In the arid expanses of West Texas, a pioneering project is redefining the future of oil recovery and carbon storage. The Tall Cotton Field, nestled in the Permian Basin, has become a testament to the potential of greenfield residual oil zones (ROZs) in enhanced oil recovery (EOR) and carbon dioxide (CO2) retention. This innovative approach, detailed in a recent study led by C. Özgen Karacan of the U.S. Geological Survey, offers a compelling narrative for the energy sector, balancing the scales between oil production and environmental stewardship.
The study, published in ‘Carbon Capture Science & Technology’ (translated as ‘Carbon Capture Science and Technology’), focuses on the Tall Cotton Field, which began production in 2015 and expanded in 2017. Unlike conventional reservoirs or brownfields, greenfield ROZs lack a main pay zone (MPZ), making them less common targets for CO2-EOR operations. However, the Tall Cotton Field’s success challenges this norm, demonstrating that greenfield ROZs can be just as promising for EOR and underground CO2 storage.
Karacan and his team analyzed production and injection data from 28 identified patterns, using ratio-trend decline analysis to forecast oil recovery and CO2 retention performance. The results were striking. Oil recovery factors varied significantly, with Phase-2 patterns outperforming Phase-1 in terms of oil recovery factors. “Phase-2 patterns generally showed higher oil recovery factors, ranging from 5% to 30%,” Karacan noted. However, Phase-1 patterns excelled in CO2 retention, storing a mean value of approximately 7130 MMscf per pattern until the end of injection.
The study’s findings have profound implications for the energy sector. By developing greenfield ROZs for CO2-EOR, companies can tap into substantial oil resources while simultaneously storing anthropogenic CO2 underground. This dual benefit could drive significant commercial impacts, making CO2-EOR a more attractive proposition for investors and operators alike.
Moreover, the study’s detailed analysis of a greenfield ROZ in the Permian Basin sets a new benchmark for future research. As Karacan explains, “This is the first study in the literature that reports a detailed CO2-EOR performance analysis of a greenfield ROZ in the Permian Basin.” This groundbreaking work allows for comparisons with MPZs and brownfield ROZs, paving the way for more informed decision-making in the field.
The Tall Cotton Field’s success story is a beacon of hope for the energy sector, demonstrating that innovative approaches to EOR and carbon storage can yield substantial benefits. As the world grapples with the dual challenges of meeting energy demands and mitigating climate change, projects like Tall Cotton Field offer a glimmer of hope, proving that progress is possible.