ESP Application for Oil Production in Naturally Fractured Granitic Basement Reservoir
In fields with increasing water cut and depleting reservoir energy, Electric Submersible Pump (ESP) installation is a sustainable production option. It helps to extend life of the wells by lower abandonment pressure and therefore increases the recovery factor. In addition, the gas lift saving from ESP conversion wells could be utilized to optimize others wells’ productivity thus boosting the total field production. Over the last 9 years, Cuu Long JOC has been conducted 5 ESP campaigns in fractured granitic basement reservoirs which bringing full of surprises. The selected field for ESP pilot was brought on production initially in 2008 with over 75,000 bopd. However, water breakthrough occurred after 8 months quickly reduced the total field production to 5,000 bopd in 2013. At the time of ESP conversion, gas lift have already optimized and it is not sufficient to maintain the rate as most of wells flowed with 95% water cut. With ESP application, the wells were able to reach 12,000 blpd and reduce the water cut not only for itself but also for adjacent wells. Despite the pump average run life is not meet the expectation, ESP application shows better efficiency in term of oil production compared to gas lift under the same reservoir conditions. This paper summarizes a process of ESP application in high temperature environment including candidate selection, ESP design and actual production performance. The learning and experience developed from 11 ESPs installation provide an insight about the potential of ESP use for oil production in fractured basement reservoir.