In the quest to combat global climate change and meet ambitious “dual carbon” goals, carbon capture, utilization, and storage (CCUS) has emerged as a critical strategy. Among the various methods of carbon sequestration, storing CO2 in saline aquifers has been identified as a primary approach. However, ensuring the security of these storage sites is paramount, and a recent study published in *Petroleum Geophysical Exploration* (originally published as ‘Shiyou shiyan dizhi’) sheds new light on evaluating fault lateral sealing capacity for CO2 storage, with significant implications for the energy sector.
The study, led by Yukun Chai from the Shenzhen Branch of China National Offshore Oil Corporation, focuses on the Enping A Oilfield in the Enping Sag of the Pearl River Mouth Basin. Chai and his team investigated the heterogeneity of mineral distribution and cementation within key faults, developing a method to evaluate fault lateral sealing capacity specifically for CO2 storage in saline aquifers.
“Most evaluation methods for lateral sealing focus on conventional hydrocarbon reservoirs,” Chai explained. “Our study addresses the need for systematic methods and frameworks tailored for CO2 storage in saline aquifers, which is crucial for ensuring storage security.”
The researchers utilized parameters such as Shale Gouge Ratio (SGR), Across-Fault Pressure Difference (AFPD), and sealed gas column height to assess the sealing performance of faults. Their findings revealed that the F1 and F3 faults in the Yuehai 320 and Hanjiang 420 layers possess static sealing capacity, with maximum CO2 plume column heights estimated between 50 to 400 meters and 175 to 300 meters, respectively.
“This study provides a basis for the quantitative screening and assessment of saline aquifers for future CO2 storage,” Chai stated. The developed spatial sealing evaluation technique for faults integrates fault throw-distance curves and single-well clay content data, enabling the generation of fault surface attributes and fault sealing ternary diagrams for quantitative evaluation.
The implications of this research for the energy sector are substantial. As companies and governments worldwide seek secure and effective methods for carbon sequestration, the ability to accurately evaluate fault lateral sealing capacity is invaluable. This study not only advances the scientific understanding of CO2 storage in saline aquifers but also offers practical tools for site selection and assessment.
“By integrating fault throw-distance curves and single-well clay content data for different layers, we can generate fault surface attributes and fault sealing ternary diagrams,” Chai added. “This enables a more comprehensive and quantitative evaluation of fault zone sealing, which is essential for the safe and efficient storage of CO2.”
As the world continues to grapple with the challenges of climate change, innovative research like this plays a pivotal role in shaping the future of energy and environmental sustainability. The study’s findings are expected to influence future developments in CCUS technologies, guiding the energy sector towards more secure and effective carbon storage solutions.