Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
Effects of Diameters Ratio on the efficiency of cleaning process in horizontal wells
Submission Author:
André Campanharo Gabriel , ES , Brazil
Co-Authors:
Renato Siqueira
Presenter: Renato Siqueira
doi://10.26678/ABCM.ENCIT2016.CIT2016-0711
Abstract
The oil and gas extraction is a process in fully development, needing always new technological advances to keep up with the problems encountered. In horizontal wells drilling, an efficient removal of cuttings from the formation is very important and the main function of the drilling fluid is the continuous removal of the cuttings generated by the drill. Various parameters affect the performance of the drilling process, which include: the geometry of the wellbore, the drill pipe rotation, the axial flow rate and the rheology of the drilling fluid. This study is concerned with the geometry factor, with the objective of evaluating the influence of the diameters ratio () on the cleaning process of horizontal wells. The diameters ratio is defined as the ratio between the drill pipe and wellbore diameters. For this study, Ansys CFX 16.0 was used, with a fluid characterized by the Herschel-Bulkley model, with specific mass =1000 kg/m3, yield stress 0 = 17.81 Pa, consistency index K = 0.26 Pa.sn and flow behavior index n = 0.74. The geometry is defined by an anular space 2.5 meters long, with variable eccentricity, inner diameter fixed at 50.8 mm and outer diameter determined by the diameters ratio (). Five diameters ratios were analyzed, varying from 0.5 to 0.9. The process parameters used are: Reynolds numbers (Re) of 200, 600 and 1000; drill pipe rotations (!) of 0, 200 and 400 rpm and eccentricities (") of 0,0.4 and 0.8. The increase of the diameters ratio causes an increment in the axial velocity, enhance the rotational effects, decrease the effective viscosity and increase the pressure loss. The understanding of the effects of diameters ratio on flow behavior is very important in order to obtain parameters to improve the efficiency of the horizontal wells cleaning process.
Keywords
Horizontal Wells, Herschel-Bulkley, CFD
