Numerical Modeling of Cuttings Transport Influenced by V-Shaped Cleaning Tools in Horizontal Wells

Hole cleaning is a critical challenge in drilling horizontal wells, where the effective wellbore cleaning could prevent drilling accidents, such as pipe sticking and well collapsing. The hole cleaning tools applied on the drillpipe are proven effective in mitigating these issues, which include straight rhombus, helical and V-shaped. Among them, the V-shaped cleaning tools could generate stronger turbulence enhancing hole cleaning efficiency. However, the flow characteristic of cuttings transport in annulus under V-shaped cleaning tools is highly complex, as it is influenced by different parameters, such as rotation speed, number of tools, and fluid flow rate. This paper established a solid-liquid flow model with multiple V-shaped cleaning tools, and the model was validated its effectiveness. The mechanisms of cuttings transport with multiple V-shaped cleaning tools were systematically evaluated through analyzing the rotation speed, tools distance and fluid flow rate in the annulus. Firstly, the results presented the internal flow behaviors formed distinct helical vortices driven by multiple V-shaped cleaning tools rotation, which changed the original flow direction and aggravated collisions between cuttings so that the flow regime has been changed from stationary flow to dune flow, and the height of the cuttings bed reduced. Then, the multiple V-shaped cleaning tools demonstrated significantly better performance, which the cuttings concentration was reduced by 23.7% compared with a single tool. In addition, the turbulence effect of multiple V-shaped cleaning tools on cuttings cleaning had a optimal distance, the cuttings concentration initially decreased and then increased with the increased distance between multiple V-shaped cleaning tools, and the best cleaning performance was at the distance between 2m and 2.5m. Meanwhile, a new cuttings concentration graphical plate for this multiple V-shaped cleaning tools was established here to provide guidance for hole cleaning in horizontal wells and supporting the optimization of distances between multiple V-shaped cleaning tools and operational parameters.