Hydraulic jet pumps and gas lift are both long-established artificial lift methods, yet they rely on very different principles. For a field engineer, the decision between the two hinges not on theory but on how each system performs under specific reservoir conditions, well geometries, and economic constraints.
Principles and Applications
Gas lift injects high-pressure gas into the production tubing through gas lift valves set at predetermined depths. The injected gas reduces the density of the produced fluid column, lowering hydrostatic head and allowing reservoir pressure to flow fluids to surface. Gas lift excels in wells with adequate casing size and gas supply, and it has wide applicability offshore and onshore.
Hydraulic jet pumps operate on the Venturi effect, where high-pressure power fluid from surface pumps is directed through a nozzle downhole. This accelerates the fluid stream, creating a low-pressure zone that entrains produced fluids into the throat and diffuser, lifting the mixture to surface. Unlike gas lift, the system does not depend on injected gas availability, but rather on hydraulic horsepower and power fluid logistics.
Operating Conditions and Well Types
Gas lift is robust in deviated and horizontal wells because no mechanical moving parts are required downhole beyond simple valves. It tolerates solids reasonably well, and it handles high gas-liquid ratio reservoirs naturally. However, performance declines in low-pressure, or low-volume wells where there is insufficient injection gas pressure or supply, and the tubular geometrics have not been properly sized for low volumes.
Jet pumps thrive in abrasive, paraffin-prone, or scaling conditions because the downhole assembly has no moving parts. They are well suited for marginal wells, deviated or horizontal bores, and fields where sand and solids would quickly erode gas lift valves. They also excel in wells requiring flexible operation across the life of the field, since nozzle and throat assemblies can be resized to match production decline without a workover rig.
Production Volume Sweet Spots
Gas lift is most efficient in medium- to high-rate wells, often in the 200 –20,000 barrels of fluid per day range depending on gas supply and infrastructure. It can sustain very high rates offshore where centralized gas compression is available. At very low liquid rates, efficiency declines as injected gas lifts mostly free gas without effective liquid carry.
Jet pumps are effective in 100–3,000 barrels per day ranges, depending on surface horsepower and power fluid capacity. They can be tuned for lower volumes late in field life by resizing inserts, something gas lift does not manage well without re-spacing valves or reconfiguring injection pressure.
Maintenance and Intervention
Gas lift is attractive from a mechanical maintenance perspective because the downhole components are simple valves with long run lives. However, the system requires a continuous, reliable source of high-pressure gas and extensive surface infrastructure (compressors, distribution lines). Compressor downtime is a major risk, and efficiency suffers when gas supply is interrupted,by external forces such as freezing problems associated with cold weather
Jet pumps place most complexity at surface in the power fluid pump system. With modern seal-less diaphragm pumps, wear from sand and abrasives is minimized and leakage is eliminated. Downhole inserts can be circulated out and replaced without the use of a workover rig, keeping interventions simple. The trade-off is higher energy demand per barrel lifted compared to gas lift.
Economics and Best Practices
Gas lift is often the most economical option in fields where gas is abundant and compression facilities are already installed. Offshore platforms and large onshore fields with centralized infrastructure favor gas lift because its per-barrel lifting cost is low once gas handling is in place. Best practices include careful valve spacing, corrosion management, and optimizing gas allocation to balance wells across a field.
Jet pumps require more investment in surface pumping and filtration but provide strong economics in hostile wells where solids, paraffin, or scaling would cause gas lift valves to fail or production to become unstable. Best practices include maintaining clean, filtered power fluid, injecting inhibitors through the power fluid loop, and proactively resizing nozzles/throats to match reservoir decline.
Pros and Cons
Gas lift’s strengths are high-volume capacity, tolerance for deviation, long run life of downhole equipment, and low operating cost where gas is cheap. Its limitations are dependence on continuous gas supply, inefficiency at low rates, and vulnerability to compressor downtime.
Jet pumps’ strengths are resilience in solids- and paraffin-prone environments, adaptability to declining production, and rigless insert replacement. Their drawbacks are lower hydraulic efficiency and higher energy costs compared to gas lift, particularly at large volumes.
Conclusion
Gas lift dominates in large fields and offshore projects where gas supply and infrastructure are assured, offering unmatched capacity for high-rate wells with relatively stable reservoir conditions. Hydraulic jet pumps excel in onshore or marginal wells where solids, wax, or corrosives compromise gas lift reliability, and where flexibility and uptime outweigh raw efficiency. The field engineer’s choice is dictated less by the theoretical efficiency curves than by infrastructure availability, reservoir trajectory, and the operational consequences of downtime.