DNV GL, the certifying body for semi-submersible drilling rigs, announced it will review approximately 100 rigs following a fatal rig accident with the COSLInnovator rig in December 2015.
According to a report by DNV, a limited number of rigs will have to undergo modifications or be submitted to operational limitations.
“Since the incident, we have made great efforts to identify what happened, understand how this could happen and, most importantly, implement actions to prevent similar incidents from occurring again,” said DNV GL’s Director for Offshore Classification, Ernst Meyer.
Fatal Rig Accident Brings Changes to the Industry
COSLInnovator was operating in the Troll field for Statoil when it was hit by a wave that shattered several windows on the facility’s two lower decks, killing one person.
In April this year, the Norwegian Petroleum Safety Authority issued a report saying the accident provided new information that should be used to prevent similar accidents from occurring in the future.
The accident involving COSLInnovator killed one person
Consequently, DNV GL published new technical guidelines to calculate the air gap, which is the distance between the highest wave crest and the bottom of the deck box.
“We have been working with rig owners, designers, operators and authorities towards a common goal; to ensure the safety of all those working on board the rigs”, Meyers added.
100 Rigs Will Undergo Air Gap Assessment
As a result, the certifying body asked all owners of DNV GL class semi-submersible rigs to provide updated documentation of the air gap on each unit.
The rigs that can confirm a positive air gap will be able to operate as normal, which applies to most of them.
“A limited number of rigs may not have a positive air gap, but most of these will be able to avoid changes,” Meyers added.
“The prerequisite is that they are able to document a positive air gap for a specific location, or that they simply do not have windows that may be exposed to waves,” he explained further.