Study On The Capacity Model Of Network Fracturing Horizontal Wells In Tight Oil Reservoirs

The tight oil resources are abundant and widely distributed in China.With the difficulty of increasing production of conventional oil reservoirs and the increasing dependence of China’s crude oil on oil,the proportion of tight oil in the total energy has been increasing year by year and has become an important energy source for oil replacement in China.For tight oil has strong inhomogeneity,complex pore structure,and poor permeability,it is difficult to obtain economic production by natural extraction means,which restricts the reasonable and efficient development of tight oil reservoirs in China.Therefore,large-scale fracturing is needed to form a complex fracture network,improve the flow capacity of the formation,and increase the permeability of the formation around the production wells in order to achieve economic and effective development.However,due to the complexity of tight reservoir reservoirs,the fractures formed by fracturing often have different morphologies and the size of each fracture is not the same.Therefore,it is important to establish a seepage model for fractured horizontal wells in tight reservoirs that takes into account the different tilt patterns of fractures to develop tight reservoirs efficiently.In this paper,the seepage model for fracture network fractured horizontal wells in tight reservoirs is developed by considering the fracture inclination angle,which is not mentioned in the existing seepage model for fracture network fractured horizontal wells in tight reservoirs.The model is based on a dual-media reservoir,the morphology of tilted fractures is described by affine transformation,the seepage equation of infinitely large tight reservoir considering the proposed steady-state fracture flow and stress sensitivity is established,linear substitution is performed by Pedrosa’s transformation and regular regression,and the simplification is carried out by using the Rasch transform to find the point source function of infinitely large tight reservoir considering tilted fractures and stress sensitivity The source function model with different boundary conditions is obtained by using the mirror mapping method,and the seepage model of complex seam network with mutually interfering multilevel fractures is established by the superposition principle.Combined with the pressure drop along the horizontal wellbore and the epidermal effect,a reliable single-well seepage model for fractured horizontal wells in tight reservoirs is finally established.Based on this single-well model,a multi-well seepage model for fractured seam networks in tight reservoirs is developed by the superposition principle considering inter-well interference.The pressure response curves and production curves of horizontal wells fractured by the seam network in tight reservoirs are plotted by using Matlab software to solve the seepage model.The presence of the fracture inclination angle in this paper will cause the fracture radial flow phase to be shorter and enter the next seepage phase earlier,and will affect the production to some extent.The seepage model and solution software proposed in this paper can provide a theoretical basis for the development and evaluation design of fractured horizontal wells in tight reservoirs.