Research on casing erosion in reservoir section of gas storage wells based on Gas-solid Two-phase flow

Abstract

Gas storage wells are characterized by large injection and production volumes and multi-cycle high-intensity cyclic injection and production, and the high-speed flowing sand particles have a strong erosion effect on the tubular column, threatening the safety of the gas storage wells' tubular column. In this paper, gas–solid two-phase flow erosion experiments and erosion simulation are used to study the effects of sand parameters, casing materials, and formation temperature on the erosion rate of reservoir section casing during gas recovery. The results show that due to the high temperature weakening the material strength of the casing in the reservoir section, the erosion rates of N80 and P110 casings increase with the growth of environment temperature. The casing erosion rate in the reservoir section increases with the raising of gas production volume, and the casing erosion rate increases rapidly when the gas production volume of the case well exceeds 162 × 104m3/d. The increases in sand particle diameter and mass flow rate also aggravate the casing erosion. The borehole dog-leg degree affects the erosion rate of the casing by influencing the attack angle of sand particles on the casing, and the erosion rate increases significantly when the borehole dog-leg degree exceeds 3°. The study results provide theoretical guidance for the building and operation of gas storage wells and are of great practical significance.