异常高压气藏开发特征的解析研究

异常高压气藏开发过程中,在视地层压力与累积产量之间的关系曲线上常出现上凸拐点现象,正确认识异常高压气藏的开发特征对合理规划异常高压气藏的开发具有十分重要的意义.为了系统研究异常高压气藏的开发特征,通过将储层流体及岩石物性参数的变化特征引入圆形封闭气藏数学模型,求得了分析异常高压气藏开发特征的平均地层压力解,并就物性参数变化对开发特征的影响,分析研究了异常高压气藏压力衰竭式开发过程中,视地层压力与累积产量关系曲线可能出现的各种特征.流体、岩石、水体等参数变化的敏感性研究结果表明,异常高压气藏视地层压力与累积产量之间的关系曲线可以表现为一条直线、或者上/下凸的曲线等多种可能的形态.为全面认识异常高压气藏的的开发特征提供了一种解析方法,为合理编制异常高压气藏的开发方案提供了理论参考.

THE ANALYTICAL STUDY OF ABNORMALLY HIGH PRESSURE GAS RESERVOIR DEPLETION CHARAC-TERISTICS

During the depletion process of gas reservoir with abnormally high pressure,there is usually an inflexion on the P/Z Vs.Gp curve.Correctly predicting the P/Z Vs.G p Curves feature is very important for gas reservoir developing management.This paper proposed an analytical method to study the abnormally high_pressure gas reservoir's depletion characteristics.Considering the gas and rock's properties variation with pressure in the mathematics model of a circle closed gas reservoir,the average pressure can be deduced by the analytical method and can be used to analyze the depletion characteristics of abnormally high_pressure gas reservoir.All the possible P/Z Vs.Gp curve's features have been discussed in this paper based on the deduced average pressure solution.The result shows that the depletion feature of the abnormally high_pressure gas reservoir is sensitive with the variation of rock's compressibility and gas's PVT and the related water.The P/Z Vs. Gp curve's feature maybe different for different properties,it can be one of a straight line or a protruding curve or a concave curve .This analytical average pressure solution can not only be used to study the depletion characteristics,but also be a theoretical reference for correctly programming the depletion strategies of an abnormally high_pressure gas reservoir.