This supervisory activity was conducted on 16-29 September 2022.


Equinor’s fully integrated drilling contracts (the IO3 model) introduce closer interaction than earlier between operator, drilling contractor and main supplier of drilling and well services. They also produce an overall reduction in manning for the offshore roles involved.

Information from meetings, audits and various whistleblowing reports has revealed specific challenges and risks associated with the IO3 model and its implementation. The PSA audit aimed to verify that Equinor had taken account of identified risks related to the model when introducing it on the Heidrun field in the Norwegian Sea.

Issues addressed in the audit included:

  • whether unintended negative HSE consequences have arisen from changes to operating parameters, and how the requirement for continuous improvement had been met
  • experience with technical solutions for the IO3 model and the human-machine interface (human factors)
  • assessments and measures for supporting the IO3 model – roles and responsibilities
  • emergency response to a well-control incident
  • risk related to changed work assignments
  • the status of cross-training between service company and drilling contractor
  • interaction between sea and shore.


The goal of the audit was to determine how Equinor, together with drilling contractor Odfjell Drilling and service provider Halliburton, manages major accident and working environment risk in the light of changes to operating parameters in contracts on fixed facilities.


The audit identified seven nonconformities from the regulations. These covered:

  • Equinor’s follow-up of IO3 on Heidrun
  • continuous improvement
  • decision basis for changes to IO3 manning on Heidrun
  • roles and responsibilities in the IO3 model
  • facilitating monitoring and control between sea and shore
  • analyses of risk conditions
  • management of expertise.

What happens now?

The PSA has asked Equinor to explain by 31 January 2023 how these nonconformities will be handled.