Safe and effective plugging of wells at Valhall

Maersk Invincible has completed the plug and abandonment (P&A) programme of wells at the Valhall field centre much sooner than planned, with no harm to people, equipment or the environment – and zero CO2 and NOx emissions.

Since May 2017, Maersk Invincible has plugged a total of 14 wells at the original drilling platform (DP). In the period 2014-2016, the first 12 wells on DP were plugged – at the time using the Maersk Reacher drilling rig.

The P&A work has been completed much faster than planned. For example, the average time per well has been reduced by 50 per cent compared with the first phase, despite a rise in the complexity of the wells towards the end of the campaign.

“We had a fantastic team in place, both onshore and offshore, many of them going back to when the P&A programme started with Maersk Reacher. The collaboration with Maersk Drilling, as with the service companies, has been excellent. Throughout the campaign, there has been a continuous search for improvements”, says Aker BP’s SVP Drilling and Wells, Tommy Sigmundstad.

Maersk Invincible has now moved to Valhall Flank North, where it will drill an injection and a production well.

Long-term plans for Valhall

Plugging wells on the DP platform is a key part of the work to modernize the Valhall field centre. The three original platforms from when the field started producing in 1982 – QP, DP and PCP – will be removed. Four wells remain to be permanently plugged prior to the removal of the DP platform.

“For the development of Valhall, the success of the P&A campaign is crucial. Above all, permanent plugging makes a key contribution to HSE because it secures the non-producing wells. In addition, the P&A team has completed its operations quickly and efficiently. This means lower costs and shorter run times”, says Vice President for the Valhall Asset, Per Mikal Hauge.

The remaining platforms at the field centre – IP, WP and PH – as well as the Flank platforms will produce for many, many years to come.

Zero CO2 and NOx emissions

Maersk Invincible has been supplied with electricity through the Valhall field when conducting the P&A scope. It is probably the first time ever a drilling rig has been powered fully from shore.

Calculations show that electrification of the drilling rig has reduced the annual local emissions by 15,200 tonnes of CO2 and 168 tonnes of NOx.

This has been a pioneer project for Aker BP, underpinning the company’s strategy of developing solutions that contribute to minimizing the environmental consequences of our activities.