ExxonMobil Corp. replaced its proved oil and natural gas reserves in 2013 by 1.6 billion boe, a 103% replacement overall and a 153% jump in crude and liquids. However, total proved reserves, which now stand at 25.2 billion boe, are flat from a year ago.

The biggest reserve additions last year were from Abu Dhabi, which added more than 700 million bbl of crude oil. However, North America’s unconventionals brought in more than 300 million boe in 2013, with gains in the United States from the Woodford and Bakken shales, as well as the Permian Basin, along with Canada’s Montney and Duvernay formations. Other additions to proved reserves were made in the Gulf of Mexico and overseas.

The 2013 numbers didn’t increase from 2012, when ExxonMobil reported that it replaced 115% of its 2012 production, adding proved reserves of about 1.8 billion boe (see Daily GPI, Feb. 20, 2013).

However, the lean toward more oil and liquids drilling was evident in the data. Proved reserves at the end of 2013 were 53% weighted to liquids, versus 51% in 2012. Natural gas now makes up about 47% of proved numbers.

ExxonMobil added 1.2 billion bbl of liquids in 2013, with natural gas providing another 400 million boe for a 52% replacement ratio. Excluding the impact of sales, reserves additions last year replaced 106% of output, the operator said.

It’s the 20th year in a row that ExxonMobil has replaced at least 100% of its output, said CEO Rex Tillerson.

“Our industry-leading record of long-term reserves replacement demonstrates the success of our global strategy to identify, evaluate, pursue and capture high-quality opportunities,” he said. “The size and diversity of ExxonMobil’s global resource base, the largest held by an international oil company, provide us with unequaled investment flexibility to profitably develop new supplies of energy to meet future demand.”The average replacement ratio over the past 10 years, usually considered a better indicator of reserves performance because of the long-term nature of the industry, is 120%. Liquids replacement over the period averaged 104%, while natural gas replacement has averaged 141% — mostly because of the XTO Energy Inc. acquisition in 2009, which made ExxonMobil the largest gas producer in the United States.

The reserves life at current production rates is about 16 years.