Introduction
Deep wells present some of the toughest conditions for artificial lift systems, where extreme depths, high hydrostatic heads, elevated temperatures, and evolving fluid properties often overwhelm conventional methods like ESPs, rod lift, or gas lift. Rod strings stretch and fail under tension, ESP motors struggle with heat and voltage drop, and gas lift requires complex completions that may not be economical at depth. Jet pumps, by contrast, are uniquely suited for these environments. With no moving parts downhole, virtually unlimited depth potential, and the ability to handle solids, gas, and high pressures through surface-driven hydraulics, jet pumps offer a reliable and flexible solution for deep unconventional wells, HPHT reservoirs, and frac flowback operations.
Advantages of Jet Pump Artificial Lift in Deep Wells
No downhole moving parts
- Jet pumps rely only on fixed nozzles, throats, and diffusers downhole.
- In deep wells where rod strings can fail under tension and ESP motors run hot under high hydrostatic heads, this absence of mechanical wear parts is a major advantage.
- Reliability improves because there’s nothing downhole to fatigue, seize, or overheat.
High-pressure lift capacity
- Surface pumps can generate thousands of psi of motive pressure, easily overcoming high hydrostatic columns in deep wells.
- Hydraulic horsepower can be scaled at surface without limitations of motor horsepower or rod loading.
Ease of retrieval and servicing
- Inserts can be retrieved by wireline, slickline, or coiled tubing without pulling the production string.
- This is critical in very deep wells, where rig interventions are costly and time-consuming.
Flexibility in operating conditions
- By swapping nozzles/throats, jet pumps can be tuned for changing production rates or fluid properties over the well’s life.
- Particularly valuable in deep wells where reservoir drive, GOR, and water cut evolve significantly.
Tolerance to solids and gas
- Deep reservoirs often produce sand and solution gas. Jet pumps handle both better than ESPs, which are sensitive to gas lock and erosion at depth.
- Tungsten carbide trims reduce erosion risk in sandy deep wells.
No depth limitation from rod stretch or motor cable
- Rod lift becomes uneconomical at ~10,000–12,000 ft due to stretch, buckling, and load.
- ESPs face cable voltage drop and cooling challenges beyond ~12,000 ft.
- Jet pumps can be set at any depth reachable by tubing, since motive energy comes from surface hydraulics.
High-temperature compatibility
- Deep wells often have higher bottomhole temperatures. Jet pumps are less affected, since there are no downhole motors or elastomer seals to degrade rapidly.
Uses in Deep Wells
Unconventional deep oil and gas wells
- Shale and tight formations with depths >12,000 ft.
- Jet pumps used for initial flowback and early production when reservoir pressure declines.
Deep high-pressure/high-temperature (HPHT) reservoirs
- Offshore or onshore HPHT wells where ESPs cannot tolerate temperature or pressure.
- Jet pumps can lift hot, corrosive fluids if metallurgy and surface power fluid system are engineered properly.
Frac flowback and cleanup at depth
- Jet pumps tolerate frac sand and high rates without downhole failure.
- They can be used temporarily in deep wells during post-frac cleanup before switching to another lift method.
Dual completion or commingled deep wells
- Jet pumps can be configured in concentric tubing or straddle packer setups, making them versatile in complex multi-zone deep completions.
Key Design Considerations for Deep Wells
- Surface pump power: Must be sized for the hydrostatic head plus friction losses; diaphragm or plunger pumps are common.
- Tubing ID: Friction losses accumulate over long vertical sections—larger ID tubing for power fluid may be justified.
- Hydrostatic compensation: Set motive pressure high enough to overcome the column of produced + power fluid.
- Material selection: HPHT wells demand chrome/nickel alloys and carbide trims.
- Separation and filtration: At surface, to keep recirculated power fluid clean under high flow/high pressure operation.
Summary:
In deep wells, jet pumps shine because they have no moving parts downhole, unlimited depth potential, tolerance for solids/gas, and flexible surface-driven power. They are widely used for deep unconventional wells, HPHT production, frac flowback, where rod lift and ESPs reach their limits.