Using Life Cycle Analysis (LCA) to Understand Potential Climate Benefits of CO2 Enhanced Oil Recovery (CO2-EOR) and Evaluate Potential Challenges Associated with Ensuring Verifiable Reductions in GHG Emissions
Abstract
CO2-enhanced oil recovery (EOR) is a form of tertiary production that is utilized to stimulate reservoirs after primary and secondary methods have been exhausted. There is significant interest in EOR as an approach for sequestration of CO2 since it generates a source of revenue to offset the associated costs of storage. Recently, the U.S. federal tax code incentives for storage of CO2 via EOR, documented in Section 45Q of Title 26, were increased with the passage of the 2018 Bipartisan Budget Act. The tax credit for EOR will increase to $35/metric ton by 2026 and has focused renewed interest on EOR.
The National Energy Technology Laboratory (NETL) has utilized life cycle analysis (LCA) to evaluate the GHG emissions associated with the production of fuel derived from EOR-crude oil against the U.S. petroleum life-cycle baseline. The most important parameters affecting the LCA result are the efficiency of crude production (referred to as the crude recovery ratio and measured in bbl/Mg CO2 stored) and the carbon intensity (CI) of the upstream CO2 (kg CO2e/kg CO2) that is provided to the EOR field. This analysis describes a general approach that we have used to analyze LCA emissions for EOR produced crude based on the combination of any CO2 source and production reservoir. Using this framework, we can evaluate the conditions under which EOR is preferable to the petroleum baseline. NETL created a model to support this analysis referred to as the CO2 Enhanced oil recovery Life Cycle (CELiC) model. As part of this analysis, we recommend a consistent accounting framework for evaluating EOR that avoids issues of double-counting that have been published in the literature. There are significant temporal considerations for LCA of EOR systems including how the CI of the U.S. electricity grid and operational changes over the life of a reservoir could affect GHG mitigation. Understanding these dynamics result in practical implications for evaluation EOR for compliance against California's Low Carbon Fuel Standard (LCFS). Given the interconnected nature of the anthropogenic CO2-EOR system, there are both practical operational and LCA methods considerations that warrant additional discussion. The goal of this analysis is not to solve these challenges, but rather to illuminate the nuances and challenges for future work.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMPA33A..05J
- Keywords:
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- 1630 Impacts of global change;
- GLOBAL CHANGEDE: 6309 Decision making under uncertainty;
- POLICY SCIENCESDE: 6324 Legislation and regulations;
- POLICY SCIENCESDE: 6339 System design;
- POLICY SCIENCES