East Siberian Field Waterflood Management

Abstract

Waterflood strategy for balancing reservoir pressure and improving sweep is proposed. Work objective was to introduce new workflow that utilizes system approach in waterflood management for maximizing field performance. The workflow included classic pattern analysis with rating of zones of interest based on complex parameters and diagnostic diagrams coupling recovery, pattern production, reservoir pressure and cumulative production before water breakthrough. Top rated patterns injection regimes are optimized with the aid of reservoir simulation. When choosing a well for conversion producing flow rates and chance of early water breakthrough or poor pressure response were considered. Detailed correlation, understanding of reservoir architecture, accurate mapping of properties and multiple simulation runs give the base for producer to injector conversion decisions. Implementing of the waterflood management workflow resulted in watercut decrease in wells with early water breakthrough and promises higher recovery for new patterns since uniform injection replacement is controlled; Process of waterflood management turned into a routine process with known deliverables, action list is made and discussed every month; Zones with uneven sweep were identified and injection rates were optimized; Process of conversion candidate selection and making a conversion priority list was mastered; Injection wells with completion damage are spotted with the use of production analysis and added to stimulation program; Intervals of water breakthrough were determined based on correlation, petrophysics and production logging, squeeze jobs were planned; Currently there are only few waterfloods online in East Siberia and sharing management experience and best practices can without a doubt add value to an existing work process or show the right route for the new one.