The task is complicated by the fact that each well is an experiment, with its own geophysical characteristics. Regions such as Pennsylvania’s Marcellus, Texas’s Eagle Ford and Alberta’s Cardium present their own unique challenges.
As fracking undergoes greater scrutiny, a view is emerging that the most obvious and pressing threat comes from poor well construction, in which broken or ill-fitting cement well casings can allow methane gas and fluids to leak into drinking water. Industry officials say constantly improving safety practices address these risks.
But fracking is a complex business. Trican’s luck ran out shortly after the second successful frack, and what should have been a 10-hour job turned into two days. The property is in the Cardium B zone, a tricky play that stumped NAL and Trican’s engineers and geologists this round.
Between 80 and 90 per cent of frack jobs go as planned. The Bowden effort wasn’t so smooth. NAL and Trican tinkered with the frack fluid recipe. They played with pressures. They adjusted the amount of nitrogen they used. But only four or five of the 12 fracks that NAL and Trican planned worked.
Clive Mountford, an engineer at NAL, thinks of a word to describe how those days feel. “Frustrating,” he says.
Regulation and science
Across North America, energy companies are facing a shifting regulatory picture that will further complicate their world.
Several U.S. states have added new rules while others have imposed a de facto moratorium on fracking. Environmental groups say the state rules don’t go far enough and want the federal government to step in, a move the industry deeply opposes.
The Environmental Protection Agency is currently in the midst of its own major study on shale gas development that is due for completion at the end of 2013 and could set the stage for federal regulation.
In Canada, federal Environment Minister Peter Kent has asked the Council of Canadian Academies to undertake a review of the environmental impact of shale gas extraction. The independent, not-for-profit council is in the midst of that work – which involves a literature review, rather than field research – and expects to report in the latter half of 2013.
Reaction among the provinces varies. Shale gas and tight oil development is booming in British Columbia, Alberta and Saskatchewan with little additional regulatory oversight, while Quebec has imposed a moratorium while it reviews the science.
Industry associations in both Canada and the United States have published new standards for disclosure of chemicals, well construction and handling of wastewater. Industry executives feel their critics are exaggerating the risks in their determination to wean North Americans off fossil fuels.
Scientists have made some progress in studying the impacts of shale gas and tight oil development. But some researchers say far more information is needed on the long-term consequences of the intensive drilling now under way in places like Pennsylvania, North Dakota and northeastern British Columbia.
Critics have warned that the practice of injecting chemical-laced water under high pressure into the earth is high-risk, and could lead over the long term to contamination of fresh water aquifers that feed wells and municipal systems. Water contamination is fracking’s hottest issue.
An independent study released last month by the University of Texas at Austin’s Energy Institute concluded that there is no evidence that fracking fluids are tainting groundwater. It notes that fresh water aquifers are typically hundreds of metres above the gas or oil zone, separated by such dense rock that fracking is required in the first place. The university’s review, however, has been criticized as a literature search, which reviewed scientific findings and regulatory documents but contained no new fieldwork.
With his colleagues from Duke University, biologist Robert Jackson has sampled well water in the Marcellus shale area of Pennsylvania, where they have been several cases of homeowners complaining of tainted water. The Duke researchers also found no evidence of fracking fluids in the water, but are back in the field doing further sampling. Mr. Jackson isn’t ready to make categorical statements about safety.
“My view is that we’re still data limited,” the Duke biologist said in an interview. “What we need most of all is more information.”