"The survey of well integrity on the Norwegian shelf revealed a number of defects and shows that both the industry and the authorities must reinforce their efforts in this area. We see a substantial potential for improvement, both as regards safety and improved recovery/value creation," say Birgit Vignes and Jan Andreassen. The PSA collegues are responsible for the study which as resulted in a report that can be downloaded from the PSA's website (see link box).
This is the first such comprehensive study of well conditions on the Norwegian shelf. Moreover, the Petroleum Safety Authority Norway is not aware of any other such thorough studies of well integrity in other offshore provinces.
406 wells studied
|- In Norway we have achieved a unique
openness regarding well integrity challenges.
We dare to talk about the problems, and the
industry shows a willingness to share its
experiences say Birgit Vignes and Jan Andreassen
The objective of the project was to improve handling of well integrity issues on the Norwegian shelf, both by giving the authorities and the industry increased knowledge and the motivation to reinforce their efforts in this field.
The study was carried out by obtaining information on well integrity from seven oil companies. A total of 406 active injection and production wells from 12 facilities were studied. There are no indications that well conditions are different on other facilities on the Norwegian shelf.
The results show that as many as 18 percent of the wells studied have some form of weakness/uncertainty as regards well integrity. Lack of well integrity can have disastrous safety consequences, with a blow out being the worst case scenario if the operator does not have a full overview of well condition at all times.
Of the 18 percent with weakness/uncertainty, 7 percent of the wells are completely shut in due to integrity issues. The consequence for these wells is loss of production worth billions of kroner, as the petroleum deposits in the reservoirs are not being produced.
"Worst wells" from the 1990s
The study also showed that wells drilled in the 1990s are over-represented as regards weaknesses in well integrity.
"This is surprising, since well integrity challenges are often linked to aging problems. There may be many reasons why we see so many weaknesses in wells drilled in the 1990s, but we cannot rule out a connection with the high level of activity during this period, in combination with cutbacks and focus on costs," say Vignes and Andreassen. Potential measures will be evaluated in Phase 2 of the project.
Among other things, the report points out four areas where improvements are needed:
Openness is important
None of the seven companies that took part in the study are flawless as regards safeguarding well integrity. At the same time, the PSA notes that there seems to be a renewed commitment to this area. The Snorre blowout in November 2004 was a very serious reminder of just how wrong things can go, and it may have contributed to the companies renewing their focus in this area.
"In Norway we have achieved a unique openness regarding well integrity challenges. We dare to talk about the problems, and the industry shows a willingness to share its experiences. This is promising as regards improving safety, but it is also a prerequisite if we are to achieve improvement," say Vignes and Andreassen.
"It is also positive that the industry sees good opportunities for mutual benefits by joining forces to find common solutions in certain areas. The industry must find a standardization solution that contributes to better documentation and overview of the conditions in the wells," say Vignes og Andreassen, and add that the challenges linked to safe wells also require cooperation and standardization efforts across shelf borders.
Facts about the PSA's well integrity project
Press contact in the PSA:
Phone +47 970 54 064