Former drilling rig manager Jack Boyd calls them “ratty” wells or “leakers.”
They’re old, shallow-depth natural gas wells, up to 100,000 of them drilled in eastern Alberta near Medicine Hat, Lloydminster and Wainwright.
Hundreds are still leaking methane gas from underground rock formations to the surface.
“A good half of them are leaking,” Boyd estimates.
|Larry MacDougall, Business Edge|
|Jack Boyd with some of the sealant he has developed to stop gas leaking from abandoned wells.|
He supervised the drilling of dozens of wells in the area before retiring from the oil and gas industry about 12 years ago.
Although the industry has been fixing the leaky wells since the 1980s, it acknowledges there are probably still hundreds with what is technically called “surface casing vent flows.”
The problem includes thousands of so-called orphan wells that were never or poorly plugged, and that no longer have a corporate owner.
“Typically it’s very small volumes” of gas escaping, says David Pryce, environment and operations manager for the Canadian Association of Petroleum Producers.
“You could probably put a latex glove over (most wells) and it would take a long time for it to fill,” Pryce says. “There are probably other wells where there’s a more significant flow.”
All wells that present a fire hazard, a danger to the public or imminent risk to the environment are identified and repaired under the “Orphan Fund.”
The industry-funded program ensures the proper abandonment of hundreds of orphan wells each year.
For wells drilled since 1995, the Energy and Utilities Board (EUB) has required companies to test for surface casing vent flows within 90 days after the drilling rig is released.
“If they find anything, they have to deal with it and they have to notify us about what they’ve done to deal with it,” EUB spokesman Greg Gilbertson says.
The methane gas leaking from old shallow wells is flammable. It is also 21 times more potent a greenhouse gas than carbon dioxide. More worrisome, there is potential for the methane to contaminate underground aquifers supplying water to farmers and ranchers.
For decades, the industry has plugged non-producing or abandoned wells by pumping in a cement grout. This forms a hard cement plug that is supposed to prevent any down-hole gas from escaping.
Too many times, however, “the cement doesn’t work,” says Ted Cyr, research director in the gas and markets development unit of Alberta Resource Development. Even pumped under pressure, the cement frequently doesn’t push far enough into microscopic-sized rock pores to totally seal off the gas flow, he says.
Sometimes the cement slumps and doesn’t completely fill the space between the well casing pipe and the surrounding rock, Cyr adds.
Other times, gas under pressure will bubble through the cement grout as it’s hardening, creating tiny channels through which gas migrates to the surface.
After he retired, Boyd started tinkering in his home workshop, trying to solve the problem of ratty wells. Through trial and error, he invented a sealant solution, a patented mixture of liquid asphalt, emulsifiers and other ingredients.
He formed a company, Seal-MastR Systems, and developed a delivery system for “squeezing” the material down a well and into gas-bearing rock formations.
Seal-EX, as Boyd dubbed his sealant, penetrates deeper than conventional cement into tiny rock pores, creating a flexible but impenetrable seal. The well is also filled with a column of the liquid sealant, creating hydrostatic pressure that acts as a further barrier to down-hole gas.
“It’s very effective,” says Cyr, who has worked with Boyd on the technology. Scientist Ernie Perkins, project leader at the Alberta Research Council, led a team that tested Seal-EX in the laboratory and observed it being used on leaking gas wells in the field. “It definitely works,” Perkins says. “This is a major shift in how we think about treating these wells, and that’s the beauty of it.”
Northstar Energy Corporation tested Seal-EX to stop a leaking well in the Provost area. “It’s an innovative idea with great potential in difficult surface casing vent flows,” says Lindsay Downey, Northstar’s completions superintendent.
Boyd says his technology can seal a well for a cost of about $30,000, compared with $45,000 for a cement plug that may not work.
Bob Wheeler, completions technologist with Canadian Natural Resources Ltd., helped Boyd test Seal-EX on a well near Elk Point that had cost the company which owned it at the time more than $1 million to try to plug the leak.
“It was one of the worst wells that we could have tried to apply (the technology) to,” Wheeler says. A series of down-hole tests revealed gas leaking from three separate formations, all of which were sealed using Seal-EX.
“I think the technology is good,” Wheeler says. “It’s one more tool that we have at our disposal.”
Despite his successes, Boyd is still trying to convince the industry to participate in a large-scale program, involving at least 30 wells, to conclusively prove the technology. He and others say Seal-EX should be included in regulatory guidelines, as a standard tool.
EUB spokesperson Gilbertson says it’s up to industry to pick the most appropriate technology to meet regulatory requirements. Boyd’s system might become part of future well-abandonment standards once it’s sufficiently proven and supported by industry associations, Gilbertson adds.
Pryce says the petroleum producers association has asked to see the research and field-test data on Seal-EX. However, it’s up to each member company to decide whether to participate in large-scale testing, he says. “The challenge for Jack is he’s got a new gizmo, and he’s got to get it in front of people and convince them that it does work the way he says it does.”
Boyd is applying for funding to the Alberta Energy Research Institute, whose recently expanded mandate includes investigating new energy-related environmental technologies.
Boyd is confident that if he can convince a few companies to provide enough wells to prove his technology, Seal-Ex will finally put the stopper on those ratty wells.