This geographical division of the markets for mineral oil does not, however, preclude the possibility that the main importers may also seek to gain a foothold in other oil producing areas in order to avoid any possible interruptions in supply due to political or military factors In 1977 as much as 22 % of the oil recovered came from the Continental Shelf areas.
Le yantukwano yemarike ngokobume benzululwazi yelizwe yezembiwa ze-oyile ayinqandi ukuba kunokwenzeka ukuba abangenisi abazintloko bangafuna inzuzo yokuxhathisa kwezinye ingingqi ezingenisa i-oyile ukuphepha iziphazimiso azinokwenzeka kuxhobisa ngenxa yemeko yezopolitiko nomkhosi ngo 1997 kangange 22% ye-oyile ebhaqwe ivela kwingingqi zelizwekazi iShelf.