US supermajor ExxonMobil has said that new plays in North America made up the bulk of the 1.8 billion barrels of oil equivalent (boe) in new proved reserves it added over 2012.
The Irving, Texas-based giant said that the liquids-rich Woodford and Bakken plays onshore the US had added almost 750 million boe in new reserves.
Canada saw more than 600 million boe in new reserve stock for ExxonMobil, including the Nabiye oils sands expansion project in Cold Lake, Albert and the Hebron offshore heavy oilfield off Newfoundland and Labrador.
Australia, Angola and Kazakhstan were further key contributors to the annual tally, which represents a 115% replacement ratio to last year's output.
At year-end 2012, ExxonMobil's proved reserves totalled 25.2 billion boe, of which 51% was liquids and 49% natural gas.
New resources added through the drill-bit included conventional discoveries in Romania, Tanzania, Nigeria, Australia and Papua New Guinea, as well as discovery and delineation at North American unconventionals, ExxonMobil said.
Earlier this month, the explorer reported an increase in annual profits to $44.88 billion from 2011’s $41.06 billion as a leap in downstream earnings made up for a dip in upstream profits over lower production and prices.