Abstract
This paper presents current advances and innovations in gas separation and regulation technologies to address high Gas-Liquid Ratio (GLR) and gas slugging conditions in petroleum wells equipped with Electric Submersible Pump (ESP) systems. The application of this design in severely problematic wells with significant gas production and slugging issues highlights the critical importance of separating and conditioning fluids before they reach the pump intake, serving as a bridge before transitioning to another artificial lift system.
Effective gas separation in an ESP system, beyond the existing ESP gas separator, involves shrouding certain ESP components. The engineered design discussed in this paper utilizes casing to enhance gas separation through several stages. These stages include isolating the pump intake using a shroud, sealing the casing with a Triple Seal Cup-Type Packer, and combining outlet and inlet sections that reverse the flow path to significantly reduce fluid velocity. This reduced velocity aids in successful gas separation. A sealed shroud above the pump intake is connected to the gas separator below the sensor, ensuring gas-free liquid flow around the motor, which helps maintain optimal motor temperatures in wells with high gas content. A study on unconventional wellbore simulations, specifically focusing on toe-down completions, highlights the impact on slugging conditions. The formation of gas slugs under these conditions can negatively affect the operation of an electric submersible pump (ESP). An alternative design, which does not require a shroud, regulates gas flow through agitation, pressure and velocity changes, and increased retention time to mix gas slugs into the liquid pool. This creates a homogeneous flow regime, or dispersed bubble flow, which also contributes to maintaining optimal motor temperatures, improving pump efficiency, and preventing gas locking conditions.
Case studies from the Permian Basin demonstrate the positive impact of selecting an appropriate downhole conditioning system. Significant improvements in sensor parameters will showcase the benefits of handling gas and sand before the pump intake, resulting in reduced shutdowns and non-productive time, ultimately enhancing fluid production. The flexibility of this design is also noteworthy, as it can be installed across a wide range of fluid production levels, gas-liquid ratios, and various tubing and casing sizes.
These advanced technologies maximize ESP efficiency in gassy wells, either by using casing to enhance gas separation or by regulating gas surges with innovative designs that convert slug flow into homogeneous flow.
