A detection and diagnosis method for tubing leakage below liquid level in gas wellbore

Abstract

The accurate detection and diagnosis of the position of tubing leakage above or below the liquid level plays an important role in the emergency response to the leakage. This paper presents a new detection and diagnosis method based on acoustic monitoring tubing leakage below the liquid level. The optimized simulation experiment system for tubing leakage was proposed with visualization and controlled flow rate design, and it can capture the annular acoustic characteristics of leakage above and below the liquid level. The leakage identification model is established by optimizing multi-dimensional acoustic characteristic parameters. The results show that when the leakage occurs above and below the liquid level, the distribution of leakage noise in time domain and frequency domain is quite different. Such model can quickly and accurately diagnose whether the leakage of wellbore tubing occurs above or below the liquid level with an accuracy rate of 99.32 %.