Curtin/CSIRO Geophysics Group Seminar, 21st September 2022
A rapid VSP acquisition with DAS in mineral exploration
Date: Wednesday, 21st September 2022
Time: 11:00 AM – 12:00 PM
Location: ARRC Auditorium, 26 Dick Perry Avenue, Kensington; Microsoft Teams
Presenter: Konstantin Tertyshnikov, Exploration Geophysics, Curtin University
Abstract: In the last decade distributed fibre optic acoustic and temperature sensing has become quite extensively utilised for various reservoir exploration and monitoring tasks. Specifically, it gained a lot of attention for downhole seismic applications due to distinct directional sensitivity of fibre optic sensors along a cable and in addition due to usual downhole acquisition geometry, where P-waves approaching receivers along a bore and a cable.
There are also standard means of cable deployments in wells: cementing behind the casing, on-tubing installations, and wireline type deployments. In the energy industry DAS currently serves in many on-shore and off-shore applications the deployment strategy varies depending on the purpose of sensing and often tend to be permanent for monitoring tasks (cemented, on-tubing) and retrievable for exploration (wireline type). Despite the popularity in the energy sector, a much slower uptake of the technology is seen in the mineral industry.
There are a number of reported successful trials of using DAS for downhole seismic in mineral exploration. Even though DAS provides more cost-effective solutions for many downhole seismic applications, for mineral exploration some deployment strategies (like cementing for deep wells) are still considered a high cost. Here we present the results of a trial of the fast deployment of fibre optics using the FibreLine Intervention (FLI) probe in a mineral borehole and demonstrate the downhole seismic acquisition results.
Biography: Dr Konstantin Tertyshnikov received a doctorate degree in geophysics from Curtin University (Western Australia) in 2014. Konstantin worked as a geophysicist and project leader on a number of geophysical exploration projects in Russia, Europe, and the Middle East. At the present time, Konstantin is a Senior Research Fellow in the Centre for Exploration Geophysics at Curtin University. His main research focus is distributed acoustic sensing technologies, CO2 geosequestration, borehole seismic, mineral exploration and seismic acquisition.
Curtin/CSIRO Geophysics Group Seminar, 18th August 2022
Time-lapse impedance monitoring using borehole seismic amplitudes of earthquake waves
Date: Thursday, 18th of August, 2022
Time: 11:00 AM – 12:00 PM
Location: WA-Kensington-B2-F3-R00-Seminar Room, 26 Dick Perry Avenue, Kensington; Microsoft Teams
Speaker: Kitty Milliken, Bureau of Economic Geology, Jackson School of Geosciences, University of Texas at Austin
Abstract:
The fine-grained sediments and rocks that constitute most of the sedimentary record have received tremendous research attention in the past decade. This talk reviews some of the technologies that have supported these advances and summarizes current knowledge of the pore-scale processes that drive the evolution of bulk rock properties of mud in the subsurface.
Electron microbeam instrumentation has been central to improving our understanding of fine-grained sediment. In particular, improvements in resolution offered by field-emission electron guns and advances in sample preparation by various ion-milling techniques have allowed researchers to see tiny grains and pores in unprecedented detail. Grain assemblages in mudrocks vary across a very broad compositional range and the initial compositions in muds have significant implications for the evolution of properties relevant to reservoir quality in mudrocks.
It is now clear that the principal diagenetic processes of sandstones and limestones, compaction, and cementation, also operate in mudrocks. Quantification of compaction and cementation is central in the quest to refine a predictive understanding of the evolution of mudrock properties in the subsurface.
Biography:
Kitty L. Milliken is a Senior Research Scientist at the Bureau of Economic Geology, University of Texas at Austin. She received a B.A. in geology (1975) from Vanderbilt University and M.A. (1977) and Ph.D. (1985) degrees from UT Austin. Her research focuses on diagenesis of siliciclastic sediments and the evolution of rock properties in the subsurface. She has authored and co-authored over 120 peer-reviewed papers and digital resources for teaching sedimentary petrography. Her current work is focused on the application of electron microbeam imaging and analysis to interpret chemical and mechanical histories of mudrocks.
Curtin/CSIRO Geophysics Group Seminar, 11th August 2022
Time-lapse impedance monitoring using borehole seismic amplitudes of earthquake waves
Date: Thursday, 11th of August, 2022
Time: 11:00 AM – 12:00 PM
Location: ARRC Auditorium, 26 Dick Perry Avenue, Kensington; Microsoft Teams
Speakers: Professor Andrej Bona and Pavel Shashkin; Exploration Geophysics, Curtin University
Abstract:
As shown by several recent studies, the amplitude of the direct wave recorded by distributed acoustic sensors can be used as a proxy for the elastic properties. This concept was recently employed by the Curtin geophysics team to monitor temporal changes of elastic properties along the wellbore using waves from both controlled sources and earthquakes. In this talk, we analyse the theoretical background of the method and discuss its variations. We then demonstrate its practical application by using waves from regional earthquakes to monitor a CO2 injection within the Otway Stage 3 Project.
Biographies:
Andrej Bona received his MSc in theoretical physics from Czech Technical University in Prague in 1997, and PhD in applied mathematics from University of Calgary in 2002. From 2002 to 2003 he was a post-doctoral fellow at Memorial University in Canada, where he subsequently worked as assistant professor till 2007. He is currently a professor at the Centre for Exploration Geophysics, Curtin University (Perth, Australia). His research interests are in seismic wave propagation, including anisotropy and imaging, with applications mostly to mineral exploration.
Pavel Shashkin received MSc in geophysics from Moscow State University in 1996. He has over 25 years’ experience in seismic data processing, workflow building and optimization, geological and geophysical data management and high-performance computing hardware and software management. Currently he is a Research Fellow at Centre for Exploration Geophysics, Curtin University, specialising in processing of diverse types of seismic data including borehole distributed acoustic sensing and passive seismic records.
Curtin/CSIRO Geophysics Seminar, 21st July 2022
Distributed acoustic sensing (DAS) for seismic-frequency laboratory measurements of elastic properties: recent progress
Date: Thursday, 21st of July, 2022
Time: 11:00 AM – 12:00 PM
Location: CSIRO Seminar room (WA-Kensington-B2-F3-R00-Seminar); Microsoft Teams
Abstract: Forced-oscillation stress-strain laboratory measurements are increasingly employed to obtain elastic and viscoelastic properties of rocks at seismic frequencies. Yet these measurements are slow time-consuming and expensive, due in part to the use of metal or semiconductor strain gauges, which need to be glued to the sample. Such gauges are fragile, have relatively low sensitivity, and measure very local strain only so that the measurements can be affected by a slight misalignment of the system assembly and local heterogeneity of the rock. The emergence of fibre-optic distributed acoustic sensing (DAS) technology provides an alternative means of measuring strain. Ultra-low strain measurements with DAS involve winding an optical fibre around the sample multiple times and connecting it to a DAS recording unit.
In this presentation we will report progress results on the development of a rock physics apparatus able to characterise elastic properties of the rocks at seismic frequencies using DAS.
The feedback of the audience is crucial to progress further.
References: Yurikov et all., (2021) The Leading Edge 40, 655-661.
Biography: Professor Maxim Lebedev is accountable for Rock Physics Experiments at Curtin University.
Curtin/CSIRO Geophysics Group Seminar, 28th July 2022
Reservoir Rock and Fluids Interactions and Their Implications on Geo-Energy and Energy Storage
Date: Thursday, 28th of July, 2022
Time: 11:00 AM – 12:00 PM
Location: CSIRO/ARRC Auditorium, 26 Dick Perry Avenue, Kensington; Microsoft Teams
Presenter: Dr Sam Xie, Lecturer, Petroleum Engineering, Curtin University
Abstract: Reservoir Rock-Fluids Interactions are important physiochemical processes, which play an important role in Hydrocarbon Recovery, CO2 Geological Storage, and Underground Hydrogen Storage. Understanding such physiochemical processes at small length scale (nano-, micro- and core-scale) will enable industry to better manage uncertainties and risks at large-scale (i.e., kilometres) for geo-energy development, CCS and Underground Hydrogen Storage.
In this seminar, Sam will reveal how the reservoir rock-fluids interactions affect in-situ wetting conditions together with initial water morphology and fluid-fluid interactions on low salinity waterflooding, which is a cost-effective and environmentally friendly technology to help industry achieve energy transition. Moreover, Sam will also present how reservoir rock-fluids interactions affect fracture mechanics, which has significant implications on CCS and Underground Hydrogen Storage through nano-scale and core-scale experimental results together with thermodynamics.
Sam’s presentation may shed light on de-risking low salinity waterflooding uncertainties, and storage integrity of CCS and Underground Hydrogen Storage in subsurface.
Biography: Dr Sam Xie is a Lecturer, Research Focus Group Lead of Petroleum Engineering Discipline at Curtin University. He is an interdisciplinary researcher specialising in fluid-rock interactions, rock flow dynamics for applications in IOR, CCS, Underground Hydrogen Storage. The goals of his research are to: 1) develop cost-effective and environmentally friendly techniques to unlock hydrocarbon resources from subsurface; 2) capture and sequestrate CO2 at subsurface to reduce carbon footprint; and 3) identify large-scale, long-term storage systems for hydrogen storage at subsurface.
Curtin/CSIRO Geophysics Seminar, 30th June 2022
Seismic attenuation parameters in volcanic rocks at a variety of scales
Date: Thursday, 30th of June, 2022
Time: 1:30 PM – 2:30 PM
Location: CSIRO/ARRC Auditorium, 26 Dick Perry Avenue, Kensington; MS Teams
Presenter: Dr Pilar Di Martino
Interpretation of seismic data is the most common geophysical method used for mapping and characterizing the interior of the Earth. However, an important portion of this data is attenuated by seismic scattering and absorption, which manifest themselves as seismic coda waves. Much uncertainty exists about the relationship between the stochastic wave-packets comprised in the seismic coda, the total attenuation we can measure from them, and the intrinsic physical properties of the propagating medium.
In this framework, this study explores the connection between attenuation and scattering parameters, with rock properties (petrophysical/mineralogical) and lays down the use of these parameters to contribute to imaging techniques of heterogeneous sequences. This is tackled through: (1) an extensive petrological and mineralogical characterization of volcanic rocks at the laboratory scale; (2) acquiring S-wave waveforms at ultrasonic frequencies and calibrating the recording of the coda waves to perform attenuation analyses; (3) modelling the full seismic wavefield in synthetic samples using spectral element methods; and (4) performing scattering and absorption tomography in a real volcano, using active data recorded at meter spacing.
The findings show the relevance of including stochastic attenuation parameters in the characterization of heterogeneous settings, like volcanoes, in which the analysis of phases provides insufficient details on the interactive processes taking place.
Short biography:
Pilar just completed her PhD through a joint programme between the University of Aberdeen and Curtin University (http://aberdeencurtinalliance.org/ ). During her time at Curtin (2019), she was based at the Centre for Exploration Geophysics working on connecting ultrasonic attenuation parameters with rock physical properties. Pilar recently joined Schlumberger in Milan as a geophysicist.
Curtin/CSIRO Geophysics Seminar, 2nd June 2022
Implementation of deep learning algorithms for digital rock analysis
Date: Thursday, 16nd of June, 2022
Time: 11:00 AM – 12:00 PM
Location: CSIRO/ARRC Auditorium, 26 Dick Perry Avenue, Kensington
Presenter: Dr. Alexandra Roslin (University of Queensland)
Nowadays, deep learning algorithms are widely used for many geosciences applications, including digital rock analysis. For example, deep learning may increase the accuracy of image segmentation or perform rock type classification, enhance the resolution of the micro-CT images and suppress the background noise. Combining deep learning algorithms and machine learning clustering may help predict rock properties based on wellbore data or rock texture depending on reservoir conditions. Deep learning is a growing area of research, and it will find more and more applications in future.
Short biography
Dr. Alexandra Roslin is a postdoctoral research fellow at the University of Queensland and visiting research fellow at Curtin University. She graduated from Novosibirsk State University with a Bachelor of Science (Geology) degree. After working for several years in the oil and gas service industry, she moved to Australia to work in unconventional gas reservoirs. She graduated from the University of Queensland with an MPhil (Earth Sciences) degree and the University of Aberdeen with a PhD (Petroleum Engineering) degree. Alexandra’s current work focuses on implementing deep learning algorithms for digital rock analysis (fracture analysis, mineral segmentation, etc.).
Curtin/CSIRO Geophysics Seminar, 2nd June 2022
Water for food, desalination and how to find fractured rock aquifers with geophysics and drilling; examples from the Wheatbelt of Western Australia
Date: Thursday, 2nd of June, 2022
Time: 11:00 AM – 12:00 PM
Location: CSIRO/ARRC Auditorium, 26 Dick Perry Avenue, Kensington
Authors/Research Team: Brett Harris, Richard George, Richard Chopping, and Matt Becker
Presenter: Brett Harris, Professor, Discipline Lead – Exploration Geophysics, WASM: Minerals, Energy and Chemical Engineering, Curtin University
Supply of high-quality water is critical for global food production. This challenge can be acute in arid to semi-arid regions. New water treatment technologies such as solar driven desalination have potential to transform brackish groundwater into water suitable for food production at reasonable cost. Does this mean that brackish groundwater held in fractured rock aquifers could be a new long-term water resource?
Fractured rock aquifers can be productive but are notoriously high-risk drill targets. Integration of geophysics and exploratory drilling will be needed for: (i) fractured rock aquifer prospectively mapping, (ii) targeting of wells at farm scale, and (iii) rapid quantification of groundwater resources across a wide range of water qualities. We will consider the status of our knowledge for targeting fractured rock aquifers and the criteria for prospectivity mapping with examples from the Wheatbelt of Southwestern Australia. Here fault systems many hundreds of kilometres long are clearly observed in magnetic imaging, but which of these structures are more likely to host viable aquifers?
We review apparent temporal and spatial association of faults and fractured rock aquifers. Finally, we review the integration of drilling and geophysics needed to facilitate distributed water supply from fractures in the context of: (i) dry land salinity, (ii) solute concentration distribution, (iii) relationships between fractured rock aquifers and water stored in regolith/cover and (iv) requirements for brine disposal from desalination processes.
Curtin/CSIRO Geophysics Seminar, 19th May 2022
Applicability of Gassmann theory to fully and partially saturated nano-porous media
Date: Thursday, 19th of May, 2022
Time: 11:00 AM – 12:00 PM
Location: CSIRO/ARRC Auditorium, 26 Dick Perry Avenue, Kensington
Presenter: Boris Gurevich, John Curtin Distinguished Professor, Director of Centre for Exploration Geophysics, WASM: Minerals, Energy and Chemical Engineering, Curtin University
Recent progress in extraction of unconventional hydrocarbon resources has ignited the interest in the studies of nanoporous media. Since many thermodynamic and mechanical properties of nanoscale solids and fluids differ from the analogous bulk materials, it is not obvious whether wave propagation in nanoporous media can be described using the same framework as in macroporous media. Application of poroelastic models to the data measured on fluid-saturated rocks is challenging, because the poroelastic effects in such complex media are often obscured by other phenomena, such as squirt flow. Nanoporous Vycor glass, which has a narrow pore size distribution, provides an excellent medium for testing those models.
We test the validity of Gassmann’s equation using two published sets of ultrasonic measurements for a model nanoporous medium, Vycor glass, saturated with two different fluids, argon, and n-hexane. Predictions of the Gassmann theory depend on the bulk and shear moduli of the dry samples, which are known from ultrasonic measurements and the bulk moduli of the solid and fluid constituents. The solid bulk modulus can be estimated from adsorption-induced deformation or from elastic effective medium theory. Substitution of these parameters into the Gassmann equation provides predictions consistent with measured data.
To test applicability of poroelastic patchy saturation models to nano-porous materials, we consider ultrasonic measurements during adsorption and desorption of n-Hexane vapor on nanoporous Vycor glass (Page et al., 1995). As vapor pressure is increased from zero to the saturation pressure, the vapor is adsorbed on the pore walls, resulting in gradual increase of the liquid fraction. The reverse process occurs when pressure is decreased, but the ‘drying’ of the nanopoorus glass is heterogeneous, resulting in a very different velocity-saturation relationship. These results suggest that ultrasonic measurements are a promising method for studying fluid distributions in nano-porous geomaterials such as shale or coal.
Curtin/CSIRO Geophysics Group Seminar, 5th May 2022
Measuring Hydromechanical Strain using Fiber Optic Distributed Acoustic Sensing
Date: Thursday, 5th of May, 2022
Time: 11:00 AM – 12:00 PM
Location: CSIRO/ARRC Auditorium, 26 Dick Perry Avenue, Kensington
Presenter: Matthew W Becker, Professor of Geology and Conrey Chair in Hydrogeology, California State University, Long Beach, California and 2022 Fulbright Scholar in Resources and Engineering Curtin University
Mapping subsurface hydraulic connectivity and storage is a requirement for petroleum resources, geothermal energy, groundwater resources, and aquifer remediation, among other applications. Hydraulic connections are complex in most geologic environments so measurements of permeability and storativity (compliance) that are averaged over screened or perforated intervals can be very limited in practice. The rapid advancement of distributed fiber optic temperature, vibration, and strain sensing has presented new opportunities to elucidate the hydraulic structure of formations.
Matthew will present our use of fiber optic Distribute Acoustic Sensing (DAS) to measure hydraulic structure in bedrock and unconsolidated media. The technical key is to push DAS to ultra-low frequency so that it can be used as an extremely high resolution (picostrain) distributed strain sensor. Examples from the laboratory and a bedrock field experiment will be discussed, as well as some preliminary results from experiments conducted in the NGL well on Curtin Campus. These results will hopefully stimulate discussion on future applications and interpretations of distributed fiber optic sensing.
Matthew Becker is a Professor of Geology and the Conrey Chair in Hydrogeology in the Geological Sciences Department at California State University Long Beach, California, USA. He holds a B.S. in Geology from Michigan State University and M.S. and Ph.D. in Civil Engineering from the University of Texas at Austin. He has held positions with Chevron USA, and Los Alamos National Labs, and U.S Geological Survey National Research Program. He was a National Academy of Science Senior Research Associate at NASA Goddard Space Centre and was a Fulbright Scholar at the University Trento, Italy. Prior to arriving at the CSULB he was an Assistant then Associate Professor of Geology at the University of Buffalo. His primary focus of research is the hydraulic connectivity of fluid flow in heterogeneous subsurface environments also but has projects in managed aquifer recharge and submarine groundwater discharge.