Pristine to Polluted | More Wells, Fewer Emissions | Next Wave of Natural Gas

PINEDALE — Natural gas operators in the Upper Green River Basin say they’ve been able to drill more wells with fewer emissions in recent years, and they can continue to maintain that trend by consolidating facilities and using advanced, emission-cutting technologies.

“Technology is key. We can make significant reductions with the right technology,” said Shell spokeswoman Darci Sinclair.

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The three main operators in the Pinedale Anticline field are Shell, Ultra Petroleum and QEP Energy Co. To date, the companies have drilled 1,775 wells, and they plan to drill hundreds more in years to come.

EnCana Oil & Gas USA is the main operator of the Jonah field on the southern end of the Anticline, where it has drilled some 1,200 wells so far. EnCana spokesman Randy Teeuwen said the company will continue to drill about 150 wells per year for the next three years. Then, if approved, it will move its rigs to the proposed “Normally Pressured Lance” field (known as NPL), where the company wants to drill 3,500 new gas wells at a rate of 350 wells per year.

According to Teeuwen, the ability to achieve emissions in the NPL below even current levels in the Jonah field depends on the ability to make a seamless transition, moving drilling rigs from Jonah to the NPL field three years from now.

“Imagine, if you will, that the drilling in Jonah is complete and we don’t have a Record of Decision for the NPL. All of the workforce goes away, and the continued revenue stream for the state and county will start to decline,” said Teeuwen.

He added that without a seamless transition, the economics become less favorable for efficiencies in production and emission reductions.

Yet environmental groups and some local residents say they will very carefully scrutinize the industry’s claims of lowering emissions in upcoming planning documents.

“I think the BLM is going to have to do some serious air quality modeling to demonstrate this can be done, and provide some objective evidence,” said Bruce Pendery of the Wyoming Outdoor Council.

Kevin Williams describes how a "three-phase" separator was refurbished with low-bleed pneumatic valves, reducing emissions of volatile organic compounds. (Dustin Bleizeffer/WyoFile - click to enlarge)

Pendery noted that even with recent emission reductions, the development is still contributing to spiking ozone, therefore the BLM is required to impose whatever restrictions necessary to meet federal standards under the Clean Air Act. And when it comes to analyzing plans to expand development, Pendery said the BLM must consider the cumulative impact to air quality in the region.

In addition to consolidating processing facilities, another major emission-cutting aspect of the proposed NPL project will be to “electrify” the field. Rather than rely on a combination of natural gas- and diesel-fired engines to operate compressors and other facilities, EnCana has asked Rocky Mountain Power to supply 20 megawatts of power to the NPL field.

Currently, EnCana’s request for 20 megawatts doesn’t stipulate a dedicated electrical generation source. So the power may come from Rocky Mountain Power’s overall portfolio of generation, most of which comes from coal-fired power plants.

“There’s nothing to prevent anyone from attempting to calculate the emissions from that power source,” said Teeuwen. “We’re confident that we wouldn’t be doing it if we didn’t think it was the right thing to do in terms of emissions.”

The Jonah and Pinedale Anticline fields are among the largest in the U.S. Unlike traditional oil and gas fields, these are “resource plays,” which means many, many wells are drilled in close proximity. In the Anticline, multiple wells are drilled directionally from a single pad. EnCana proposes a similar drilling pattern in the NPL.

Operators say this type of consolidated development allows for several efficiencies, such as central pipeline systems that eliminate truck traffic and the tailpipe and dust pollution that comes with it. Additionally, operators in the Pinedale Anticline requested and got permission to expand their year-long drilling operations to include areas previously under seasonal restriction as big game wintering range.

Similarly, EnCana officials say the Jonah field has served as a testing ground for best practices in cutting emissions. Teeuwen said the field was originally designed with a large number of small facilities to separate gas, water and condensate (light oil), but that meant a large number of fittings and potential leak points. The company consolidated those facilities, and hired six full-time employees to scour the field searching for leaks and plugging them.

EnCana also developed “flareless flowback” systems seven years ago, ending a long-standing practice of flushing out wellbores by venting and burning off gas directly into the atmosphere.

“That was the way you did it in those days,” Teeuwen said. “Now the BLM has made it (flareless flowback) mandatory and you hardly see that done anymore.”

Regulatory and industry officials say that these voluntary emission-cutting measures in the Jonah and Pinedale Anticline are likely to become enforceable requirements for new development projects.

Halliburton performs hydraulic fracturing services in the Pinedale Anticline. (Dustin Bleizeffer/WyoFile - click to enlarge)

For the past several years, operators in the Upper Green River Basin have implemented an ozone response plan to cut daily activity to essential operations when the state detects atmospheric conditions thought likely to contribute to occasional spikes in ozone concentrations. Because the spikes occur in the winter, when there’s widespread snow cover in the basin, many local residents have asked state and federal regulators to force the industry to slow down — or even completely shut down — during the coldest winter months.

Wyoming Department of Environmental Quality administrator John Corra claims his agency doesn’t have the authority to shut down drilling unless it is an acute threat to human health.

But it’s an idea that some local residents and environmental groups say the BLM — which potentially has such authority — should consider as an option for new projects.

Shell, QEP and Ultra Petroleum say that while they have increased their overall drilling rate, they have actually reduced the number of rigs and overall activity thanks to the very nature of the cookie-cutter resource play and efficiencies afforded by year-round drilling.

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Currently, the three companies employ a total of 15 rigs, eight of which are powered by engines equipped with catalytic converters to reduce nitrogen oxides (NOx).

The other seven rigs will be retrofitted with the same low-emission technology by the end of this year, according to the operators. For each rig that is converted, annual NOx emissions are cut from 80 tons to 5 tons. That means the current fleet of 15 rigs emits about 610 tons of NOx annually. Next year, the fleet of 15 rigs will emit about 75 tons annually.

Year-round drilling “makes it economical to employ some of the technologies we’re talking about,” said Sinclair. “To outfit a rig with catalyst technology … it can cost up to $500,000 per rig.”

As for the rate of drilling, “the pace becomes less relevant because you’ve so significantly controlled those emissions. … It’s not the number of rigs so much as what are the emission volumes?” said Sinclair. “You also have to be aware that if you shut down and move out for a few months out of the year, there’s so many implications with that … and that includes socio-economic impacts.”

BLM officials seem to agree with industry that maintaining steady operations is preferred.

“It’s better to have a stable workforce throughout the year, rather than bringing in a large number of folks during the summer,” said Wyoming BLM’s Bill Hill. “If we can work out the other impacts associated with that, like the mule deer herd. … Year-round (drilling) we see as a better solution.”

— Contact Dustin Bleizeffer at 307-577-6069 or dustin@wyofile.com.



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Published on May 17, 2011

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