Mechanism and sensitivity analysis of an inflow control devices (ICDs) for reducing water production in heterogeneous oil reservoir with bottom water

Abstract

The improved oil recovery (IOR) mechanism of ICDs is usually contributed to equalizing pressure drop to achieve an evenly distributed inflow profile along the horizontal section. Substantially, in heterogeneous oil reservoirs with bottom water, the intrinsic mechanism is changing the pressure distribution in formation to effectively utilize the energy of bottom water. In this work, a reservoir-ICD-wellbore coupled model was established and the corresponding simulator was developed. In the rest of the paper, this model was used to discover the mechanisms of ICDs in heterogeneous reservoir with bottom water. Finally, the sensitivity of many factors on oil recovery factor and IOR of ICDs were demonstrated. The results show that ICDs can improve the recovery and delay the water coning. The intrinsic mechanisms of ICDs contains both equalizing pressure drop around the wellbore and changing the direction of lateral flow to increase the sweep volume of bottom water, but ICDs is essentially a shallow profile control technique. The IOR of ICDs is significant in strong heterogeneous oil reservoirs; the IOR increases as the well production rate and oil viscosity increase; as Kv/Kh (the ratio of vertical to horizontal permeability) and HD (dimensionless water avoidance height) increase, the IOR first increases and then decreases, the optimal values are related to the permeability heterogeneity.