Abstract: A mathematical model for multiphase non-Darcy flow is proposed, and a corresponding finite deference discretization method for this model is also developed, then a well-grid flow equation to simulate non-Darcy flow is deduced. Based on existing black-oil simulator, the simulating methods mentioned above are implemented, which makes the engineering simulator possess the ability to simulate multiphase flow in low permeability reservoir. The two-phase start-up flow parameters can be attained by combining experimental results and oil field performance data. It should make the simulating results accord with production characteristics of low permeability reservoir. By analyzing computation result, differences between forecasting results based on different flow laws are also demonstrated. To measure overall producing state of reservoir, a concept of start-up coefficient is proposed. Preliminary evaluation on well-spacing adaptability for developing permeability of 2×10^-3μm² reservoirs by water flooding is given.

Key words: low permeability, non-Darcy flow, multiphase, well-grid equation, engineering simulator, start-up coefficient

摘要： 建立了多相非达西渗流数学模型,构造了该模型的有限差分离散化方法;推演了模拟低渗透油藏非达西渗流的井-网格流动方程;基于原有黑油模拟器实现了这套模拟方法,使工程化模拟器具备了模拟低渗多相非达西流的能力;综合室内实验结果和矿场动态资料而得到的两相非达西渗流参数,使得模拟结果符合低渗透油藏的开发动态特征。通过对计算结果的分析,指出了基于不同流动规律预测开发指标的差别,提出了度量储层动用状况的启动系数概念,初步评价了注水开采渗透率为2×10^-3μm²油藏的井距适应性。

关键词: 低渗透, 非达西渗流, 多相, 井-网格方程, 工程化模拟器, 启动系数