Blackford Dolphin

DNV is set to introduce new plugging and abandonment (P&A) guidelines for offshore wells, which are expected to result in reduced costs of 30%-50%.

The certification body said that that optimised project execution and new technology could offer a cost saving of $32bn in the Norwegian Continental Shelf (NCS) alone.

In next 40 years, the cost on the Norwegian Continental Shelf (NCS) alone is estimated to be Nkr1,870bn ($108bn).

In its upcoming guideline, the company will use accepted risk-approach methodology taking into consideration environmental, as well as safety risk aspects.

According to DNV, P&A of offshore wells represents a significant cost to operating companies and national authorities.

Authorities are required to decommission the offshore wells when they find no production from an oil or gas reservoir or if it is no longer profitable.

Using the process, migration of hydrocarbons to the surface can be avoided.

"This means that hazardous wells will get the attention they deserve, and benign wells will avoid excessive rig-time and expenditure."

DNA estimates that there are around 2,350 wells in the NCS that will require P&A, and 3,000 more wells are set to be drilled in the future.

There are close to 5,000 offshore wells in the UK that need to be decommissioned.

DNV GL oil and gas senior principal engineer Per Jahre-Nilsen said: "With current practices, the wells on the NCS will require the deployment of 15 rigs full-time over the next 40 years.

"Based on the 2013 cost, this is equivalent to more than a tenth of the current value of Norway’s sovereign wealth fund (GPFG)."

Said to be under development, DNV’s new guidelines are expected to be released in the second half of this year.

"This means that hazardous wells will get the attention they deserve, and benign wells will avoid excessive rig-time and expenditure."


Image: Blackford Dolphin. Photo: © DNV GL AS.