Carbon Storage

Supporting commercial-scale
geologic storage in mineralization-
and buoyancy-dominated reservoirs

PNNL has led research in applied subsurface science for over 50 years. Leveraging this diverse background, we support the U.S. Department of Energy's Office of Fossil Energy and Carbon Management (DOE-FECM) Carbon Storage program with deep domain expertise and broad computational capabilities.

cylinder — PNNL conducted the first injection of supercritical CO2 into a basalt reservoir. Data and samples taken from the Wallula, Washington, site two years later confirmed that the basalts converted CO2 into minerals much more rapidly than other storage formations, offering the potential to store CO2 in a solid form that is immobile and poses no risk of leakage. Nathan Johnson | Pacific Northwest National Laboratory

Tools for real-time CO₂ storage management

To help accelerate commercial-scale deployment of geologic CO₂ storage, our scientists are working to deliver solutions for real-time imaging of the subsurface by bringing together domain experts in geophysics, geochemistry, data science, and high-performance computing. PNNL’s R&D 100-winning E4D-RT technology provides subsurface project real-time feedback on the fate of fluid injected into the subsurface.

Under the Carbon Storage program, we are working to extend these capabilities to the deep subsurface using multiphysics joint inversion tools. This ability to rapidly acquire, process, and develop insights from monitoring data yields unprecedented tools for field operators, offering both real-time imaging of the subsurface and improved reliability of reservoir forecasting. In the CO₂ storage world, this is a step change similar to the difference between anticipating the weather by looking at the horizon or looking at a predictive multimodel forecast.

Basalt cliffs overlooking the Columbia River at the Wallula Gap, Wash. Oct. 2020 — *PNNL researchers are exploring how injecting carbon dioxide into basalts is turning the fluid into a solid. Photo by Andrea Starr | Pacific Northwest National Laboratory*

CO₂ mineralization storage

Project risks associated with long-term CO₂ storage site stewardship present a barrier to investment in commercial-scale carbon capture and storage (CCS) projects in the United States. This is because a large fraction of the CO₂ injected into conventional sedimentary storage reservoirs remains mobile over long time frames. Work pioneered at PNNL has demonstrated the potential for rapid CO₂ mineralization in basalt reservoirs, the dominant geology in the inland Pacific Northwest, India, and other environments including deep offshore regimes.

Instead of waiting hundreds or thousands of years for CO₂ to mineralize, the Wallula injection project—the first to demonstrate supercritical CO₂ injection into basalts—confirmed that the majority of CO₂ had been transformed to carbonate minerals in just under two years.

With our experience siting and characterizing projects, including developing the first Class VI permit ever granted (FutureGen 2.0), PNNL is focused on transforming fundamental and laboratory science into meaningful solutions to real-world challenges facing CO₂ storage field operators.

Carbon Sequestration or storing carbon dioxide underground may be one approach to reducing atmospheric levels of the greenhouse gas. Storing it in basalt formations creates a chemical reaction in which the CO2 is transformed into a mineral similar to limestone enabling permanent storage underground. A field study by researchers at the Department of Energy’s Pacific Northwest National Laboratory shows that chemical happens quickly. Within two years, CO2 injected underground in Washington state had converted to the carbonate mineral ankerite.

CO₂ storage siting and permitting

Over the last two decades, PNNL has been a major actor of several initiatives led by DOE-FE aimed to accelerate the development of CCS. PNNL served as the subsurface lead for DOE-FECM’s FutureGen 2.0 Project, and in this capacity, secured the first-ever Class VI Underground Injection Control permits issued by the U.S. Environmental Protection Agency. Since 2011, PNNL has been actively engaged in the National Risk Assessment Partnership (NRAP), which is focused on the development of science-based methodologies and platforms for quantifying risks amid system uncertainty and to better inform decision-making for carbon storage sites.

Regional carbon storage initiatives

The ADM Decatur CO₂ injection project in the United States and the Boundary Dam project in Canada have helped regulatory and industrial stakeholders frame the institutional and policy structures needed to support commercial-scale CCS deployment. These early projects have resulted in the build-out of Regional Carbon Sequestration Partnership demonstrations and CarbonSAFE projects to qualify these basins for commercial-scale storage.

Wallulaplant — PNNL conducted the first injection of supercritical CO2 into a basalt reservoir. Data and samples taken from the Wallula, Washington, site two years later confirmed that the basalts converted CO2 into minerals much more rapidly than other storage formations, offering the potential to store CO2 in a solid form that is immobile and poses no risk of leakage. Stock photo.

CarbonSAFE

PNNL is supporting multiple CarbonSAFE projects across the United States, both on-shore and off-shore. Researchers at PNNL also provide expertise in site screening, CO₂ transport evaluation, multiphase flow simulation, and risk assessment. PNNL remains one of the rare institutions with such extensive experience in all aspects of a CCS project, from technical expertise to programmatic regulatory understanding, and from site selection to site permitting.

NRAP

At the same time, programs like NRAP have given developers and regulators tools for quantifying and mitigating risk in subsurface CO₂ storage projects. PNNL developed the NRAP State of Stress Analysis Tool (SOSAT) so operators can make operational decisions related to geomechanical risks during the carbon storage site screening and characterization phases. SOSAT also quantifies the current state of stress and how a state of stress changes as the result of subsurface fluid injections.

SMART

Leveraging the data and insights gained from these efforts, DOE’s CO₂ Storage program has extensively scoped and demonstrated the multi-institution Science-informed Machine Learning for Accelerating Real-Time Decisions in Subsurface Applications (SMART) Initiative to develop tools for operators of commercial-scale storage projects.

The SMART Initiative aims to leverage recent advances in science-based machine learning to significantly improve the efficiency and effectiveness of commercial-scale geological carbon storage. As a part of this initiative, PNNL is co-leading efforts to improve real-time forecasting and history matching during storage site operation, contributing to the development of fast-forward models for a virtual learning environment for site operation, as well as physics-informed machine learning for stress estimation and induced seismicity mitigation.