Crude heated to desalter temperature with recovered heat
How an onshore oil gathering station handling 80 kL of crude a day can trim-heat crude and desalter wash water to 110 °C using heat recovered from warm produced water, and what it saves against a furnace-oil fired line heater.
▶Video: Waste-heat recovery heat pumps
V10 · 2–2.5 minLifting warm water from condensers, effluent and process cooling to useful heat
Video coming soon01Problem statement
- Wax and emulsions. Waxy crude must be kept hot to break emulsions and separate salt water. A few degrees short of target leaves salt and water in the dispatched crude.
- Fired heaters in a hydrocarbon area. Open-flame line heaters need careful permitting, flame monitoring and regular inspection near hydrocarbon handling.
- Produced water heat is wasted. Produced water at 60–65 °C is cooled in ponds or tanks before injection or treatment.
- Losses between fuel and process. Burning furnace oil in a boiler or heater and distributing the heat loses a quarter or more of the fuel's energy before it reaches the process.
- Compliance, safety and handling. Fired equipment brings boiler inspections, fuel storage and unloading, flue emissions and an attendant on every shift.
02Use case
The reference station separates and treats about 80 kL a day of waxy crude before dispatch. Crude leaves the crude/crude exchanger at about 75 °C and needs trim heating to 110 °C for the desalter, and separated produced water arrives at 60–65 °C.
| Heat user | Process temp. | Basis | Heat, kWh/day |
|---|---|---|---|
| Crude trim heating | 75 → 110 °C | 80,000 L/day, ρ 0.85, cp 2.0, after crude/crude exchanger | 1,322 |
| Desalter wash water | 35 → 110 °C | 4,000 L/day (5% of crude), 35 → 110 °C | 348 |
| Crude storage tank holding | 60 °C held | 2 tanks × 120 m² × 2 W/m²K × 30 K × 24 h | 346 |
| Storage and pipework standing losses | – | about 5% | 101 |
| Total useful heat | 2,117 | ||
Averaged over 20 running hours, the heat pumps need about 106 kW.
03P&ID
Tags: HP heat pump, TK tank, SG steam generator, P pump, PHE plate heat exchanger, TCV temperature control valve, TIC temperature indicating controller (panel), TT temperature transmitter, MT moisture transmitter, PT pressure transmitter, LT level transmitter, FS flow switch, NC normally closed. Process fluids are heated through their own exchanger, coil or jacket.
04Solution
System description
- 4 × SE-WWUHT-27 (108 kW total) (SE-WWUHT water-source, R245fa) delivering 120 °C, covering the day's 2,117 kWh in about 19.6 running hours.
- A 3,500 L insulated storage tank decouples the heat pumps from the process peaks.
- Heat source: warm produced water from separators at about 60 °C. Cooling the produced water before injection or treatment is a by-product.
- The furnace-oil fired line heater stays connected behind a normally closed valve as standby.
- Produced water from the separators passes through a filter and an intermediate exchanger. A clean water loop carries its heat to the heat pump evaporators.
- The heat pumps make pressurised hot water at 115–120 °C into a buffer tank, which feeds a shell-and-tube crude trim heater and a wash water heater.
- Crude tank coils run on the cooler return water, so the heat is used twice.
- The existing line heater stays in place as standby.
Selected equipment
| Model | SE-WWUHT-27 × 4 |
|---|---|
| Heating capacity | 27 kW each, 108 kW total |
| COP | 2.93 at the data sheet's rated condition (60/55 °C source water) |
| Power input | about 36.8 kW total at rated conditions |
| Rating | water or steam to 120 °C, R245fa |
| Supply temperature | 120 °C |
| Storage | 3,500 L insulated tank |
Ratings from the Sunniva TDS 2026 data sheets.
Control philosophy
TT-101 at the top of the buffer tank holds 118 °C by staging the heat pumps. TIC-201 sets crude outlet temperature to the desalter at 110 °C. TIC-202 controls wash water and TIC-203 controls tank coils. If TT-101 falls below 112 °C the control system starts the standby line heater.
05Energy saving and ROI
Change any input to match a customer's site. Defaults are typical Indian prices for October 2026. The installed cost is a placeholder; replace it with the actual quotation.
| Existing | Heat pump | |
|---|---|---|
| Daily consumption | – | – |
| Annual energy cost | – | – |
| Cost per kL crude | – | – |
| CO₂ per year | – | – |
06Benefits
No open flame for trim heat
Heat arrives as hot water, so normal running needs no fired heater in the process area.
Steady desalter temperature
Water-heated exchangers hold the desalter inlet steady, which helps salt and water removal.
Cooler produced water
Produced water leaves at 40–45 °C, easier on injection pumps, membranes and treatment.
Lower energy cost
Each kWh of electricity delivers about 2.9 kWh of heat at the required temperature, against well under one kWh of useful heat per kWh of fuel burnt.
No flame on site
No burner, flue or fuel tank for this duty, and no fuel deliveries to schedule.
Built-in redundancy
Several machines share the load. If one is serviced, the others and the storage carry most of the day, with the existing heater in reserve.
07Engineering pointers
Site data to collect
- Crude throughput, API gravity and pour point
- Crude temperatures after the crude/crude exchanger and at the desalter
- Produced water flow and temperature
- Current line heater fuel use
- Hazardous area classification drawing
- Present fuel or electricity use and monthly bill
- Sanctioned electrical load and spare capacity
- Space for the heat pumps and storage, with service access
Design notes
- Hazardous area. Locate heat pumps and panels in a safe area or use certified equipment. Follow the site's hazardous area classification and permit system.
- Produced water chemistry. Produced water is saline and may carry H₂S, oil and sand. Use titanium or duplex exchangers on the produced-water side and keep it out of the heat pump.
- Pressurised hot water. At 115–120 °C the hot water loop must be pressurised to at least 3 bar. Rate the buffer tank and PHEs for this.
- Electrical. About 37 kW of heat pump input at rated conditions, plus pumps and fans. Check spare sanctioned load before ordering.
- Source stream. The source must give up roughly two-thirds of the heat delivered. Confirm its flow and temperature over a full production day, and filter it before the evaporator.
- Water quality. Scale forms quickly above 60 °C. Use softened make-up and keep the heat pump loop closed, with process fluids on the far side of an exchanger or coil.
Service and warranty
Sunniva has supplied 5,000+ heat pumps since 2012, with nine service technicians across India, including remote sites such as Leh. All components carry a one-year warranty.
Talk to us
Crude heated to desalter temperature with recovered heat
How an onshore oil gathering station handling 80 kL of crude a day can trim-heat crude and desalter wash water to 110 °C using heat recovered from warm produced water, and what it saves against a furnace-oil fired line heater.
▶Video: Waste-heat recovery heat pumps
V10 · 2–2.5 minLifting warm water from condensers, effluent and process cooling to useful heat
Video coming soon01Problem statement
- Wax and emulsions. Waxy crude must be kept hot to break emulsions and separate salt water. A few degrees short of target leaves salt and water in the dispatched crude.
- Fired heaters in a hydrocarbon area. Open-flame line heaters need careful permitting, flame monitoring and regular inspection near hydrocarbon handling.
- Produced water heat is wasted. Produced water at 60–65 °C is cooled in ponds or tanks before injection or treatment.
- Losses between fuel and process. Burning furnace oil in a boiler or heater and distributing the heat loses a quarter or more of the fuel's energy before it reaches the process.
- Compliance, safety and handling. Fired equipment brings boiler inspections, fuel storage and unloading, flue emissions and an attendant on every shift.
02Use case
The reference station separates and treats about 80 kL a day of waxy crude before dispatch. Crude leaves the crude/crude exchanger at about 75 °C and needs trim heating to 110 °C for the desalter, and separated produced water arrives at 60–65 °C.
| Heat user | Process temp. | Basis | Heat, kWh/day |
|---|---|---|---|
| Crude trim heating | 75 → 110 °C | 80,000 L/day, ρ 0.85, cp 2.0, after crude/crude exchanger | 1,322 |
| Desalter wash water | 35 → 110 °C | 4,000 L/day (5% of crude), 35 → 110 °C | 348 |
| Crude storage tank holding | 60 °C held | 2 tanks × 120 m² × 2 W/m²K × 30 K × 24 h | 346 |
| Storage and pipework standing losses | – | about 5% | 101 |
| Total useful heat | 2,117 | ||
Averaged over 20 running hours, the heat pumps need about 106 kW.
03P&ID
Tags: HP heat pump, TK tank, SG steam generator, P pump, PHE plate heat exchanger, TCV temperature control valve, TIC temperature indicating controller (panel), TT temperature transmitter, MT moisture transmitter, PT pressure transmitter, LT level transmitter, FS flow switch, NC normally closed. Process fluids are heated through their own exchanger, coil or jacket.
04Solution
System description
- 4 × SE-WWUHT-27 (108 kW total) (SE-WWUHT water-source, R245fa) delivering 120 °C, covering the day's 2,117 kWh in about 19.6 running hours.
- A 3,500 L insulated storage tank decouples the heat pumps from the process peaks.
- Heat source: warm produced water from separators at about 60 °C. Cooling the produced water before injection or treatment is a by-product.
- The furnace-oil fired line heater stays connected behind a normally closed valve as standby.
- Produced water from the separators passes through a filter and an intermediate exchanger. A clean water loop carries its heat to the heat pump evaporators.
- The heat pumps make pressurised hot water at 115–120 °C into a buffer tank, which feeds a shell-and-tube crude trim heater and a wash water heater.
- Crude tank coils run on the cooler return water, so the heat is used twice.
- The existing line heater stays in place as standby.
Selected equipment
| Model | SE-WWUHT-27 × 4 |
|---|---|
| Heating capacity | 27 kW each, 108 kW total |
| COP | 2.93 at the data sheet's rated condition (60/55 °C source water) |
| Power input | about 36.8 kW total at rated conditions |
| Rating | water or steam to 120 °C, R245fa |
| Supply temperature | 120 °C |
| Storage | 3,500 L insulated tank |
Ratings from the Sunniva TDS 2026 data sheets.
Control philosophy
TT-101 at the top of the buffer tank holds 118 °C by staging the heat pumps. TIC-201 sets crude outlet temperature to the desalter at 110 °C. TIC-202 controls wash water and TIC-203 controls tank coils. If TT-101 falls below 112 °C the control system starts the standby line heater.
05Energy saving and ROI
Change any input to match a customer's site. Defaults are typical Indian prices for October 2026. The installed cost is a placeholder; replace it with the actual quotation.
| Existing | Heat pump | |
|---|---|---|
| Daily consumption | – | – |
| Annual energy cost | – | – |
| Cost per kL crude | – | – |
| CO₂ per year | – | – |
06Benefits
No open flame for trim heat
Heat arrives as hot water, so normal running needs no fired heater in the process area.
Steady desalter temperature
Water-heated exchangers hold the desalter inlet steady, which helps salt and water removal.
Cooler produced water
Produced water leaves at 40–45 °C, easier on injection pumps, membranes and treatment.
Lower energy cost
Each kWh of electricity delivers about 2.9 kWh of heat at the required temperature, against well under one kWh of useful heat per kWh of fuel burnt.
No flame on site
No burner, flue or fuel tank for this duty, and no fuel deliveries to schedule.
Built-in redundancy
Several machines share the load. If one is serviced, the others and the storage carry most of the day, with the existing heater in reserve.
07Engineering pointers
Site data to collect
- Crude throughput, API gravity and pour point
- Crude temperatures after the crude/crude exchanger and at the desalter
- Produced water flow and temperature
- Current line heater fuel use
- Hazardous area classification drawing
- Present fuel or electricity use and monthly bill
- Sanctioned electrical load and spare capacity
- Space for the heat pumps and storage, with service access
Design notes
- Hazardous area. Locate heat pumps and panels in a safe area or use certified equipment. Follow the site's hazardous area classification and permit system.
- Produced water chemistry. Produced water is saline and may carry H₂S, oil and sand. Use titanium or duplex exchangers on the produced-water side and keep it out of the heat pump.
- Pressurised hot water. At 115–120 °C the hot water loop must be pressurised to at least 3 bar. Rate the buffer tank and PHEs for this.
- Electrical. About 37 kW of heat pump input at rated conditions, plus pumps and fans. Check spare sanctioned load before ordering.
- Source stream. The source must give up roughly two-thirds of the heat delivered. Confirm its flow and temperature over a full production day, and filter it before the evaporator.
- Water quality. Scale forms quickly above 60 °C. Use softened make-up and keep the heat pump loop closed, with process fluids on the far side of an exchanger or coil.
Service and warranty
Sunniva has supplied 5,000+ heat pumps since 2012, with nine service technicians across India, including remote sites such as Leh. All components carry a one-year warranty.