低（特低）渗透油藏极限注采井距确定的新方法探索

国内外许多实验表明，当储层渗透率低到一定程度后，其渗流特征不符合达西定律，即当驱动压力梯度较小时，流体不能流动，只有当驱动压力梯度达到一定值后，流体才开始流动。而低（特低）渗透油藏具有低孔、低渗的特点，因此具有较高的启动压力梯度，即渗流呈“非线性”特征，在低（特低）渗透油藏井网部署中必须考虑该因素。低渗油藏油水渗流时启动压力现象的存在，使注采井距理论上存在一个最大值，结合单井产量公式，可以计算出给定注采压差条件下低渗油藏的最大注采井距，从而为合理注采井网的部署提供依据。为此，本文基于低渗透油藏的渗流机理的分析和研究，推导出了适合低渗透油藏的极限注采井距的新的方法。

Research on Limited Producer-injector Spacing in Low (Ultralow) Permeability Reservoir

Many domestic and foreign experiments showed that when permeability of reservoir was low to a certain degree,its flow characteristics was incompatible with Darcy 's law,that is,when the driving pressure gradient is small,fluid can not flow only when the driving pressure gradient up to a certain value,fluid flow begin.The low(ultra-low) permeability reservoirs with low po-rosity has high start-up pressure gradient,its percolation feature is a "nonlinear",so,the low(ultra-low) permeability oil well network deployment must take into account the factors.Combina-tion with single well production formula,the largest producer-in-jector spacing can be calculated under conditions of given injection and production pressure difference in low permeability reservoir.Therefore,based on the analysis and research of percolation mech-anism in low permeability reservoir,the new approach for determi-ning limited producer - injector spacing in low permeability reser-voir has been derived.