Director's Corner - Subsea Bolt Failures

July 20, 2016 - The conditions experienced by subsea equipment are, to put it mildly, extreme. On January 4th, 2010, a few months before the Deepwater Horizon tragedy shook the nation, a blowout preventer test demonstrated just how reliable that equipment needs to be. It was early evening, and the crew aboard the Ocean Confidence, a semisubmersible drilling rig in the Gulf of Mexico, was testing a blowout preventer (BOP). As the test approached 14,000 psi, all twenty of the 16-inch long, 3-inch diameter bolts at the connection between the upper and middle double ram BOPs suddenly failed. Luckily, this was a shipboard test, not a situation where the BOP was needed to prevent catastrophe.

Less than three years later, also in the Gulf of Mexico, bolt failures caused the Discover India’s lower marine riser package to become separated from the BOP stack. As a result, over 400 barrels of synthetic-based drilling fluids spilled into the Gulf. BSEE’s investigation into the incident concluded that hydrogen induced stress corrosion cracking due to hydrogen embrittlement led to the fracturing of the installed bolts.

These two well documented examples of bolt failures are only the tip of the iceberg.  Bolts are among engineering’s most simple creations, but they hold together most of the subsea infrastructure used in oil and gas exploration. I’m not sure anyone has counted all individual bolts involved in an offshore operation from drilling through production, but the number is in the thousands. With so much at stake during these operations, we have a responsibility to the workers and the environment to make sure that every one of those bolts can handle the stresses they are designed to withstand.

America has long been a leader in the world’s energy sector, so it is not surprising that many in the international community have taken notice of the bolt problem we identified. So far, luckily, we know of no major incidents anywhere that are related to bolt failures. However, in February of 2016, we became so alarmed by the danger the bolt problem poses to offshore operations that we issued a nationwide safety alert. We know that disaster can occur because of bolt failures, and it is up to all of us to make sure they don’t occur.

I believe that we have a real chance to put the post-Deepwater Horizon reform mentality into practice by addressing the bolt issue, and for that reason I have asked a number of BSEE staff to dedicate themselves to the bolt problem. Among the most important steps we are taking, let me point to five:

• The reporting requirements in the Well Control Rule, effective July 28, 2016, mandate reporting of all safety-critical equipment, including bolt failures. This will finally allow us to build a database and get a real sense of how often bolts are failing;
• We are working with international and domestic regulators to identify global bolt failure incidents and causes;
• We have assembled, with the American Petroleum Institute, a work group to address the bolt problem;
• Through our SafeOCS near-miss reporting system, we are now able to receive information on equipment failures directly from contractors and offshore workers;
• This year alone we have had numerous meetings and discussions with the energy industry, bolt manufacturers, API and other organizations to determine ways to improve quality assurance, manufacturing specs and proper installation and use of subsea bolts. These meetings will continue as part of the process that will lead to solving the bolt problem.

The bolt problem has probably been around for quite a while – in fact, we know of an incident dating back to 2003. That we have not had a major incident so far may be due to luck more than anything else. How long that luck will last is not a question I think any of us is comfortable answering. We have a problem, and we need to address it, with vigor, immediately. Recently General Electric became aware that some of the bolts were failing on equipment they produced. They did the right thing, and issued a global recall. That’s the kind of proactive mentality that drives a responsible company and that matches BSEE’s perspective. I am determined to dig as deeply as possible to find out exactly how widespread the bolt problem is, and to make sure we develop traceability and accountability in the chain that connects original equipment manufacturers, contractors, and operators. It will take some time before the bolt problem is solved, but at least we know we are now on the path toward a solution.

For more information on this issue visit our bolts page.