The Global CCS Institute is careful to distinguish this integrated approach from both conventional EOR and dedicated carbon storage. In conventional EOR, the primary and often sole objective is to maximize oil production at the lowest possible cost, with little regard for the long-term fate of the CO2 used. Conversely, dedicated storage projects, often referred to as "saline aquifer storage," involve injecting CO2 into deep formations that contain no oil or gas, with the exclusive goal of permanent sequestration. The Institute views CO2-EOR with CCS as a middle ground—a hybrid model that uses the revenue from oil production to offset the high capital costs associated with carbon capture and transportation infrastructure.
This economic reality forms the basis of the Institute’s argument that EOR combined with CCS could provide a "transitional route" toward the wider deployment of dedicated CO2 storage. The infrastructure required for EOR—such as large-scale pipeline networks and injection facilities—is largely identical to what will be needed for massive dedicated storage hubs in the future. By allowing the oil industry to lead the initial build-out of this infrastructure, the costs of carbon management can be shared, and the technology can be refined at scale. This "learning by doing" phase is seen as a critical step in de-risking CCS for other industrial sectors that may not have the same profit margins as the oil and gas industry.
However, the potential for this transitional route is not uniform and depends on a variety of site-specific factors. The guidance points out that geology is the primary constraint; not every oil field is suitable for CO2 injection, and not every rock formation is capable of securely containing the gas for thousands of years. Beyond geology, access to a steady and affordable supply of captured CO2 is essential. This requires a proximity to industrial clusters or the development of long-distance transport networks. Furthermore, the regulatory environment plays a decisive role. For these projects to succeed, there must be clear legal frameworks governing pore space ownership, long-term liability for the stored gas, and standardized rules for how carbon storage is credited against emissions.
Perhaps the most significant warning in the new guidance is that permanent storage alone does not automatically equate to a net climate benefit. The Institute stresses that a project’s overall impact on the atmosphere must be viewed through the lens of a comprehensive Life Cycle Assessment (LCA). An LCA accounts for all emissions associated with the project, including the energy used to capture and compress the CO2, the emissions generated during the drilling and extraction of the oil, and, most importantly, the downstream emissions produced when the resulting oil is eventually refined and burned by end-users.
If the amount of CO2 stored underground is less than the total emissions generated by the project’s operations and the combustion of the produced oil, the project may still result in a net increase in atmospheric greenhouse gases. Because of this complexity, the Global CCS Institute is calling for the establishment of consistent boundaries and common accounting rules. Without a unified global standard for assessing the climate impact of individual CCS-EOR projects, it becomes difficult for investors, regulators, and the public to distinguish between genuine decarbonization efforts and projects that merely use carbon storage as a tool for continued fossil fuel expansion.
