Norway: Temporarily Abandoned Wells Pose Environmental Threat

The Petroleum Safety Authority Norway (PSA) acquired and processed information from eight operating companies that are responsible for the 193 temporarily abandoned wells on the Norwegian shelf. The survey shows that 38 per cent of these wells do not have two intact barriers pursuant to the intention in the regulations.

In February 2011, the PSA received documentation pertaining to well integrity status and the companies’ future plans for the temporarily abandoned wells on the Norwegian continental shelf. Temporarily abandoned wells are defined as all wells/wellbores, with the exception of active development wells (production/injection wells) and wells that have been permanently plugged and abandoned pursuant to regulatory requirements.

Along with consultants from Sintef and Wellbarrier, we have reviewed and analysed the documentation received. The analyses were carried out based on regulatory requirements, NORSOK standard D-010 and the Norwegian Oil Industry Association’s (OLF’s) guideline no. 117 relating to well integrity. The analyses reveal inadequacies and weaknesses as regards the companies’ compliance.

The analysis shows that 74 of the 193 (38%) temporarily abandoned wells are in the well integrity categories ”red, orange and yellow” according to OLF guideline no. 117, which corresponds to various degrees of barrier failure. In addition, the analysis has revealed that a number of these wells have been temporarily abandoned over a very long period of time.

“We have asked the relevant operating companies to review the reports and to address the identified conditions, both specifically for the individual company and in general for the industry. We assume that the companies will implement measures to improve the integrity of the temporarily abandoned wells, so they satisfy the “green” category criterion with intact well barriers. The companies must also assess their practices as regards a time perspective for temporary abandonment of wells.“, PSA said on its website.

The companies are obliged to submit their assessment of the conditions identified in the reports, and the measures the company will implement by 1 November 2011.

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Source:PSA Norway , October 6, 2011