Mumbai High North Platform Disaster

Abstract

The Mumbai High oil field is located in the Arabian Sea, 160km west of the coast of Mumbai, India. The field is operated by Indian operator Oil and Natural Gas Corporation (ONGC) and is the largest oil field in India. Located in the field’s northern block was a production complex, 100km from shore, consisting of four bridge-linked platforms. The Mumbai High North (MHN) platform was constructed in 1981 and outfitted for production of 80,000 barrels of crude oil per day. In July 2005, a multipurpose support vessel (MSV) was completing a diving campaign at MHN when a crewmember was injured. Upon recovery of the diving bells, the MSV requested the injured employee to be transferred to the platform. Weather conditions were unfavourable the day of the event, with monsoon rains and high winds, prohibiting the use of the MHN’s helicopter. The leeward crane of MHN was out of commission at this time, so the vessel began to approach the platform on its windward side. During the approach, the master had noted that the starboard thrusters pitch was slow moving. After the injured crewmember was successfully transferred to the platform, the MSV experience a heave from ongoing ocean swells and struck several marine risers. The resulting gas leak ignited rapidly and spread to adjacent risers with no fire protection. Fluid flow in the risers was not contained by emergency shutdown valves due to their overall length. Rescue operations were unsuccessful in recovering 22 lives that day. At the time of this incident, no regulatory body or organization for the governance of offshore safety in oil and gas existed in India. Serious issues concerning the platform and it’s export risers, as well as lack of risk mitigation aboard the MSV, were discovered. Shortly after the incident, U.S. governing bodies signed an MOU with the Indian petroleum directorate to share common knowledge and develop comprehensive rules and regulations.