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

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.