低渗透油藏油井流入动态研究

针对低渗透油藏的渗流为非达西流且存在启动压力的特点,建立了低渗油藏垂直井单相原油渗流的流入动态关系式,并提出了有效地层压力的概念,同时推导了油气两相渗流的流入动态关系式.为了考虑油井完善性对产能的影响,将流动效率定义为在相同压差下非完善井的实际产量与理想完善井的产量之比,这样便于数学描述,且其物理意义更加明确.在此基础上,探讨了油、气、水三相流体渗流动态关系的计算方法.分析结果表明,稳定流动时,达西流只是非达西流的一个特例.安塞油田53井次的现场应用资料表明,平均误差不超过10%,所建立的流入动态关系式有较强的适应性.

Study on inflow performance of oil wells in low-permeability reservoirs

The inflow performance relationships (IPR) for the single-phase and two-phase flow in vertical wells of low-permeability reservoirs are established. The concept of effective formation pressure is presented. The flow efficiency is defined as the ratio of actual rates of non-perfect wells to the rates of ideal wells, in consideration of the effect of non-perfection on well rates. This definition is easily described by mathematics, and its physical meaning is clear. The calculating methods of IPR for oil-gas-water flow are discussed. The analysis shows that Darcy flow in steady fluid flow is only a special case of non-Darcy flow. The application of field data from 53 wells to validate the models shows that the average calculation error is within 10%. The established IPR are suitable for different cases and can be widely used in practice.