Infographic: Platts Analytics sizes up oil's carbon intensity from North Sea to Venezuela

Oil pumped offshore Norway and the US Gulf Coast continued to rank among the lowest in carbon intensity while crude from Venezuela's Orinoco Belt and a few fields in California, Canada and the Middle East were among the biggest emitters, according to the latest calculations by S&P Global Platts Analytics.

The updated rankings published Feb. 15 look at the carbon intensity of 104 crude streams across the world, with values expressed in kilograms of carbon dioxide equivalent per barrel of oil equivalent.

Many oil and gas producers are scrutinizing the emissions impact of their portfolios to determine which fields will have staying power as fossil fuel investment shrinks. Carbon pricing and other climate policy could create a premium for the least-intensive crude streams.

The Oil and Gas Climate Initiative, a CEO-led consortium of companies responsible for about one-third of global production, has set targets to reduce upstream carbon intensity to 17 kgCO2e/b by 2025 and bring an end to routine flaring by 2030. Of the 104 fields ranked by Platts Analytics, 39 would currently meet the 2025 target.

Producers are reducing upstream emissions through cogeneration facilities, modernizing compression plants, improving leak detection, ending venting and reducing flaring.

Environmental groups say the efforts do nothing to eliminate Scope 3 emissions, which are the vast majority of global warming emissions tied to the use of fuels in airplanes, cars, petrochemicals and elsewhere downstream.

Platts Analytics' calculations represent the greenhouse gas emissions of a field's current operations from the wellhead to storage or export terminal, including upstream activities like flaring and venting but not exploration and drilling.

Offshore efficiencies

The calculations show a massive range of upstream impacts, from 1.6 kgCO2e/boe for Norway's offshore Johan Sverdrup to 1,460 kgCO2e/boe for Venezuela's Orinoco Belt.

Offshore UK and Norway producers increasingly use renewable power to run their platforms instead of coal or natural gas, which sharply reduces emissions per barrel produced.

Offshore Gulf of Mexico production also claims low carbon intensity because advanced subsalt imaging practices have helped drillers target the most efficient reservoirs. These fields range from 12.1 kgCO2e/boe to 23.1 kgCO2e/boe under the latest estimates.

Kuwait's Burgan field, new to the list, is the lowest onshore stream at 16.8 kgCO2e/boe.

Platts Analytics carbon analyst Varaleka Pant said Burgan -- along with Saudi Arabia's offshore Safaniya and UAE's onshore Fateh, both of which are below 20 kgCO2e/boe -- show that even aging fields can have low per-barrel carbon intensities, given high production volumes and limited flaring.

Cleaning up the upstream

Methane controls largely determine where US onshore shale drillers fall on the CI scale, and the entire sector will be forced to tighten these emissions further under the Environmental Protection Agency's latest proposed methane rule. US onshore operations range from about 18.1 kgCO2e/boe in the Permian and Delaware basin to 95.4 kgCO2e/boe near the Louisiana Gulf Coast, according to Platts Analytics.

Canadian oil sands operations on the list have CI values of 43.6 kgCO2e/boe to 119.8 kgCO2e/boe, driven by the need for gas-powered steam injections to mine the heavy bitumen. Some producers are trying to lower emissions with cogeneration and solvent-based assistance.

California's medium to extra-heavy San Joaquin oil ranks second-highest on the list at 177.9 kgCO2e/boe because the aging field requires large steam injections and heavy water management.

The extreme carbon intensity of Venezuela's Orinoco belt shows that this crude stream would face challenges in a world with tight carbon budgets, even if not for the existing sanctions limiting its reach. The crude has high levels of dissolved gas that gets flared out, and the fields use energy-intensive processes like delayed coking and hydrocracking to upgrade the crude quality, Pant said.

"Reduction in wellhead flaring and adoption of integrated energy technologies such as cogeneration systems can help significantly bring down the carbon intensity for the oil-rich Orinoco Belt," she said.

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