Abstract
Heavy oil reservoirs cover up two third of the world's hydrocarbon reservoirs. Even though it is vast energy resource, heavy oil recovery is not considered economical due to its high viscous properties. Generally horizontal wells are more suitable for heavy oil recovery. When the heavy oil is produced with water drive, a water breakthrough is expected in the higher permeable zones of the reservoir or in the heel of the well. Once water has reached the well, heavy oil reservoirs tend to produce more water than oil. In order to overcome this issue, inflow control devices are being used. Conventional inflow control devices (ICDs) are only capable in in delaying a water breakthrough. The disadvantage of ICDs is that, it cannot control the water inflow, once the water breakthrough has occurred. Autonomous inflow control valve (AICV) is designed to choke or stop the inflow as soon as the water breakthrough takes place. In order to evaluate the performance of AICVs for different reservoir conditions, OLGA-Rocx simulations were carried out. Simulations with fractured, heterogeneous and homogeneous reservoirs were performed. By comparing the obtained results with conventional ICDs it was found that the AICVs have a superior potential in limiting the water inflow to the base pipe (86% reduction in water accumulation compared to normal ICDs in fractured reservoirs). It was also observed that, AICVs are more effective in heterogeneous and fractured reservoirs as it can restrict the early water breakthrough. Even in homogeneous reservoirs, AICVs have the capability in controlling the water inflow. As a result, oil production rate would also be reduced compared to the ICD system, however, the lifetime of the well will be increased by using AICV.