伊拉克B油田白垩系Mishrif组碳酸盐岩储层分类

Classification research on carbonate reservoir of the cretaceous Mishrif formation in B oilfield,Iraq

伊拉克B油田白垩系Mishrif组为厚层礁滩相碳酸盐岩,受成岩作用影响储层非均质性极强,采用常规的储层分类方法难以准确的刻画储层孔隙结构之间的差异性。根据取心井实测孔隙度和渗透率资料,采用Winland R_(35)将研究区储层划分为五种类型,每种类型储层孔隙度和渗透率之间相关性较好。结合毛管压力和相渗曲线,研究发现不同储层类型对应的毛管压力特征和相渗特征差异较大,充分体现了碳酸盐岩储层受成岩作用影响非均质性强的特征。储层类型的划分对于构建精细的地质模型和提高数值模拟的精度具有重要的意义。

The cretaceous Mishrif formation of B oilfield is mainly consist of reef-shoal facies carbonate, and the reservoir heterogeneity is strong caused by the diagenesis. The conventional reservoir classification method is difficult to accurately depict the differences between reservoir pore structure.Porosity and permeability data of coring core samples are used by Winland R_（35） method to divided reservoir types,which can be divided into five types in the study area, and each type of reservoir has good correlation between porosity and permeability.Combining with capillary pressure and relative permeability curves,it found that different reservoir with different capillary pressure and relative permeability characteristics,which can be fully embodies the carbonate reservoir heterogeneity affected by the diagenesis.The division of reservoir types has great important meaning to build fine geological model and improve the accuracy of numerical simulation.