Carbon-Negative Crude Oil

Carbon Dioxide Removal (CDR) and Negative Emissions Technologies (NETs) burst onto the center stage of climate mitigation in late 2018. That year, the IPCC, the US National Academies, and the UK Royal Society, among others, concluded that eliminating and avoiding emissions, while still essential for averting catastrophic climate change, is no longer sufficient. Now, and for decades to come, we must also actively remove CO2 from the atmosphere. These calls for CDR were followed by a flurry of Net Zero commitments by nations, corporations, and investors. The timelines associated with Net Zero commitments—2050 is frequently cited as a deadline—have redoubled the importance of NETs, even though the consequence of the commitments is not yet widely understood. Current discussion is focused on eliminating emissions, for example by fuel substitution, and on avoiding emissions, for example through carbon capture and storage (CCS). Examining energy consumption over the last century reveals first that replacing fossil fuels with renewables by 2050 will require the growth of renewable energy supplies at very large rates, and second that sustaining such growth rates for other energy sources for thirty years is unprecedented. The growth rates required for CCS are similarly extraordinary. Every year in which targets for elimination and avoidance are not reached adds yet more carbon that must be removed from the atmosphere. The transportation sector is particularly challenged in this regard. It is impractical to avoid emissions from myriad vehicles, and difficult to eliminate emissions for some modes of transport. In this context, carbon-negative crude oil can play a valuable role. While nature-based solutions offer a route to CDR, engineered and natural/engineered hybrid NETs are likely to be necessary to accomplish CDR at scale. Unfortunately, few rapidly scalable options for NETs exist. Thus, the idea of coupling established, already scaled technologies for injecting and producing fluids in subsurface hydrocarbon reservoirs, such as CO2 enhanced oil recovery, with rapidly growing technologies to remove CO2 from the atmosphere, such as direct air capture, is timely. We describe how to operate this coupled process so that more carbon is removed from the atmosphere than is emitted during the production, processing, and combustion of oil. We discuss advantages and drawbacks of carbon-negative crude oil relative to other forms of CDR and to other paths to decarbonizing transportation, ranging from capital efficiency and speed of implementation to social desirability and technology lock-in. Some types of reservoirs are not good candidates for carbon-negative hydrocarbon production, though the concept would still mitigate operators’ Scope 3 emissions. Field and lab data that support or constrain feasibility of these options are discussed.