Effect of Gas-Oil Ratio on Oil Production for a Niger Delta Well

Abstract

This study delves into the intricate relationship between gas-oil ratio (GOR) and oil production rate in a vertical well within the framework of reservoir engineering. The investigation employs advanced reservoir modeling techniques, drawing insights from Prosper software simulations and well data analysis. A comprehensive methodology involving PVT data, inflow performance relationship data, and sensitivity analysis guides the exploration of GOR's impact on oil rate. The selected well configuration, a vertical well, serves as the experimental canvas for this study. Through meticulous analysis of reservoir and well data, an Inflow Performance Relationship (IPR) curve emerges. This curve is developed using the Darcy reservoir model available within the Prosper software, reflecting the intricate interplay between fluid dynamics, pressure gradients, and production behavior. Further expanding the analysis, the study explores the IPR-Vertical Lift Performance (VLP) curve, spotlighting the well's behavior at a top node pressure of 250 psig. Subsequently, the study dives into the realm of sensitivity analysis, seeking to unravel the nuanced connection between oil rate, GOR, and well head pressure. The captivating findings are encapsulated, a visual testament to the intricate dance of fluid dynamics. The results paint a vivid picture of the GOR's role in oil rate modulation. The correlation between GOR and oil rate is revealed to be a delicate balance, illustrated by a crescendo and diminuendo as GOR rises beyond the bubble point. Above the bubble point, the gas's continuous expansion within the solution propels oil production. The study's intricate examination of well head pressure offers further illumination. The result further exposes the inverse relationship between well head pressure and oil production rate, as heightened well head pressure curtails pressure drawdown and subsequently reduces the amount of oil lifted to the surface. The study concluded that Oil production rate increases with increase in gas-oil ratio up to a maximum above which oil production starts decreasing. The decrease in oil production starts when gas is released from the oil. An increase in well head pressure led to a decrease in oil production. This is attributed to a decrease in pressure drawdown between the bottom of the well and the well head.