油气地质与采收率2013，Vol.20Issue(1)：74-76,80,4.
低渗透油藏非达西渗流瞬时压力计算方法
Calculation method for the transient pressure of non-Darcy seepage flow in low-permeability reservoirs
摘要
Abstract
The non-Darcy unsteady seepage flow model containing moving boundary conditions in low-permeability reservoirs is high-ly nonlinear, and it is hard to obtain its accurate analytical solution. In this paper, the characteristics of the existence of threshold pres-sure gradient of the non-Darcy seepage flow is incorporated into the continuous equation, and then, the mathematical model of non-Darcy unsteady seepage flow is built, which can describe the characteristics of moving boundary in low-permeability reservoirs. However, it doesn't contain any moving boundary conditions so as to be convenient for the numerical computation. The Douglas-Jones predictor-corrector method is masterly adopted to obtain the numerical solution of transient pressure of the model, and its accuracy is verified by the fixed-point iteration numerical method. Result analysis shows that the curve of transient wellbore pressure of the non-Darcy unsteady seepage flow model in low-permeability reservoirs is different from that of the classical Darcy seepage flow model. And, there is an inflexion in its curve. Before the inflexion, the moving boundary hasn t arrived at the outer boundary with constant pressure yet, when the crude oil is produced by the elastic expansion of fluid and rock; after the inflexion, the moving boundary has propagated to the outer boundary with constant pressure, and the energy of the outer boundary with constant pressure is supplemented.关键词
低渗透油藏/预估校正法/非达西渗流/启动压力梯度/数值解Key words
low-permeability reservoirs/Douglas-Jones predictor-corrector method/non-Darcy seepage flow/threshold pressure gra-dient/numerical solution分类
能源科技引用本文复制引用
刘文超,姚军,孙致学,王月英,李晓燕,李小辉..低渗透油藏非达西渗流瞬时压力计算方法[J].油气地质与采收率,2013,20(1):74-76,80,4.基金项目
国家自然科学基金青年科学基金项目"基于离散裂缝模型的低渗透油藏压裂水平井流动模拟研究"(11102237). （11102237）
