|I have been making most of these points about the problems of well case integrity from the outset of the campaign based on my own knowledge of first principles and the evidence of experts like Prof Tony Ingraffea. Here we have Karlis Muehlenbachs, a geochemist and a leading authority on identifying the unique carbon fingerprint or isotopes of shale and conventional gases, at the University of Alberta, expanding on these points based his own research and U.S. Federal studies:
The findings, which clearly contradict industry assurances, didn’t surprise Muehlenbachs, who has studied leaking wells in Alberta’s heavy oil fields for decades.
“The shale gas boom combined with hydraulic fracking will cause wellbores to leak more often than run-of-the-mill conventional wells,” says Muehlenbachs. “The problem is going to get worse, not better.”
Muehlenbachs, who has been fingerprinting leaking gases since 1994, says that hydraulic fracking, which as we know, injects water, chemicals and sand into rock formations at high pressures, may create more leaks in wellbores overtime. (As industry searches for deeper and more extreme hydrocarbons, it must blast open tight rocks with more brute force over larger land bases than conventional operations.)
According to Schlumberger, the world’s largest oilfield company, there are problems galore. In 2003, the company reported that 43 per cent of 6,692 offshore wells tested in the Gulf of Mexico by U.S. Regulators were found to be leaking. In fact, by the time a well gets 15 years old, there is a 50/50 probability it will leak significantly and therefore contaminate other zones, wells, or groundwater.
“That’s amazing. It’s not Greenpeace reporting this but Schlumberger in the Oilfield Review,” says Muehlenbachs. (Reliable data on well integrity – see below – is hard to find, but a University of Calgary study found that in Alberta approximately five per cent of all wells leak, while leakage rates in Norway range from 13 to 19 per cent from producing wells.)
The University of Calgary study on ‘Well Design and Well Integrity’ can be found here: http://www.ucalgary.ca/wasp/Well%20Integrity%20Analysis.pdf
Muehlenbachs also recognises the industry’s propensity to tell blatant lies.
Although petroleum engineers now admit that companies routinely blast fluids and gas into other industry wells hundreds of metres away (B.C., Texas and North Dakota have all documented such cases), they still claim that “fracture communication incidents” can’t happen with groundwater.
Muehlenbachs, who has documented numerous cases of groundwater contamination, calls such denials dishonest. “Such claims do more harm than good to industry. Don’t they realize that social license matters to industry?”
Whenever methane leaks from one well into a neighboring wellsite, “industry says let’s fix the leaks,” says Muehlenbachs. “But as soon as the leaks enter groundwater, everyone abandons the same logic and technology and says it can’t happen and the denials come out. In Alberta, it’s almost a religious belief that gas leaks can’t contaminate groundwater.”
Yet it happens routinely. At a conference in Washington D.C. last month sponsored by ‘Resources for the Future’, Muehlenbachs showed evidence that shale gas drilling activity in Quebec and Pennsylvania had in several cases resulted in surface contamination.
The debate about whether leaking shale methane comes from heavily fracked zones creating faults into groundwater or along poorly cemented wellbores is immaterial to landowners, says Muehlenbachs. “You don’t care if it comes from fracking or a bad cement job, you suffer the consequences all the same, and lose your well water.”
Given these findings and a Duke University study that found extensive methane contamination of domestic water wells in a heavily fracked area, Muehlenbachs recommends that regulators do rigorous gas and water testing. In addition to baseline isotope testing of methane for all water wells and groundwater sources, Muehlenbachs says regulators must also test for ethane and propane (the shale gas fingerprint) as well as gas from abandoned wells and natural seeps and gases from well casings.
This is certainly is not part of our Environment Agencies regime of testing at present.
FOOTNOTE – Courtesy of Will Cottrell:
For the record, the audio for the event you mention is at http://video.rff.org:8000/~rff/111411.mp3, while Muehlenbachs’ slides are here – http://www.rff.org/Documents/Events/Seminars/111114_Managing_the_Risks_of_Shale_Gas/Muehlenbachs%20Nov%2014%20FINAL.pdf