Introduction of New Drilling Technology Provides Continuous High Build Rate Capability in Complex Corkscrew Well Trajectory, Accessing Unswept Reserves in the North Sea

In areas of the United Kingdom Continental Shelf (UKCS) operators are progressively seeking to drill increasingly complex well profiles to access un-swept reserves. Wells of such complexity require the introduction of new drilling technology to meet the challenge. In a recent UKCS operation, operator objectives for a wellbore required continuously high rates of curvature and tight dogleg severity control in a soft formation with unconfined compressive strengths (UCS) of 5 to 10 kpsi.A new, integrated high build-up rate rotary steerable system (RSS), capable of delivering up to 12°/100ft in an 8½-in. hole, was implemented as a solution to achieve and optimize the wellbore placement, thus accessing untapped reserves beneath the offshore platform. In this mature field, collision avoidance with existing wells presented an additional challenge. Focusing on a total system approach, new polycrystalline diamond compact (PDC) drill bit technology was designed to integrate with the high build-up rate (BUR) drilling system. The PDC bit includes features for a smooth torque response, enhanced rate of penetration (ROP), improved durability, and precise steering control. Proprietary software provided confidence in the planning phase that the bit responses, in combination with the deployed steering system and the overall BHA set-up, would deliver the demanding well profile.This paper presents the details of the integrated drilling technology, as well as the background of pre-drill planning and setup processes necessary for the successful application where no offset experience was available. In addition, this paper details the process management and implementation steps during the service introduction of the new drilling technology. The final performance of the integrated system that drilled the ‘corkscrew’ profile in one drilling run, providing the required well placement and hole quality will be shown. The overall new approach enables the industry to utilize previously inaccessible reserves and drive field economics further.