CFD method for analysis of the effect of drill pipe orbital motion speed and eccentricity on the velocity profiles and pressure drop of drilling fluid in laminar regime

Type : Publication
Auteur(s) :  Hicham Ferroudji, Ahmed Hadjadj, Titus Ntow Ofei, Mohammad Aziz Rahman, Ibrahim Hassan, Ahmed HADDAD
Année :  2019
Domaine : Mécanique
Revue : Petroleum and Coal
Résumé en PDF :  (résumé en pdf)
Fulltext en PDF :  (.pdf)
Mots clés :  Orbital motion, eccentricity, velocity profiles, pressure drop, drilling fluid, laminar flow

Résumé : 

Due to the axial and lateral loads applied to the drill pipe during the drilling process, this last may loseits stability and begins to make complicated motions like the orbital one. In the present paper, thisorbital motion of the drill pipe is modelled using CFD method to investigate its effect on the axial andtangential velocity profiles in the wide and narrow regions of the eccentric annulus (E=0.2, E=0.4,E=0.6 and E=0.8), as well as, effect of the orbital motion speed on pressure drop gradient of drillingfluid is studied. Our results show that increment of the orbital motion speed from 100 to 400 rpmcauses an increase of 913% of the maximum axial velocity, however, this increment is estimated atabout 100% in the case where the drill pipe makes pure rotation for the eccentric annulus (E=0.8),Moreover, orbital motion of the inner pipe prevents the secondary flow to appear in the wide region ofeccentric annulus. For all eccentricities, the tangential velocity of the orbital motion case in the narrowregion for 400 rpm speed is 120% higher than pure rotation one