§ Mr. Sillarsasked the Secretary of State for Energy how many potential oil bear- 712W ing structures there are in the Scottish sector of the North Sea; how many remain unexplored; and how many such structures are known to exist off the Scottish West coast.
§ Dr. J. Dickson MabonAs I said in answer to a Question on 15th November 1976, there are no sectors within the United Kingdom Continental Shelf, but because of the three systems of law in the United Kingdom it is necessary to define the areas of their respective jurisdictions. The resulting divisions are solely for this purpose.
It is not possible to be certain how many potential oil-bearing structures there are in the United Kingdom sector of the northern part of the North Sea. About 900 geological structures have been identified, but a large proportion of these are so small that even if they do contain petroleum, the quantities will be insufficient for commercial exploitation. Over 250 have been tested. Seismic surveys continue to be carried out and will further assist in the evaluation of this area.
Much of the area to the west of Scotland is underlain by very old rocks at shallow depth which are not of the type to contain petroleum, but the area is as yet unlicensed and a proper evaluation is not yet possible.