气井产量递减分析方法应用

The application of production decline analysis for gas wells

确定气藏参数的方法常常是关井测压。然而,我国有许多气藏渗透率特别低,压力恢复所需的时间特别长,有时长达几个月。因此,有必要研究根据气井生产史确定气藏参数的方法,避免关井给生产带来的损失。本文对具有生产记录的气井,采用现代产量递减分析方法反求地层参数,并用标准化时间和标准化压力半对数图,作为检验计算结果正确与否的标准。实例对比表明,对于没有关井测压的气井,可以用该方法反求气藏参数。

The most common method to determine a gas reservoir＇s formation parameters is well shutting and then pressure measuring. However, in China, there are many low permeability gas reservoirs, and they need a very long period for the building up of the bottom hole pressure, sometimes this period lasts several months. Therefore, it is necessary to study the method that can determine the reservoir parameters according to well production histories, so as to avoid the economic loss caused by well shutting. For the wells with production logs, this paper yields the formation parameters with the modern production decline analyzing method, and the semi--log figure between the standard time and the standard pressure is used as the criterion to validate the calculation results. Practical calculation and comparison indicates that. for wells without well shutting and pressure measuring, this method can be used to resolve the reservoir parameters.