A novel technique for extracting methane from hard-to-reach coal deposits is set to be applied at a project site in Wyoming, US.
Technology from Ciris Energy – which focuses on the microbial bioconversion of carbon – has been approved by the Wyoming Department of Environmental Quality for deployment at Ciris Energy’s project near Buffalo. The company also received permission from the Wyoming Oil and Gas Conservation Commission.
Ciris Energy injects chemical “nutrients” into underground coal seams to stimulate native microbes that convert the coal into methane. A company official said the permission demonstrates regulator satisfaction with the environmental soundness of the process.
“We’ve had to do a lot of work in trying to describe what it is we try to do and regulators have really taken an interest and effort to understand and hear us,” said Milan Hall, vice president of finance and controller for Ciris Energy in a phone interview.
The 10 year permit allows for injections into an underground coal seam to enhance and restore naturally occurring methane generation. The permit for this project, located in Campbell County, will require extensive monitoring both during and after injection operations.
The permit also requires Ciris to maintain the water quality within the coal seam at existing quality levels. Further, the Wyoming Oil and Gas Conservation Commission approval docket #500-2014, grants Ciris final approval for this microbial conversion project.
Ciris Energy is the only company in the world fully permitted for continuous injection and circulation to restore microbial conversion of coal and produce clean burning natural gas.
We are grateful to the Wyoming DEQ and Wyoming Oil and Gas Conservation Commission for their hard work and thoroughness during this permitting process,” said Greg Jenkins, CEO of Ciris Energy.
“The requirements for careful monitoring and maintenance of water quality reflect Ciris Energy’s commitment to environmentally sound practices.” Jenkins added.
“Developing new forms of coal use are essential economically, environmentally, and politically. With its processes, Ciris is a leader in significantly enhancing the value and environmental aspects of using low rank coals,” Jenkins said.
This permit is the second of which Ciris has been issued for trials of its bioconversion technology. The first seam for which the company received a permit has already produced methane – in 2012 – however, the Ciris has noted production of the gas has so far been relatively “low”.
Underground coal gasification: the same, but completely different
Similarities have been drawn between Ciris’ technology and technique and underground coal gasification (UCG). While there are parallels, there are also clear differences.
“We rejuvenate the native microbe population that created the gas in the first place,” Hall said, adding that it was “not underground coal gasification”, but that the results were much the same. The process accelerates what would occur naturally as microbes chew through coal seams and convert the commodity into methane.
Nutrients “you could eat”
To local populations where hydraulic facturing (‘fracking’) takes place, the drilling rigs are synonymous with the danger of chemicals and gas leaking into water systems. ‘Fracking’ and its purported dangers are often associated with all unconventional drilling projects, including tight sands, coalbed methane (CBM) and UCG.
Addressing environmental concerns over the chemicals used by Ciris Energy, Hall explained that there was no need for local populations to worry: “We have a proprietary reservoir modelling program and a modeller who has developed a way where we can understand how the fluids are moving – and that’s one of the key accomplishments with what we did with that first permit.”
“We understand how to move the nutrients through the seam,” Hall added.
The result is being able to distribute the nutrients needed by the microbes – not using pressure like hydraulic fracturing would – of which Hall said none are “out of the ordinary” in people’s daily lives. He said the chemicals used are mixed in a Ciris facility before going downhole, but the contents are innocuous.
“It’s nutrients,” Hall said. “Honestly some of the stuff we put down there you eat.”
These “food grade” nutrients are also unlikely to affect local populations, since there are no domestic use water wells within a mile of the project. Indeed, water in the area has already been classed as only suitable for agricultural use.
Even if there were local drinking wells, Hall believes the permits would still have been issued, because Ciris Energy offers “environmentally sound practices”.
Written by Sam Dodson
Read the article online at: https://www.worldcoal.com/cbm/15072014/microbes_to_convert_coal_into_methane_cbm74/