Overview
Jet pumps are widely used in artificial lift due to their flexibility, reliability and durability. With no moving parts downhole, their mechanical simplicity is advantageous, but achieving maximum run life and efficiency requires meticulous installation. Proper tubing configuration, jet pump setting depth, and adherence to safety procedures are critical to ensuring reliable operation and minimizing workover frequency.
Jet Pump Installation Procedures
Successful jet pump deployment begins with surface preparation and careful planning of the downhole assembly. For conventional standard or reverse flow, the bottomhole assembly (pump cavity) is typically run on the production tubing, while some applications utilize an existing sliding sleeve within the downhole completion. Gas well deliquification is accomplished by utilizing concentric strings of tubing, typically integral joint or coiled tubing inside of production tubing. Engineers should verify that the bottomhole assembly is clean, debris-free, and dimensionally within tolerance. While extremely versatile, proper jet pump placement and tubing configuration is critical for success.
Before installing the jet pump into the well, the nozzle and throat (mixing tube) should be properly inspected and confirm that all components meet the designed specifications. Even small deviations can significantly alter jet pump system performance.
Prior to installing the jet pump into the wellbore, a standing valve must be installed into the bottomhole assembly. The Standing Valve ensures the wellbore stays full at all times and also allows the jet pump to be reverse circulated to surface for inspection and optimization. The standing valve is typically installed at surface by dropping into the tubing and pumped into place. Once the standing valve is installed the wellbore can be filled with liquid and circulated until the tubing and casing are confirmed to be clean.
Once the Standing Valve is installed and the wellbore is clean, the jet pump can be placed inside the tubing and pumped down to the bottomhole assembly. Once landed, the tubing string should pressure up as all fluids being pumped pass through the nozzle. Production should begin immediately after the injection pressure reaches the designed set point.
Downhole Configurations
Jet pumps are extremely versatile, but proper placement and downhole system design are critical for success.
Conventional Completion
The most common configuration is commonly known as a “Conventional” completion, where the jet pump is placed in the tubing string, set just above a production packer, as close to the formation as possible. All fluid produced from the well is lifted through the jet pump. Normal Flow or Reverse Flow production configurations each have benefits and drawbacks.
Normal Flow – Power fluid in injected down the tubing and returns up the casing annulus with all fluids produced. Produced fluids are sent to collection while power fluid continues to circulate in the loop. Primary benefit to Normal Flow is the jet pump can be reverse circulated to surface for inspection and maintenance. Drawback to normal flow is produced solids can settle on the packer, or if production is corrosive the cemented casing is exposed to these fluids.
Reverse Flow – Power fluid injected down the casing annulus and returns up the production tubing along with all fluids produced. Primary benefit to Reverse flow is produced solids move at a higher velocity and are collected at the surface. Corrosive fluids do not come into contact with the production casing, and Power Fluid can be treated at the surface prior to reinjection down the casing. The drawback to reverse flow is the jet pump cannot be circulated to surface as with normal flow. Jet pump must be set and retrieved via slickline.
Concentric String Completion
“Concentric String” completions utilize Integral Joint or Coiled Tubing inside production tubing. Concentric designs are used when gas to liquid ratios are too high to produce with a conventional setup. In a concentric design, the liquids are intended to be produced through the jet pump and the gas is to flow up the casing annulus. This design is achieved by hanging off a tubing string in the well, with a seating nipple below the perforations or in the heel of a horizontal well.
Jet pump is run in on small tubing inside the production tubing and set into the seating nipple at the end of the tubing. Power fluid is injected into the small tubing and returns flow up the inner annulus between small tubing and production tubing. Liquids produced from the wellbore lower the hydrostatic head to the point where the gas can flow from the formation up the casing annulus. This method of gas well deliquification is intended for low volume production where GLR is too high to produce with conventional jet pump design.
Safety Protocols for Deployment
As with all oilfield applications, Jet pump installations require rigorous safety protocols to mitigate risks to personnel and equipment.
Conclusion
Downhole installation of jet pump systems is a straightforward but highly detail-sensitive process. Proper handling of the pump and components, thoughtful downhole jet pump configuration, and adherence to safety procedures ensure a successful deployment. By treating installation as an engineered process rather than a routine intervention, operators can maximize pump life, reduce workover costs, and maintain consistent production rates in challenging well environments.