Objective
On 15 December 2015, the PSA carried out an audit of Statoil's planning and execution of the TTRD (Through Tubing Rotary Drilling) method for intervention, drilling and completion of wells at Gullfaks C.
TTRD involves drilling a sidetrack well from an existing, conventional well. The greatest benefit of this method is that new reservoirs can be reached without the need to remove existing Christmas trees, production tubing or casings. TTRD wells are particularly useful for reaching isolated pockets of oil and gas on mature fields in a cost-efficient manner.
These types of well operations differ in many respects from conventional methods and may therefore entail a different risk scenario. The objective of the audit was to monitor how Statoil, along with other stakeholders, is safeguarding the planning, experience transfer and execution of TTRD operations with regard to the regulations and its own requirements.
The audit was conducted at Statoil's premises at Sandsli.
Result
No non-conformities were detected during this audit.
One improvement point was identified, relating to plans for follow-up and improvement following an earlier incident.
We have requested Statoil's evaluation of the improvement points by 6 May 2016.