JL气田HS组气藏产水气井压力恢复试井解释

Well test interpretation of pressure bulid-up for water-producing gas wells in HS group gas reservoir of JL gas field

JL气田HS组气藏为底水气藏,随着开采年限的增长,气水界面由2010年的-3643 m上升到2017年的-3615 m,导致高含水气井数量越来越多。为此,提出高产水气井压力恢复试井解释方法。采用该方法对JP井进行压力梯度分析,判断井筒内气液界面在-1000 m处;该井压力恢复试井解释时双对数分析导数曲线开始下掉后又上升,有一个突然变化,为此采用内边界为变井筒储集试井解释模型,解释出地层压力33.7 MPa,储层平均有效渗透率12.5 mD,较好的处理了井筒中出现相态重新分布问题。该方法可有效提高高产水气井压力恢复试井解释结果的准确性。

HS group gas reservoir in JL gas field is the type of bottom water gas reservoir.With the increase of production years,the gas-water interface rises from-3643 m in 2010 to-3615 m in 2017,which leads to more and more high water cut gas wells.Therefore,the interpretation method of pressure build-up test for high production gas wells is studied.This method is used to analyze pressure gradient of JP well and the gas-liquid interface in the wellbore is estimated at the depth of-1000 m.The derivative curve of double logarithmic analysis firstly drops and then rises and there is a sudden change.For this reason,a well test interpretation model with variable wellbore storage reservoir is adopted,the formation pressure is estimated by 33.7 MPa,average effective permeability is 12.5 mD,which can well deal with the problem of phase redistribution in wellbore.This method can effectively improve the accuracy of interpretation results of pressure build-up test in high water-producing gas wells.