Numerical simulation of liquid-solid two-phase flow in cementing displacement based on kinetic theory of granular

Abstract

Ensuring displacement efficiency is a prerequisite for improving the quality of primary cementing of horizontal Wells. At present, most of the research focuses on the displacement rule between fluids (displacing fluid and displaced fluid). However, in actual cementing conditions, there are not only fluids but also cuttings in the annular. This paper proposes a liquid-solid two-phase flow displacement model based on the kinetic theory of granular flow. Displacement efficiency and cuttings migration in the horizontal annulus are evaluated by the computational fluid dynamics method. The results show that increasing the casing rotation speed makes the annular fluid and cutting axial velocity distribution more uniform. When the eccentricity is 0.6 and the casing rotation is increased from 0 rpm to 30 rpm, the displacement efficiency reaches 94.21 %, an increase of 6.01 %, and the volume fraction of cuttings is reduced by 2.72 %. When the yield stress of drilling fluid is less than 3.0 Pa, the axial velocity of the narrow annular fluid increases significantly, the displacement efficiency exceeds 90 %, and the volume fraction of cuttings decreases by 2.5 %. With the increase of displacement, the axial velocity of the annular flow field increases significantly. When the displacement reaches 2.4 m³/min, the displacement efficiency increases to 92.8 %, and the volume fraction of cuttings decreases to 0.9 %. The research results are helpful for better understanding the complex flow problems of the liquid-solid phase in the annulus. They can provide a theoretical basis and reference for optimizing the parameters of horizontal well cementing.