For shale operators in prolific basins like the Permian, electric submersible pumps are a cornerstone of the artificial lift stack. Able to provide the ideal range of volume capacity in narrow casing sizes, ESPs are one of the few forms of lift suited to produce high flow rates economically and efficiently. A challenge with producing in these conditions, however, is gas interference.
Characterized by long lateral sections that penetrate multiple areas of the producing reservoir, unconventional wells are more susceptible to the buildup of air pockets across undulations in the horizontal section of the wellbore. As the well starts producing, this air can be drawn into the fluid mix, known as “gas slugs.” Because ESP systems generate lift by pushing fluid through stages, when gas slugs enter the pump, it can disrupt the flow of fluid to the surface. Artificial lift engineers have developed technologies over the years to reinforce the ESP’s ability to handle gas production, including ESP gas separators, helicoaxial stages, and tapered pump configurations. Whenever possible, however, the operator’s best chance to eliminate gas-related setbacks is to prevent free gas from entering the pump altogether.
ESP Shroud Configuration
Perhaps one of the most simple devices for gas avoidance, an ESP shroud works by leveraging the natural separation of production fluid and gas. The top of the shroud is clamped just above the pump intake, and the jacket (a long cylindrical section of casing or pipe) extends to just below the motor. Fluid in the annulus is drawn down to enter through the bottom of the shroud, while air naturally rises to the top of the annulus through the path of least resistance. By discouraging gas from entering the intake and directing fluid past the motor, the ESP shroud configuration helps eliminate the risk of gas locking in the pump while continuously cooling the motor during operation.
For one Permian operator, Valiant installed a shrouded ESP system comprised of a 400 series pump, a 5.5″ diameter coated steel shroud, a gas separator, a seal, and a 50 HP motor. The gas separator was used in conjunction with the shroud to ensure any additional gas could be diverted at the intake to prevent blockages in the pump.
Get Around the Gas with Valiant’s Suite of Intercept Gas Solutions
Valiant offers a comprehensive portfolio of solutions to mitigate gas interference and optimize your ESP operations for efficient, uninterrupted run life. By combining downhole technologies with variable speed drive automation and tailored field experience, we apply a multi-faceted approach to help you manage gas production and ensure profitable performance over the life of your application.