花岗岩潜山双重孔隙介质油藏地质建模方法

A Geological Modeling Method for Dual Porous Reservoirs in Granite Buried Hills

花岗岩潜山裂缝型油藏受构造、风化、溶蚀等作用影响,其储层具有双重孔隙特征,其地质建模研究一直为业内难点和热点。为此,综合运用测井、地震、岩芯、试井等多方面资料,深入剖析了裂缝成因,明确了断层和“沟脊”地貌为该区裂缝分布的主控因素;进而,采用DFN(Discrete Fracture Network)建模技术,形成了以裂缝成因控制的花岗岩潜山地质建模方法。即以裂缝成因为依据建立了裂缝分布的趋势体,以之为约束,建立花岗岩潜山裂缝网络模型,进而得到等效裂缝属性模型,并通过测井、试井等资料校验模型的可靠性。应用该方法,建立渤海A油田花岗岩潜山的地质模型,该模型较好地表征了油田裂缝分布特征,为开发方案编制奠定了基础。

Fractured oil reservoirs in granite buried hills are influenced by tectonic motion,weathering,and corrosion.Since layers in these reservoirs are dual porous,geological modeling of these layers has been a difficult task but is also an important topic in the field.Hence,this work combines logging,seismic,core,and well testing data to thoroughly investigate the causes of fracturing.It is determined that faults and“gully ridge”landforms are the major factors that determine the fracture distribution in the region.Subsequently,the discrete fracture network(DFN)modeling technique was used to develop a geologic model for the fracture mechanism in the granite buried hills.Fracture distributions are created and used as a constraint to form a fracture network model for the granite buried hills.An equivalent fracture attribute model was obtained and its reliability was tested using information such as well logging and testing data.A geological method for the granite buried hills in the Bohai A Oilfield was constructed using this method.This model better characterizes the fracture distribution in the oil field and provides a foundation for formulating exploration plans.