Upcoming methane emissions regulations are driving major changes in wellsite designs. As of 2021 in BC and 2022 in Alberta, you may no longer vent fuel gas for pneumatics and alternatives can be expensive.
New emission regulations are coming to legacy wellsites as well. By 2022 in BC, all gas pneumatic devices will be required to vent less than 6 scf/hr. In most cases where valves throttle, like chokes or pressure control valves, dynamic venting of the actuator can be an order of magnitude higher. In these situations, it will be impossible to meet regulations without converting to instrument air or electric actuation.
The challenge in eliminating venting is related to generating power. Options to produce a few hundred watts of power are common with thermoelectric generators, fuel cells or solar. Conversely, options to generate greater than 30 kW of power are common, although expensive, with microturbines or larger gas generators. A typical multi-well pad using a 5-horsepower instrument air compressor requires approximately 5 kW to power the air compressor and site, fitting neatly right in the middle of this gap.
An Alberta start-up, Westgen Technologies, has managed to overcome this challenge. They have developed a well-gas fueled power generation and air compression system with a comparable or lower capital cost than most current fuel gas pneumatic and TEG designs. Their design, producing 6 kW, 20 kW or 30 kW of power, uses a solar hybrid approach coupled with redesigned lubrication system allowing the system to run one year between oil changes and up to 15 years between rebuilds.
The module, named EPOD, combines power generation, air compression and common electrical components into a pre-commissioned package. This turn-key design follows industry trends towards modularization and reduces installation time and costs. The unit comes with a large UPS, 24 VDC and 120/240 VAC distribution systems and is pre-setup to install the Producer’s control panels and integrate with their SCADA system. It provides the option of adding electric heat trace and can reduce ancillary wellsite costs, such as solar systems for chemical injection pumps. Using this system, Producers can meet regulations while reducing capital and maintenance costs. It comes pre-configured to generate carbon credits in Alberta and offsets carbon tax in BC and Saskatchewan, an added economic incentive.