increase near the wellhead of an injection well associated with CO2 injection at the Aneth oil field in southeastern Utah, USA.
1.5. CASE STUDIES OF GEOPHYSICAL MONITORING
In Chapter 19, Bauer et al. present a case study of microseismic monitoring at the Illinois Basin Decatur Project of the Midwest Geological Sequestration Consortium. The project site is located in east‐central Illinois in the north‐central area of the Illinois Basin in the midcontinent region of the United States. For over three years, the project safely injected nearly 1.1 million tons of supercritical carbon dioxide into the base of a 500‐m thick saline sandstone reservoir at a depth of 2.14 km. They collected a unique data set encompassing an extensive quantity of microseismic and concurrent operational monitoring data before, during, and after injection operations, and presented results of microseismic event location and focal mechanisms. They demonstrate the compatibility of technical and operational activities under evolving and challenging conditions.
In Chapter 20, Balch and McPherson present an overview of the Phase III of the Southwest Partnership on Carbon Sequestration (SWP) in Farnsworth, Texas, USA. The project has completed its injection period with the storage of over 700,000 tonnes of CO2 at an active commercial‐scale CO2‐EOR field. They summarize the interrelationship of monitoring activities, the status of postinjection monitoring, and the optimization required to maximize storage while providing the greatest oil production incentive to the field operator, among others.
In Chapter 21, Hovorka gives an experimental study of testing and assessing geophysical monitoring methods for tracking CO2 migration during large volume injection at the Southeast Regional Sequestration Partnership project in Cranfield, Mississippi, USA. The project uses several geophysical tools to detect CO2 in the injection zone, including time‐lapse 3D seismic, 3D VSP, time‐lapse cross‐well seismic, electrical resistance tomography, borehole gravity, time‐lapse wireline sonic, pulsed neutron logging, and fluid density logging. The experiment reveals the strengths and weaknesses of different monitoring methods. Interference among different monitoring tools is significant. The site operator should avoid deploying as many tools as possible, but rather select best tools for the job and deployment condition. Monitoring data play an important role in calibrating the reservoir model.
In Chapter 22, Romdhane et al. describe a case study on quantitative monitoring at Sleipner in Norway. They evaluate a methodology combining high‐resolution seismic‐waveform tomography and rock physics inversion for monitoring the CO2 plume at Sleipner. They show that using multiparameter seismic inversion or multiphysics integration of data can lead to a better discrimination between the different effects of CO2 injection/migration on rock physics properties and reduce inversion uncertainties.
Finally, in Chapter 23, Bergmann et al. present an overview of geophysical monitoring of CO2 injection at Ketzin in Germany. They describe seismic measurements and electrical resistivity tomography performed during the period of site development and CO2 injection. They find that a combination of several geophysical methods is preferred.
ACKNOWLEDGMENTS
This work was supported by the U.S. Department of Energy (DOE) through the Los Alamos National Laboratory (LANL) operated by Triad National Security, LLC, for the National Nuclear Security Administration (NNSA) of U.S. DOE under Contract No. 89233218CNA000001, and through Lawrence Livermore National Laboratory (LLNL) under Contract DE‐AC52‐07NA27344. We thank the AGU Publications Director Dr. Jenny Lunn and Dr. Estella Atekwana of the AGU Books Editorial Board for their careful review and valuable comments. We also thank David Li of LANL for his review. This chapter is approved for public release by LANL (LA‐UR‐21‐27246) and by LLNL (LLNL‐BOOK‐824879).
2 Geodetic Monitoring of the Geological Storage ofGreenhouse Gas Emissions
Donald Vasco1, Alessandro Ferretti2, Alessio Rucci2, Giacomo Falorni3, Sergey Samsonov4, Don White5, and Magdalena Czarnogorska4
1Energy Geosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
2 TRE ALTAMIRA Srl, Milan, Italy
3 TRE Altamira Inc., Vancouver, British Columbia, Canada
4 Canada Centre for Mapping and Earth Observation, Natural Resources Canada, Ottawa, Ontario, Canada
5 Geological Survey of Canada, Natural Resources Canada, Ottawa, Ontario, Canada
ABSTRACT
Geodetic monitoring involves the repeated measurement of the deformation of the Earth. As discussed here, it is a cost‐effective approach for inferring reservoir integrity and detecting possible leakage associated with the geological storage of greenhouse gas emissions. Most geodetic methods have favorable temporal sampling, from minutes to months depending upon the technique adopted, and can detect anomalous behavior in a timely fashion. Satellite‐based approaches such as Interferometric Synthetic Aperture Radar (InSAR), with their high spatial resolution and broad coverage, are particularly well suited for monitoring industrial‐scale storage efforts. Multitemporal analysis, such as permanent scatterer techniques, are improving the accuracy of surface displacement measurements to better than 4 – 5 mm. New satellites, including the recent X‐band systems, are allowing for the routine estimation of two components of deformation. Data interpretation and inversion techniques may be used to relate the observed displacements to injection‐related volume change at depth. InSAR monitoring was used successfully at a gas storage site at In Salah, Algeria, where it was determined that the flow in the reservoir was influenced by large‐scale fault/fracture zones. InSAR observations are also key components of the monitoring programs at the Aquistore CO2 storage project in Canada, and the Illinois Basis Decatur Project in the United States. Current InSAR data from both sites indicate no major surface deformation that might be attributed to the stored carbon dioxide, suggesting that the injected fluid remains at depth.
2.1. INTRODUCTION
Geodetic monitoring, the repeated measurement of displacements and strains, both on the surface and within the interior of the Earth, provides an important class of techniques for assuring the safety of geological storage and for detecting leakage. There are important advantages associated with geodetic methods. The observations are usually gathered frequently in time, from every few minutes to every few months, depending upon the type of data. There are a diverse set of instruments for measuring strain and displacement in various configurations, either on the Earth's surface, at depth, or even from space. Thus, geodetic measurement may often be gather remotely, greatly simplifying data collection and allowing for cost‐effective monitoring, particularly in comparison with more intrusive techniques such as seismic surveys. The Earth often deforms in response to fluid injection, particularly at the volumes and rates associated with the geological storage of carbon dioxide. Therefore, geodetic observations are sensitive to fluid volume and pressure changes and may be used to monitor the fate of injected fluids. The magnitude of surface
