Keynote speakers

Sunday, 20 June 2021

12th Annual MTS Lecture

To be determined

Monday, 21 June 2021

Keynote address

Ahmad Ghassemi

Professor, University of Oklahoma

Some recent advances in reservoir geomechanics

Keynote description

Petroleum rock mechanics, or more generally reservoir geomechanics, has been a major research and development theme since at least the early 1990s when the need to cope with practical challenges in wellbore stability, hydraulic fracturing, and reservoir compaction necessitated accounting for the role of coupled poroelastic and later thermo-poro-chemoelastic processes. The renewed interest in unconventional petroleum and geothermal energy resources has given impetus to a new flurry of experimental and modeling research in reservoir geomechanics with emphases on reservoir creation and management and seismicity mitigation. This keynote will present recent developments with reference to reservoir stimulation and seismicity and resource extraction potential, highlighting the critical role geomechanics continues to play in geothermal and petroleum reservoir development.

Speaker’s biography

Ahmad Ghassemi is the McCasland Chair Professor in the Mewbourne School of Petroleum and Geological Engineering at the University of Oklahoma and Director of the Reservoir Geomechanics and Seismicity Research Group. He has a Ph.D. in Geological Engineering and specializes in geomechanics for unconventional geothermal and petroleum reservoir development. Dr. Ghassemi has been working on modeling and experimental rock mechanics for over 25 years with emphasis on physics-based simulation of multi-stage hydraulic fracturing, coupled geomechanics / fluid flow in naturally fractured reservoirs, wellbore stability, induced seismicity, and experimental characterization of reservoir rocks and their response to injection. His teaching interests include reservoir geomechanics, reservoir stimulation and modeling, and petrophysics.

Monday, 21 June 2021

Early Career Keynote Address

Hiroki Sone

Assistant Professor, University of Wisconsin-Madison

Ductile deformation of seemingly brittle rocks and their importance in modern geomechanical problems

Keynote description

Rocks encountered at engineering depths typically behave as a linear-elastic medium and fail by brittle fracturing when tested at short time scales of most rock mechanics tests. However, at longer time-scales, crustal rocks can also exhibit time-dependent ductile deformational behavior due to their porous nature and/or the presence of some ductile phases. Such ductile behavior must be accounted for in geomechanical analyses for accurate prediction of deformation and stress. This talk will show laboratory data of some crustal rocks that characterize the ductility of seemingly brittle rocks and present analyses that demonstrate their geomechanical significance.

Speaker’s biography

Hiroki Sone is an assistant professor in the Geological Engineering program at University of Wisconsin-Madison. He received education in geology and geophysics, and his expertise is in experimental rock mechanics and geomechanics. Research interests include earthquake fault mechanics, geomechanics of unconventional and geothermal reservoirs systems, in-situ stress measurement techniques, and rock physics. Recently, he has focused on studying the long-term ductile properties of clay-rich rocks and fault rocks with implications for stress accumulation/relaxation in the lithosphere over time, long-term productivity of unconventional gas reservoirs, and integrity of waste disposal sites. His teaching interest includes rock mechanics, geomechanics, tectonophysics, and design of underground openings.

Tuesday, 22 June 2021

3rd ARMA Distinguished Lecture

Mark Zoback

Professor of Geophysics, Stanford University

Utilizing physics-based models to manage the risk of injection-induced seismicity associated with unconventional oil and gas production

Keynote description

The occurrence of earthquakes induced by wastewater injection and hydraulic fracturing is well documented in areas of unconventional oil and gas development around the world. In this lecture, the reasons how and why these earthquakes occur will be described, and the steps that can be taken to minimize the occurrence of such earthquakes will be outlined. One key step is the identification of potentially problematic faults prior to fluid injection (or hydraulic fracturing); another one is related to understanding how pressure diffusion and/or poroelastic stress transfer affects the likelihood of triggering fault slip.

Speaker’s biography

Mark D. Zoback is the Benjamin M. Page Professor of Geophysics at Stanford University, Director of the Stanford Natural Gas Initiative, and Co-Director of the Stanford Center for Induced and Triggered Seismicity. Dr. Zoback conducts research on in situ stress, fault mechanics, and reservoir geomechanics with an emphasis on shale gas, tight gas, and tight oil production. He is author of two textbooks and author or co-author of about 400 technical papers. His first book Reservoir Geomechanics was published in 2007 by Cambridge University Press. His online course, based on this book, has been completed by over 10,000 students around the world. A new book titled Unconventional Reservoir Geomechanics, written with Arjun Kohli, was published in 2019.  Dr. Zoback has received numerous awards and honors, including election to the U.S. National Academy of Engineering in 2011 and the Robert R. Berg Outstanding Research Award from AAPG in 2015.

Wednesday, 23 June 2021

Keynote address

Matthew Pierce

President, Pierce Engineering

Post-peak and residual strength of rock masses

Keynote description

Estimating the post-peak strength of rock masses remains a challenge for practicing rock mechanics engineers. Different criteria have been proposed, ranging from the use of a disturbance factor or reduced rock mass quality within the Hoek-Brown criterion to the adoption of a Mohr-Coulomb criterion informed by a fully bulked soil or rockfill. This keynote lecture will offer a critical review of existing approaches and will outline the need for a criterion that honors well-established rock mass and rockfill behaviors, including non-linearity of the shear strength envelope, cohesion weakening, frictional strengthening / weakening, and the sensitivity of shear strength to porosity, rock block strength, and rock block angularity. Applications of the criterion to the analysis of tunneling and mass mining will be presented to illustrate the relevance of the underlying behaviors, followed by a discussion of potential directions for future research and development.

Speaker’s biography

Matthew E. Pierce is an independent geological and mining engineering consultant with 25 years of experience in the geomechanical analysis of underground and open pit mines, with specialization in the forecasting of caveability/overbreak, fragmentation, recovery/dilution, infrastructure stability, and surface subsidence and the assessment of hazards related to induced seismicity and inflows. He has pioneered methods for the estimation of rock mass properties and has developed specialized tools and constitutive models for the study of mining-induced rock mass yield, fragmentation, collapse, and gravity flow from tunnel-scale to mine-scale. In 2013, Dr. Pierce received the Rocha Medal for outstanding Ph.D. thesis in rock mechanics from the International Society for Rock Mechanics and Rock Engineering (ISRM) for his study of gravity flow and draw control in caving mines.