十屋断陷深层储层异常低压与次生孔隙发育带耦合关系分析

大量铸体薄片、扫描电镜分析结果表明,松辽盆地东南隆起区十屋断陷发育异常低压体系,十屋断陷深层储层有效储集空间类型为溶蚀成因的次生孔隙,孔隙度可达到20%左右,这是形成优质储层的主要原因。深层储层普遍发育异常低压体系,实测地层压力系数多介于0.6～1.0之间。统计结果表明,研究区异常低压与次生孔隙之间有着很好的耦合关系和成因联系,深层异常低压的形成与该区登娄库组(K₁d)末期地层抬升和剥蚀有关,在此过程中地层温度降低,碳酸盐胶结物溶解度增大,溶解作用增强,从而形成次生孔隙。抬升和剥蚀作用越强烈区域,溶蚀作用也就越明显。

Coupling relationship analysis in deep reservoir between subnormal pressure and secondary porosity zone in Shiwu depression

A lot of analysis of cast thin section and SEM show that,underpressure system developed in Shiwu depression in southeast uplift area of Songliao Basin.The type of effective storage spaces of the deep reservoir in Shiwu depression is secondary pore caused by dissolution,porosity can reach about 20%,this is the main reason for the formation of high quality reservoir.Underpressure system of deep reservoir is developed widely,measured formation pressure coefficient ranges between 0.6 and 1.0.The statistic results show that there is a good coupling relationships and genetic relationship between abnormal low pressure and secondary pore in the study area.The formation of abnormal pressure is associated with the uplift and denudation of the end of Denglouku Formation(K₁d)in this area.The formation temperature begin to decrease in this process,the solubility of carbonate cement begin to increase,dissolution enhance,thus the formation of secondary pore.The stronger uplift and denudation is,the more obvious corrosion effect is in this region.