大庆长垣南部扶余油层高阻水层成因机理

Genetic Mechanism of High Resistivity Water Layer in the Fuyu Oil Layer of Southern Daqing Placanticline

采用岩心观察、铸体薄片鉴定、物性分析、X射线衍射分析、扫描电镜等方法,以岩石物理学为理论基础,对大庆长垣南部扶余油层高电阻率水层的成因机理进行研究.结果表明:低矿化度的地层水、高含量的碳酸盐岩矿物、低含量的黏土矿物是大庆长垣南部扶余油层中高电阻率水层形成的主要原因;压实作用和胶结作用对储层致密化起到主控作用,压实作用过程中的泥岩脱水和胶结作用过程中的碳酸盐富集都有利于高电阻率水层的形成;储层致密化会使大庆长垣南部扶余油层中岩石颗粒的孔隙结构变复杂,从而会改变其导电路径,其中一端封闭的孔隙、对称封闭的孔隙和孤立的孔隙均无导电能力,从而导致岩石的导电能力有所降低,最终有利于大庆长垣南部扶余油层中高电阻率水层的形成.

Based on the theory of petrophysics,the genetic mechanism of high resistivity water layer in the Fuyu oil layer in the south of Daqing Placanticline was studied by means of core observation,casting thin slice identification,physical property analysis,X-ray diffraction analysis and SEM analysis.The results show that low salinity formation water,high content of carbonate minerals and low content of clay minerals are the main reasons for the formation of high resistivity water layer in the Fuyu oil layer of southern Daqing Placanticline.Compaction and cementation are the main control factors of reservoir densification,and mudstone dehydration in the course of compaction and carbonate accumulation in the course of cementation are beneficial to form high resistivity water layer.Reservoir densification will complicate the pore structure of rock particles in the Fuyu oil layer of southern Daqing Placanticline and change their conductive paths.The pores closed at one end,symmetrically closed pores and isolated pores have no electrical conductivity,which is conducive to the formation of high resistivity water layer in the Fuyu oil layer of southern Daqing Placanticline.