Study Of Geological Characteristics And Remaining Oil Distribution Of E₁f₃ Formation,wa 2 Fault Block In Gaoyou Sag

According to WA 2 fault block,the fine reservoir description has been performed,and a fine 3D geological model has also been achieved.Futhermore,the water flooding development effectiveness has been evaluated.The distribution regulation of the residual oil have been researched by reservoir numerical simulation technology.The following conclusions have been achieved through the research.(1)Aiming at the fault block reservoir during middle and high water-cut stage,fine division and correlation of stratigraphy has been carried out,focusing on the location of small layers and the identification of small faults.Based on fine division and correlation of stratigraphy,the recongnition to the distribution of minor faults in WA 2 fault block has been got by the well-seismic combined method.The reservoir characteristics and sedimentary microfacies have been studied,and the distribution region of favorable reservoir has been pointed out.Reservoir heterogeneity has been carried out for problems in development.Based on this,a fine three-dimensional geological model has been established according to WA 2 fault block..(2)The water flooding development effectiveness of WA 2 fault block has been evaluated systematically from seven aspects,particularly in terms of the analysis to water flooding effect,producing degree of geological reserve and the adaptability of strata and well pattern.It has been found that there were obvious differences in water injection effect between different sedimentary microfacies on the plane,and the vertical heterogeneity between layers impacts seriously on the water injection effect.According to formation property and producing degree of single layer,the contradiction between layers are prominent,so the adaptation of the layer series is bad.The producing degrees of E₁f₃^1-10?E₁f₃² are higher than that of the others.The control degree is 80.5%,while the producing degree is 66.3%in current well pattern,so the adaptation of well pattern is not very well.(3)The remaining oil distribution has been studied.There are four types of remaining oil distribution,include the high part of structure,fault shielding,detention area and sparse well pattern.The main form of remaining oil is detention area forced by sedimentary microfacies or well pattern.The influencing factors of residual oil distribution are sedimentary microfacies,interlayer heterogeneity,faults and development methods.Sedimentary microfacies is the main factor which influence the distribution of remaining oil in horizon.And the primary factor of influencing remaining oil distribution in vertical is reservoir heterogeneity.