Question: How can we unravel the links between induced microseismicity and the stress field?

Dr. Volker Oye graduated Goethe University Frankfurt, Germany in 2000 (Diploma thesis on true amplitude migration) and made a PhD at University of Oslo and NORSAR in 2004 on Observation and Analysis of Microearthquakes. In the following years Oye worked on induced and triggered microseismicity in various environments such as mines, hydrocarbon reservoirs, geothermal reservoirs, CO₂ storage and also on lab-scale acoustic emissions. Since 2013 Oye is head of the Department on “Earthquakes and the Environment” at NORSAR.

Hypothesis Statement: Small, critically stressed fractures that are distributed in clusters with variable orientation are triggered to slip as a response to small changes in the in-situ stress field, associated with minor increases in pore pressure.

This research theme will cover many aspects of processing, interpreting, and understanding the relation between microseismic waveform data and anisotropy changes of the in-situ rock conditions. In addition, this research will compare field-scale observations of induced seismicity with acoustic emission (AE) data from laboratory experiments. Because laboratory experiments use fully characterized rocks samples and rigorous control on perturbations, e.g., the applied stress field, it will work with both waveform data from AEs and field-scale observations of microseismic events. Rock samples will be cut and prepared in the laboratory to mimic a fracture zone at in-situ stress and pressure conditions. By injecting fluids at low pressures, the artificial fracture will be tested for slippage and AEs. Computational experiments will be conducted to understand the effect of pressure propagation at the continuum scale to cause microseismicity in small clusters as a consequence of very low pore pressure increases.

This research question directly aims at an improved understanding of the mechanism of injection-induced microseismicity. By comparing field-scale measurements of microseismic events with laboratory experiments on real rocks, this research will vary in-situ rock conditions (e.g., stress field and pressure changes) in real and simulated geologic settings to derive relations for stress- and pressure-induced triggering
of field-scale microseismicity.

Robert Bauer, MS University of Illinois, Urbana-Champaign Robert Bauer is an Engineering Geologist at the Illinois State Geological Survey, a Division of the PrairieResearch Institute at the University of Illinois. He has 38 years of experience with coal mine subsidence, landslides,soil and bedrock behavior during earthquakes, and underground excavation. He is a Licensed Professional Geologist.

Pierre Cerasi, PhD SINTEF Dr. Cerasi has been employed with SINTEF since 2000. His experience in geomechanics, as a leader and scientist, includes projects related to sand production, borehole stability in shales, geomechanics applied to carbon capture and storage (CCS), and formation damage. His work includes laboratory experiments, numerical simulations, and theoretical models. Dr. Cerasi received his PhD in biomechanics from the Paris University Denis Diderot in 1996.

Scott M. Frailey, PhD University of Illinois, Urbana-Champaign Dr. Scott M. Frailey is the Director of the GSCO2 and the chair of the Executive Committee. He provides scientific and technical leadership, as well as maintaining the functionality of the Center in terms of communication, collaboration, personnel assignments and recruitment of staff and advisory committee members. Scott's specific research is in the area of reservoir characterization that includes core analyses, well log analyses, and pressure transient analyses to provide reservoir rock properties to geocellular models for use in multiphysics flow and transport modeling.

Bettina Goertz-Allmann, PhD NORSAR Bettina Goertz-Allmann is a senior research scientist in the microseismic monitoring group at NORSAR, Norway, since fall 2012. She earned her PhD in 2008 with a focus on earthquake source physics at Scripps Institution of Oceanography, University of California, San Diego. After earning her PhD, she spent several years at the Swiss Seismological Service at ETH Zurich, first as a postdoctoral researcher and later as a senior assistant. Her research interests are earthquake scaling relations, source parameter estimation, and earthquake rupture imaging. Her current research focuses on analysis of induced microseismicity in geothermal and CO2 storage environments.

Roland T. Okwen, PhD University of Illinois, Urbana-Champaign Dr. Roland T. Okwen is a reservoir engineer at the Illinois State Geological Survey (ISGS), University of Illinois at Urbana-Champaign. As a member of the ISGS, he has contributed to the Midwest Geological Sequestration Consortium’s Phase II pilot studies in the Illinois Basin and continues to assist in the development of performance curves to act as screening tools for carbon dioxide (CO2) enhanced oil recovery floods. He was the principal investigator (PI) of a project that quantified the CO2 storage efficiency of different depositional environments. Currently, he is the PI of a project titled “Brine Extraction and Treatment Strategies to Enhance Pressure Management and Control of CO2 Plumes in Deep Geologic Formations.” Before joining the ISGS, Dr. Okwen was a Postdoctoral Research Associate at the Schlumberger Cambridge Research Center in the United Kingdom. He earned his PhD in civil engineering from the University of South Florida (2009), MS in petroleum engineering from the Technical University of Denmark (2005), and BS in chemistry from the University of Buea (1997). His research interests are in geological sequestration of CO2, enhanced oil recovery, reservoir geomechanics, and unconventional resources.

Sergey Stanchits, PhD AcEmission Consulting Sergey Stanchits received a PhD in physics and mathematics from Ioffe Physical-Technical Institute of the Russian Academy of Sciences in 1990. He has over 37 years of experience in Acoustic Emission application for research in Rock Mechanics laboratories in Russia, USA, and Germany. For 5 years, he worked for the US Geological Survey and then for the German Research Centre for Geosciences for over 10 years. Since 2010, he is the Head of Acoustic Technology in the Schlumberger Research Center, Fracture Dynamics and Performance Department, investigating hydraulic fracturing of rock by means of advanced Acoustic Emission technique.