Exxon Mobil Corporation Announces 2012 Reserves Replacement Totaled 115 Percent

Exxon
Mobil Corporation (NYSE:XOM) announced today it replaced 115 percent
of its 2012 production by adding proved oil and gas reserves totaling
1.8 billion oil-equivalent barrels, including a 174 percent replacement
ratio for crude oil and other liquids.

'ExxonMobil′s industry-leading record of long-term reserves replacement
is a result of our strategic focus on quality resource capture,
disciplined investment and excellence in project execution,? said Rex W.
Tillerson, chairman and chief executive officer. 'Replacing production
with new sources of oil and gas enables ExxonMobil to develop new
supplies of energy that will be critical to support future demand,
economic growth and improved living standards.?

At year-end 2012, ExxonMobil's proved reserves totaled 25.2 billion
oil-equivalent barrels, which was made up of 51 percent liquids and 49
percent natural gas. At year-end 2011, ExxonMobil's proved reserves base
was 24.9 billion oil-equivalent barrels, made up of 49 percent liquids
and 51 percent gas.

Liquid additions during 2012 totaled 1.4 billion barrels or 174 percent
of production and natural gas additions totaled over 400 million
oil-equivalent barrels for a 56 percent replacement ratio. Excluding the
impact of asset sales, reserves additions during 2012 replaced 124
percent of production.

It was the 19^th consecutive year that ExxonMobil replaced
more than 100 percent of its production. The average replacement ratio
over the past 10 years -- considered a better indicator of reserves
performance due to the long-term nature of the industry -- was 121
percent. Liquids replacement over the period averaged 102 percent and
natural gas replacement averaged 145 percent. The reserves additions
made over the 10-year period comprise a diverse range of resource types
and have broad geographical representation. ExxonMobil′s reserves life
at current production rates is 16 years.

Reserve additions in 2012 from the liquids-rich Woodford and Bakken
plays in the United States totaled almost 750 million oil equivalent
barrels. Proved reserves additions in Canada, including performance
revisions and the Nabiye expansion project at Cold Lake, Alberta, and
the Hebron project offshore Newfoundland and Labrador, added more than
600 million oil-equivalent barrels. Other additions to proved reserves
were made in Australia, Angola and Kazakhstan.

Reserves additions in 2012 reflect new developments with significant
funding commitments as well as revisions and extensions of existing
fields resulting from drilling, studies and analysis of reservoir
performance. The annual reporting of proved reserves is the product of
the corporation′s long-standing, rigorous process that ensures
consistency and management accountability in all reserves bookings.

During 2012, ExxonMobil added 4 billion oil-equivalent barrels to its
resource base, driven primarily by resource additions in the United
States and Canada, as well as Romania, Tanzania, Nigeria, Australia and
Papua New Guinea. Additions include continued success in by-the-bit
exploration discoveries, undeveloped resource additions and strategic
acquisitions. ExxonMobil′s by-the-bit conventional exploration success
in 2012 included discoveries in Romania, Tanzania, Nigeria, Australia
and Papua New Guinea. In addition, discovery and delineation of North
American unconventional assets contributed to the resource base.
Overall, the corporation′s resource base totaled 87 billion
oil-equivalent barrels at year-end 2012, taking into account field
revisions, production, and asset sales. The resource base includes
proved reserves, plus other discovered resources that are expected to be
ultimately recovered.

CAUTIONARY NOTE: Proved reserves in this release, for 2009 and later
years are based on current SEC definitions, but for prior years the
referenced proved reserve volumes are determined on bases that differ
from SEC definitions in effect at the time. Specifically, for years
prior to 2009 included in our 10-year average replacement ratio,
reserves are determined using the SEC pricing basis but including oil
sands and our pro-rata share of equity company reserves for all periods.
Prior to 2009, oil sands and equity company reserves were not included
in proved oil and gas reserves as defined by the SEC. For years prior to
2009 included in our 19 straight years of at least 100 percent
replacement, reserves are determined using the price and cost
assumptions we use in managing the business, not the historic prices
used in SEC definitions. Reserves determined on ExxonMobil's pricing
basis also include oil sands and equity company reserves for all periods.

The reserves replacement ratio is calculated for a specified period
utilizing the applicable proved oil-equivalent reserves additions
divided by oil-equivalent production.

The terms 'resources? and 'resource base? include quantities of
discovered oil and gas that are not yet classified as proved reserves
but that are expected to be ultimately recovered in the future. The term
'resource base? is not intended to correspond to SEC definitions such as
'probable? or 'possible? reserves.

The term 'project? as used in this release does not necessarily have the
same meaning as under SEC Rule 13q-1 relating to government payment
reporting. For example, a single project for purposes of the rule may
encompass numerous properties, agreements, investments, developments,
phases, work efforts, activities, and components, each of which we may
also informally describe as a 'project.?

About ExxonMobil

ExxonMobil, the largest publicly traded international oil and gas
company, uses technology and innovation to help meet the world′s growing
energy needs. ExxonMobil holds an industry-leading inventory of
resources, is the largest refiner and marketer of petroleum products,
and its chemical company is one of the largest in the world. Follow
ExxonMobil on Twitter at www.twitter.com/exxonmobil.

ExxonMobil

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