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8752971 
Meetings & Symposia 
Extracting value from a dormant marginal offshore oil field, the Okwori field case 
Stenger, BA; Guinot, FJ; Aubert, O; Clauss, C; Otevwemerhuere, J; Ezeukwu, TE 
2006 
Society of Petroleum Engineers 
6 
3136-3147 
English 
Since first oil was achieved in March 2005, Addax Petroleum's Okwori field offshore Nigeria validated the deployment and illustrated the benefits of recent technical and contractual solutions for improving the economics of projects previously shelved for lack of commercial attractiveness with more traditional approaches. Addax Petroleum's Okwori project demonstrated the feasibility of developing small and geologically complex offshore oil fields in medium water depth of 440 feet, far away from pre-existing facilities and with less than 50 millions barrels of proven and probable technical reserves (proven and probable technical) at project sanction. The Okwori oil field development went therefore a step further than the usual subsea tie-back to a larger pre-existing offshore production facility. The Okwori development concept used horizontal subsea trees flowing to a leased spread-moored Floating Production Storage and Offloading (FPSO) vessel via flexible subsea flowlines and risers. In the subsurface, the Okwori wells combined multiple selective completions hydraulically controlled from the FPSO and expandable sand screen as sand exclusion solution; this particular combination in subsea wells for a small field marked another technological first in the offshore oil industry. Okwori leased production facilities had built-in capability for additional tie-backs such as Nda oil field development now planned for mid 2006 or for later re-deployment in other parts of the acreage depending on further exploration and appraisal drilling in the planning stage at time of writing. Review of field operations to date highlighted a steep learning curve in the formulation of completion design, completion fluids, stimulation, sand exclusion, and bean-up/bean-down procedures. Copyright 2006, European Association of Geoscientists and Engineers.