Study On Hydraulic Fracturing In Low Permeability Reservoir By Numerical Simulation

With the rapid development of China's economy,the domestic consumption of oil and gas is getting larger and larger,and the situation of domestic oil and gas resources has become more and more severe as the development time increases.Up to now,China's high-permeability oil fields have basically entered the stage of high water cut development,and the annual output decline form is severe.Therefore,increasing the production of low-permeability reservoirs has become increasingly important.Currently,the most effective method to improve the recovery rate of low permeability reservoirs is hydraulic fracturing technology.The main reason is that hydraulic fracturing technology can form complex fracture networks in low permeability reservoirs,thereby expanding the single well coverage and reducing oil and gas seepage.Resistance,effectively reduce mining costs.However,at present,there are still several problems with the hydraulic fracturing technology to exploit low-permeability reservoirs during on-site fracturing:(1)the mechanism and rules of hydraulic fracturing crack propagation are not well understood;(2)the fracture propagation is subject to various fracturing Influence of construction parameters;(3)Research on the law of crack propagation after natural fractures and hydraulic fracturing fractures intersect,etc.In view of the above problems,this paper uses ABAQUS finite element software to analyze the propagation law of hydraulic fracturing fractures and the expansion law of hydraulic fracturing fractures when they intersect with natural fractures,and draws the following conclusions:(1)Perforation direction and level The smaller the angle of in-situ stress,the higher the peak injection point pressure required for fracture propagation,thus making the normal phase flow effect in the cohesive unit stronger,and the smaller the fracture width,the longer the fracture length.(2)The greater the displacement of fracturing fluid,the longer the fracture length and the greater the fracture width.(3)Under the same conditions,the smaller the intersection angle of the crack,the easier it is to open it along the direction of the natural crack after the artificial crack intersects the natural crack;Natural cracks are penetrated;the greater the horizontal stress difference,the easier it is for artificial cracks to penetrate natural cracks.