Every oil sands facility needs a bullet-proof winterization plan. The simple objective of any good winterization plan is to protect people and assets from cold weather hazards. Sub-zero temperatures in central and northern Alberta extend from October to late May. Temperatures well into the -40°C are (sadly) not uncommon in Fort McMurray.
Slips, trips and falls are the leading cause of injuries in the oil sands, caused mainly by ice build-up that occurs around the process plant. Frost bite is also a major concern for field and maintenance personnel performing work outdoors during winter months.
However, every oil sands operator’s biggest nightmare is an unexpected outage or major failure in the dead of winter. A running process plant is relatively easy to keep warm. A stopped process plant is like a sitting duck waiting to be shot.
Incidents and accidents happen to the best of facilities. A good winterization plan doesn’t guarantee everything will go smoothly, but does help mitigate some of the risks. Here’s our Winterization Checklist to help get you started:
- Make sure the warehouse is well stocked with winter gear. This should include cold-weather gloves, balaclavas, head bands, neck gaiters and hand/foot warmers. Make sure all items of clothing are fire-retardant if applicable.
- Make sure there are adequate warm-up shelters shielded from the wind. This is especially important for maintenance and field personnel working in remote locations with few process buildings.
- Consider equipping outdoor field personnel with winter spikes or crampons, depending on the service. Note that crampons do not perform well in areas of the process plant equipped with serrated grating.
- Make sure all field vehicles are ready for winter. Replace windshield wipers and washer fluid if necessary. Make sure safety kits include thermal blankets.
- Make sure any critical sections of heat tracing are operational, especially on small-bore piping and dead-legs. Make sure all insulation blankets are properly installed, particularly on high-maintenance sections of piping.
- Consider increasing the hold temperature to at least 10°C for any critical segments of piping susceptible to freezing.
- For intermittent heat tracing running on temperature control, consider switching the heat tracing to “ON” to ensure the pipe wall temperature stays warm. Note that non-ferrous piping (such as FRP) or lined piping (such as epoxy, rubber or neoprene-lined pipe) may have limitations on maximum surface temperature.
PIPING & DRAINS
- Check for leaks along water piping, particularly near the flanges. Leaky flanges need to be repaired before winter sets in.
- Pay extra attention to bitumen lines. Since bitumen can freeze solid in winter when not flowing, make sure all bitumen lines are properly blanketed and shielded from the wind.
- Make sure all NNF (not normally flowing) pipelines are either drained or heat traced.
- Review winter operating procedures for lines that are periodically left stagnant, such as large-bore dilution lines and tailings piping. Large bore piping can still freeze if not flowing for an extended period of time.
- Ensure steam traps are operational and heat traced. Steam piping should be always free of any condensate build-up. This is especially important in preventing water hammer.
- Be aware of potential for ice build-up near steam traps that dump condensate to grade. Consider diverting condensate to a safe area or barricading the area.
INSTRUMENTS & VALVES
- For outdoor instruments located in heated boxes or shelters (such as analyzers or autosamplers), make sure the box heaters are functioning.
- Pay extra attention to safety relief valves, including rupture disks on slurry lines. The inlet piping should be insulated, heat traced and clear of obstructions.
- Consider constructing temporary shelters around any outdoor equipment that requires frequent maintenance or is not rated for cold weather start-up. This typically includes pumps and heat exchangers, but could also be extended to high-wear isolation or control valves.
- Make sure all temporary shelters have an adequate number of air changes and safety exits (depending on the size of the shelter). In a hydrocarbon plant, shelters should also be equipped with LEL detectors and should not obstruct the fire suppression system.
- Steamy buildings can be very problematic in winter, particularly in buildings with under-designed HVAC systems and an insufficient number of air changes. Condensate formed inside the building can result in ice build-up or reduced visibility. Consider installing temporary heaters to increase the indoor temperature and reduce humidity.
- Be aware of any small bore piping located near the exit doors. Small diameter piping can freeze very quickly in winter if the mandoor or maintenance bay is left open for too long. Consider insulating all piping installed near the exits.
- Make sure sand/gravel is available outside every process building, especially near the exit doors.
- Make sure the water heaters in the safety showers are operational. Shower water should be at least 15-20°C.
- Be aware of water dripping from HVAC units installed outside the building. Water will turn to icicles in winter and may require the area to be fenced off.
VESSELS & PIPERACKS
- Be aware of any leaks around outdoor vessels and piperacks. These can quickly turn into large icicles in winter months which pose a real threat to pedestrians and vehicles passing below. Consider barricading the area if leaks cannot be repaired.
PONDS & DITCHES
- Make sure the water level in emergency dump ponds are relatively low before winter sets in. The ponds will freeze over during winter, limiting their holding capacity.
- Raise any submersible pumps out of water ponds.
- Clean debris and obstructions out of run-off ditches along roads, in the corridor and near the process plant.
- In an oil sands mining facility, make sure the raw water storage ponds are topped up in the event of low-level conditions in the Athabasca River.
- Conveyor belts can harden when the temperature gets very cold, making them more brittle than normal. Check the belts for any defects that need to be patched.
- Check the belt-wetting system. Make sure the glycol/hot water system is ready for winter.
- Make sure all fire hydrants are properly freeze protected by filing with glycol solution above the frost line.
- If using generators for back-up emergency power, this is good time to bump-test the generator and top-up the diesel storage tank.