In the future, wells on the Norwegian continental shelf might have to be designed so that it is sufficient to drill one relief well to stop a blowout. The requirement will create major constraints in the design of multilateral wells. Now the industry is warning that these rules will lead to higher costs and lower resource utilization. It is the Deepwater Horizon blowout in the Gulf of Mexico which has raised the issue. The suggestion that wells should be designed so that one relief well is sufficient will have "major consequences", according to the Norwegian oil and gas association. Good utilisation of resources and security are the arguments they use against the requirement proposal. - This proposal will lead to major negative consequences in terms of costs and resource utilization. In some cases, the requirement could also increase the possibility of a well incident, says Maiken Ree, HSEQ Information Manager in the Norwegian oil and gas association. A simple calculation shows what this requirement might cost for one field with subsea wells. A multilateral well with four sidetracks can have a reservoir zone of 12,000 feet. If you instead need to develop the field with individual wells, where each has a 1500 meters reservoir zone, seven individual wells must be drilled to replace the single multilateral well. In such a case, the drilling costs can increase with NOK 2 billion (€ 240 million), you can also miss resources worth over NOK 2 billion (€ 240 million), according to the Norwegian oil and gas.