Ultra-low powered pneumatic device replacement solves reliability issues, eliminates emissions

Pneumatic chemical injection pumps have been used for decades in the oil and gas industry, leaving behind a huge environmental footprint.

One could argue the best and easiest way to target and reduce emissions is to replace these pumps with a solar chemical injection pump.

Jacklin Huber, operations manager of LCO Technologies Ltd., said many of the solar powered chemical injection pumps currently on the market have been historically fraught with issues starting with reliability and leading to an on/off style nature.

The CROSSFIRE technology, an ultra-low powered common platform, which can be configured as a chemical injection pump, or an instrument air compressor, may be the answer to improving overall system reliability.

The controller remains the same regardless of the configuration, and is considered the brains of the technology. Fluid ends, cylinders or diaphragms are attached to the platform for the different applications.

Speaking at a Petroleum Technology Alliance Canada (PTAC) webinar in July, Huber said autonomy is one factor that reinforces the reliability of the CROSSFIRE technology.

Huber said the CROSSFIRE is extremely energy efficient, and like most chemical injection applications, it runs on less than one amp of power draw.

“This means that the system can run on solar for weeks, not days, without requiring a massive amount of solar infrastructure,” she said.

“In addition, the motor was specifically designed to have no inrush, which is a phenomenon when you’re starting the motor. The motor pulls a very high amount of current for a very short period of time. And this is what damages solar infrastructure over time. So by eliminating this inrush phenomenon, we’re also adding durability to your overall solar infrastructure.”

Turning to an example application for chemical injection, Huber said if you injected 20 litres per day at 500 PSI, the average current draw off the CROSSFIRE’s pump is 275mA or 6.6 watts.

“To put that into perspective, that’s less power than an eight-watt LED light bulb,” she said. “So when we talk ultra low power consumption, that’s what we mean. Let’s say if I were to use 200-watt solar panels, and two 110-amp batteries, that would yield 17 days of autonomy. So if we're socked in with no sun or the solar panels are stolen, there's enough juice stored into the system to run this pump for 17 days.”

The CROSSFIRE technology can replace up to four pneumatic pumps with one unit, said Huber.

 “In addition to eliminating the methane emissions, we also track and store stroke count data in our controller, and this can be used to quantify the emissions reductions for carbon offset credit programs,” said Huber. “So this can help you pay for an offset equipment cost.”

Huber said the efficiency and reliability of the overall CROSSFIRE drive system is based on its brushless, sensor less, rare-earth variable speed drive motor.

Unlike most of its competitors, the CROSSFIRE boasts a vertically oriented motor drive system. “This orientation allows us to exploit not only the four-headed geometry, but use the energy from all 360 degrees of the rotation, which means there’s no wasted travel,” said Huber.

Huber also touted the benefits of the CROSSFIRE’s field serviceability, where the industry standard 5100 series fluid ends are used and its chemical management, which is based on a variable speed drive pump.

“This will maintain your ratio of chemical to production throughout the production range, delivering chemical proportionate to flow or whatever process variable you choose, and continuously run, well modulating,” she said. “This method gives you the best possible results from your chemical.”

Currently there are a few environmentally friendly alternatives for pneumatic instruments like dump valves and level controllers that emit methane into the atmosphere, including replacing pneumatic instruments with electric instruments or retrofitting high- to low-bleed instrumentation.

 “We can all agree that [retrofitting] is a really great place to start,” said Huber. “And I think a lot of producers have already gone through this transition. And it's a really great place to start because you’re reducing your methane emissions. But ultimately, we're not solving the problem because we’re just venting less.”

The CROSSFIRE instrument air compressor produces clean, dry compressed air as opposed to production gas, which can be put into the same pneumatic instrumentation on-site without changing anything in the control loop.

Adapting the CROSSFIRE for new applications

The CROSSFIRE platform can be adapted to other applications, including vent gas capture from tanks.

The company is currently working on a diaphragm compressor for vapour recovery units or VRUs, another variation of the CROSSFIRE, to address an application in the field for tank venting, said Steve Froehler, head inventor and owner of LCO Technologies. He found that the technology “applies itself very nicely to I think the whole VRU opportunity there,” he said.

The company started testing its prototype in July to reconfirm findings from the initial testing that look promising, said Froehler.

“It’s funny when you’re dealing with air, when you’re trying to compress gas, efficiency is ultimately the target,” he said.  “It’s a surprisingly hard target to hit. And the issues that we've encountered over the years here have been numerous and they keep us on our toes, that’s for sure.”

The company is applying the findings and information from its initial installation site and applying to other sites.

Froehler said gas from tanks can be stored and used as blanket gas with excess destroyed or straight to flare or used for generating power. This may include adapting the CROSSFIRE technology to crank case venting and packing box vents on compressors.