松辽盆地致密气藏暂堵转向压裂裂缝扩展规律研究OA

Tight gas reservoir in Songliao Basin is an important field for deep natural gas exploration and de-velopment.Due to the deep burial depth(3 000～5 500 m),low porosity,and permeability,natural frac-tures are underdeveloped,with a large pressure difference(8～12 MPa).Conventional fracturing fractures have a single shape,small reservoir transformation volume,and low production.Therefore,achieving the complexity of artificial fractures in deep tight gas reservoirs is the main direction of improving the transforma-tion effect.In order to demonstrate the feasibility of forming complex fractures through temporary plugging and fracturing in tight gas reservoirs in the Songliao Basin,a simulation experiment of temporary plugging and fracturing in full diameter rock cores was conducted using a true triaxial fracturing simulation system to evaluate the characteristics of hydraulic fracturing crack initiation,expansion,and temporary plugging and fracturing in tight gas reservoirs under different gravel conditions.The results show when the difference in stress between the two directions is high,bilateral symmetrical single fractures are formed after fracturing.After using temporary plugging fracturing to promote the turning direction,the complexity of the fractures is increased,and the morphology of the fractures becomes more complex.The large particle size of gravel cau-ses local tortuosity of hydraulic fractures,forming a large number of shear micro-cracks around the gravel.The fracture morphology is more complex,and the overall fracture morphology of rock samples without gravel is lower than that of rock samples with gravel.