Numerical Simulation Of Cement Annulus Interface In Directional Well Flow

In the course of cementing.improving the displacement efficiency in cementing engineering is a basic premise to prevent drilling fluid channeling, guarantee the bonding strength of set cement and improve the scaling property of cement sheath. The displacement efficiency is affected by many interacted parameters, such as the technologic measures, formation condition, wellbore geometry, fluid mobility, cementing tools and so on. Due to the complexity of influencing factors, it is difficult to precisely simulate the displacement by means of laboratory experiments. It is, hence, of practical importance to systematical study the annular displacement mechanism by numerical simulation.Based on the large-scale CFD software FLUENT, the effects of rheological parameters, eccentric annulus, special well condition and other variables on the displacement efficiency were studied by means of numerical simulation, and establish the annulus 177.8mm* 215.9mm displacement model.The eccentricity of tilted ring replace the empty influence on, the value in the engineering application of the common eccentricity range, fixed and certain factors remain unchanged. The simulation results different eccentric degree of longitudinal displacement and displacement efficiency changes. And This paper change the degree of eccentricity and the density difference or the eccentricity and the angle of the well.the combination analysis of the influence of multiple factors.In accordance with the same method, analyzes the deviation angle, density difference, displacement profile changes under the influence of three factors:speed and displacement efficiency changes. At last, the simulation results show that increasing the density difference between the cement slurry and the drilling fluid.the consistency coefficient of cement slurry and the plastic viscosity of cement slurry, all help to improve the displacement efficiency of cement slurry. On the contrary.if those factors of the liquidity index of cement slurry, the consistency coefficient of drilling fluid.the plastic viscosity of drilling fluid and so on match discomfort. it will reduce the displacement efficiency of cement slurry. Research results can contribute to better understand the annular displacement mechanism in cement squeezing.and provide necessary theoretical foundations for the design and execution of cementing.