ESP installation in Very High Gas Environment (GOR 500 m3/m3), Using Multi Vane Pump and Tail-Pipe in PDO

Abstract

Abstract Running ESP in gassy environment was always a big challenge causing frequent pump gas lock and ESP motor to overheat due lack of sufficient fluid to cool it and eventually shorten ESP run life. ESP was found to be the most suitable Artificial Lift method for WELL-01 as per the conducted Artificial Lift modelling. However, any selected ESP system has to have the capability to handle high Gas Oil Ratio (GOR), which was estimated around 500 m3/m3. After exploring all available technologies for handling high GOR in the market, decision was made to use the Centurion Multi Vane Pump (MVP) stage which was presented as the latest solution for gas handling. MVP integrates the three principles of Gas handling to a level of 90% of free gas at the pump intake: - Balancing holes mitigate the pressure difference and thrust loading. If gas forms because of low pressure area, it can easily escape through those holes. - It has a split vane design. As a general rule when dealing with gas, the more homogenous the fluid, the better. The split vane design allows turbulent mixing to occur, which favourable for flow capacities to carry the gas without becoming stagnant. - The steep discharge angle of the MVP transmits a greater amount of Kinetic energy to the liquid, increasing lift at lower flow rates In addition to that and for more precautionary measures, ESP installed in 5.5" shroud cross-overed to 2 7/8" tail-pipe in order to produce from below perforations to minimize the risk of gas entry to the pump. The total concept (MVP + Gas separator + tailpipe) worked well as the system last for almost three years after installation with a permanent annulus pressure of 38 bar. WELL- 01 was meant to assess the reservoir potential and is the first high GOR (200‒500 m3/m3) well completed with an ESP system capable to handle such level of GOR.