Benefits Evaluation of Deepwater Intelligent Completion on Three Isolated Productive Zones Offshore Nigeria

Abstract

This paper describes the experience and advantages of both the operator and service company in using Intelligent Completion (IC) technology in deepwater challenging environment. Following a feasibility and risk analysis study performed by the operator, a single well with a triple zone the IC was selected as the best completion solution compared to a dual zone or single wells cluster solutions. The increased cost of this technology was justified by the overall CAPEX project reduction, increment of expected cumulative production and anticipated reservoir's lower layers production. While two zones IC can be completed with the flow control valves run above the gravel packed zones, the same cannot be done in triple zone IC; in this case, to allow fully independent zonal monitoring and control, two out of three of flow control valves and gauges needs to be run inside the lower zone gravel pack assemblies, bringing a complete new set of interface challenges between the upper and lower completion equipment. Equipment and procedure's risks were addressed and mitigated through Failure Mode and Effects Criticality Analysis (FMECA) reviews and completion System Integration Test (SIT). Flow control valve's choke design were also checked, based on the expected production profiles and downhole PVT, to cover the entire production rate and achieve the best draw down applicable. The well was completed across November and December 2008 with no incident and lost time and the completion solution adopted proved not only to solve all the initial reservoir challenges but also to reduce the number of well interventions, workover costs and risk. The well was successfully started up in February 2009 with a NPV increment of 15% and a reservoir recovery factor increase of 6%.