Philosophy of Inflow Control Devices in Optimizing Heavy Oil Recovery

Abstract Reservoir quality and mobility contrast plays a vital role in defining how fluid flows into the wellbore. For non-conventional oil reservoirs with viscosities over 25 cp, the lower mobilities pose a challenge for inflow into the well, this can however be managed with long horizontal wells. A major challenge, however, is the very rapid water breakthrough and attendant water cut development owing to the higher mobility ratio resulting in water fingering through the oil to the producers. The business objective was clearly outlined to identify and deploy technologies to accelerate and optimize recoveries from available heavy oil resources within the portfolio. The value of autonomous inflow control devices was tested exhaustively on a notional horizontal well with a drain length of 1500ft in a Niger Delta reservoir with viscosity of 34cp and 87cp. This was done in collaboration with two artificial lift technologies - gas lifting, GL and electrical submersible pumps (ESPs). The results revealed that including the autonomous inflow control devices resulted in increased breakthrough time by about 6 months, acceleration in time to 1 MMstb by 1.5 - 3 years, and incremental ultimate recovery by 0.4 MMstb. The economics of deploying the valves were also considered and returned incremental NPV, IRR and breakthrough owing to the acceleration obtained by delaying the water breakthrough and the attendant evolution.