Crude fundamentals, including production, trade, quality and pricing data.

Carbon Intensity Methodology


The Energy Intelligence Upstream Carbon and Greenhouse Gas Intensity Tracker evaluates the carbon intensity (CI) and Greenhouse Gas (GHG) with the upstream production process of around 100 global crude grades covered in our World Crude Oil Data (WCOD) service. It is a powerful comparative and analytical tool that builds on available data from several sources but also adds up-to-date analysis of factors contributing or minimizing emissions.

Definition: CI measures kilograms of carbon dioxide equivalent released per barrel of oil produced. It encompasses both carbon and other greenhouse gases (GHGs).

The Energy Intelligence Carbon Intensity Tracker provides a write-up and data in both the crude and country profiles in WCOD:

At the crude stream level:

  • Carbon intensity metrics: Data on CI is presented when available from varying sources such as The Oil- Climate Index plus gases: RMI, Oil Climate Index plus Gas Model v.1.0 — 2022, Oil-Climate Index (OCI —2016), the International Council on Clean Transportation (ICCT — 2014, 2011 and 2010) and corporate data. The data is generally listed in kg CO2e/bbl and converted from grams of carbon dioxide equivalent per megajoule by multiplying by 6.119 when needed (source of conversion rate: BP). The focus is on emissions at the upstream oil production level. This includes drilling, production, processing and transport. Data on emissions at the midstream and downstream levels are also provided when available. When possible, key contributors to a stream’s CI and more generally GHG are explained, whether it be the age of contributing fields, energy-intensive production methods, flaring, the gravity or carbon-rich reservoirs.  
  • GHG reduction measures: Measures operators have taken to reduce emissions at the production level are listed. These include electrification (via renewable power generation), carbon capture technology, efficiency improving technology and flaring reduction or elimination. Petrobras, for example, is active in implementing new technology including reinjecting carbon directly into the reservoir, preventing ventilation to the atmosphere, flare gas recovery systems and low-emissions valves. It is also planning to electrify future floating production, storage and offloading systems.
  • Corporate strategies: When possible, operators’ general corporate approach to GHG emissions at the upstream level and how it might affect the crude stream in question is listed.

At the country level:

  • Carbon intensity and Greenhouse gas metrics: When available, a country average of CI or GHG at the upstream level is provided and any relevant emissions data relating to the production of oil and gas. When possible, the relative standing of a country in comparison to a world average is pointed out, helping identify if its oil and gas production sector is generally more or less carbon intensive than others.  
  • Country policies and regulations: This section identifies the country’s overall standing on emissions reduction strategies. It identifies if a country is a signatory of the Paris climate act, if it submitted a nationally determined contribution and a net-zero strategy, and lists out its emissions reduction targets and regulations on emissions. Regulations can be market-based, voluntary or traditional. Relevant and significant investments in low-carbon assets and renewable energy are discussed. Similarly, targets, policies and the most active oil and gas companies in the country are discussed.

Ranking crude streams’ carbon intensity and greenhouse gas
Based on available data and information crude streams are ranked as Very Low, Low, Medium, High and Very High for around 100 crudes across 45 countries, allowing for cross-country and crude comparisons. Available CI and GHG data is sometimes outdated and can vary significantly by source. Furthermore, data can measure CI either at the field level (OCI & OCI+) or at the crude stream level (ICCT), and the composition of the latter can change as newer oil from different fields or formations is added to a blend. Additionally, there is generally a lack of transparency from companies and countries on accurate emissions measures and therefore the provided write-ups and rankings can help better gauge the standing of a specific crude stream compared to others. The level of CI of a crude stream depends on varying factors such as the age of contributing fields, the quality of the oil, the gas and water contents of reservoirs, diverse production methods that vary in intensity and resulting emissions, carbon richness of reservoirs and others. Finally, operators can take measures to mitigate emissions such as reducing flaring. Due to this, Energy Intelligences expects that rankings of CI are likely to change over time, rendering certain data that are not updated regularly insufficient to evaluate CI. (See Annex for a noncomprehensive list of factors affecting carbon intensity.)

Rankings of crude streams were determined based on the distribution of available data. Therefore, a crude stream that is considered:

OCI (kg CO2e/bbl)Rank (GHG Emissions rank) OCI+ gases (kg CO2e/boe)
0-35Very Low0-70
99+Very High191+

* The OCI+ (kg CO2e/barrel oil equivalent) is on a slightly different basis than the OCI (kg CO2e/barrel oil only).
* The OCI was an oil model with a heavy concentration on enhanced oil recovery (heavier oils). It didn’t handle fracking. And it insufficiently handled the gas from light oils. OCI+ has fully added gas through the lifecycle and is believed to better account for the emissions from lighter oils (that have a lot of associated gas).
* When data is available in g CO2e/MJ it is converted to kg CO2e/bbl by multiplying by 6.119 (BP).
* The OCI+ default to 20-year global warming potential (GWP) results. There’s a toggle for 100-year GWP (OCI). Methane has a 12-year lifetime; so, using 100-year GWP makes no sense when accounting for CO2e emissions. Note the OCI was the reverse: it defaulted to 100-year GWP and offered a toggle to 20 year GWP. (Source OCI).

    Annex – Factors affecting carbon intensity
    The Oil Production Greenhouse Gas Emissions Estimator Model (Opgee) used for the Oil-Climate Index (OCI) takes into account many inputs on production methods, processes and other factors that are found to impact carbon intensity. Below is a list of 12 parameters that Energy Intelligence found to be of particular importance.

    Production Methods
    Methods used to extract oil vary depending on geology and reservoir pressure. Typically, the lower the reservoir pressure, the more energy needed to extract oil and the higher emissions are.
    Gas lifting• This option is used when gas is not injected into the reservoir but injected into production string to reduce the pressure at the reservoir interface and induce production from the reservoir. The more gas needed for injection, the more carbon intensive the process.
    Downhole pump• This option is used to allow production when the naturally occurring energy of the reservoir does not suffice to produce fluids at a desired wellhead pressure.
    Flooding• Method used to enhance oil recovery and maintain reservoir pressure (gas, water, steam). Flooding occurs when the amount injected is greater than that produced.
    Production Practices
    These vary depending on the quality of the hydrocarbons. Typically, the more processes and steps needed to prepare the oil for transport, the more carbon intensive the crude stream is.
    Flaring-to-oil ratio• An upstream operating decision regarding the amount of gas flared for every barrel of oil produced, measured in standard cubic feet of gas per barrel. The more gas is flared, the higher the carbon intensity.
    Gas-to-oil ratio• The estimated total amount of gas production associated with the production of one barrel of oil, measured in standard cubic feet of gas per barrel. Higher gas-to-oil ratios necessitate more energy to separate out the oil and therefore lead to higher emissions.
    Water-to-oil ratio• The total amount of water generated when producing oil, measured in barrels of water produced per barrel of crude oil produced. Higher water-to-oil ratios necessitate more energy to separate out the oil and therefore lead to higher emissions.
    Upgrading• An energy-intensive upstream process in Opgee that converts extra-heavy oil, bitumen and oil sands into synthetic crude oils of varying qualities by primarily removing excess carbon and converting it into petcoke. This process is particularly carbon intensive.
    Diluent• Light petroleum products (natural gas condensates, naphtha) added to heavy crudes to decrease its viscosity and facilitate its transportation.
    Injection• Methods used to enhance oil recovery and maintain reservoir pressure (gas, water, steam). In injection, a fraction of the gas/water produced is reinjected.
    Land-Use Impacts
    Determined the emissions impact from land-use change.
    Ecosystem carbon richness• It controls the amount of carbon emissions per unit of disturbed land, and varies from semi-arid grasslands (low potential carbon emissions) to forested (high potential carbon emissions).
    Field development intensity• The intensity of development can be chosen to be low, medium, high. High-intensity development resembles California thermal enhanced oil recovery operations, well production and injection wells are drilled on tight spacing. Low-intensity development resembles conventional natural gas development or directional drilling from centralized drill pads, where the land disturbed per well is small.
    Determined the emissions impact from land-use change.
    Transport• Parameters which determine transport modes and distances. Includes the fraction of crude oil transported by each mode of transport and the transport distance (one way) of each mode.
    Other Factors Not Included in the Opgee Model
    Electrification• The use of electricity instead of hydrocarbons to power production platforms reduces emissions. Especially when using low-carbon power sources such as solar and wind power.
    Carbon capture• Emitted carbon can be captured and stored, either via carbon capture, utilization and storage (CCUS) or direct air capture (DAC)

    OCI: Oil-Climate Index,, created 2015 and updated 2016.
    ICCT: ICCT Crude GHG Calculation Methodology,, 2014.
    Masnadi, MS, et al. "Global carbon intensity of crude oil production." Science 361.6405 (2018): 851-853.