In conventional drilling, the screw centralizer rotates with drilling string at a high speed. When drilling fluids passes through the screw centralizerin annulus, the drastic swirl generated by screw centralizer inevitably influences on the debris lifting of drilling fluid to some extent. Based on the turbulent flow theory of gas/solid phases, 3-D fluid dynamics model is established through finite volume method and is numerically computed in this paper, and the debris lifting capacity of screw centralizer in gas drilling is quantitatively evaluated. Numerical computation results indicate that the initial debris concentration at the inlet port has more obvious influences on the debris lifting capacity. The velocity of lifted debris increases along with the increase of the initial debris concentration; the bigger the particle diameter is, the more obvious the lifting effect of the drastic swirl is. The numerical computation can be used as a guideline for the design of screw centralizer.
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