Beleaguered Tullow Oil said on 15 January it expects to report pre-tax impairments and exploration write-offs of about $1.5bn in its 2019 results in March, mainly due to a $10 reduction in the group’s long-term accounting oil price assumption to $65/barrel and a reduction in 2P reserves at the TEN development in Ghana.Chief financial officer Les Wood told a conference call with analysts the $1.5bn was made up of $700m of impairments, for the oil price and reduction in the Enyenra field reserves, plus $800m of exploration writeoffs, notably for recent wells offshore Guyana.