考虑启动压力的菱形井网整体压裂优化设计

从整体压裂改造的角度分析了正方形反九点面积井网和菱形反九点面积井网的特点,结果表明菱形反九点面积井网更适合低渗透、特低渗透油藏压裂改造。应用数值模拟的方法研究了启动压力梯度对菱形井网压裂井日产油量、累积产油量、含水率、采出程度、地层压力等参数的影响。结果表明,启动压力梯度对低渗、特低渗透油藏各项生产动态指标的影响很大,在生产过程中不能忽略。从整体压裂的角度出发,研究了受启动压力梯度影响的非均质油藏菱形井网最佳井排距,分别以采收率和采油速度为优化目标,得到了不同的优化结果,绘制了相应的理论图版,这些图版可以用来指导低渗透油藏菱形井网的优化设计。在进行井网设计时,应充分考虑到将来进行压裂改造时裂缝走向对油水井的影响,从而避免井网与裂缝不匹配的问题,实现开发压裂一体化设计。

Integral Fracturing Optimization Design on Diamond Shaped Well Pattern Considering Starting Pressure Gradient

The features of square inverted nine spot well pattern and diamond shaped inverted nine spot pattern were analyzed, from the perspective of integral fracturing reconstruction, the result shows that diamond shaped inverted nine spot well pattern was more adaptive to low permeability and ultra-low permeability reservoir stimulation. Through numerical simulation methods, influence of starting pressure gradient on production indexes of fractured producers in diamond shaped well pattern was studied. It shows that starting pressure gradient affects greatly the production indexes and cannot be neglected in field development. From the perspective of integral fracturing, well space and well array distance in diamond shaped well pattern are optimized in heterogeneous reservoir. With recovery and production rate as the optimization goals, optimal results are obtained respectively. Meanwhile, corresponding theoretical chartboards are plotted which can direct the optimal design on diamond shaped well pattern in low permeability reservoir. In well pattern design, influence of fracture orientation on oil and gas wells should be considered in future fracturing stimulation to avoid the incompatibility between well patterns and fractures.