填的中等尺度裂缝发育,可以改善储层物性;非渗透性致密砂岩层的存在有利于保护储层孔隙。

Characteristic and main control factor of tight sandstone reservoir in Baka J2x Tuha basin

To explore development mechanism and primarily controlling element of compacted sandstone reservoir of J2x formation,according to the methods of petrographic thin section、cast body chip、capillary pressure analysis、X-ray diffraction analysis,study the petrological characteristics、hole roar structure、property characteristics of reservoir.The result show that:the reservoir is mainly consists of medium sandstone,thick sandstone and thin sandstone is less than it;reservoir space type is consist of grain dissolve inside hole、residual intergranular pore、microporosity and microfracture,grain dissolve inside hole is the main part,belongs to the typical low porosity sandstone reservoirs.Based on this,comprehensive analyzing the relationship of dense sandstone and diagenesis,considering that:compaction and cementation lead to reservoir densification;dissolution is the principal factor of reservoirpore development;Not filled crack in Xishanyao formation is develop,it can be used as the oil and gas migration channels and reservoirs;non-permeability of tight sandstone is conducive to the reservoir pore.