Integration of an Intelligent Completion into an Existing Subsea Production System

Abstract

Abstract Shell U.K. Exploration and Production, operator in the U.K. sector of the North Sea for Shell, Esso and other co-venturers, identified an application for an intelligent well completion within their existing Osprey development and initiated a project to engineer the required equipment interfaces. A feasibility study was undertaken to determine the possibility of modifying the existing Xmas tree, subsea control system and completion installation tools to incorporate intelligent well functionality. Project management of the interfaces required to prepare the necessary completion equipment involved mechanical, electrical and hydraulic services being retro-fitted to an existing design. All equipment was successfully modified and integrated prior to the completion of the sidetrack drilling operations from the existing well slot. Logging of the completed well system showed that the lower zone was not oil bearing and the well was plugged back and a conventional completion installed. The project demonstrated that integration of an intelligent completion into an existing subsea system was feasible and also highlighted that interface management of the various components is critical to the overall success of the system. Application of Intelligent Well technology is shown to demonstrate potential for acceleration of production and reduction of intervention costs in complex well completions. Enhancement of production and increases in ultimate recovery is predicted for reservoirs where this technology is fully applied. Introduction PES (Petroleum Engineering Services Ltd.) first identified the commercial potential for the development of a remotely controlled reservoir management system, compatible with conventional mono-bore, tapered bore and multi-lateral well architecture. This system would provide the means to reduce operating expenditure and optimise production rate and recovery throughout a field's producing life. The PES system development commenced in 1993. Shell International were involved in discussions with PES and encouraged Shell Expro to participate in the Joint Industry Project (TIP) with PES and major oil industry Operators. Upon completion of the development process of this system PES entered into an alliance with Halliburton to promote the joint marketing of their combined multi-lateral completion and remote control monitoring systems. Since then many other companies have been forming alliances to develop intelligent completion solutions. In August 1997 the first installation of an intelligent completion was realised by PES in the North Sea. Shell UK Osprey Project An intelligent well application was identified within the Shell Expro Osprey field to complete the OU-PI side track well as a dual zone selective producer on the Rannoch and Etive formations. The actual well targets of the OU-PI sidetrack were not known in detail at the start of the project, but because of long manufacturing lead-times the intelligent well related equipment was ordered in early January '97. As justification for this decision the economic evaluation of the OU-P2S4 well which had been designed with the same objectives as OU-PI was used. The OU-P2S4 well had a primary target in the Rannoch formation; subsequently the well was planned for recompletion on the Etive (1999) and Upper Ness formation (2000). OU-PI was suspended and the xmas tree recovered for refurbishment and modification to accept the additional penetrations required for the intelligent well system. OU-PI was side-tracked to the new location on the Osprey Main Horst.