Study on the effect of fracture characteristics to ultra-low permeability reservoirs development

A mathematical model was derived for flow in ultra-low permeability reservoir with hydraulic fracturing, including three coupling sections: low-velocity non-Darcy flow in matrix, flow in elliptical area around fractures and nonlinear flow in fractures. Based on data from test areas, the effects on hydraulic fracturing development of artificial fracture length, flow conductivity, and angle to development effect were clarified by numerical simulations. According to fracture characteristics and production data of test areas, effect of natural fracture pattern, and degree of fracture development on developing ultra-low permeability reservoir was studied. Analysis results show that optimal values of half-length of artificial fracture are 70m~85m, flow conductivity 30D.cm~40D.cm and fracture angle 0~25 degrees.