COMPREHENSIVE ASSESSMENT OF WATER INJECTION EFFICIENCY IN THE RESERVOIR PRESSURE MAINTENANCE SYSTEM

Abstract

Abstract. The paper presents the results of a comprehensive study on the effectiveness of the reservoir pressure maintenance (RPM) system through water injection at the Kenbai oil field. The relationship between daily water injection volumes and production performance indicators was analyzed based on long-term field data. It was established that a decrease in the daily water injection rate below 1650 m³/day leads to a significant decline in total fluid and oil production due to deterioration of reservoir energy and pressure depletion. Conversely, an increase in injection volumes contributes to production growth with a time lag of 3–8 days, which is associated with filtration flow inertia and reservoir heterogeneity. These patterns are обусловлены the complex geological structure of the field, lithological heterogeneity of productive formations, permeability variations, and the highly viscous physicochemical properties of the oil. The study also evaluates the technological efficiency of the existing waterflooding system and identifies optimization potential at the late stage of field development. Based on field performance analysis, the feasibility of implementing flow-diverting technologies is substantiated. In particular, the application of large-volume gel systems (LGS) is justified as an effective method for stabilizing oil production, improving sweep efficiency, and reducing water cut in producing wells under conditions of advanced water breakthrough.