Incidents occurring during decommissioning

Given the increased focus in recent times on decommissioning of older installations and equipment, IMCA has put together a summary of incidents relating to decommissioning, that may be of interest to members.  This summary includes a number of events or incidents over the last fifteen years that have involved decommissioning activities. 

A brief breakdown of those events or incidents in which one of the IOGP Life-saving Rules was broken (not all of them) indicates the following:

• Safe mechanical lifting – 5
• Bypassing safety controls – 4
• Line of fire – 3
• Working at height – 2
• Work authorisation – 1

Further information on decommissioning of offshore structures can be found in Appendix 5 of IMCA LR 006, HSSE 019, D 060, M 187 – Rev. 2.1 Guidelines for Lifting Operations.   

• Saturation diver exposed to chemicals from pipeline – February 2025

During pigging and decommissioning operations, a saturation diver was exposed to the contents of a pipeline, which was chemically treated seawater.

• UK HSE: Incident during rig decommissioning leads to fatality – October 2024

Two men were working ashore as demolition operatives on decommissioning and dismantlement of offshore structures. The two workers were removing an overhanging piece of metal pipework (known as a skirt pile), weighing in excess of 27 tonnes, from a gas rig jacket when it gave way. The pile struck the mobile elevating work platform (MEWP) containing the men, throwing them to the ground about 12 metres below.

•  Offshore platform decommissioning near miss – September 2024

There was a near miss incident for two workers beneath a swinging suspended load while decommissioning part of a monopod offshore platform in the northern waters of Western Australia. The workers were cutting through the monopod’s main leg (caisson) when the topside, which was rigged to a crane on a vessel, unexpectedly moved and detached from the supporting monopod and swung over the workers.  

• Person struck and injured during lifting operations – March 2024

During decommissioning activities on board a spar, where a fire water pump skid had to be removed, the skid unexpectedly came free and made contact with an adjacent nitrogen vessel, which had previously been cut 95% loose. The sudden and unplanned release of energy led to the nitrogen vessel tank striking someone in the line of fire. He fell backwards, hit his head and fell, and was medevaced to a hospital onshore.

• BSEE: Overhaul Ball falls to deck resulting in High Potential near miss – July 2023

While conducting crane operations during decommissioning/well abandonment, a 350kg crane “headache ball” fell 8m to deck and landed less than 60cm from one of the riggers.     

• Hydraulic Oil Leak to Sea from Downline Fitting – November 2022

During decommissioning, cutting work was being conducted using a diamond wire saw. A third-party supplier’s technician noticed a sudden drop in pressure, and it was discovered that 100 litres of hydraulic oil had been released to sea.

• LTI: Diver suffered crush injury to finger – September 2022

A diver sustained a crush injury to his finger when a diving support vessel was working on a decommissioning project. Divers were working to re-instate a side panel on a subsea tree. While the diver’s hand was positioned between the panel and the tree, the vessel heaved, causing movement on the panel, causing the diver’s finger to be crushed. The diver sustained a fracture and laceration to his right-hand ring finger, resulting in an LTI.

• UK HSE: worker falls from height during oil platform decommissioning – April 2022

A worker involved in the dismantling of the Brent Bravo platform in the North Sea fell 15m when part of the platform unexpectedly collapsed owing to corrosion affecting the structural integrity of the platform.

• Rigging failure during riser recovery – soft slings parted – February 2021

During decommissioning activities, there was a recovery of a 10m riser section with buoyancy modules attached. The riser section dropped 2.5m to deck when the soft slings parted after rubbing on the sharp edge of the Deadman Anchor (DMA. Control measures were being followed with all personnel standing clear of the lifting area, and no-one was injured.

• Dropped wooden block in conductor support frame – September 2019

During a decommissioning project, a wooden wedge, weighing approximately 13 kg, dropped 6m, striking a rigger’s hard hat and shoulder on its way down.  The rigger suffered minor cuts; it was fortunate that his injuries were not more serious. 

• Load exceeding safe working load (SWL) leads to overstressed and damaged rigging – September 2017

During decommissioning operations, shears were used to cut a pipeline. The shear tool was rigged to the crane in a vertical fashion. The shear tool was placed on the pipeline at the cut location and when the shear jaws closed around the pipe to make the cut, the shear tool was pulled downward due to the ‘bird’s beak’ design of the jaws. As a result, the load quickly increased the tension on the rigging over the safe working limit (SWL) of the rigging resulting in damage (deformation) to the rigging. There was property damage but no injuries.

• Diver loss of consciousness during underwater burning activities – November 2016

A diver lost consciousness during underwater burning activities during decommissioning and removal of a subsea structure. The diver was nearing completion of the final horizontal cut on the securing collar doubler plate when a suspected ‘blow back’ occurred. This ‘blow back’ is believed to have caused the diver to lose consciousness.

• Fall fatality during platform abandonment – July 2012

An offshore employee was fatally injured while assisting in plugging and abandonment of a well and decommissioning a production platform. The incident occurred at night; the worker, working at the top of the well, was dragged by a load into an exposed well-access opening in the deck, and fell to his death.