In hydraulic jet pump artificial lift systems, the choice and management of power fluid are just as critical as pump design or well configuration. Power fluid acts as both the energy source and the medium that drives the Venturi-based lift process, meaning its properties directly impact efficiency, reliability, and long-term economics. From fluid selection and cleanliness to gas management, corrosion control, and hydraulic configuration, each decision made at the surface influences how the system performs downhole. This paper provides a practical field engineer’s perspective on the key considerations required to design, operate, and troubleshoot jet pump applications effectively.
1) Fluid selection & compatibility
What you send down matters as much as how much you send.
- Water vs. oil vs. produced water. Water is cheap and incompressible (good for hydraulic efficiency) but can drive corrosion/scale. Diesel or light crude improves lubricity and corrosion resistance but can be costly and may create emulsions on return. Produced water is common but needs solids control and corrosion management.
- Compatibility with formation fluids: Avoid power-fluid/produced-fluid blends that form tight emulsions or precipitates (asphaltene destabilization, carbonate scale, iron sulfide). Pre-screen with bottle tests.
2) Cleanliness, solids & filtration
Nozzles and throats hate grit.
- Filtration train: Coarse strainer (1/16” perforation) up to 100 mesh are most common. The finer the mesh, the more often cleaning is required
- Solids management: Desanders/hydrocyclones or settling ahead of filters if produced water is used. Magnetic traps can be used for mill scale/iron fines.
- Erosion control: Keep velocities sensible in small-ID lines; use long-radius bends and hardened trims. If solids are persistent, choose tungsten-carbide nozzles/throats and hardened seats.
3) Gas management
Entrained gas in the power fluid is the fast lane to cavitation and performance loss.
- Degas at surface: Use knock-out/flash tank or skim vessel before filtration.
- Operating rule: Keep free gas at pump suction ≈0% for the power-fluid leg (treat it like a hydraulic pump, not a multiphase machine).
4) Corrosion, scale, and biofouling
- Corrosion control: Corrosion inhibitors can be injected into the pump suction. Validate long term erosion control with with ER probes or coupons.
- Scale management: Squeeze or continuous injection scale inhibitors when mixing with high-salinity produced waters.Calcium Carbononate, Calcuim Sulphate, and Barium Sulphate are commonly treated for in Jet Pump operations. These compounds generally form where pressure or temperature changes occur.
- Biofouling: If using surface water or lightly treated produced water, dose non-oxidizing biocide and monitor ATP counts.
5) Temperature & viscosity
Temperture and viscosity have a minor impact on overall jet pump performance and are rarely taken into consideration.
- Viscosity window: Jet efficiency drops as μ rises (Reynolds number falls). Above ~10–20 cP at downhole temperature, expect reduced coefficient recovery and higher required ΔP.
- Thermal effects: Power-fluid compression across the nozzle and friction in tubing add heat; confirm elastomer limits and consider insulation or heat-trace for winterization topside.
6) Surface pump suction quality (NPSH & cavitation margin)
Your surface pump sets the tone for the whole system.
- NPSH available vs. required: Provide ≥1–2 m (3–7 ft) margin at all rates/temperatures after accounting for suction losses and vapor pressure.
- Suction piping: Short, straight, one or two sizes larger than the pump inlet; full-port valves; large-radius elbows; flooded suction preferred.
- Pulsation & transients: Use suction stabilizer and discharge pulsation dampener to Reduce stresses on surface pump piping.
7) Hydraulics in the wellbore (pressure losses & configuration)
- Friction losses: Calculate ΔP in power-fluid down tubing (or annulus) and return up the opposite conduit. Small IDs spike friction; consider upsizing power-fluid conduit if nozzle pressure margin is tight.
- Annulus vs. tubing: Tubing power-fluid drive is easy to service but has drawbacks when solids or corrosives are present.
- Packer strategy: Single-packer (common) vs. retrievable designs—ensure seal integrity to ensure proper jet pump system performance.
8) Reliability & maintainability
- Design for dirty days: Provide parallel filter housings with bypasses. Include a flush loop for cold-start or waxy returns.
- Pressure reliefs: Relief valves on discharge and return legs; burst discs as secondary protection where mandated.
- Materials: Hard-faced trim (WC), corrosion-appropriate metallurgy, and erosion-resistant bends in high-velocity sections.
9) Energy & economics
- Hydraulic HP math (quick check):
HHP ≈ (Q_pf × ΔP_nozzle) / (1714 × η_surface × η_jet) [US units; gpm & psi]
Verify you’re not paying for ΔP you lose to friction instead of the nozzle. - Recycle fraction: Some systems recirculate a portion of clean power fluid; optimize recycle vs. fresh takeoff to balance energy and filtration cost.
10) Startup, transients & seasonal issues
- Startup: Fill/bleed air, ramp motive pressure slowly, confirm return flow before reaching design pressure.
- Slugging & fallback: Maintain back-pressure to prevent diffuser stall during rate swings.
- Cold weather: Heat-trace/exposed lines; choose pour-point-depressed fluids if oil-based; protect instruments from freezing.
11) HSE & compliance
- High-pressure discipline: Hydrotest lines, tag reliefs, guard flanges where personnel exposure is possible.
- Containment: Secondary containment for tanks; leak detection on buried lines; SDS and chemical handling compliance for treatment packages.
Quick field checklist
- Clean, degassed power fluid verified (lab check and ΔP across filters stable).
- Corrosion/scale program active; metallurgy/elastomers confirmed.
- NPSH margin at surface pump and no air in suction.
- Motive pressure set after calculating true line losses to the nozzle.
- Back-pressure control on return leg; pulsation control on discharge.
- Nozzle/throat match current fluid density/viscosity; erosion-resistant trims installed.
- Instrumentation logging motive P, Q, T, and filter ΔP; alarms set.
- Startup/slugging procedures posted; reliefs tested; cold-weather plan ready.
Conclusion
Successful jet pump performance is rarely limited by hardware; more often, it is the quality, conditioning, and management of the power fluid that determines system reliability and production results. Clean, compatible, and well-treated motive fluid minimizes erosion, prevents cavitation, and reduces downtime, while proper hydraulic and surface pump design safeguards efficiency. By integrating best practices in filtration, gas separation, corrosion and scale control, and seasonal preparedness, operators can extend equipment life, lower operating costs, and maintain steady production even under harsh well conditions. Ultimately, attention to power fluid management is the difference between a jet pump that merely operates and one that delivers sustainable performance across the life of the well.