Erosion of punched screen in natural gas hydrate exploitation

The purpose of the study is to accurately predict the erosion wear rate and service life of screen pipe protective sleeve in natural gas mining. Firstly, according to the reservoir and completion characteristics, the flow channel model of the screen was established. Secondly, the discrete phase model(DPM) was used to simulate the erosion failure process of sand particles in the gas-liquid mixed fluid against the punched screen. The variation of the erosion rate of screen wall under the action of gas, liquid and solid three-phase flow with the flow velocity, sand volume fraction, liquid volume fraction and opening height was analyzed. Finally, according to the erosion condition of screen pipe, the life prediction model of the punched screen based on the maximum erosion rate and allowable erosion width was deduced to predict the life of screen pipe. The results show that the biggest erosion rate part of the punched screen structure is the edge area near the opening surface at the bottom of screen. The erosion rate of the punched screen increases exponentially with the increase of flow rate. It shows a linear increase trend with the increase of sand volume fraction and liquid volume fraction. The predicting service life of the punched screen decreases obviously at the initial stage of increasing speed. The predicting service life decreases with the increase of liquid volume fraction and particle volume fraction and the decrease of opening height. The decrease of the opening height reduces the overall flow area of the screen, resulting in the increase of flow velocity at the slot, the erosion wear of the screen is more severe and the predicting service life decreases. © 2022, Central South University Press. All right reserved.