A search and rescue operation is underway off the coast of Gabon following the sinking of the Borr Drilling jack-up rig Prospector 5 on Sunday. The offshore drilling contractor confirmed that the rig went down during jacking operations as it was positioned to begin a new drilling campaign.
At the time of the incident, 115 people were on board the vessel. While 110 personnel have been safely accounted for, five individuals remain missing. The company has not yet released the identities or nationalities of those still unaccounted for as emergency efforts continue at the site.
Preliminary information provided by Borr Drilling indicates that the rig suffered a “punch through” event during preload activities. In offshore drilling, a punch through occurs when one of the rig’s support legs unexpectedly pierces through a crustal layer of the seabed into a softer layer of soil underneath. This sudden loss of resistance under a single leg causes the platform to lose equilibrium and tilt sharply. According to the company, this event led to a catastrophic loss of stability and the subsequent sinking of the Prospector 5.
Preloading is a standard safety procedure in which the rig’s ballast tanks are filled to simulate its full operating weight, ensuring the legs are firmly planted before drilling begins. The failure during this critical phase suggests the seabed was unable to support the load as anticipated by the preliminary site surveys.
The Prospector 5 was under contract to support the drilling operations of BW Energy offshore Gabon. The loss of the rig is expected to impact the timeline for BW Energy’s planned campaign in the region, though the companies have not yet commented on the long-term status of the project.
Investigations into the cause of the punch through and the structural failure of the rig are expected to follow the conclusion of the search for the missing crew members. Operations in the area remain focused on the rescue mission and monitoring the site where the rig was lost.
