Tioga Air Heaters Case Studies
Setting the Standard: When the North Slope Demands Performance, Tioga Steps up to the Plate
26 February 2021
Since our origins in Tioga, North Dakota, we’ve prided ourselves in making heaters that are reliable enough to be trusted in rigorous conditions, such as the environmental extremes common in the oil industry. Over time, our reliability became so consistent that from the get-go, many of our oil industry customers would start their oil rig designs assuming that they would use Tioga heaters. Simply put, when these customers planned for an oil operation and began to design their oil rigs, they’d design their air heating system around the specifications of our equipment. Such was the case for a company planning an oil drilling operation along Alaska’s North Slope, where they prepared to install one of the world’s deepest land-drilling oil rigs. Once Tioga got involved, we worked to provide yet another customer with the Tioga Advantage.
When it comes to oil drilling ventures, it can be years before everything is designed, installed, and operational. In this case, our customer contacted us when they began making plans around ten years ago. At that point we could only provide a rough estimate to help them establish their budget, and it took about six years for us to tweak our estimates until a final quote was agreed upon. Once everything was in order, we built them three IDF 14 heaters and an IDF 21 to their exact specifications. And considering the needs of an oil rig in the arctic, their specifications were rather uncommon.
When life gives you natural gas, make gas-fueled heaters
The most important custom modifications had to do with how our units are to be fueled. In the isolated North Slope of Alaska, the oil rig will be stationed at a fairly remote location, where complications to diesel deliveries could lead to limited fuel availability. Considering the freezing temperatures of the arctic, a lack of fuel for heaters could prove fatal. Instead of solely relying on diesel, the drilling company looked to natural gas as an alternative fuel. Natural gas is a byproduct of drilling, and regulations require them to recapture part of the gas anyways, so utilizing readily available fuel would both cut down expenses and limit the rig’s dependence on fuel deliveries. Thus, Tioga modified the heaters to accept both diesel and natural gas, but this change introduced two new issues that we’d have to account for: the quality of the gas itself, and the fuel demand being shifted onto the onsite gas supply.
While basically “free” and readily available, the natural gas extracted from oil drilling is nowhere near as refined as the gas you’d purchase from a utility supplier. The combustion byproducts of this gas are quite acidic and poisonous, and over time condensate from the combustion could eat away the metal on our units. To compensate for this, we designed the exhaust stacks of the heaters to collect condensate and drain it outside of the units, keeping it away from critical components such as the heat exchanger.
But don’t put all your eggs in one basket
Beyond the issues of acidic condensate, the drilling company also had to account for the availability of the natural gas itself. The gas might be readily available in a general sense, but that’s no guarantee that there’s enough to use at every given moment of the rig’s operation. Thus, we designed the heaters to automatically accept diesel as a backup when gas pressure dropped below a certain threshold. When gas pressure drops, the units will switch to the diesel stored in their day tanks, and the units can then be switched back to gas when pressure returns. The day tanks themselves are also automated; when diesel levels are low, a float switch in the tank activates a pump that draws fuel from the oil rig’s main bulk tank. The bulk tank was originally going to rely solely on gravity feeding, but since arctic temperatures tend to make diesel quite viscous and gel-like, a pump was added for better fuel distribution.
Heaters geared up for the coldest of cold
These were the most significant modifications made to the air heaters. While these changes made the units more expensive than our base models, they offer a potentially massive cost advantage: over the life of these units, the savings from using the oil well’s gas instead of diesel may end up covering the overall costs of the heaters. Once the rig is operational, these savings will depend on how much gas is available from drilling and pumping.
The heaters were manufactured, modifications and all, about four years ago and were approved by representatives from the oil company. They were then shipped to the yard where the oil rig was being constructed. As of February 2020, the rig is on its way to the operating site in Alaska. There, all access roads and work surfaces have been covered in ice, the rig will be installed on the Tundra, and we will provide onsite startup assistance during commissioning. The customer will handle day-to-day operation of the heaters, but we can expect to provide technical support, spare parts, and maybe even annual maintenance for years to come.
As with all of our heater sales, we’re prepared to take whatever steps necessary to provide our customers with the Tioga Advantage. This time, we went above and beyond to make our units work in some of the most hostile conditions on Earth.