Computational Study of Heavy Oil Production with Inflow Control Devices

Abstract

Recovery of heavy oil is associated with challenges in terms of early water or gas breakthrough caused by the fingering phenomenon. This study is related to Californian heavy oil production and includes 2D simulations of heavy oil with viscosity 300cP in horizontal wells with autonomous inflow control devices (AICDs). The simulations were carried out using ANSYS/Fluent as the Computational Fluid Dynamics (CFD) software. Volume of Fluid (VOF) is used as the multiphase model. Preliminary studies are performed and a model for heavy oil production has been developed and validated against experimental data found in literature. Grid resolution tests and time step dependency tests are performed. 2D simulations were carried to study reservoir flow, annular flow and flow through the AICDs into the production pipe. Before breakthrough the analysis of data gives quite realistic results which can be theoretically justified. The simulations clearly stated the fingering phenomenon and the effect on breakthrough and oil production. Higher pressure drop is observed near the well bore (or across AICD) as the finger growth takes place. Simulation of two pipe sections in a homogeneous reservoir does not reflect the function of AICDs adequately. This is due to negligible frictional pressure drop in the pipe which breakthrough at approximately the same time in the two sections. This study has /identified the formation of fingering in heavy oil reservoir with water drive and according to the simulated results, oil production is highly affected by fingering behaviour, since it enables the early water breakthrough while most of the oil is left unproduced.