Eventos Anais de eventos
ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
COMPUTATIONAL FLUID DYNAMICS AND HEAT TRANSFER IN ROTATING PDC DRILL BIT UNDER DIRECT AND REVERSE CIRCULATION
Submission Author:
Deivid Barbosa , PR
Co-Authors:
Deivid Barbosa, Roderick Gustavo Pivovarski, Vinicius Daroz, Alan Lugarini de Souza, Eduardo Matos Germer, Admilson Franco
Presenter: Deivid Barbosa
doi://10.26678/ABCM.ENCIT2018.CIT18-0787
Abstract
Polycrystalline Diamond Compact (PDC) drill bits are employed in deep water oil well drilling operations, due to their increased robustness and lifetime. In the direct circulation mode, the drilling fluid is descendant through the drill pipe and ascendant in the annular section. Alternatively, in the reverse circulation mode, the drilling fluid is descendant through the annular section and ascendant through the drill pipe. The latter mode may be used for more stable downhole formation and by the fact that it dismisses the need for rigid risers. A thorough computational fluid dynamics (CFD) parametric study on turbulent flow around rotating drill bits still lacks in the literature. In the present work, turbulent fluid flow and heat transfer in a rotating primitive PDC drill bit model is performed for a broad range of volumetric flow rates. The primitive geometric model consists of a simplified reproduction of commercial bits, yet keeping unimpaired their functional features. The proposed model reduced computational time by 92%, compared to a commercial drill bit geometry. Numerical simulations allowed prediction of recirculation zones in the fluid domain and intensified wear regions over the bit surfaces. Head losses, turbulent flow patterns and temperatures were also evaluated in both direct and reverse circulation, the latter showing reduced vorticity and friction.
Keywords
Oil well drilling, Reverse Circulation, Computational Fluid Dynamics, SST turbulence model
