The Application of Rotary Closed-Loop Drilling Technology to Meet the Challenges of Complex Wellbore Trajectories in the Janice Field

Abstract

Abstract It is usual for initial development wells on marginal fields to follow a conservative drilling programme using conventional technology with known drilling performance. In the case of the Janice Field situated in block 30/17a of the UK North Sea it became apparent, following field appraisal, that to effectively exploit the reservoir it was necessary to drill complex 3D well trajectories. Such wells would require significant directional work with large associated costs. Specific challenges included high torque and drag profiles, slow rates of penetration, limitations of conventional directional drilling techniques, tight target tolerances and the requirement for effective reservoir navigation. After careful consideration, the operator, Kerr-McGee North Sea U.K. Limited determined that the application of Rotary Closed Loop Steerable (RCLS) technology was part of the appropriate technical and economic solution for the drilling of these wells. This paper describes how the combination of RCLS and conventional drilling technology was used to achieve the field development objectives. This provided a unique opportunity to make a direct comparison between RCLS and conventional steerable technology on similar 3D complex well trajectories. Specifically, key performance factors were measured enabling quantitative and qualitative statements to be made of drilling performance with the two technologies. The experience gained provides an insight to where it is appropriate to use this new technology and demonstrates the applications for which this technology can provide significant technical and economic advantages.