Mechanism and Cuttings Removal Effect Analysis of an Efficient Vortexing Cuttings Removal Tool under Sliding Drilling Condition

Le résumé fourni par la source

Summary In the process of sliding drilling in highly deviated wells and horizontal wells, cuttings accumulate at the lower side of the borehole to form a cuttings bed, which is difficult to remove. To address the difficulty of removing cuttings beds during the sliding drilling process in horizontal and highly deviated well sections, this paper proposes awe propose a vortexing cuttings removal tool (VCRT). The internal flow field model of the VCRT has been established, and the computational fluid dynamics (CFD) method is used to analyze flow field variations. The results indicate that under the sliding drilling conditions of horizontal wells, when VCRT is installed near the bit, the cuttings volume fraction at the low side of the annulus is reduced by 18% compared to the conventional cuttings removal tool (CCRT). When the VCRT is installed in the section with a cuttings bed, the cuttings volume fraction at the low side of the annulus flow fluid is reduced by 36% compared to that with the CCRT. Therefore, the approximate installation location of the tool is determined based on comparative CFD analysis of two installation positions, and it is recommended to install the VCRT in the section with the cuttings bed. This tool has been applied in an oil field in Jiangsu, China, and field tests demonstrate that at a drilling fluid flow rate of 30 L/s, the rotational speed of the rotating blade can reach 400 rev/min, the pressure drop in the VCRT field is 1.6 MPa, and the friction resistance of the drill string will be reduced by 35.90%. Through CFD analysis, the working mechanism of the VCRT and its cuttings removal efficiency are revealed. The CFD results show good agreement with experimental data, and these findings provide important theoretical support for VCRT applications.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.