Improving ESP Performance in Low Productivity Gassy Wells: Case Study

Abstract

The electrical submersible pump (ESP), has become the most efficient and reliable artificial-lift method worldwide. However, in wells with high gas volume, they are highly affected by gas bubbles flowing through each component, affecting: the motor temperature, lifting efficiency, the integrity of the motor and cable. Thus, High gas interference might cause multiple intermittent shutdowns due to Gas Lock and eventually shorten the run life of the ESP. ESP at Well #A was first installed and directly had a problem with High Gas Interference resulting in a pre-mature ESP failure and costly well intervention to restore well-deferred production. A detailed discussion with a technology provider and reference case studies come up with an integrated solution to have the proper gas handling system in addition to adjusting VSD logic to operate on PID current mode. The present study shows a successful ESP optimization through VSD settings in combination with a comprehensive gas handling system that allowed management of low productivity high GOR ESP applications. This gas handling system for ESP was complemented by installing [PMM motor, tandem gas separators with vortex technology, compression mixed-flow stages in a wide range centrifugal pump, advanced gas handler (AGH), and Monel armor leaded power cable]. The system was able to manage GOR>2,000 SCF/STB with WC of <10%, Productivity index of 0.2 BPD/psi, and 75% of free gas flowing into the pump intake. This paper contains all the descriptions of each component in the ESP gas handling system. The system was able to increase well production by reducing gas-locking production shutdowns, stabilizing motor current fluctuations, increasing ESP lifetime, and increasing reservoir life by increasing drawdown and allowing effective pump operation at lower intake pressure. The same directions were successfully applied in another two wells with low productivity gassy behavior; Well #B and Well #C. And, by monitoring ESP performance for a longer period, the pump showed a stable operation, by successfully mitigating the high gas interference trips. Thus, the implementation of this integrated solution in wells with high GOR has been demonstrated to be an effective solution. Also, it provides opportunities to expand the use of ESP in gassy wells, previously thought to be unsuitable.