低渗透油藏不稳定渗流压力传播规律研究

针对目前低渗透油田开发过程中压力传播规律研究存在的不足,基于拟启动压力梯度模型,运用稳态逐次替换法并结合物质平衡原理,建立了油井定产量生产及定压力生产时地层压力传播规律数学模型。通过模型求解,得出了地层中压力传播规律。在定产量模型中,随着压力传播距离的增加,压力传播速度变慢,且随着产油速率的增大(减小)、压力在传播相同距离时所用时间变短(变长),压力传播速度变快(变慢);在定压模型中,随着井底流压的减小(增大),压力在传播相同的距离时所用时间变短(变长),压力传播速度变快(变慢)。

Study On Pressure Propagation in Low Permeability Reservoirs

At present, there exists a series of problems in the study of pressure propagation in low permeability reservoirs. In view of this,this paper develops mathematical models by using steady state replacement method and material balance law based on pseudo-threshold pressure gradient model to study pressure propagation in low permeability reservoir under constant rate and constant pressure production conditions. Through solving mathematical models,pressure distribution and propagation rule are obtained. To constant rate model,the farther the pressure propagation distance is,the slower the pressure propagation velocity will be.Thus,time decresases(increases) when the production rate becomes low(high) in the same pressure propagation distance .To constant pressure model, time decresases(increases) when the bottomhole flowing pressure becomes low(high) in the same pressure propagation distance.