井下节流气井的井底压力确定新方法

A new method for determining the downhole pressure of gas wells with throttler

针对气井压力计测试方法测取节流器以下井段压力存在困难,回声仪测压方法有时测不准液面等问题,推导了具有节流效应影响的压力公式:由节流器上流油压与套压的变化关系,计算出积液深度,再从油套环空采用井深迭代方法,得到一种新的计算井底压力的方法.通过气田现场应用表明:该方法与回声仪测压方法的静压平均相对误差小于2%,流压平均相对误差小于6%;与压力计测试方法的静压和流压平均相对误差分别小于9%和4%.该方法能比较方便和准确地得到气井井底压力,是气田动态监测的一种可靠手段.

In present,it is difficult to measure the downhole pressure of gas wells with throttler using pressure gauge,and the liquid level measured using echometer is also not accurate.The downhole pressure calculating formula with throttling effect is derived.The liquid depth is calculated from the relationship between the liquid pressure above the throttler and casing pressure,and then the downhole pressure is obtained by well depth iteration in the annular space between oil tubing and casing.The application cases show that the average relative errors between the downhole static pressure and flowing pressure calculated using this method and those obtained using acoustic pressure testing are less than 2% and 6% separately,and the average relative errors between the downhole static pressure and flowing pressure calculated using this method and those obtained using pressure gauge are less than 9% and 4% separately.The proposed method can conveniently and accurately gain downhole pressure for gas wells,and it is a reliable gasfield dynamic monitoring way.