ABSTRACT
Deep Saline Formations (DSFs) are increasingly recognized for their significant role in geological carbon dioxide (CO2) storage, a crucial part of Carbon Capture and Storage (CCS) strategies aimed at mitigating climate change. Nevertheless, formation overpressure, capillary breakthrough pressure, and injectivity impairment often compromise the actual CO2 Storage Efficiency (CSE) in these formations, potentially reducing storage efficiency by up to 22%. However, comprehensive knowledge of Pore Space Utilization (PSU) in CO2 storage in deep saline formation must be improved to address this inefficiency. This study presents a first-of-its-kind work combining a comprehensive review with a proposed innovative concept on the viability and effectiveness of the Simultaneous or Alternate Aquifer Injection (SAI) method to enhance CO2 storage within DSFs. Further, a conceptual future direction for optimizing CO2 storage in deep saline formations was proposed. We introduced the Simultaneous or Alternate Aquifer Injection (SAI) as a useful approach to optimizing PSU and CSE in DSFs. This method is similar in principle to Water Alternating Gas (WAG) used in CO2-EOR. While there is a lack of data on the SAI process, WAG data shows that incremental CO2 is stored in a reservoir when water is introduced in a CO2-EOR, thereby increasing the oil recovery and CO2 storage. This incremental ranges from 3–100% CO2 stored in a formation. The SAI method can enhance CSE by approximately 25% on average compared to traditional injection methods when using this as an analog. Our study further highlights the complexities of the SAI method and its potential to enhance storage efficiency and capacity, which is crucial for large-scale CCS implementation. We compared various trapping mechanisms, their impacts on CSE, and how they can be potentially augmented through the SAI to increase PSU in saline aquifers to mitigate climate change. The SAI method, involving simultaneous or alternate injection of CO2 and brine, may yield a novel approach to managing the movement of the CO2 plume in the aquifer reservoir, thereby maximizing storage efficiency and minimizing leakage risks. While our review of the SAI method shows promise, it still poses technical, regulatory, and economic challenges. Our review findings emphasize the need for more integrated dynamic modeling, numerical simulations, and sensitivity analyses for successful implementation. With adequate experimental and simulation support, the SAI approach has the potential to revolutionize CO2 storage operations in DSFs, contributing significantly to global net-zero carbon emission goals.
Abbreviation
CEGR | = | CO2 storage with enhanced gas recovery |
CEOR | = | Geological Storage of CO2 through Enhanced Oil Recovery |
CCS | = | Carbon capture and storage |
CO2 | = | Carbon dioxide |
CSE | = | CO2 Storage Efficiency |
DSF or DSFs | = | Deep Saline formation or Formations |
EPA | = | Environmental Protection Agency |
GCS | = | Geological CO2 storage |
GSCA | = | Geological Storage of CO2 in Deep Saline Aquifer |
GtCO2 | = | Giga-tonnes of Carbon dioxide |
PSU | = | Pore Space Utilization |
SAI | = | Simultaneous or Alternate Aquifer Injection method |
scCO2 | = | Supercritical CO2 |
UIC | = | Underground Injection Control |
WAG | = | Water-Alternate-Gas Injection |
WAG-EOR | = | Water-Alternate-Gas Injection- Enhanced Oil Recovery |
Disclosure statement
No potential conflict of interest was reported by the author(s).
Additional information
Notes on contributors
Stella I. Eyitayo
Stella I. Eyitayo is a Reservoir Engineer and Ph.D. Candidate at Texas Tech University, specializing in the sustainable management of water and energy resources. Her research focuses on the treatment and recycling of produced water, optimization of geological CO2 storage, and the development of numerical simulation models for CO2 containment. Stella holds a background in chemical and petroleum engineering, with her expertise extending to reservoir modeling and simulation, reserves estimation, and well testing design. With over a decade of experience as a Petroleum Reservoir Engineer, Stella has significantly contributed to field development and reservoir management. Her work not only advances the technical boundaries of her field but also actively contributes to the mentoring and development of upcoming engineers in the industry.
Nachiket Arbad
Dr. Nachiket Arbad is a distinguished PhD graduate from Texas Tech University, specializing in well integrity and geological carbon sequestration. His doctoral research, supported by a DOE-sponsored Carbon Capture and Storage project, was conducted under the guidance of Drs. Marshall Watson, Lloyd Heinze, and Hossein Emadi. Prior to his PhD, he earned a Master’s in Petroleum Engineering from the University of Oklahoma and a Bachelor’s in the same field from the University of Pune, India. Dr. Arbad is a prolific scholar with several publications to his name and holds two provisional patent from his research endeavors. His professional journey spans over 13 years, including roles as a Well Engineer, subject matter expert in cloud-based drilling software, and a consultant in the oil and gas industry.
Oladoyin Kolawole
Dr. Oladoyin Kolawole serves as an Assistant Professor of Geomechanics and Geotechnical Engineering at the New Jersey Institute of Technology (NJIT), where he also founded the Geomechanics for Geo-Engineering and Sustainability (GGES) Lab. A graduate in geotechnical engineering from Texas Tech University, he has a profound background in experimental and computational studies on porous materials. His groundbreaking work on “biogeomechanics” examines the mechanical responses of rocks under biological processes, aiming to mitigate geohazards and address climate change issues. Dr. Kolawole has received the Future Leader Award and the Distinguished Service Award from the American Rock Mechanics Association (ARMA) and contributes actively to the U.S. National Academies’ Committee on Geological and Geotechnical Engineering. His publications span several peer-reviewed journals and conference papers in his field.
Marshall C. Watson
Dr. Marshall C. Watson is the Department Chair, Roy Butler Chair, and an Associate Professor of Petroleum Engineering at Texas Tech University’s Bob L. Herd Department of Petroleum Engineering. He holds a Ph.D. and M.S. in Petroleum Engineering from Texas Tech University, and a B.S. in Chemical Engineering from Cornell University. Dr. Watson specializes in petroleum reserves evaluation and economics, enhanced oil recovery (EOR) in new and mature fields, and unconventional reservoirs with a focus on coalbed methane. His expertise extends to cementing and ensuring wellbore integrity. Registered as a professional engineer in Texas, Wyoming, and Louisiana, Dr. Watson’s work has significantly influenced both academia and industry practices in petroleum engineering.