New Solution to Critical Injector-Producer Spacing Shaped Invert 9-Spot Area Well Pattern for Low-Permeability Reservoir

In view of the improper injector--producer spacing and low producing degree of lowpermeability reservoir, according to water flooding characteristics of low-permeability with invert 9-spot well pattern, areal sweeping efficiency formula was adopted to calculate the areal sweeping efficiency for reservoir area; multiple linear regression was used to fit the mathematic model of areal sweeping efficiency, which was then used to work out the critical injector producer spacing under different injection-production pressure difference. Meanwhile, effective drainage factor was also used to calculate critical injector producer spacing, whose credibility of fitting data more than 95%. The computed results can be used to adjust the injector producer spacing of poor reservoirs and improve production efficiency of thin and poor reservoirs. Comparison of the data that include differential pressure, permeability, threshold pressure gradient, reasonable injection-production well pattern and space. etc from one block, in which injection pressure is high and difficult injection, which adjust well pattern and space can alleviate injection-production problem, and also estimation all the factors except water-sensitivity. etc.