致密火山岩气藏产能方程修正方法研究与应用

Research and application of productivity equation correction method for tight volcanic gas reservoirs

二项式产能方程是气藏开发中重要的资料分析手段,可以通过试井数据求解,但致密火山岩气藏压力稳定慢,产能试井过程中,实测数据绘制的指示曲线会出现截距小于0的情况,导致方程无法正常求解,需要对公式进行修正处理。以致密火山岩气藏气井C2井为例,分析指示曲线异常原因,参考现有方程修正方法,校正处理产能试井井底流压数据,推导新的产能二项式修正方程,应用于致密火山岩气井,得到结果比“一点法”的结果更加稳定,且充分利用试井测试数据,能为无阻流量求取和后续开发生产方案制定提供依据。

The binomial productivity equation is a pivotal tool for analyzing data in gas reservoir development,typically resolved using well test data.However,in tight volcanic gas reservoirs,the pressure remains stable and changes slowly,which can lead to challenges during productivity well tests.Specifically,the indication curve generated from measured data may have an intercept less than 0,rendering the equation unsolvable in its standard form,thereby necessitating a correction to the formula.Taking the Well-C2 of tight volcanic gas reservoir as an example,the reason of abnormal indication curve is analyzed.By reviewing and adapting existing equation correction methods,the bottom hole flowing pressure data from the productivity test well is adjusted,leading to the derivation of a new corrected binomial productivity equation.It is applied to the tight volcanic gas well,and the result is more stable than the result of single-point method.It can fully leverage the well test data and provide the basis for the calculation of open flow capacity and the formulation of subsequent development and production plan.