PSEUDO-CATENARY PROFILE WELL PLAN AND TORQUE AND DRAG EVALUATION FOR AN EXTENDED REACH WELL

Torque and drag is a key factor to limit horizontal departure of an extended reach well(ERW), optimization of directional profile can be used to reduce torque and drag and increase horizontal departure. Pseudo-catenary profiles exhibit some benefits in terms of reducing torque and increasing the ability to run tubulars in Extended Reach Drilling(ERD). This paper introduced calculation equations with which Pseudo-catenary profiles can be planed, and maximum inclination can be determined to ensure pseudo-catenary profiles meaningful in geometry an engineering. Comparisons and evaluations in torque/drag between catenary profile, pseudo-catenary profile and slant profile were made. Results show pseudo-catenary profile has less torque and drag compared with slant profile, function of reducing torque and drag is limited by changing directional profile due to the small ratio of the length of curved section to total depth, but pseudo-catenary profiles provided a new choice for ERW profile plan.