Wyoming report: Pavillion gas wells properly drilled; more study needed by Benjamin Storrow, August 6, 2014, Star-Tribune
Natural gas wells in the Pavillion Gas Field were properly drilled and maintained, but more study is needed to prove if energy operations contaminated drinking water in the region, according to a draft report released by Wyoming regulators Wednesday.
Those findings were among the conclusions of a preliminary study released by the Wyoming Oil and Gas Conservation Commission. The report is one of three investigations Wyoming is conducting into polluted drinking water near the town of Pavillion. The state is also reviewing disposal pits and testing water quality in the area. All three investigations will be combined in a final report.
Wyoming Oil and Gas Supervisor Mark Watson said Wednesday’s draft contained “no major conclusions as far as potential for contamination.” [Would anyone expect otherwise, with Encana paying for and thereby controlling it?]
“That won’t be done until the final report,” he said. [Will the final say water well owners or nature is to blame for Encana’s shallow fracs and leaking waste pits?]
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Industry representatives contend the contamination occurs naturally in the rocks where water wells were drilled.
The U.S. Environmental Protection Agency initially and tentatively reported natural gas operations in the region were the cause of nearby polluted well water but later backed away from that claim.
Reactions to the report’s findings ranged widely.
John Fenton, chair of the Pavillion Area Concerned Citizens, said he was frustrated by what was not in the report. A well across from his house was among three wells identified as lacking cement bond logs. A well in his field was one of seven listed as in need of a mechanical integrity test.
“What is looks like to me is we are set up for years of testing and monitoring,” [Like Canada’s Council of Canadian Academies recommending industry frac families slowly, get the science later] Fenton said. “Answers are a damn long way off.”
Encana, for its part, praised the investigation. The findings show wells in the field were properly constructed and provide no pathways to pollute drinking water, said Doug Hock, a company spokesman.
He said the finding of deep water wells was not surprising. Those water wells were drilled through gas bearing rock, Hock said. The report found rock containing gas began at 699 feet in places while wells were drilled to 750 feet.
“Our contention is the water wells were drilled further than they should been,” [Blame the water well owners, without disclosing the chemicals Encana injected? What kind of shoddy investigating is that?] Hock said.
An EPA spokesman said the agency was aware of the report and was reviewing its findings.
The draft unveiled Wednesday is the first study to examine the integrity of wells in the gas field. The state’s investigation was based on company filings to the oil and gas commission, the Office of the State Engineer and other government data.
The study appeared to raise as many questions as it answered.
It concluded “all wells were properly permitted, drilled, completed, and operated in compliance with applicable state and/or federal rules and regulations.”
Mechanical integrity tests of five wells showed no signs of leaking wells. [Why not discuss the results of integrity tests on all the wells?]
But the report also found the casing on 30 percent of the 50 natural gas wells reviewed was shallower than three nearby water wells. One water well was deeper than the casing of 10 nearby gas wells.
Natural gas wells are encased in cement to prevent leakage.
That means contamination from a natural gas well could leak into the water well below it. The possibility also exists that naturally occurring gas found in those water wells could have contaminated other sources of drinking water.
Either way, more information is needed, the report said. [What’s the state going to do? Study until Encana’s done with the field, and then claim nature did it?]
“The presence or absence of cement is only one of several factors to be considered in determining if a potential pathway exists behind the casing that could allow migration upward or downward,” wrote Robert King, the report’s author. “Other factors include hydrostatic pressure differentials, formation rock properties (permeability and porosity), gas/water contacts, location with respect to other wells, geologic and hydrologic environment, and drilling mud characteristics.”
Complicating matters further is a lack of information on the water wells drilled in the area. Seven of the 15 water wells reviewed for the report do not have a permit filed with the Office of the State Engineer, which regulates water use. Information on when those wells were drilled, their depth and casing size, among other details, were missing, the report said.
Wyoming is also missing information on how individual gas wells were fracked.
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King recommended the state obtain the missing information on water wells and stimulation. Geologic and hydrologic studies are also needed to better understand the flow of gas and water between rock formations in the area, he said. [Too late for those studies now. Does it sound like Encana and the state are playing delay game?]
The task of determining which wells were fracked could be especially difficult, Watson said, as ownership of the field has changed hands several times. Records of what was done by a previous owner might have been lost, he said. [Why not then just focus on Encana’s perfs, fracs, recompletions and servicing activities?]
The findings released Wednesday will be sent to Encana Oil and Gas, the operator of the field, and EPA for comment and review. The public will be given 30 days to comment on the initial conclusions as well.
Initially, the draft was to be kept private, but the state reversed course after landowners appealed to share the preliminary findings with the public. A spokesman for Gov. Matt Mead praised its release, saying the state needs “valid and reliable information” regarding Pavillion’s water while stressing it was only a draft.
This article was updated to correct two errors. An earlier version said some natural gas wells were shallower than three water wells. They are not. The cement casing on those natural gas wells was shallower than the water wells. The state also has information on which wells were fracked, but does not have information on the chemicals used in frack jobs.
[Has the state asked Encana what chemicals the company injected during drilling, perforating, lost circulation, fracing, acidiging, servicing? The EPA did, and Encana refused to cooperate. How will the state make Encana cooperate? Does the state’s review have any credibility without comprehensive details on all chemicals injected into each of all the gas wells?]
Draft Wyoming report: Gas wells in Pavillion area not leaking produced gas into groundwater by Mead Gruver, Associated Press, August 06, 2014, The Republic
A draft state report released Wednesday on a possible explanation why well water in a central Wyoming gas field smells foul and tastes bad points away from leaky gas wells as a source of the problem.
Testing showed no evidence gas wells in the Pavillion area are leaking produced gas into the ground or providing a route for deep gas to seep into aquifers tapped for household water, [Refer to slide below, research including by Alberta’s energy regulator shows that more gas well leakage is from shallower, intermediate zones, not deeper producing zones, and what if Encana frac’d into aquifers at depths where water wells get their water from?] according to the draft report by the agency that regulates oil and gas development in Wyoming.
The release of the Wyoming Oil and Gas Conservation Commission report, which examined 50 gas wells within a quarter-mile of 15 water wells, [gas migrates much further than a quarter-mile or 400 metres; regulator and industry reports show industry’s leaking and or deeply injected fluids can migrate over 6 miles, a lawsuit on water wells contaminated by industry’s migrating gas, had filings showing the gas migrated from over 1.5 miles away, in Alberta, industry’s deeply injected gas migrated 3,625 metres (over two miles)] opens a 30-day period for the public and others to weigh in on the draft findings.
Encana, the petroleum company that owns the Pavillion gas field, pointed to the latest findings as evidence their gas wells aren’t to blame. “The report confirms that the natural gas wells in the Pavillion Field were soundly constructed and provide no migration pathway into domestic water wells,” Encana spokesman Doug Hock said in an emailed statement.
Local residents say their well water turned foul around the time gas drilling picked up in their area eight years ago. The draft report on the problem is the first of three planned by the commission and the Wyoming Department of Environmental Quality.
The U.S. Environmental Protection Agency, in a 2011 draft report, theorized gas development, including hydraulic fracturing, played a role. … However, the EPA has yet to finalize its draft report or submit it for peer review. Last year, the EPA handed its Pavillion area investigation over to the state.
Part of a $1.5 million grant from Encana is funding the new state investigations. The first draft report examined the results of pressure testing of 41 wells by Encana between 2011 and 2013. [Why not review pressure testing when citizens’ water wells went bad, why so many years later? Does it sound like the most damning information, like what chemicals Encana injected is being purposely avoided in the state’s review?]
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State officials initially planned to release the draft to the EPA and Encana for review, with public release only after the report was finalized. The draft report was released publicly Wednesday in response to requests by The Associated Press and the Powder River Basin Resource Council that cited Wyoming’s open records law.
“We’re just happy we’ve got it at the same time Encana has it,” said Jill Morrison with the resource council, which has been working with Pavillion residents on their water problem. “It’s complex, and we’re going to be taking a really careful look at it with the assistance of an expert.”
The report also found that potentially helpful information about how the water wells were developed, including how deeply they were drilled, is lacking. Seven of the 15 wells do not have water well permits on file with the State Engineer’s Office, the report noted.
State officials plan to release two more reports by year’s end on new sampling of Pavillion-area water wells and an investigation into whether old petroleum industry waste pits might have caused the problem. [Emphasis added]
Slide above from Ernst presentations
Above – 2007 presentation: Factors Affecting or Indicating Potential Wellbore Leakage (EUB is now the AER)
In 2011, Dr. Muehlenbachs presented in Washington (slides included below) that more than 70% of casing gases come from the intermediate layers of energy well bores, not the target or “deep” zone:
