Abstract: Average gas pool pressure is currently determined by shutting up of wells which is fraught with difficulties. Wells with super-high pressure or high flow rate can not be closed, and wells in tight pools with low permeability, to be closed for a long time, will incur heavy economic losses. At all events, shut-in of gas wells would seriously affect the producer and the consumer, and it would mean too high a cost just for taking the average formation pressure. To overcome the above, the authors have attempted to introduce a system identification method to compute the average pressure based on records of daily output of gas wells without shutting up the well. It is no doubt economical and practical.

摘要： 目前常采用关井的方法来确定气藏平均地层压力,但是应用该法通常将遇到一些困难。有的井不能关(超高压气井、高产井等);有的井关井时间太长(低渗气藏上的气井),经济损失较大。总的来说,关井会严重地影响气矿和用气单位的生产,如果专门为获得平均地层压力而关井,其代价太大。本文为克服上述困难进行了一些初步尝试,采用系统辨识方法来计算气藏平均地层压力,仅以日常气井生产记录为基本资料,不需要关井测试,无疑具有较高的经济效益和实用性。

关键词: 平均地层压力, 低渗气藏, 计算方法, 系统辨识方法, 传递函数, 关井时间, 渗流系统, 压力函数, 井底压力, 非线性系统