Wyoming company extracts 98 percent of methane trapped in well water 

BY ERIC LIDJI FOR GREENING OF OIL 

A Wyoming company claims to be able to extract methane trapped in well water.

HyCap Energy said its new device, called the HyCap Separator, extracted almost 98 percent of the methane trapped in well water without using chemicals or additional power during a two-day test this past April at a government-run oil field in Wyoming.

The Rocky Mountain Oilfield Testing Center, a U.S. Department of Energy facility that runs the Naval Petroleum Reserve No. 3, where the test occurred, backed up those claims.

The HyCap Separator was tested on an oil well, but would prove particularly useful for unconventional wells, such as the numerous coalbed methane wells in Wyoming.

Conventional natural gas reservoirs are usually in a “cap” above oil reservoirs, which in turn are usually above water reservoirs. Coal beds, though, are imbued with water throughout. The pressure of all that water keeps methane inside the coal bed. To extract the methane from the coal bed, producers relieve that pressure by removing the water.

Methane is the main component of natural gas.

Coalbed methane wells frequently raise environmental concerns, particularly about how to dispose of the large amounts of produced water, which includes high saturations of heavy metals and organic compounds picked up underground. One issue that isn’t talked about nearly as much, though, is the methane still stuck, or “entrained,” inside that water.

Entrained methane is problematic for a number of reasons. Technically, it’s a contaminant. It’s troublesome for treatment plants, and it can clog water pipelines.

It’s also wasteful, since many producers simply vent it into the atmosphere. That’s not only a problem because the methane isn’t being produced without being put to use, but also because methane, as a greenhouse gas, is 20 times more effective than carbon dioxide at trapping heat in the atmosphere, according to the U.S. Environmental Protection Agency.

Device breaks down production stream into droplets

HyCap Energy claims to not only remove this methane, but also capture it for use.

That claim has support from the U.S. Department of Energy, but because a patent is still pending on the device, HyCap Energy is reluctant to publicly detail how it works.

Bret Wolz, of HyCap Energy, gave some clues, though.

He said the HyCap Separator doesn’t add anything to the production stream, such as chemicals. It doesn’t require any power, other than the power already provided by the downhole pump inside the well. And the device doesn’t have any moving parts.

Wolz noted that it also extracted about 75 percent of the oil entrained in the well water, saying, “If it’s a hydrocarbon or a very specific gravity difference, we can pull it.”

RMOTC said it “breaks the well production fluid into small droplets to facilitate the separation of entrained gases and lighter hydrocarbon liquids from the produced fluids.”

If successful, the HyCap Separator also could be used to keep gas out of drinking water wells, a major concern in a region with documented gas migration incidents going back more than a century. If so, it could be implemented in water wells nationally, and could become useful in other unconventional plays, such as shale gas. Wolz said HyCap Energy hasn’t yet had the resources to explore how the device might work in those other settings.

Although several technologies exist for managing produced water at coalbed methane wells, including downhole devices that keep the produced water from ever reaching the surface, oil and gas officials in Wyoming didn’t know of any device in operation that separated and captured methane from the produced water stream coming out of wells.

RMOTC believes it is the first such device tested at NPR-3, also known as Teapot Dome.

RMOTC is a working oil field where private companies and academic groups can test new devices and technologies at their own expense. The facility doesn’t endorse the viability of technologies, but does act a springboard, such as sending out press releases.

Could significantly increase production rates

The water left behind by the device wouldn’t necessarily be potable. It would still have a small amount of methane in it, as well as the dissolved solids picked up underground.

But the amount of methane captured could potentially be huge. Wolz said that of the roughly 30,000 wells in production in the Powder River Basin —a coalbed methane region in northeast Wyoming currently producing around 4.5 billion cubic feet per day — are 85 percent efficient, then his device could add another 675 million cubic feet per day.

HyCap Energy is still testing the device and until a patent is approved, the company is only looking to lease it to producers. Wolz estimated that the device would cost around $55,000, but said that a single device could be used on several wells simultaneously.

Contact Eric Lidji at ericlidji@mac.com

Links of interest

HyCap Energy

Rocky Mountain Oilfield Testing Center