Gå til hovedinnhold

Supervision of the use of radioactive sources on Heidrun

In the period 10 - 12 December 2002 and 26 - 28 March 2003, and 5 May 2003 the Norwegian Petroleum Directorate and the Norwegian Radiation Protection Authority conducted a supervision activity for "use of radioactive sources" - Heidrun and Statoil.

The supervision was directed towards Statoil Stjørdal / Statoil Stavanger (STA) and their suppliers, the contractor companies Baker Hughes Inteq (BHI), Schlumberger Oilfield Service (SLB), represented by Anadrill, and Prosafe Boring (PRO).
Verifications were made on board the Heidrun TLP installation (photo).

Background for the supervision

Handling of radioactive sources is a risky activity. The number of incidents with loss of radioactive sources in wells has increased. There is an increasing trend to the effect that sources are being left in the wells, which could lead to unfortunate consequences for subsequent production.

The purpose of the supervision

The purpose of the supervision was to verify that the operator and contractors handle radioactive sources in connection with well and drilling activities in compliance with, regulations, company procedures, governing documents for this type of activity, and whether one seeks to use alternative non-radioactive logging methods.

The authorities' objective is to motivate so that the use of radioactive sources is reduced and alternative equipment is developed.

In addition we wanted to verify that the use of permanently mounted radioactive control sources on board complied with current requirements from the Norwegian Radiation Protection Authority.

The result of the supervision

Our main impression following the supervision is that radiation protection is reasonably well safeguarded on Heidrun.

Statoil seems to keep informed about the radioactive sources on board at any given time and their use, as well as checking that the operators of equipment with logging sources are authorized.

Inspection of control sources seems to be well safeguarded. When logging sources are used the supplier's procedures and guidelines are followed. Knowledge of these among Statoil's personnel is limited.

We noted that Statoil's management takes a positive view of the use of alternative methods due to HES gains in relation to the use of traditional radioactive sources. The technical expertise, however, believe that current technology does not provide accurate enough measurement data when alternative methods are used.