Canadian Overseas Petroleum says it and its partner ExxonMobil on block LB-13, offshore Liberia, West Africa, are to relinquish the block.
The two have elected not to enter into third exploration period and surrendered their rights to the LB-13 license, resulting in the expiration of the LB-13 production sharing contract on 25 September.
Last year, ExxonMobil's deepwater Mesurado-1 exploration well on block LB-13 failed to find hydrocarbons. The well was Exxon's first in the country and was drilled 50mi offshore Liberia in 2500m water depth, using Seadrill's West Saturn drillship.
The well, targeting oil in a sequence of Late Cretaceous Santonian aged sands, intersected 145m (475ft) of net sand of which 118m (387ft) was deemed to be reservoir quality. But, no hydrocarbons were indicated by the logging while drilling operations performed across the targeted intervals.
COP said the relinquishment will result in an impairment of its exploration and evaluation assets amounting to US$15.6 million.