Intelligent-Well Completions in Agbami: Value Added and Execution Performance

Abstract

This article, written by Senior Technology Editor Dennis Denney, contains highlights of paper OTC 20191, ’Intelligent-Well Completions in Agbami: A Review of the Value Added and Execution Performance,’ by Adekunle Mojeed Adeyemo, Chris Aigbe, Ike Chukwumaeze, SPE, David Meinert, SPE, and Steven Shryock, SPE, Chevron Nigeria, prepared for the 2009 Offshore Technology Conference, Houston, 4-7 May. Use of intelligent-well-completion (IWC) technology has grown, even with perceived risks associated with installation and longevity of the systems. In the Agbami field, offshore Nigeria, for which 80% of the development wells are planned with IWC installations, understanding these risks was key in justifying IWCs. The methodology used to quantify the realizable value from zonal control and data acquisition and a review of the execution performance for the initial IWC wells are presented. Introduction First production from the Agbami field was 29 July 2008, and it was producing at 140,000 BOPD at the time of writing. Peak production of 250,000 BOPD (not accounting for facilities downtime) was expected by the end of 2009. The Agbami field, discovered in 1998, is 70 miles offshore Nigeria at a water depth of approximately 5,000 ft. The field is a northwest/southeast-trending doubly plunging anticline, with a significant thrust fault through the crestal axis of the structure. As Fig. 1 shows, the field has four main reservoirs: 17MY, 16MY, 14MY, and 13MY. Approximately 80% of the field in-place volume and reserves are in the deepest sand (17MY), having average porosity of 18% and average permeability of 270 md. The field-development plan has 38 subsea wells (including 20 producers, 12 water injectors, and six gas injectors) tied back to a floating production, storage, and offloading (FPSO) vessel through subsea flowlines. The drilling-and-completion program is spread over three development-drilling stages. The project is in Stage 1, with eight producers and two gas injectors on line. Pressure maintenance will be by peripheral water injection and crestal produced-gas reinjection to ensure compliance with a “no flare” policy. Geologic and Engineering Considerations The field has multiple lobes within each major reservoir. Although these sand lobes, or zones, are in pressure equilibrium geologically, the vertical/lateral connectivity under dynamic conditions is uncertain. Therefore, waterflood and gasflood fronts are likely to advance through the reservoirs at different rates, leading to conformance issues. To optimize field performance and recovery, IWCs with downhole control valves are installed in the Agbami wells. The system will provide zonal information and control of production from and injection into the completed subreservoir zones. IWCs will enable zonal production/injection management for optimal field development and oil recovery.