关键词: 气藏, 异常高压, 开发特征, 解析方法

Abstract: 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.

Key words: gas reservoir, abnormally high pressure, depletion characteristics, analytical method