OIL WELLS

Water coning and cusping are significant challenges encountered during oil production, particularly in reservoirs with bottom or edge water drives. These phenomena occur due to the unfavorable movement of water into the production wellbore, compromising oil recovery efficiency and resulting in economic and operational losses. Water coning refers to the upward movement of water from an underlying aquifer towards a vertical well, while water cusping describes a similar lateral movement of water towards a horizontal well. These occurrences are typically caused by pressure differentials induced during hydrocarbon production, where the drawdown pressure at the wellbore exceeds the critical rate, causing water to breach the oil-water contact (OWC) and flow into the well. The onset of water coning and cusping can severely reduce the oil-to-water ratio, leading to increased water production, higher separation and disposal costs, reduced oil recovery, and premature well abandonment. Understanding the mechanics of water movement in the reservoir and its interaction with the wellbore is essential for designing effective reservoir management strategies. This project explores the mechanisms, causes, consequences, and predictive models associated with water coning and cusping. It also reviews various solutions and mitigation techniques including critical production rate management, well completion optimization, reservoir simulation, and advanced recovery technologies such as horizontal drilling and inflow control devices (ICDs). The study is motivated by the increasing need to optimize hydrocarbon recovery from mature fields and minimize water handling costs, especially in the face of global energy demands and declining oil reserves. Emphasis is placed on the use of analytical and numerical methods to predict water breakthrough and design production strategies that minimize water influx. Examples of such methods used are change plot comparison, water cut vs time and cumulative oil.