低渗透油田反九点井网面积波及效率影响研究

根据低渗透油藏面积注水开发的特点，在流管模型的基础上，推导出了考虑启动压力梯度的反九点井网面积波及效率和油井见水时间计算公式，解决了低速非达西渗流不同于达西渗流的面积波及效率理论计算问题。研究表明，低渗透油田反九点井网中角井和边井的见水时间和面积波及效率不同，需要对边井和角井采取不同的工作制度以调节水驱均匀程度。为低渗透油藏反九点井网的开发设计和评价提供了理论依据。

Study of Areal Sweep Efficiency for Invert 9-Spot Pattern of LowPermeability Reservoir

Based on the characteristics of water flooding exploitation in low-permeability reservoir and the stream tube model，and by taking the start-up pressure gradient into consideration，we establish the areal sweep efficiency formula and waterbreakthrough time formula. The formula help solve the theoretical problem of the calculation of areal sweep efficiency of lowspeednon-Darcy seepage flow，which is different from Darcy seepage flow. The results show that the water breakthrough timeand areal sweep efficiency of invert 9-spot pattern in low-permeability reservoir are different in borderline well and corner well.It is necessary to adopt a different working system to adjust to the uniformity degree of water flooding in borderline well andcorner well. This research provides theory basis for development and evaluation of low-permeability reservoir.