Faulty bolts could sideline offshore drilling rigs

FEBRUARY 7, 2013—In a Safety Alert on January 29, the Bureau of Safety and Environmental Enforcement (BSEE) directed the suspension of operations of offshore drilling rigs in the Gulf of Mexico that use GE-manufactured bolts on the Lower Marine Riser Package to connect the Blowout Preventer (BOP).  Before returning the rigs to service, the bolts would have be certified by an independent third-party to be in compliance with recommended heat-treatment practices or the existing bolts would have to be examined and certified by an independent third-party that they are fit for purpose.

The faulty bolts came to light during a BSEE meeting with industry on January 24 which reviewed a pollution incident involving the discharge of synthetic base mud (SBM) into the Gulf of Mexico (GOM) due to a loss of integrity of a LMRP H-4 connector. During the meeting, a qualified third-party presented preliminary evidence that the stress corrosion cracking caused by hydrogen embrittlement was a contributor to the incident.  Zinc electroplating without proper baking, as per ASTM B633, was cited as a possible cause of the hydrogen embrittlement.  During the meeting, BSEE was informed of two other rigs as having H-4 connector bolt failures.

BSEE recommended that operators should make an inventory of their contracted rigs [currently involved in well operations in the GOM Outer Continental Shelf or planned to conduct well operations in the GOM] and investigate the bolts of the LMRP and Wellhead connectors. 

For detailed instructions on identifying affected bolts please refer to the Safety Notice issued by GE Oil and Gas on January 25, 2013, titled,  “H4 Connector Bolt Inspection Required(P/N H10004-2)” at the following: http://www.ge-energy.com/connector-update.jsp

Operators with H-4 connectors, as identified in GE’s safety notice, and that have been verified through documentation that the connector contains any affected bolts, should immediately notify BSEE.  You should also consult with your contractors and subcontractors to determine the appropriate inspection, disposition and corrective actions.  BSEE will require an independent third-party certification that confirms proper inspection and refurbishment processes were completed prior to reinstallation of any affected bolts.   

Operators should review the QA/QC programs for all equipment vendors (contracted and subcontracted) to ensure that all equipment is being manufactured to the required specifications.   

Special attention should be given to ensure proper heat treating has taken place in accordance with the specifications.

As a result of the news, Investment banker Dahlman Rose says share prices of the offshore drilling group were coming under pressure and could be negatively affected for the first quarter by this work stoppage depending on the length of the downtime associated with the maintenance.

Dahlman Rose says Diamond Offshore has already stated that it will replace the bolts on 30 BOPs, representing two-thirds of its fleet. Each repair is expected to take one day per BOP and be completed within six weeks. This would include rigs that are not located in the GOM.

Other operators are determining which LMRP connectors are using the faulty GE bolts and, therefore, need to be replaced.