关键词: 菱形反九点,   ,  启动压力梯度,   ,  应力敏感,   ,  不等缝长,   ,  数值模拟

Abstract: Fracture length of fractured well is the important factor to determine the fracturing effect. Taking the diamond shaped inverted nine spot pattern in a block of Xinjiang oilfield as an example, based on the reservoir numerical simulation software.Considering the starting pressure gradient and stress sensitivity, the cumulative degree of reserves recovery of crude oil is simulated under the conditions of different fracture length. The relationship between the reserves recovery degree of hydraulic fracture and comer well, edge well and central well is analyzed. The comparison results show that: the fracture of edge well may give rise to the invasion of injected water, corner well cannot be affected by injection well, causing the precipitous decline of production rate in corner well. For the central injection well, it is not only to reduce the fracture length in order to improve the water drive spread coefficient, but also to ensure that the length of the fracture is enough to supplementary formation energy. The best solution: the diversion capability of fracture is 20 μm2·cm,the fracture length of corner well is 100 to 120 meter, the fracture length of edge well is 50 meter, the fracture length of central well is 50 meter. This conclusion provides new recognition for the optimization of fracture parameters.

Key words: Diamond shaped inverted nine spot pattern,    , Threshold pressure gradient,    , Stress sensitivity,    , Unequal fracture length,    , Numerical simulation