How to Prevent Deepwater Spills
Safety upgrades are critical but could mean higher prices for oil and gas.
A culture of tighter safety and more experienced regulators might have prevented the BP Deepwater Horizon leak. But equipment modifications and new technology will be needed to minimize the risk of such deepwater oil leaks. According to some petroleum engineers, recommended technology upgrades could price some deepwater resources out of the global energy market.
This could help extend the six-month moratorium on deepwater drilling instituted by President Obama last month. “I tend to be kind of a glass half empty guy, but I think there’s a 50/50 chance that the current six-month moratorium will stretch out,” says Paul Bommer, a senior lecturer in petroleum engineering at the University of Texas at Austin.
Documents and statements released by various federal investigators point to several decisions and at least one faulty piece of equipment that allowed uncontrolled gas and crude to blow out and destroy the Deepwater Horizon rig in April, initiating the worst oil spill in U.S. history.
Engineers contacted by Technology Review insist that conclusive answers will come with completion of the investigations, but criticize, for example, BP’s decision to install a continuous set of threaded casing pipes from the wellhead down to the bottom of its well. “The only thing I can figure is they must have thought it was a cost-cutting deal,” says Bommer of BP’s well design.
This can be problematic in deep, high-pressure wells for two reasons. First, it seals off the space between the casing and the bore hole, leaving one blind to leaks that sneak up around the casing pipe (as the BP Deepwater blowout is suspected to have done). Second, the long string gives gas more time to percolate into the well. A preferred alternative in high-pressure deepwater is a “liner” design in which drillers install and then cement in place a short string of casing in the lower reaches of the well before casing the rest of the well. This design enables the driller to watch for leaks while the cement is setting. “It takes a more time and costs a little more but it’s a much safer way to do it,” says Geoff Kimbrough, vice president for deepwater operations at Houston-based drilling consultancy New Tech Engineering.
Kimbrough cautions that transforming corporate cultures will take time because choosing the more conservative operation can easily cost $10 million to $20 million. Not all companies have leaders who readily support these decisions, says Kimbrough: “The courage to do that doesn’t come overnight. It comes from years and years of support from senior management.”
Regulatory ideas for how to push a culture of safety appear in a 30-day safety review delivered to Secretary of the Interior Ken Salazar late last month, and include establishing new drilling guidelines, operator certification requirements, and tougher inspection regimes. Kimbrough says the Interior Department must simultaneously boost its internal training so that it can effectively review drilling plans.
Attention has also focused on the failed blowout preventer, or BOP, that could have saved the Deepwater Horizon. The Interior safety review calls for upgrades to BOPs to address various failure mechanisms that may have doomed the Deepwater Horizon, such as placement of redundant shear rams strong enough to cut through the toughened threading between casing pipes.
One inherently safer option that many petroleum engineers are considering is bringing BOPs to the surface. In this scheme the BOP on the wellhead thousands of feet below the ocean surface is backed up by a second BOP on the drill rig that would be accessible for more regular inspection and testing. Doing so would mean hardening the risers that link the wellhead and the drill rig to handle extreme pressures.
It’s a suggestion that Kimbrough thinks is impractical. “The cost would be somewhere near prohibitive,” he says. “Just the cost to develop the system would be astronomical.” Mandating something like that would delay new drilling by at least several years. “You’re talking about years to develop and test and prove up something like that.”
But Bommer says the potential costs are likely to be small compared to the economic impact and incalculable ecological damage that the Gulf region has sustained from BP’s leak. In Bommer’s view, if such “brute force” safety engineering pushes oil and gas companies to question whether it’s economically viable to tap deepwater reserves, so be it. “Cost is the last thing people should be thinking about now,” he says.
Another area pegged for technology development is deepwater leak response. BP’s ad-hoc response to the Deepwater Horizon leak has revealed the lack of equipment and procedures for high-pressure remote operations. BP’s CEO Tony Hayward acknowledged as much last week, saying that despite assurances in its drilling permit applications, BP “did not have the tools you would want” to respond to a deepwater leak.
In fact, the tool shortage for deepwater intervention is an issue long recognized by petroleum engineering researchers. The months-long process of drilling a relief well was, until now, the only proven fallback available in cases where the BOP fails to stop a blowout. A 2003 presentation by Texas A&M University researchers modeling deepwater blowouts cited reliance on relief wells as evidence of a “fatalistic mind-set in the industry.”
The lack of progress since then supports that assessment. Since 2005 Congress has left deepwater research primarily in the hands of the Research Partnership to Secure Energy for America, a U.S. Department of Energy-supported petroleum industry consortium in Sugar Land, Texas. But RPSEA has focused its $17 million annual budget for deepwater R&D on production-related issues.
Drilling engineers say the BP accident could finally provide the impetus for deepwater response tools. Funding to perfect some of the schemes that BP has thrown at the spill, they say, should spawn an entire deepwater response industry, analogous to the well-control contractors who secure hundreds of dangerous onshore wells per year worldwide.
James Pappas, RPSEA’s vice president of technical operations, claims that his consortium is already beginning to refocus its research agenda toward safety-related R&D. For example, he sees an opportunity to improve sensing capabilities inside deepwater wells after the drill bit is pulled: “That’s a weak spot right there, a blind side, that we haven’t really addressed as an industry.”
But Pappas and other engineers acknowledge that better training, BOPs, and response tools may not convince an outraged country that a sequel to the Deepwater Horizon disaster is impossible. They say it may take more radical upgrades to drilling technology to lift the current six-month moratorium. “We have to go back to square one and prove that we’re reliable and responsible enough to take care of our business,” says Pappas.
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