考虑脱气的异常高压油藏产能模型研究

在前人研究的基础上,从异常高压变形介质油藏的基本渗流规律出发,考虑了井底附近地层压力下降后渗透率下降对渗流的影响,同时考虑启动压力梯度对油藏渗流的影响,也考虑了井底流压低于原油饱和压力时脱气对产能的影响,从而提出了一种考虑脱气的异常高压油藏产能新模型,可为对合理开发异常高压变形油藏的提供理论上的依据。利用该模型对储层不同压降水平下的产能进行考察,曲线呈现出明显的拐点,因此可确定不同平均地层压力下优化的最大生产压差。

Productivity model of abnormally high pressure oil reservoir with degassing effect considered

Based on previous studies and beginning with the basic pattern of percolation in abnormally high pressure deformation medium, this paper studies the influences of permeability decrease on percolation after the formation pressures near the well bottoms having dropped, the influences of start - up pressure gradient on percolation of fluids in reservoirs, and the influences of degassing on productivity when bottom hole producing pressure getting lower than crude saturation pressure. A new productivity model of abnormally high pressure oil reservoir with degassing effect considered is built to provide a theoretical basis for rational development of abnormally high pressure deformation reservoirs. This model is used to study productivity at different pressure drawdown of reservoirs, and the curve shows a distinct inflexion, therefore the optimized maximum producing pressure differentials under different average formation pressures can be determined.