Application
Diesel Generators for Oil and Gas Sites
On an oil and gas site the generator is often the only source of electricity, and there is nobody standing next to it. That combination — unattended, remote, continuous, and inside an area where a release of hydrocarbon gas is a credible event — is what makes this application different from every other one on this site.
Packages for oil and gas duty are normally quoted between 500 kVA and 2000 kVA, in ISO or purpose-built containers, with area classification taken into account, fire and gas detection, remote telemetry and a documented shutdown philosophy.
Requirements
What an oil and gas specification has to state
| Item | Typical requirement | Why it changes the package |
|---|---|---|
| Area classification | The classified zone at the installation point, usually determined in a hazardous area study, with the equipment selected for it | Determines whether the package can sit in the classified area at all, and what protection the electrical equipment needs |
| Engine air intake protection | An automatic air intake shut-off valve where the engine could draw in hydrocarbon gas | An engine that ingests gas can run away and destroy itself; the valve is the standard protection |
| Exhaust protection | Spark arrestor and a cooled or insulated exhaust route, with surface temperatures considered | Prevents an ignition source and protects anyone passing close to the pipework |
| Fire and gas detection | Detection in the enclosure, linked to automatic engine shutdown and fuel isolation | A remote package has to fail safe without an operator |
| Suppression | Clean agent or aerosol suppression for the machine room and the control room | Detection without suppression only protects the report, not the asset |
| Shutdown philosophy | Emergency shutdown on gas detection, fire detection, low oil pressure, overspeed, high coolant temperature and low fuel level | The alarm list and the shutdown matrix have to be agreed before the panel is built |
| Redundancy | Two sets at 100% each, or N+1 where the load justifies it | Without a grid connection, a single set is a single point of failure |
| Climate | Design ambient from -20 °C to 55 °C depending on location, with sand and dust protection | Drives the cooling package, the oils, the batteries and the heaters |
| Corrosion | C5-M paint system and stainless or GRP external fixings for coastal and offshore sites | Salt and hydrogen sulphide attack ordinary coatings quickly |
| Transport and lifting | Certified lifting points and, offshore, a container certified to the applicable offshore standard | Defines whether the unit is a standard ISO box or a certified offshore container |
| Telemetry | Remote monitoring over satellite or the site network, with the points list agreed up front | Nobody is on site, so the data is the maintenance strategy |
Configurations
Configurations we quote most often
| Rating per set | Typical arrangement | Fits | Range page |
|---|---|---|---|
| 500 kVA / 400 kW | Two sets, one running and one standby | Wellhead and small process facilities | 500 kVA |
| 800 kVA / 640 kW | Two sets at 100% each | Pump stations, camps and mid-size process plants | 800 kVA |
| 1000 kVA / 800 kW | Two or three sets, N+1 | Refinery auxiliaries and larger process loads | 1000 kVA |
| 2000 kVA / 1600 kW | Multiple sets in parallel | Main power for large remote facilities | 2000 kVA |
Reference configuration
A worked example
This is an illustrative configuration, not a delivered project. It shows how the requirement table above turns into a specification. Replace the figures with your own load list before pricing.
| Parameter | Example value |
|---|---|
| Continuous load | About 420 kW of pumps, cooling and accommodation |
| Duty | Prime power, running continuously |
| Rating selected | Two sets at 800 kVA / 640 kW, prime rating, one running and one standby with automatic changeover |
| Package | Containerized, lined, with a partition between the machine room and the control room |
| Hazardous area measures | Air intake shut-off valve, spark arrestor, exhaust routed clear of the classified area |
| Detection and suppression | Heat and gas detection with automatic shutdown and fuel isolation, plus suppression in both compartments |
| Autonomy | 72 h of fuel on site, refuelled by road tanker on a scheduled run |
| Climate | Design ambient 50 °C with sand and dust protection |
| Telemetry | Status, alarms and fuel level reported over the site network to the control centre |
| Maintenance | Service visits scheduled by running hours, because the site is 300 km from the nearest workshop |
Questions
Questions we are asked about oil and gas sets
Can a diesel generator be installed inside a hazardous area?
That is decided by the area classification study, not by the generator supplier. Diesel engines are normally kept outside Zone 1, and in Zone 2 the package is assessed as a whole: ignition sources are identified, the enclosure ventilation is designed to prevent the accumulation of a flammable atmosphere, and electrical equipment is selected for the zone. Any package proposed for a classified area should come with the reasoning documented.
Why does an engine on a gas site need an air intake shut-off valve?
Because a diesel engine will run on hydrocarbon gas if it is drawn into the intake, and it has no throttle to stop it. The engine can accelerate beyond its governed speed, and it can only be stopped by cutting off its air. An automatic intake shut-off valve, closed on gas detection or overspeed, is the standard protection on engines operating where a gas release is credible.
How much redundancy does a site with no grid connection need?
At least two sets where the load can be carried by one, so that a set can be serviced or repaired without stopping the process. Where the process cannot tolerate a changeover gap, the second set runs in parallel rather than standing by. On a site with no alternative supply at all, the redundancy decision is really a production risk decision, and it is usually made by the operator rather than by the electrical contractor.
What is the usual fuel autonomy for a remote site?
Longer than a building would use, because the delivery is a road journey rather than a phone call: 48-72 h of running is common, and longer where the access road is seasonal. At 0.24-0.27 litres per kWh delivered, 400 kW of load consumes roughly 2 300-2 600 L per 24 h, so 72 h of autonomy means a storage installation measured in tens of thousands of litres, with bunding, transfer pumps, water separation and stock control.
How is an unattended set monitored?
Through the control panel’s own telemetry: engine status, running hours, fuel level, battery voltage and the full alarm list, reported to a control centre over the site network, radio or satellite link. The important part is deciding which alarms are actionable and who responds to them, because a remote package generates data whether or not anybody is scheduled to read it.
Related
Related applications and ranges
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Diesel generators by application
How the requirement changes between data centres, hospitals, hotels, sites and oil and gas.
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Containerized sets
Enclosure build, certification and what goes inside the box.
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800 kVA class
640 kW, a common block for a two-set remote power station.
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1000 kVA class
800 kW per set where the process load is larger.
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Construction sites
Prime power duty on a site that moves.
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Request a quote
Send the process load, the area classification and the climate, and we build the package scope.
Specifying a remote power package?
Send the process load, the area classification at the installation point, the design ambient and the fuel autonomy. Those four answers define most of the package.