Geological Characteristics And Fracturing Parameters Optimization Of Chang 6 Reservoir In Xunyi Exploration Area

The Xunyi exploration area is located on the edge of the Ordos Basin.The geological characteristics of the Chang-6 reservoir are analyzed by combining the features of the basin's regional geology,combined with drilling core observations,logging data analysis,comprehensive rock sheeting,mercury injection,scanning electron microscope and so on.The Chang 6 reservoir in the study area is located in the front of the Yijun Delta.The main sedimentary facies are subfacies subaqueous distributary channel,distributary Bay deposit,and estuarine sand dam.The source direction is south-west,showing"South High North low,East High West low"tectonic grid.The study shows that the main rock types of the Chang 6 reservoir are lithic feldspar sandstone and feldspar lithic sandstone,and the pores are mainly secondary pores.The porosity of the rock is between 4%¹6%,the average porosity is 10%,the permeability is between 0².0×10^-3?m²,and the average permeability is0.59×10^-3?m².The research area is a low permeability reservoir with low natural productivity.It needs fracturing to obtain industrial oil flow.Before fracturing,we must first determine the mechanical parameters of reservoir rock,calculate the original crustal stress,and analyze the orientation of fractures.According to the reservoir characteristics,the permeability is divided into 4 levels,and the effective thickness is divided into 3 levels.The fracture length,the dimensionless diversion capacity,the perforation parameters,the displacement and other fracturing parameters can be obtained under the simulated cross experiment according to the fracturing software.