Optimizing Recovery: Retrofit Autonomous Inflow Control Device (AICD) Completions in Viscous Oil Horizontal and Vertical Wells - A Case Study

Abstract This paper presents a comprehensive case study on the deployment and evaluation of retrofit Autonomous Inflow Control Device (AICD) completions in both horizontal and vertical wells within a mature, viscous oil reservoir in North America. Historically subjected to primary, secondary, and tertiary recovery operations, the field currently exhibits complex water management challenges, including coning, early breakthrough, and vertical heterogeneity. To address these, retrofit AICDs were installed within existing completions, such as standalone screens and slotted liners, and perforated interval completions without the need for full well workovers. Field results and simulation analysis demonstrate that AICD completions enhanced reservoir conformance, reduced water cut, and improved hydrocarbon recovery in both horizontal and vertical or slanted wellbores. In vertical wells, the addition of inflow control significantly delayed water encroachment in thinner pay zones and enabled selective drainage of higher oil saturation intervals. In horizontal wells, performance was improved by managing drawdown and minimizing early water breakthrough, especially in segments exposed to high mobility contrasts. This shift toward controlled drawdown and pressure-balanced production has also reduced operational costs associated with artificial lift and water handling. The study outlines lessons learned from multi-well implementations, including candidate selection criteria, completion design considerations, and the influence of formation integrity and natural borehole behavior on AICD effectiveness. Notably, the benefits observed in some wells are attributed in part to natural annular baffles formed via reservoir collapse, highlighting the need to evaluate geomechanical conditions during retrofit planning. The paper emphasizes that while AICD retrofits offer a promising low-intervention strategy for rejuvenating underperforming wells, successful outcomes are contingent upon appropriate well selection, reservoir conditions, and completion integrity. The integration of AICDs into both vertical and horizontal wells provides a scalable solution for optimizing recovery and extending economic field life in mature, water-prone assets.