Last winter was yet another tough season for well operators in the Bakken. With temperatures consistently at or below -29 C (-20 F), operators are required to provide heat on site to keep the personnel warm and pumps working or they risk losing significant amounts of revenue through lost production. Operators currently bring in diesel-fueled flameless heaters to provide portable heat. This older technology provides sufficient heat, but the cost of diesel fuel can be up to $10,000 per month per well, and maintenance can add an additional $5,000 per month.

The team at Dynamo Micropower visited Bakken oil well operators in February 2014. Dynamo personnel saw their struggle with winter conditions and also saw an immense untapped resource in the gas wasted through flaring. The operators all wanted a product that could turn flare gas into useful heat, but there were no such products in the market that could at the same time meet the tough demands of the oil and gas industry in terms of uptime and reliability. Ultimately, the operators were looking for a heater that provided the same or better performance, lowered their maintenance time and costs, and reliably ran on locally available fuels ranging from propane to wellhead gas.

Product development
The team focused in particular on reducing operating cost and increasing reliability. The result was the TurboCore TC700H, a unique fuel-flexible gas turbine engine specifically designed and built to provide well operators with portable heat in cold climates. Dynamo’s manufacturing partner, Multitek Inc., integrates the TurboCore TC700H into a complete flameless heater. Multitek’s first product, the MT700C Air Heater, has the following specifications and features:
• High performance: up to 700,000 Btu/hr of heat and 141 cu. m/min (5,000 cf/min) of air flow;
• Compactness: the flameless heater is 30% to 50% smaller than competing heaters of the same performance;
• Fuel-flexible: the system accepts a variety of gaseous fuels, including CNG, propane and flare gas;
• The ability to set it and leave it: the control system automatically maintains the desired heat output regardless of the type of fuel source or fuel quality;
• Reliability: the system has very little mechanical wear, is highly reliable and requires maintenance only a few times a year; and
• Less noisy: the heater produces no more and generally less noise than competing heaters of the same performance.

TurboCore technology is delivered in two components: the TurboCore engine and TurboCore control system. The engine is built around an automotive-type turbocharger and a proprietary combustion chamber. The combustion chamber geometry is specifically designed to improve air-fuel mixing and achieve greater combustion stability over a wide range of fuel inputs, from 31,770 Btu/scm (900 Btu/scf for natural gas) to 84,720 Btu/scm (2,400 Btu/scf for propane).

As a result, the engine is truly fuel-flexible and can burn a very wide range of fuel types without needing to change any hardware. The turbocharger has only one moving part and achieves very high mean time between failures with a passively lubricated bearing system. Furthermore, gas turbines are inherently more power-dense than reciprocating engines, and the engine produces equivalent heat output with a much smaller package.

The control system interfaces with an electronically controlled fuel valve and adjusts the valve setting to continuously maintain the desired heat output. The control system can do this without any knowledge of the type of fuel coming into the heater, whether it is natural gas, wellhead gas or propane. The operator never has to worry about what type of fuel is used to run the heater.

Multitek’s flameless heater mixes the TurboCore engine exhaust with ambient air drawn by a supply fan. The heater produces heat very efficiently because nearly all of the energy in the fuel is converted to useful heat. Gas turbine engine exhaust also has a higher temperature than diesel engine exhaust, so the flameless heater can achieve higher temperatures than competing heaters. Lastly, the exhaust catalytic converter keeps emissions in the heated air well within the Occupational Safety and Health Administration recommended levels and also reduces total wellsite emissions when compared to diesel-fueled heaters. An additional heat exchanger can be installed as a part of the flameless heater to produce completely clean warm air.

Case study
In 2015 Multitek Inc. built four preproduction units of the MT700C flameless heaters incorporating the TurboCore TC700H. The heaters were then taken throughout the Midwest and the Bakken and were tested on site with distributors and operators. The heaters received considerable positive feedback from these customers during preproduction trials. Customers praised the simplicity of the unit, smaller package and improved performance compared to competing heaters in the market. More importantly, customers experienced substantially reduced operating costs by using natural gas or wellhead gas to produce heat rather than the diesel fuel required by competing products. Well operators ultimately saw savings of up to $10,000 per month (equivalent to 50% of operating cost for heating) by using the product.

After successfully proving the value proposition of the flare gas-burning gas turbine technology in the heater market, Dynamo is now focused on commercializing its PowerCore products, a line of electric power generators that run on flare gas. The first Power Core product is a 10-kW generator that can be used in a variety of oil and gas applications, including small pumps, auxiliaries at well pads and cathodic protection for pipelines.

Ultimately, the company believes that its technologies can provide opportunity to save more than $2/bbl in production expense, resulting in significant savings for the oil and gas industry.

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