Lessons Learned: Anchor-Handling Failure Leading to Gas-Release Incident

The Bureau of Security and Environmental Enforcement (BSEE) investigated a gas-release incident within the Gulf of Mexico. The case highlights anchor-handling dangers throughout offshore operations and gives classes to enhance planning, communication, and procedural compliance.

What Occurred

A diver assist vessel (DSV) was engaged in recovering two bow anchors from the seafloor close to a subsea nicely website forward of recompletion work by a jack-up rig. Whereas maneuvering down present, the vessel’s No. 1 bow-anchor wire grew to become entangled within the nicely. Regardless of repeated efforts to free the wire, it snagged on the annulus-valve meeting, shearing a number of studs and detaching the valve from the tubing spool. This precipitated a major fuel plume to succeed in the floor. The DSV retreated roughly 1,900 ft, and an emergency response was initiated. Nevertheless, a number of key preparation steps had not been accomplished by the lease operator earlier than mobilization.

Why It Occurred

The incident occurred as a result of insufficient planning and coordination between the operator and contractor. A simultaneous operations (SIMOPS) assembly and hazard evaluation weren’t carried out, and the Security and Environmental Administration System (SEMS) plan didn’t clearly outline when such steps had been required. Communication failures compounded the scenario, as key personnel weren’t knowledgeable when the job started or what duties had been being carried out. The absence of an anchor tug made it tough for the vessel to carry place in sturdy currents, rising the chance of entanglement. As soon as the emergency occurred, response efforts had been hindered as a result of essential drawings weren’t available and the substitute valve was not configured for diver dealing with, delaying the securing of the discharge.

Actions Taken

Corrective actions targeted on enhancing procedural readability, tools readiness, and communication. These included the advice for pre-job checklists, clearer SEMS necessities, higher contingency planning, and stakeholder coordination earlier than mobilization.

Classes Discovered

Use a pre-job guidelines to substantiate all preparatory steps, together with marking pipelines and contemplating climate or delays.
Revalidate all essential steps if delays happen earlier than remobilizing.
Conduct formal SIMOPS and hazard assessments to determine and management dangers.
Maintain a pre-mobilization evaluate with all stakeholders to substantiate scope, readiness, and security measures.
Guarantee clear communication between vessel crews, contractors, and operators at each stage.
Embody anchor-handling methods that account for currents and vessel drift.
Affirm that essential documentation is out there onboard earlier than operations.
Guarantee subsea set up or restore planning entails divers instantly.
Present refresher coaching on offshore planning, communication, and procedural compliance.
Replace SEMS protocols to outline when SIMOPS and hazard assessments are necessary.