Revenue (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure Of Revenue [Abstract]

Disclosure Of Detailed Information On Revenue [text block]

Amounts in US$ '000	2017		2016		2015
Sale of crude oil		279,162		145,193		162,629
Sale of gas		50,960		47,477		47,061
		330,122		192,670		209,690