Exploring Emissions Trends Across the O&G Value Chain

emissions. oil. gas

During the webinar – which took place under the theme, From Well to Atmosphere: Navigating emissions in the oil and gas value chain – experts unpacked several topics including CO2 footprint regarding Liquified Natural Gas (LNG) and piped gas sources; crude source and refinery emission mapping; and Scope 3 emissions from E&P activity.

Remme kicked off the session by discussing emissions tracking in the upstream sector, stating that, “If we focus on the upstream side, we can see that around one gigaton annually comes from upstream oil and gas assets, roughly split 2/3 towards extraction and 1/3 towards flaring.”

In terms of various segments, Remme stated that the average global CO2 emissions for all supply segments is approximately 18 kg per barrel of oil equivalent (boe), with flaring accounting for about 5 kg CO2/boe of that 18. This can serve as a useful benchmark to evaluate whether your assets are above or below the global average, he emphasized. However, there are significant differences in emissions between oil fields and gas condensate fields, with oil fields having an average of around 22 kg of CO2 emissions per boe produced, while gas fields emit only around 13 kg per boe produced. Remme explained that these differences highlight the need to examine emissions at the segment level.

Moving on to the value chain, Remme added that, “When we look at transportation, refining and liquefaction with midstream and downstream elements, we estimate the carbon to be around 1.2 gigatons annually. A little bit more than the upstream dimension for each year.”

He continued that further breakdown reveals that these emissions can be categorized as those stemming from oil production, those stemming from barrels, and those stemming from gas production, specifically from exported gas. Additionally, energy activities account for approximately 300 million tons of CO2 emissions annually.

Kicking off his discussion, King stated that, “When we look at upstream and also look at the mid and downstream, there is around 2.2 gigatons of CO2 emitted annually with 75% of that stemming from the liquids in the midstream and downstream segment. So, it’s really clear that this is an important and key area to look at and expand our research.”

He continued by stating that when examining the first stages of oil and gas production, a crucial step is to analyze the molecules produced at the wellhead. A study of the emissions impact of crude on upstream and midstream operations can provide valuable insights. For instance, a comparison of the emissions intensity of the top 15 crude grades by production in 2021 reveals a significant variation in emissions between different crude grades. While Iranian light has a high emissions intensity of 35 kg per barrel, other crude grades such as Arab light, Kuwait, and WTI have lower emission intensities ranging from 10 to 13 kg per barrel. This underscores a 20-25 kg per barrel disparity based on crude grade selection, without considering downstream refining and end-use combustion.

Regarding the top producing companies in Africa, King stated that when analyzing the midstream emissions, there is a clear correlation between the production slate of companies and their emissions intensity. Companies such as bp and ENI, with high gas production and lighter crudes, have lower midstream emissions intensities of approximately 15 and 13 g per barrel, respectively. In contrast, ExxonMobil has heavier and more crude-focused productions, particularly in Africa, resulting in midstream emissions of around 25 kilograms of CO2.

 “The upstream side and the mid- and downstream side, which corresponds to around 2.2 gigatons of CO2 emissions, is far outweighed by end use combustion, which is around 20 gigatons of CO2, or 90% of the total emissions coming from the oil and gas sector. This obviously has a substantial impact on crude grade and liquids and where you get your supply from,” King concluded.

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Onur Yilmaz

Onur Yilmaz