Reservoir Characteristics And Geological Model Of Fei3 Formation In The South Of Jiannan Oilfield

Jiannan gas field which is situated at Western hubei-eastern chongqing,is the subset structure unit of the Shizhu Synclinorium.Due to the complex geology background,the faults cause the fracture deposited,the reservoirs are characterized by low Porosity and Permeability,and the strong heterogeneity.Along with infilling well pattern,earlier research in the accurate reservoir description is not deeply enough has restricted the later work.Under the direction of the study of high resolution sequence stratigraphy,synthesize the data of the cores and well logs etc.,the sequence framework has been established.Based on the regional sedimentary background,unit the data of logging data,core wafer and so on,analysis the microfacies on the single well,the well tie section and the surface synthetically in the isochronous stratigraphic framework.Through analyzing the rock type,pore space and pore structure etc.,unit the physic property parameter from the log interpretation,the text evaluate the character of reservoir synthetically and forecast the favorable distributive area of reservoir.Then built the 3D geological model base on the software of Petrel by using the methods of Stochastic Modeling.The geology model can establish a foundation and provides some basis for further study.Some out comes have been achieved based on this study:(1)According to the principle of stratigraphic correlation,Fei3 reservoir can be divided into four short-cycles in ascending order,named SC1,SC2,SC3,SC4,which are corresponding to Fei31,Fei32a,Fei32b,Fei33 respectively.(2)Research area distinguished marine carbonate rocks in Lower Triassic.Fei3 whose microfacies transit from the platform margin slope facies to the open platform facies undergo a process of sea level decrease.The platform margin slope facies are deposited in Fei31.Fei32a and Fei32b which are corresponding to Psammitic beach and oolitic beach developed the platform margin shallow facies.The open platform facies are deposited in Fei33.(3)According to the relation of physic property and log interpretation,the text built matrix porosity model,matrix permeability model and gas saturation model.Fine reservoirs controlled by the distribution of microfacies are distinguished where the beach were.The reservoir had low matrix porosity,low matrix permeability,strong heterogeneity.Reach area develop ? class reservoir and III class reservoir,and the II class reservoir extend linearly in the area of the high point of the structure.(4)With the software of Petrel,making the stratic interface to be the surface of the subzone,using which adjusted the seismic reflection interface to built the Structure Model.Building Facies Model and Attribute Model restricted by the variogram.Last using the stochastic methods of Sequential Indication Simulation to built the scattered model of facies;and then we built the continuous model for Attribute Model by the methods of Sequential Gaussian Simulation under the control of the Facies Model.