Resources and proved reserves


Report April 2, 2019

In this article

Resources and proved reserves


Commercial discoveries exceed average of IOC competitors by nearly 2 billion oil-equivalent barrels since 2013
(Source: Wood Mackenzie.)

ExxonMobil added nearly 1.3 billion oil-equivalent barrels in 2018 through successful exploration and strategic acquisitions. More than 700 million barrels were added through highly attractive by-the-bit discoveries in Brazil and Guyana that add to existing planned developments. These resource additions provide low cost-of-supply opportunities for future profitable volumes growth. Furthermore, we added more than 2.2 billion oil-equivalent barrels through net revisions, largely driven by our unconventional assets.

The size and diversity of our global resource base provide us with investment flexibility to profitably develop new supplies of energy to meet growing demand.

Resource additions(2)

(percent, oil-equivalent barrels added)

Resources base changes(2)

(billions of oil-equivalent barrels) 2018 5-year
Resource additions 1.3 3.6
Revisions to existing fields 2.2 (0.3)
Production (1.4) (1.5)
Asset sales (0.9) (0.4)
New change versus year-end 2017 1.1 1.4


(2) See Frequently used terms



Stabroek block resource estimate increases to 5 billion barrels after 10th discovery

The discovery of more than 5 billion gross oil-equivalent barrels in less than four years is a testament to ExxonMobil’s technical expertise and rigorous evaluation processes. These capabilities enable the pursuit of high-potential opportunities in frontier areas like Guyana. In 2018, we made five discoveries at Hammerhead, Longtail, Pacora, Pluma, and Ranger. We are evaluating development options in the southeastern portion of the block, with the potential to combine Pluma with prior Turbot and Longtail discoveries into a major new development area.

Learn more about our project in Guyana

Proved reserves

Our proved oil and natural gas reserves total approximately 24 billion oil-equivalent barrels. These reserves represent a diverse portfolio distributed across geographic regions and development types, with liquids comprising 64 percent, up from 57 percent in 2017. Proved developed reserves, or reserves with installed production facilities, account for 68 percent of the proved reserves base. Our average reserves life is approximately 17 years at current production rates.

Employees discuss construction progress at the Perla Negra tank battery in the Delaware Basin, one of many facilities designed to support our development plans in the Permian.

Proved reserves additions in 2018 replaced approximately 313 percent of production. We added approximately 900 million oil-equivalent barrels of proved reserves associated with project and drilling activities, field performance, acquisitions, and sales. As a result of higher crude oil prices in 2018, approximately 3.6 billion oil-equivalent barrels, including bitumen at Kearl in Canada, qualified as proved reserves additions at year end.

ExxonMobil has a successful track record of proved reserves replacement. Over the past 10 years, we replaced 108 percent of the reserves we produced, including the impact of asset sales. Looking forward, we will continue to develop the most profitable resource opportunities as we progress our inventory of nearly 100 projects. Our development planning organization collaborates with our technology organization to create innovative concepts that maximize value from development projects.

Proved reserves distribution(1)

(percent, oil-equivalent barrels)

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The size and breadth of our business provides a critical foundation for long-term success. It enables investments in the development of advanced technologies by leveraging benefits across a large base of operations. Facilities and businesses operated consistently around the globe accelerate experience and learning – replicating innovations, improving effectiveness, and driving down cost. Our size allows us to pursue a wide range of value-accretive investments across the commodity price cycle – specifically taking advantage of counter-cyclical opportunities.

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Technology has led to the development of industry-advantaged assets, processes, products, and applications. We invest in fundamental science and research, leading to advances in existing processes and products, as well as new discoveries. This allows us to meet the evolving needs of society, lower operating and project costs, and develop higher-value processes and products.

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Strong business fundamentals underpin investments

Our view of global energy and product demand and supply through 2040 informs long-term strategies and investments.

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We maximize value across the entire value chain, ensuring the whole is greater than the sum of the parts. The different sectors we serve and products we make provide further diversification, helping to mitigate the impact of commodity price cycles. Our integrated business provides additional scale, allows us to share support organizations and facility infrastructure, and capture synergies in organizational capabilities and competencies.

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