关键词: 致密火山岩气藏, 二项式方程, 产能方程修正, 指示曲线异常, 无阻流量

Abstract:

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.

Key words: tight volcanic gas reservoir, binomial equation, productivity equation correction, abnormal indicator curve, open flow capacity