Risk assessment of low wellhead fatigue life

Justifying operations without costly intervention


A well operator needed to perform drilling operations despite analysis identifying low wellhead fatigue life.

DNV GL solution

The solution used DNV GL’s broad expertise in wellhead fatigue and followed the recommended practice DNVGL RP-0142 which included:

  • Reviewing the fatigue report, assessing conservative assumptions, erroneous inputs and invalid assumptions, which may invalidate, or compromise reported fatigue life 
  • Facilitating FMECA risk assessment workshops for the operations, reservoir, HSE, and wells disciplines from the operator. Each sub-assembly was reviewed in turn according to associated failure modes. The consequences of fatigue related failures were reviewed in detail.

Outcome and benefits

Areas of challenges were identified and technical recommendations produced, providing an action plan for the customer to gain assurance that drilling activities could be carried out safely. This course of action was far cheaper and quicker than any other alternative, which would have involved significant project changes.