异常高压气藏气井产量递减自动拟合模型

AUTOMATIC DECLINE-CURVE ANALYSIS MODEL OF GAS WELLS IN ABNORMAL HIGH PRESSURE GAS RESERVOIRS

根据Fraim导出的考虑岩石和水压缩性的定井底流压生产拟稳态气井产量和标准化时间关系,文章建立了异常高压气藏气井产量递减自动拟合数学模型。通过编制的气井产量递减自动拟合软件,可以确定异常高压气藏地层参数。用数值模拟预测的异常高压气藏气井产量递减数据,对模型的有效性进行了对比。对比研究表明,对异常高压气藏,用考虑岩石和水的压缩性气井产量递减自动拟合模型,比用不考虑岩石和水的压缩性的气井产量递减自动拟合模型计算结果更精确。此外,文章还给出了异常高压气藏标准化时间计算步骤。

Based on the relationship between the production rate and the standard time of gas wells producing in quasi-steady state at constant bottom hole pressure which takes into account the compressibility of rock and water, the paper puts forward the automatically matching mathematical model that can be used in Decline-curve analysis of gas wells in abnormal high pressure gas reservoir. The formation parameters can be determined through programming the mathematical model into software. Comparative study has been made by using the decline data of gas well predicted from the numerical simulator in abnormal pressure reservoir. The study shows that the formation parameters obtained from the model in the paper are more accurate than that of the model which doesn′t considered the compressibility of rock and water. Moreover, the paper presents the calculation procedure of the normalized time of gas wells in abnormal high pressure reservoirs.