古龙凹陷葡萄花油层低饱和度油藏成因

在对古龙凹陷葡萄花油层油气成藏要素分析的基础上,综合利用岩石物性测试、压汞、恒速压汞、密闭取心分析等多种技术方法,定量、半定量地研究了葡萄花油层低饱和度油藏的成因。研究表明:葡萄花油层孔隙结构差,油气运移毛细管阻力较大,原油驱替水不充分,是低饱和度油藏的主要内因;地层较平缓,构造幅度低,小于油水过渡带的高度,是形成低饱和度油藏的强化因素;油藏构造调整导致早期油藏遭到破坏、晚期油藏分异不充分是低饱和度油藏的一个重要原因。

Genesis of low oil-saturated reservoir of Putaohua oil layer in Gulong Sag

On the basis of reservoir formation of Putaohua layer in Gulong Sag,various methods including rock physical properties test,mercury intrusion,constant-rate mercury injection and confined core have been comprehensively applied to quantitatively and semi-quantitatively determine the low oil saturation genesis.The result shows that the main reasons of low saturation are the inferior pore structure of layers,relative great capillary resistance of hydrocarbon migration and insufficient crude oil flooding water,relatively flat strata and low amplitude structure which is lower than the height of oil-water transition zone are the reinforcing factors;the early stage reservoir damage and late stage insufficient reservoir differentiation resulted from reservoir structure adjustment mainly lead to the formation of low saturation reservoir.