渤南洼陷沙四上亚段砂岩储集层特征及其控制因素

Reservoir characteristics of the upper sub-member sandstones of the fourth member of Shahejie Formation in Bonan Sag and their influencing factors

以碎屑岩储层地质学理论与方法为指导,通过岩心观察、铸体薄片鉴定,以岩心物性、孔隙结构等资料分析为基础,研究渤南洼陷沙四上亚段砂岩储集层的主要岩性特征、储集空间、孔喉特征、物性特征及其受控因素。研究表明:渤南洼陷沙四上亚段砂岩储集层岩石类型以岩屑长石砂岩为主;储集空间以粒间孔、粒内溶孔、铸模孔等次生孔隙为特征;储集层孔隙结构分为3种类型(Ⅰ类、Ⅱ类、Ⅲ类);储集层物性较差,总体为低孔低渗或低孔特低渗储集层;储集层物性受沉积相、物源体系及成岩作用的控制,其中沉积相是储集层形成的基础,物源体系控制物性平面分布,成岩作用决定次生孔隙发育。

The characteristics of lithology,reservoir space,casting thin sections,pore-throat features,physical property of the target sandstone reservoir and their influencing factors are studied based on core observation,cast thin section analysis and physical property data and pore structure under the guidance of geologic theories and methods of clastic reservoir rocks. The results show that: the target sandstones are mainly debris arkose,the reservir space is mainly composed of secondary intergranular pore,intragranular dissolved pore and mold pore,there are three types of pore structure( Ⅰ,Ⅱ,Ⅲ),the reservoir is of physical property of low porosity and low or superlow permeability. The physical property of the reservoir is affected by sedimentary facies,provenance system and diagenesis. The reservoir type is the basis of sedimentary facies,the provenance system controls the plane distribution of physical property,and the development of the secondary pore is controlled by diageneses.