Keynotes

KEYNOTES

Confirmed Keynote Speakers

Institute of Mine Seismology- Chairman and Head of Research

“Ground Motion Hazard”

Aleksander graduated from the Silesian University of Technology in Poland with a PhD in seismology in 1981 where he also worked as an Assistant Professor. In 1985 he took a position as a Head of the Seismology at Anglo American Co-orporation in South Africa. From 1991 he was appointed the Managing Director and Head of Research at ISS International Limited (ISSI) in South Africa and from 1994 also the Managing Director of ISS Pacific (ISSP) in Australia. In 2010 he founded the Institute of Mine Seismology in Australia and in South Africa, which acquired both ISSI and ISSP, and became its Chairman and Head of Research.

His main areas of expertise are: monitoring seismic rock mass response to mining, quantification of seismic sources and near-source ground motion, deterministic and probabilistic seismic hazard assessment in mines, and the application of quantitative seismology to rock mass stability.

He is the editor and the main author of the book “Seismic Monitoring in Mines” published by Chapman and Hall in 1997 in London (ISBN 04I2753006). Recently he has authored the Mine Seismology Reference Book: Seismic Hazard, published by the Institute of Mine Seismology.

Professor Emeritus- Laurentian University, Canada

“Ground control in bursting ground – A critical review of design principles”

Peter is a graduate of the Federal Institute of Technology in Zurich, Switzerland, and the University of Alberta in Edmonton, Canada. Since 1987 until his recent retirement, he was Professor and Chair for Rock Engineering and Ground Control at the Bharti School of Engineering of Laurentian University in Sudbury, Canada. In 2000, he was seconded to the Centre for Excellence in Mining Innovation (CEMI) as Founding Director and then as Director of the Rio Tinto Centre for Underground Mine Construction (RTC-UMC). He also holds an Adjunct Professorship at the University of Waterloo in Canada.

Dr. Kaiser is the author of more than 350 technical and scientific geomechanics publications. He has received many awards including awards from the International Society for Rock Mechanics, the Canadian Geotechnical Society and the Canadian Institute of Mining. He is a Fellow of the Engineering Institute of Canada (EIC) and the Canadian Academy of Engineers and, in 2013, was awarded the Julian C. Smith Medal of for his “Achievements in the Development of Canada” and was named the “Tunneller of the Year” by the Tunnelling Association of Canada.

He is a specialist in applied research for underground construction and mining. His interests lie in geomechanics, mine design, rock engineering, ground control in bursting rock and the application of innovative technologies to increase mine safety and productivity. He brings extensive experience from both the industrial and academic sectors, having served as consultant to numerous consulting companies, mines, and public agencies. He has supported contractors, mining companies and public sector clients during Coroner’s inquests and litigations on four continents.

Consultant- Institute of Mine Seismology, South Africa

“Seismic sources and rockburst damage – observations from South African and South American mines”

Gerrie is a graduate of the University of the Orange Free with a PhD in Geology. Over 30 years of experience in research projects focussed on the tectonic evolution of Namaqualand Metamorpic Complex andits transition into the Haib Province. Since 1985 research focussed on mine seismology: fault stability, mine layout and seismic hazard, short term seismic hazard, seismic source mechanisms, the integration of numerical modelling with seismic monitoring and the forensic analyses of dynamic deformation processes. The results of his studies have been around 40 publications in conference proceedings and scientific journals, mainly on aspects of mine seismology.

Management of Seismicity Induced by Caving Mining under High Stress condition

Studied Mining Engineering at the Universidad Técnica del Estado; Santiago de Chile and obtained his MSc in Mineral Economy at the Curtin University, Australia.

Throughout his carrier, he gathered many years of experience in mining implementing the geomechanics approach in the design and operation. He has involved in the developed of a control seismicity induced system in the biggest underground mine in hard rock. He has authored many papers of caving mining.

At El Teniente Mine, various geomechanical problems can be recognized, however, the most complex phenomenon, and which generates a greater impact into the mining operation is the induced seismicity. Induced seismicity may generate damage (rock burst) consequence to both the mine infrastructure and the people. These damages also affect, undoubtedly, to the fulfilment of the production goals, which detriment the mining business.

Since the eighties to date, with the aim of tackling the problem, it has been implemented a series of mitigation measures, which have addressed both from a strategic point of view, and as tactician. In strategic terms, measures have been implemented associated with the development and improvement of the mining methods, the mining rate control, the installation of seismic monitoring systems, and the incorporation of hydraulic fracturing, among others. Regarding the tactical order measures, these have been associated with the change in the mining designs and improvement of ground support systems drifts.

The following chart shows the number of rock bursts per year and the primary mineralization mining in thousand tons per day (Ktpd). It can be observed a decrease of the frequency of rock bursts, due to mitigation measures which goes hand in hand with the understanding of the problem.

Invited Lecture

Head, Department of Seismology, Institute of Geophysics, PAS
Chair, Triggered and Induced Seismicity (TAIS) Working Group, IASPEI

“A catastrophic event in Rudna copper-ore mine in Poland on November 29th, 2016: what, how and why”

November 29, 2016 a M3.4 seismic event occurred in the mining sector G-23 of Rudna copper-ore mine in Legnica-Glogow Copper District in south-western Poland. The event caused an extended damage. Adjacent excavations were completely destroyed as far as up to more than 1km from the event epicenter. As a consequence, eight miners lost their lives. Neither the occurrence of this event nor its size was exceptional. The underground copper-ore mining in Rudna, carried on at the depth some 900 m in hard and rigid rocks, has been accompanied by intense induced seismicity. Yearly about one thousand events of local magnitude above 1.5 are registered. Occasionally, events of magnitude M4 and stronger occur. This seismic activity gives rise to considerable ground motion, which affects buildings and other surface structures from the area. However, the tragic result of the November, 29th event was exceeding. This was the greatest tragedy in the 55 years history of KGHM “Polska Miedź” SA, the company, which carries on copper ore exploitation in Legnica-Glogow Copper District.

 

The seismicity on Rudna mine is monitored by an in-mine system composed of 32 stations and a surface network comprising 15 stations. Moreover, 43 free field accelerometric stations record ground motion due to seismic events. We present here the details on this event and the results of an integrated, comprehensive analysis aiming at understanding of reasons of the event occurrence and its exceptional damaging aftereffects. The analysis is based on recordings of the above mentioned seismic and ground motion systems, supplemented by geological and mining information provided by the mine. The geomechanical model and the seismic and mining context are linked with the source mechanism and spectral parameters of the event in order to explain the coseismic and post seismic effects, as well as an anisotropic pattern of ground motion.

Invited Presentation

Chief Technology, ESG Solutions, Canada

“Potential of Seismic Analysis in Hydraulic Fracture Stimulations in Mining: Learnings from Over a Decade of Application in the Petroleum Industry”

Over the past two decades, microsesimic monitoring has become the approach most often used to gain an in-situ understanding of the reservoir’s response during hydraulic fracture stimulations (HF). From initial monitoring performed in the Cotton Valley and Barnett Shale plays in Texas, circa 2000, to monitoring now being conducted throughout North American unconventional plays, we review the evolution of microseismic monitoring from data collection (single versus multi-well array configurations, adaptation to monitoring of long lateral stimulation wells with lengths over 3 km), to standard data analysis and the incorporation of unique microseismic approaches to constrain and validate reservoir models, and to design optimal economic extraction programs (eg., topology and percolation theory, collective description of deformation). Furthermore, we discuss the variations in microseismic behavior for different stimulation programs such as zipper-fracs, and stimulation proppants, fluids, pressures, and slurry-rates. We use the collective understanding from the petroleum industry to consider the prospective application of HF techniques to the mining industry, the potential of utilizing microseismic monitoring approaches for charactering the stress and fracture state resulting from stimulation programs, and tying the fracture complexity to improving extraction approaches and economics.

University of British Columbia, Vancouver, Canada

Modeling multi-scale processes in hydraulic fracture propagation using the Implicit Level Set Algorithm (ILSA)

In this talk I describe an implicit level set algorithm (ILSA) suitable for modeling multi-scale behavior in planar hydraulic fractures propagating in three dimensional elastic media. The novel ILSA scheme (Peirce 2015, Dontsov & Peirce, 2017)) is able to represent the required multi-scale behavior on a relatively coarse rectangular mesh. This is achieved by using the local front velocity to construct, for each point of a set of control points, a mapping that adaptively identifies the dominant length scale at which the appropriate multi-scale universal asymptotic solution needs to be sampled. Finer-scale behavior is captured in a weak sense by integrating the appropriate universal asymptotic solution for the fracture width over partially filled tip elements and using these integrals to set the average values of the widths in all tip elements. The ILSA solution shows good agreement with a multi-scale reference solution comprising a radial solution that transitions from viscosity to toughness dominated propagation regimes. The ILSA scheme is also used to model blade-like hydraulic fractures that break through stress barriers located symmetrically with respect to the injection point. For the zero toughness case, the ILSA solution shows close agreement to experimental results. The multi-scale ILSA scheme is also used to provide results when the material toughness KIc is non-zero, and in which fluid from the fracture leaks into the porous rock. In this case, different parts of the fracture-free-boundary can be propagating in different regimes. We demonstrate how these reference solutions have been used to construct reduced order models that can execute in a fraction of the original computational time. I also provide examples in which this methodology is used to model multiple hydraulic fractures that propagate simultaneously in parallel planes. These multi-fracture models highlight surprising dynamics between the interacting fractures that indicate significant potential for using numerical design to improve production.