Failure analysis and erosion prediction of tee junction in fracturing operation

Abstract

Erosion wear in piping is an unavoidable degradation process in the oil and gas industry that causes pipe wall thinning and leads to economic losses and potentially produce personal injuries. The mechanism of pipe erosion remains poorly understood. This study focused on predicting the erosion of a tee junction (T) under various flow types during fracturing operation. The failure analysis of tee junction was determined from its macroscopic features and scanning electron microscope (SEM) images and allowed definition of the failure mode and failure mechanism were defined, which appeared to be significantly different from what has been considered to be traditional. The failure analysis and fluid mechanics theory were used to build a computational fluid dynamics (CFD) simulation method to predict the erosion of the tee junction. The model of two-phase flow in a tee junction indicated that the solid-phase flow is determined by combined effects of the main tube flow, the flow inertia, and the turbulent flow. The distribution of the erosion in the tee was significantly different for various flow types and the simulation results were consistent with the results of the failure analysis. This model of predicted local distribution of erosion wear can assist the monitoring of pipe walls to prevent accidents and reduce maintenance labor.