Bud's Offshore Energy (BOE)

An interesting study published in the Proceedings of the National Academy of Sciences (PNAS) was brought to my attention by leading offshore energy historian Tyler Priest. The study used airborne observations and emissions reports to measure the carbon intensity (CI) of Gulf of Mexico oil and gas production. Their CI measure is grams of CO₂ equivalent of greenhouse gas emissions per megajoule of energy produced.

The authors conclude that inventory emissions of CO₂ (as reported to BOEM) “are generally consistent with observations from our aircraft survey, suggesting that combustion is well represented in the federal inventory.“

However, that is not the case for methane (CH₄) emissions which are underestimated by the Federal inventories. As summarized in the chart below, deepwater facility methane emissions are consistent with the reported inventories, but shelf emissions in State and Federal waters differ significantly.

Comments:

• As previously discussed, the lower CI for deepwater production is entirely consistent with expectations. When the most modern 5% (57) of GoM platforms are producing 93% of the oil and 76% of the gas, their CI should be impressive (which indeed it is).
• As summarized using ONRR data, more gas-well gas was vented from 2015-2021 than was flared, which is not what you want from a GHG standpoint. Gas wells are predominantly at shallow water facilities, many of which are not equipped with flare booms.
• Oil-well gas, most of which is produced at deepwater platforms, is flared rather than vented by a ratio of approximately 4 to 1.
• About 15 years ago, the Federal government (MMS) considered requiring that older production platforms be retrofitted with flare booms, but safety, space limitations, and cost considerations precluded such a regulation. Instead, additional flaring/venting limits, and measurement and reporting requirements were imposed.
• One bad actor may have been a major contributor to the shelf methane emissions observed during the study’s observational flights. That company entered into bankruptcy proceedings. Presumably those issues have been resolved and more rigorous monitoring and enforcement practices have been implemented. I’ll be looking at the 2022 ONRR flaring and venting data for evidence of such improvement. The remainder of the 2022 data should be available in May.
• The subject study’s only observational measurements were in August 2020. Followup airborne measurements would be helpful.
• The study only considered production emissions. Shelf facilities are primarily natural gas producers and would thus have a lower relative CI when consumed.
• When will updated BOEM GOADS flaring and venting data be available? The latest data are for 2017 (cover below)? Are GOADS data being compared with ONRR and World Bank data?

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