Environmental and Operational Performance of CO2-EOR as a CCUS Technology: A Cranfield Example with Dynamic LCA Considerations

Abstract

This study evaluates the potential of carbon dioxide-enhanced oil recovery (CO2-EOR) to reduce greenhouse gas emissions without compromising oil production goals. A novel, dynamic carbon lifecycle analysis (d-LCA) was developed and used to understand the evolution of the environmental impact (CO2 emissions) and mitigation (geologic CO2 storage) associated with an expanded carbon capture, utilization and storage (CCUS) system, from start to closure of operations. EOR operational performance was assessed through CO2 utilization rates, which relate usage of CO2 to oil production. Because field operational strategies have a significant impact on reservoir engineering parameters that affect both CO2 storage and oil production (e.g., sweep efficiency, flood conformance, fluid saturation distribution), we conducted a scenario analysis that assessed the operational and environmental performance of four common and novel CO2-EOR field development strategies. Each scenario was evaluated with and without stacked saline carbon storage, an EOR/storage combination strategy where excess CO2 from the recycling facility is injected into an underlying saline aquifer for long-term carbon storage. The dynamic interplay between operational and environmental performance formed the basis of our CCUS technology analysis. The results showed that all CO2-EOR evaluated scenarios start operating with a negative carbon footprint and, years into the project, transitioned into operating with a positive carbon footprint. The transition points were significantly different in each scenario. Water-alternating-gas (WAG) was identified as the CO2 injection strategy with the highest potential to co-optimize EOR and carbon storage goals. The results provide an understanding of the evolution of the system’s net carbon balance in all four field development strategies studied. The environmental performance can be significantly improved with stacked storage, where a negative carbon footprint can be maintained throughout the life of the operation in most of the injection scenarios modelled. This information will be useful to CO2-EOR operators seeking value in storing more CO2 through a carbon credit program (e.g., the 45Q carbon credit program in the USA). Most importantly, this study serves as confirmation that CO2-EOR can be operationally designed to both enhance oil production and reduce greenhouse gas emissions into the atmosphere.

Evaluation of Dimethyl Carbonate as Alternative Biofuel. Performance and Smoke Emissions of a Diesel Engine Fueled with Diesel/Dimethyl Carbonate/Straight Vegetable Oil Triple Blends

“…Based on the studied criteria, the best engine efficiency is reached by B20CO containing 9% DMC and 11% CO. The implementation of the strategy studied here would not only reduce soot from the transportation sector, but could also be part of carbon capture, use and storage (CCUS) technology for the treatment of anthropogenic CO 2 [41], since DMC can be synthetized from CO 2 as a starting material.…”

Towards Indicators for a Negative Emissions Climate Stabilisation Index: Problems and Prospects

“…This position, however, is also criticised for its potential to prolong the fossil era [60,85]. BECCS and DACCS may also be associated with fossil extraction through EOR [15,86,87]. The latter could be captured by other proposed indicators, such as those related to indirect emissions, carbon leakage or displacement.…”

A Novel Approach to Stabilize Foam Using Fluorinated Surfactants

“…Foam has different applications in oil and gas industry such as in drilling, hydraulic fracturing, and in enhanced oil recovery (EOR) [2][3][4][5][6]. CO 2 flooding is one of the most commonly used EOR method that involves the injection of compressed CO 2 [7][8][9]. In EOR methods that employ low viscous fluids as displacing slugs such as CO 2 flooding, the foam is applied to improve the sweep efficiency by controlling the gas mobility.…”