One of the limitations of achieving full potential in pumped wells is the presence of excessive free gas at pump intake. Presence of free gas at pump intake affects the pump performance negatively, reducing the liquid rates and the pressure added by the pump. This performance reduction may sometimes be quite severe, resulting in unstable pump operation, significant production losses, lower reliability and increased operating costs due to premature equipment failure. Currently some operators need to produce wells under challenging operational conditions with very high free gas ratios. ESP in wells with a high free gas liquid ratio that requires the use of special gas handling technologies is becoming more and more common. Recent advances in ESP gas handling technologies expand the use of ESPs to more gassy applications in the industry.
This paper presents the methods used, the results and learnings from the application of ESPs with various gas handling technologies based on real field data. Present natural flow conditions were simulated to determine the operating envelope for each well. ESPs were evaluated for the selected design ranges governed by the drawdown (bubble point) constraints. The operating envelopes for each selected well were established over its life cycle with various free gas volumes and water cuts.
The paper confirms that ESP can operate successfully with the pump intake gas fraction up to 75% through use of appropriate gas handling technologies and challenging the norms.