川中蓬莱地区须二段和须四段储层孔隙结构特征及影响因素  

Pore structure characteristics and controlling factors of 2nd and 4th member reservoirs in Upper Triassic Xujiahe Formation of Penglai area, central Sichuan Basin

作　　者：赖锦[1] 王贵文[1,2] 王书南[1] 柴毓[1] 吴恒[1] 张永辰[1] 赵显令[1] 

机构地区：[1]中国石油大学(北京)地球科学学院,北京102249 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249

出　　处：《中国地质》2013年第3期927-938,共12页Geology in China

基　　金：国家大型油气田及煤层气开发科技重大专项"低渗透碎屑岩储层品质与岩石物理相测井评价方法"(编号:2011ZX05020-008)资助

摘　　要：通过岩心观察并充分利用普通薄片、铸体薄片、扫描电镜分析、压汞测试和核磁共振实验等资料,对蓬莱地区须家河组须二段和四段储层岩石学、物性和孔隙结构特征等进行了研究。认为储层岩性主要为长石岩屑砂岩及岩屑砂岩,储集空间主要是粒内、粒间溶孔,属于低孔低渗非均质性较强储层。孔隙结构具细小孔隙、微细喉道、细歪度和孔喉分选、连通性差的特征。利用压汞参数辅以核磁参数等将储层孔隙结构划分为四类,并对不同类型孔隙结构的特征进行归纳总结。最后从构造、沉积和成岩作用三方面入手详细探讨了不同孔隙结构类型的成因机理及控制因素。认为构造和沉积作用是影响储层孔隙结构的先决条件,而成岩作用类型、强度及其演化是决定储层孔隙结构特征的关键因素。以上研究成果对研究区须二和须四段储层的分类评价及下一步的天然气勘探具有指导意义。Petrologic characteristics, physical properties and pore structure characteristics of Xu 2 （2nd member of Upper Triassic Xujiahe Formation） and Xu 4 reservoirs were studied by means of core observation, normal thin section and casting thin section observation, scanning electron microscope analysis, mercury injection test and nuclear magnetic resonance experiment. The results show that the lithology of Xu 2 and Xu 4 reservoirs is dominated by feldspar lithic sandstone and lithic sandstone, the main reservoir space consists of intragranular corrosion pores and intergranular corrosion pores, and the reservoirs are characterized by low porosity and low permeability with strong heterogeneity. The pore structure is overall characterized by small pores, tiny throats, fine skewness, and poor sorting and connectivity on the mercury injection curves. The reservoir pore structure can be divided into 4 types based on the parameters obtained by the mercury injection experiment together with the nuclear magnetic resonance experiment, and the typical characteristics of the four different pore structure types are summarized separately in this paper. Lastly the formation mechanism and controlling factors of various pore structure types are discussed in three aspects of tectonism, sedimentation, and diagenesis. It is demonstrated that the tectonism and sedimentation are the prerequisite conditions affecting the reservoir pore structure, while the types and intensity of diagenesis and its evolution sequence are the key factors for determining the pore structure characteristics. The above research results can provide guidance for the classified evaluation of Xu 2 and Xu 4 reservoirs and for the further gas exploration in the study area.

关 键 词：孔隙结构 须二段和须四段 蓬莱地区 压汞 成岩作用 分类评价 

分 类 号：P618.130.21[天文地球—矿床学]