Water treatment technology for coal-bed methane wells on the rise

Water discharged from coal-bed methane wells isn’t always friendly to plants, but two companies are working to change that.

Harmon Systems International LLC, of Bakersfield, Calif., is
treating methane water with a "sulfur burning" generator, reducing alkalinity to make it more like rainwater so it can be used to irrigate fields.

http://www.usatoday.com/tech/news/2004-04-05-water-treatement_x.htm

"This water is beneficial. It should not be viewed as a waste or a byproduct," said Terry Dong, a partner with the company. "If (coal-bed) water is amended … it will benefit everyone."

Dong is among a growing number of water resource specialists finding work in the Powder River Basin as a result of the ongoing methane boom.

His company’s generator adjusts the ability of water to adhere to sodium, which affects how the water interacts with soil.

The U.S. Bureau of Land Management has estimated the industry could extract up to 7.5 trillion gallons of coal-bed water to produce all the recoverable reserves in the basin.

Methane operators typically pour the water into stock tanks or reservoirs, some which contain sand so the water filters back into the ground. They also mist it, atomize it, re-inject it into the ground and spray it onto dusty roads.

When conditions permit, methane water can be used to irrigate alfalfa and other crops.

But the biggest concentration of development is moving westward to an area where methane water and dirt just don’t mix well. Essentially, the combination of salty water and saline soils can block plants from soaking up the water.

Adjusting the characteristics of the water can provide a resource that ranchers usually have in limited supply, Dong said.

The sulfur burners provide a controlled combustion process that oxidizes sulfur and produces acid, which lowers the alkalinity of water passing through the burner.

Dong said a sulfur burner can treat production water from a group of about a dozen wells or more at a cost of "pennies on the barrel."

"It solves a problem for the producer. But if you can also show the end-user that this is a benefit, it should alleviate the major concern that surface owners have," Dong said.

Another treatment method used in the region is ion exchange.

Sheridan-based EMIT Water Discharge Technology is pumping 13,000 barrels of production water per day through two devices that introduce resin. The resin removes sodium, then both the sodium and resin are separated from the water.

What is left is a briny solution, about 100 barrels per day, that is trucked to an approved injection well site for disposal.

"We are removing sodium from the water, not adding anything to manipulate it," said Terry Olson, a manager for EMIT.

The water is also used to irrigate alfalfa fields on a ranch on Dead Horse Creek, a tributary to the Powder River.

The cost can range from less than 10 cents per barrel to more than 25 cents per barrel, Olson said.

His two units each have a capacity of 200 gallons per minute, and EMIT is constructing three larger units at a shop in Casper.

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