Study On Numerical Simulation Of Integrated Fracturing In Low Permeability Reservoir

Hydraulic Fracturing is an important technology of stimulation, it is extensively used in the development of low permeability reservoirs. At present, hydraulic fracturing has developed into integrated fracturing of low permeability reservoirs from the stimulation of single well. According to the simulation of different parameters influencing production performance in reservoirs and fractures, numerical simulation of integrated fracturing technology supply theoretic reference to newly developed area fracturing exploitation and to optimize designs in conditions of given flood pattern.Actuating pressure gradient generally exists in low permeability reservoirs. On the basic of surveying and studying documents about integrated fracturing and numerical simulation technology, a reservoirs-fracture model with actuating pressure gradient is established in this paper, and is solved with finite difference method. The software of integrated fracturing for low permeability reservoir is developed with Visual Basic 6.0. The main factors of influencing the productivity ,which include fracture half length, fracture width, fracture conductivity, bottom hole flowing pressure of production well, actuating pressure gradient of reservoir, water saturation, formation permeability, well spacing and so on, were analyzed systematically by using the self-developed software, moreover each parameter was optimized for improving production. In five-spot pattern, at the same time, the bigger the fracture half length of production well is, the bigger the production is, but the amplification is smaller and smaller; the influence of fracture half length on production performance is very small in injection well ; the influence of fracture width on production performance is very small; the bigger the fracture conductivity is, the bigger the production is, but the amplification is smaller and smaller; the lower the bottom hole flowing pressure of production well is, the higher the drawdown pressure is, the higher the production is; the influence of actuating pressure gradient on production performance can't be neglected, and must be given great attention; the influence of formation permeability anisotropy on production performance is greatly, especially when the major permeability and fracture extension have the same orientation; the influence of well spacing on production performance is greatly.