Use of Variable Stabilizer in Horizontal Wells

Abstract

ABSTRACT This paper outlines the background, concept, preplanning, supervision and achievements made by use of variable gauge stabilizers in rotary drilling of horizontal wells. The experienced performance and behavior of PDM motor versus the variable gauge stabilizers are reviewed. The requirements and ability to drill at high penetration rates over long hole sections and with small vertical targets still being able to control the vertical depth within a target limit of ± 2.0 m are shown feasible. Examples from the Oseberg field will show results of the drilling operations including drilling parameters, BHA's, ROP, hole trajectory, torque and drag during the drilling and results of the consequent setting and cementation of pipe in the horizontal section. The conclusions are; (1) rotary drilling of horizontal section gave higher ROP (m/hr), (2) inclination was satisfactory controlled with a variable gauge stabilizer over a horizontal section of 174 m, eliminating several trips and (3) this technique will enable vertical tolerances of horizontal wells as narrow as ± 1.0 m over long horizontal sections, even at high penetration rates.