Expert: Green completion technology varies by natural gas region - Business, Government Legal News from throughout WV

Expert: Green completion technology varies by natural gas region

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Green gas well completions are the law the land, since the U.S. Environmental Protection Agency issued rules in April to control air emissions from the oil and gas industry.

The regulations require processes to reduce pollutants from a range of industry facilities, with most of the reductions coming through green completions at the wellhead.

So, what is this green completion technology?

"It's not one-size-fits-all," said Andrew Paterson, executive vice president for technical affairs for the Marcellus Shale Coalition of Canonsburg, Pa. "It all depends on the kind of well that you're drilling."

Green completion addresses the moment in the life of a shale well between drilling and production: the period of perhaps a week when what's coming out of the ground is not just wastewater, but isn't yet mostly natural gas.

"When the well flows back it's got sand and water and hydrocarbon liquids and gas," said Paterson, adding that the equipment is simple. "You separate them by reducing the pressure and surface area — you have a vessel that allows the pressure to drop and the gas rises and the liquids and solids drop."

Where the gas is dry, as it is in the Marcellus shale in northwestern Pennsylvania, producers use a two-phase process to separate the gas from the flowback, he said.

In wet gas regions, like the Marcellus in West Virginia's northern panhandle, it takes more equipment because a three-phase separation is needed: gas from hydrocarbon liquids from flowback.

And some reservoirs return more sand in the flowback than others, in which case green completion also requires a sand separator.

"So it's definitely something that's different according to whatever basin you're in," Paterson said. "It'll vary from basin to basin and within basins."

Oilfield equipment suppliers in each basin build the equipment that's appropriate for their area, he said. Equipment is typically rented from the suppliers at prices that vary depending on pressures and volumes and numbers of components to be separated. But, "it takes a lot of wear and tear and it's portable and you're using it to deal with high-pressure fluids and sand, so it's not cheap."

The EPA said when it issued its rules that about half of fractured wells already undergo green completions. Paterson doesn't know what share of Marcellus wells are green but said, if wells that are flared are included, he is confident that most wells are green.

Range Resources operates mostly in the wetter southwestern Pennsylvania Marcellus region and uses green completions on all of its fractured wells, according to Corporate Communications and Public Affairs Director Matt Pitzarella.

"It doesn't take a petroleum geologist to figure out we don't want to burn or lose the gas," Pitzarella said. "It would be like saying McDonald's has to stop throwing away French fries at the end of the day."

Range began using green completions for safety reasons, he said, after several well fires in the industry. By capturing hydrocarbons and putting them into the production line, green completion minimizes fire risk by eliminating combustible storage and leaks at the well site.

The company likes capturing the salable material, he said.

The EPA indicated that the captured methane and liquids can more than pay for the process and Pitzarella agrees, although he said the agency overestimated the amount of methane that is escaping.

"They didn't take into account the fact that the technology has improved over past five years or so — less methane is coming out, and less vapor from condensate (natural gas liquids)," he said.

Although the industry is still evaluating the nearly 600-page rule, most agree with it, he said.

"All signs indicate that it's going to be reasonable — we don't anticipate that it will stifle new development," he said.

He thinks the rule addresses future conditions more than current conditions.

He cited limited air-quality studies conducted by the Pennsylvania Department of Environmental Protection in 2010 in the southwest and northeast Marcellus production regions that showed safe and compliant air quality — although the department acknowledged that cumulative emissions from more wells could be higher.

"You've heard people say, ‘An individual well might be fine, but what if there are 100 wells and they add up?'" Pitzarella said. "That's what this rule addresses."

In his view, the rule meets the needs of a diverse range of stakeholders.

"if your concern is purely safety, it addresses that — there should not be fires. If your concern is public health, this addresses that. If your concern is environmental, it obviously has environmental benefits," he said. "And although any new regulation clearly has some impact, this isn't going to bring anything to a screeching halt. The final part is, this is reasonable public policy."

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