Conceptual Design for a Hybrid Deepwater Work over System BNW Project Musa Mohammed Shell Nigeria Exploration and Production Company

摘要

Subsea well intervention equipment has always been a highly capital intensive investment. This cost challenge is of most significance for smaller field tie-backs in deepwater offshore environment. There is a requirement for open competitive tendering for a scope above a cap of $250,000 prevalent with some Production Sharing Contract [PSC] terms in Nigerian deep offshore developments. This presents a scenario for possible multiple vendor equipment to be deployed within the same field. The Bonga North West [BNW] project is a representative case of this scenario. In order to explore opportunities for reducing capital investment, the team developed a concept that allows possible use of SNEPCo owned existing work over equipment supplied by vendor A for intervention on a vertical deepwater tree supplied by vendor B. The proposed retrofit system is expected to be used for full bore well access for wireline/coil tubing operation and other intervention operations on wells in the BNW field. The system is designed for deployment either from a DP Rig or an offshore installation and intervention vessel. This paper outlines the functional requirements for the interface equipment, associated risks, challenges and opportunities. The system is based on field-proven technology and is designed to be in line with Shell Global Well Control philosophy as well as relevant industry and regulatory standards.