VIC

Vic Tech Night - A new Full Spectrum FALCONⓇ airborne gravity and aeromagnetic survey over the Otway Basin, Victoria

Tuesday, October 1, 2019
1800
1930

Dr Mark McLean, Geological Survey of Victoria presents a talk titled A new Full Spectrum FALCONⓇ airborne gravity and aeromagnetic survey over the Otway Basin, Victoria.

Tickets here

Our next meeting will be a joint event with the Young Professional Group and will happen on the 1st of October 2019. As usual it will be held at the Kelvin Club from 6 pm onward.

We will have the pleasure to welcome Dr Mark McLean from the Geological Survey of Victoria with a presentation about the Falcon survey that was acquired recently in the Otway Basin.

Please register before the 30/09/2019 noon time using the Eventbrite link.

In case of dietary requirement please email directly to vicpresident@aseg.org.au.

Abstract

Seismic surveying has been demonstrated to be the most effective technique to image sub-surface geological structure, particularly within sedimentary basins characterised by sub-horizontal stratigraphy where seismic energy is readily reflected back to the surface. However, there are some examples where seismic acquisition does not provide the most effective results: 1) where the area of interest lies along the coastal transition zone making acquisition problematic, 2) where there are sub-vertical geological structures (such as faults) which cause the seismic energy to be reflected away from the sensors and 3) where volcanic rocks attenuate the seismic signal.

Airborne Gravity Gradiometry (AGG) is a technique which measures very small changes in Earth’s acceleration. This approach is appropriate for the Otway Basin particularly in the transition zone where the geology is poorly understood. Qualitative interpretations can be made in map view, but data can also be quantitatively modelled using forward and inversion modelling processes. This approach makes airborne gravity gradiometry a complementary dataset for most of the seismic in the Otway which is dominated by 2D lines. Therefore, airborne methods provide an opportunity to not only ‘fill in the gap’ along the coast between seismic data collected off-shore and onshore, but there is also potential to add further detail to horizon geometries in between the more widely spaced (3-4km) seismic lines.

A new airborne Full Spectrum Gravity and magnetic survey has been undertaken as part of the Victorian Gas Program (VGP) using CGG’s FALCON® airborne data acquisition system. Flying commenced in August 2018 and was completed by early January 2019 (12 weeks). A total of 31042 line km of gravity, gravity gradiometry (Full Spectrum), magnetic and laser scanner data were acquired along 500 m spaced lines in a NW-SE orientation and 15000 m perpendicular tie lines. The surveyed region includes approximately 16000 km2 of the Otway Basin in Victoria, stretching from the edge of the Otway Ranges to the South Australian border, and from south of the Grampians to approximately 18 km offshore. Data were acquired at an altitude of 150 metres, increasing to 300 metres over built-up areas. A single engine Cessna Grand Caravan 208B was used to conduct the onshore portion of the survey and a DHC-6-100 (Twin Otter) aircraft was used for the offshore component. The survey has resulted in the largest airborne gravity dataset ever collected in Victoria and provides superior quality gravity imagery, compared with pre-existing data.

This presentation will visit a range of topics including the initial rationale for the survey, survey design, instrumentation and acquisition, but some emphasis will be placed on the new Full Spectrum product now being offered by CGG. This survey is the first publicly available Full Spectrum Falcon survey and is intended to capture the full spectrum of wavelengths by conforming the short wavelengths from the gravity gradiometry, with the longer wavelengths obtained from concurrently acquired conventional gravity.

Bio

Mark completed Arts/Science and Master of Science degrees at Monash University and then completed a PhD at The University of Melbourne in 2008 which involved acquisition, interpretation and modelling of an airborne geophysical survey over the Lambert Rift region in East Antarctica. Since then, Mark has worked at the Geological Survey of Victoria building regional 3D framework and rock property models using geological and geophysical datasets. Mark's time is now split between the GSV, and The University of Melbourne where he lectures in Applied Geophysics.

 

VIC:Winter Joint social evening with PESA and SPE

Wednesday, August 28, 2019
1700
2200

Dear VIC member,

 

Please join us for our Winter Joint social evening with PESA and SPE.

 

It will happen on the 28th of August 2019 from 5 pm at our usual venue, Henry & the Fox

 

Venue: Henry & the Fox, 525 Little Collins St, Melbourne VIC 3000

 

Fee:  $10, payable in cash at the venue.

 

RSVP: email directly to vicpresident@aseg.org.au before 23/08/2019 COB with dietary requirement.

VIC Technical night: QGIS for Geoscience – Drill holes & more.

Wednesday, July 31, 2019
1800
2000

Registration: https://www.eventbrite.com.au/e/aseg-technical-night-qgis-for-geoscience-drill-holes-more-tickets-65611958133

Please join us on the 31st of July at 6 pm, at the Kelvin Club.

We will have the pleasure to listen to Roland Hill from MMG Ltd who will be presenting about: QGIS for Geoscience – Drill holes & more.

Please RSVP on Eventbrite by the 30/07/2019 noon.

Any dietary requirement please email directly to vicpresident@aseg.org.au

Abstract:

Earlier this year MMG's Group Manager for Innovation & Geophysics, Roland Hill, made a small but influential splash amongst the Geoscience community with the release of his QGIS plug-in. QGIS is an open-source, cross-platform Geographic Information System. It's small CPU footprint and low RAM requirements makes it well suited to academic and professional applications alike, while it's availability in 48 languages makes QGIS ubiquitous amongst geoscientists world-wide. In short, it's a useful, versatile piece of software which MMG, and many companies like it, use daily. And that is exactly what makes Roland's contribution so important – it’s extremely useful. His plug-in already extended the use of the standard package and with this update, Geoscience for QGIS v1.0, user functionality is extended even further to allow creation and display of drill hole sections

Bio:

Roland Hill is a geophysicist with 28 years’ experience exploring for gold, copper and zinc throughout Australia, Africa, SE Asia and South America. He is currently Group Manager Innovation & Geophysics for MMG based in Melbourne. An accomplished software developer, he specialises in integration of open source libraries for geospatial processing and visualisation.

SEG DISC 2019: Physics and Mechanics of Rocks: A Practical Approach

Thursday, August 22, 2019
09:00
17:00

 See here for more details adn registration: https://seg.org/Education/Courses/DISC/2019-DISC-Manika-Prasad

Intended Audience

  • Seismic imagers and interpreters who want to learn how fluids, stress, and other environmental effects change seismic signatures
  • Geophysicists who wish to derive rock properties and constrain well-to-seismic ties
  • Geologists and sedimentologists looking to develop predictive models of sedimentary environments and stratigraphic events
  • Reservoir engineers to build porosity, permeability, and fluid coverage models for reservoir simulations using 3D and 4D seismic data
  • Basin modelers and completions engineers to evaluate stresses from well log and seismic data
  • Geoscientists doing formation evaluation and well logging interpretations
  • Basin managers and team leaders who wish to evaluate the accuracy of predictions and understand risk and errors in models

Prerequisites (Knowledge/Experience/Education Required)

Attendees should have an understanding of basic rock properties such as porosity, permeability, sediment compositions and depositions, and structural geology. It will be helpful to have familiarity, but not necessarily expertise, in seismic properties. The accompanying textbook will include mathematical details, data and problem solutions for mineral modulus calculations, rock stiffness calculations for textural symmetries, velocity binning in flow zones, pore stiffness, and Gassmann fluid substitution. The lecture will focus on fundamental rock physics principles, applications, and analysis of results.

Course Outline

The course is organized into two main sections: Section I. Rock Physics Fundamentals (introductory section) and II. Advanced Topics in Rock Physics (application section):

Rock physics fundamentals

In this section, I will:

  • Review fundamental principles underlying rock physics, and rock properties
  • Investigate the effects of fluids on rock properties
  • Derive basic rock physics correlations and explain why and how they work
  • Review rock properties that can be mapped with remote sensing

Advanced Topics in Rock Physics

In this section, the student is introduced to:

  • Poroelasticity
  • Attenuation and dispersion
  • Geomechanics
  • Complex electrical conductivity and permeability
  • Investigate the causes for complications and deviations from basic correlations
  • Examine existing empirical and theoretical models
  • Discuss selected case studies in rock physics

Learner Outcomes

On completion of the course, the learner should be able to

  • Describe and explain the applications of rock physics for reservoir characterization, formation evaluation, and field monitoring
  • Identify and evaluate existing and potential technologies applicable to rocks physics and rock mechanics for reservoir/formation studies
  • Identify, list, and describe the physical properties of rock, and relate these properties to the mechanical behavior of rocks
  • interpret and predict the effect of mineral properties (e.g. clay minerals) on the load-bearing capacity and strength of rocks
  • Integrate and model elastic wave propagation, electrical conductivity, and fluid flow in rocks
  • Evaluate and assess errors in experimental data, uncertainty, and the value of theoretical models
  • Develop expertise in rock physics interpretations of seismic and electrical conductivity to identify fluids and quantify saturations
  • Gather key strengths in rock physics interpretations by developing a broad understanding of existing or potential technology transfers between engineering and earth science fields that relate rock physics to reservoir geophysics and reservoir engineering
  • Gain knowledge and expertise to understand physical and mechanical behavior of rocks through examples of stress-dependent changes in strains, seismic velocity, electrical conductivity, and pore structure
  • Interpret rock physics and rock mechanics data and model elastic wave propagation, electrical conductivity, and fluid flow in rocks
  • Assess errors in experimental data, assess the uncertainty and the value of rock physics models
  • These learning objectives will allow geoscientists and engineers to:
  • Distinguish major trends in and control factors for velocity and impedance changes in the subsurface
  • Describe and evaluate velocity and impedance data for changes in fluids and stresses
  • Apply basic rock physics techniques to evaluate reservoirs
  • Identify and select the best practice workflows when using rock physics for seismic interpretations
  • Analyze complex conductivity data to interpret reservoir properties

 

Abstract

Rock physics is an interdisciplinary branch of geophysics that explains geophysical remote sensing data, such as seismic wave velocities and electrical conductivity, in the context of mineralogy, fluid content, and environmental conditions. Thus, rock physics interpretations often require inputs from physics, geology, chemistry, chemical engineering, and other fields. For example, seismic waves travel faster in cemented rocks than in loose sediments. Since the physical behavior of rocks controls their seismic response, rock physics brings key knowledge that helps with the interpretation of rock properties such as porosity, permeability, texture, and pressure. Rock physics combines indirect geophysical data (such as seismic impedance, sonic log velocities, and laboratory measurements) with petrophysical information about porosity, fluid type, and saturation for use in reservoir characterization, evaluation, and monitoring. Typically, rock physics is used by petroleum engineers doing reservoir simulations, geologists evaluating over-pressures and making basin models, and anyone doing a monitoring survey to map fluids from 4D seismic. For all such purposes, an understanding of wave propagation is required to relate seismic properties (e.g. velocity and attenuation) to the physical properties of rocks and to evaluate seismic data in terms of subsurface petrophysical parameters.  For example, an application of rock physics is seen in 4D seismic data (i.e. repeated seismic data acquired from the same field), where fluid saturation changes are evaluated from changes in velocity using fluid substitution models. Another rock physics application is to understand and predict the effect of clay minerals on the load-bearing capacity and strength of rocks using fundamental knowledge about the properties of clay minerals (e.g. CEC, surface area, dispersability, charge, sorption, plasticity, etc.), the clay water content, as well as the effects of their distribution within the rock. Thus, an effective prediction of rock properties from indirect measurements requires a solid understanding of the physical behavior of rocks under in situ conditions of pore and confining pressures and fluid saturations.

During this one-day short course, I will provide the earth scientist and engineer with a foundation in rock physics to describe the physical processes that govern the response of rocks to the external stresses essential for reservoir characterization. The course will also offer practical guidance to help better analyze existing data. A major goal of this course is to offer practical instruction and provide working knowledge in the areas of rock physics and rock mechanics for rock characterization.

VIC Technical Lunch - Muon GeoTomography

Wednesday, April 17, 2019
12:00
14:00

AMIRA International, the ASEG and AusIMM have teamed up to arrange a special lunchtime meeting on the 17th of April 2019, at which the exciting new geophysical technique of Muon GeoTomography will be presented by Don Furseth, the CEO of CRM.

 

Lunch will be held at the Kelvin Club from noon and is a paying event.

 

You will find event details as well as an abstract and a speaker bio on the Evenbrite link below.

 

https://www.eventbrite.com.au/e/aseg-amira-ausimm-technical-lunch-tickets-59748190446

 

Please RSVP on Eventbrite before the 12/04/2019 COB.

 

Abstract

Muon GeoTomography is a new geophysical technique providing 3D density imaging and monitoring using naturally-occurring cosmic ray muons. Unlike other geophysical techniques, muon geotomography provides straight line imaging (enabling accurate 3D localization), is passive (using naturally-occurring cosmic ray muons), is impervious to mechanical or electrical noise, and can see through conductive cover.

CRM GeoTomography Technologies (CRM) based in Canada, is commercialising the technology and has detectors in the field:

• Large (for brownfield applications)

• Compact (for submerged/other locations)

• Borehole - Detectors for HQ boreholes are in development, with field trials expected in early 2020.

CRM has published successful results for:

• A VMS deposit (zinc/lead/copper/silver) under rugged terrain (Myra Falls, BC, Canada / Nyrstar),

• A MVT deposit ( zinc/lead/other) at 450 m depth (Pend Oreille, Washington, USA / Teck), and

• A high-grade Uranium deposit at 600 m depth (McArthur River, Canada / Orano & Cameco).

Other applications include:

• Brownfield and greenfield mineral exploration;

• Block cave (air gap) monitoring; detection of voids and old workings;

• Other 3D density imaging and monitoring applications for resources/industrial, safety and security.

 

Bio

Don is an engineering physicist and entrepreneur with 30+ years of experience commercializing advanced, multi-disciplinary technology, with an emphasis on imaging and remote sensing. With engineering degrees from the University of British Columbia and Simon Fraser University, Don has worked in a variety of roles ranging from applied research, to product development, product management, operations and executive roles. Technologies have spanned photonics, satellite remote sensing, synthetic aperture radar, other imaging technologies, systems engineering and most recently muon geotomography. In recent years, Don has led a team to commercialise muon geotomography - a 3D density imaging and monitoring technology that can help exploration geologist discover, and deliver other new 3D insights.

SEG Distinguished Lecturer Tour: Boris Gurevich

Wednesday, March 13, 2019
17:30
19:00

2019 Pacific South Honorary Lecturer Tour

Seismic attenuation, dispersion, and anisotropy in porous rocks: Mechanisms and Models
Boris Gurevich, Curtin University and CSIRO, Perth, Australia

Understanding and modeling of attenuation of elastic waves in fluid-saturated rocks is important for a range of geophysical technologies that utilize seismic, acoustic, or ultrasonic amplitudes. A major cause of elastic wave attenuation is viscous dissipation due to the flow of the pore fluid induced by the passing wave. Wave-induced fluid flow occurs as a passing wave creates local pressure gradients within the fluid phase and the resulting fluid flow is accompanied with internal friction until the pore pressure is equilibrated. The fluid flow can take place on various length scales: for example, from compliant fractures into the equant pores (so-called squirt flow), or between mesoscopic heterogeneities like fluid patches in partially saturated rocks. A common feature of these mechanisms is heterogeneity of the pore space, such as fractures, compliant grain contacts, or fluid patches. Using theoretical calculations and experimental data, we will explore how this heterogeneity affects attenuation, dispersion, and anisotropy of porous rocks. I will outline a consistent theoretical approach that quantifies these phenomena and discuss rigorous bounds for attenuation and dispersion.

Time table

Date State Venue Start time Contact
13 March WA Celtic Club, 2nd floor, 48 Ord Street, West Perth 18:00 Heather Tompkins
15 March ACT Geoscience Australia 12:30 James Goodwin
19 March Qld XXXX brewery (Alehouse), Black Street, Milton 17:30 Ron Palmer
20 March NSW 95-99 York St 18:00 Mark Lackie
21 March Vic The Kelvin Club 18:00 Seda Rouxel
25 March SA/NT Coopers Alehouse 18:00 Kate Robertson
27 March Tas Geology Lecture Theatre, University of Tasmania 13:00 Mark Duffett

Biography

Boris Gurevich has an MSc in geophysics from Moscow State University (1976) and a PhD from Institute of Geosystems, Moscow, Russia (1988), where he began his research career (1981–1994). In 1995–2000 he was a research scientist at the Geophysical Institute of Israel, where he focused mainly on diffraction imaging problems. Since 2001, he has been a professor of geophysics at Curtin University and advisor to CSIRO (Perth, Western Australia). At Curtin he has served as Head of Department of Exploration Geophysics (2010–2015) and since 2004 as director of the Curtin Reservoir Geophysics Consortium. He has served on editorial boards of Geophysics, Journal of Seismic Exploration, and Wave Motion. He is a Fellow of the Institute of Physics and has more than 100 journal publications in the areas of rock physics, poroelasticity, seismic theory, modeling, imaging, and monitoring of CO2 geosequestration. His research achievements include development of advanced theoretical models of seismic attenuation and dispersion in heterogeneous porous rocks.

Sponsors

Platinum sponsors
Gold sponsor

Victorian Branch Technical night:

Thursday, March 21, 2019
18:00
19:00

Please join us on the 21st of March 2019 from 6pm at the Kelvin Club, to listen to this year’s Asia Pacific SEG honorary lecturer.  We will have the pleasure in welcoming Prof. Boris Gurevitch from Curtin University, who will present his latest work on Seismic attenuation, dispersion, and anisotropy in porous rocks: Mechanisms and Models.

Understanding and modeling of attenuation of elastic waves in fluidsaturated rocks is important for a range of geophysical technologies that utilize seismic, acoustic, or ultrasonic amplitudes. A major cause of elastic wave attenuation is viscous dissipation due to the flow of the pore fluid induced by the passing wave. Wave-induced fluid flow occurs as a passing wave creates local pressure gradients within the fluid phase and the resulting fluid flow is accompanied with internal friction until the pore pressure is equilibrated. The fluid flow can take place on various length scales: for example, from compliant fractures into the equant pores (so-called squirt flow), or between mesoscopic heterogeneities like fluid patches in partially saturated rocks. A common feature of these mechanisms is heterogeneity of the pore space, such as fractures, compliant grain contacts, or fluid patches. Using theoretical calculations and experimental data, we will explore how this heterogeneity affects attenuation, dispersion, and anisotropy of porous rocks. I will outline a consistent theoretical approach that quantifies these phenomena and discuss rigorous bounds for attenuation and dispersion.

Full abstract and biography are available in the Eventbrite registration link.  Please register before COB on 18/03/2019.  For all dietary requirements, please email vicpresident@aseg.org.au directly.

The event is sponsored by Shell

 

 

Victorian Branch Technical night: Integration of geological uncertainty into geophysical inversion by means of local gradient regularization

Thursday, February 21, 2019
18:00
19:30

You are cordially invited to our first technical meeting of the year to be held on 21st of February 2019, at the Kelvin Club from 6 pm.  We will have the pleasure in welcoming Jeremie Giraud from the University of Western Australia who will present his research on " Integration of geological uncertainty into geophysical inversion by means of local gradient regularization"

 

Abstract

We introduce a workflow integrating geological modelling uncertainty information to constrain gravity inversions. We test and apply this approach to the Yerrida Basin (Western Australia), where we focus on prospective greenstone belts beneath sedimentary cover. Geological uncertainty information is extracted from the results of a probabilistic geological modelling process using geological field data and their inferred accuracy as inputs. The uncertainty information is utilized to locally adjust the weights of a minimum-structure gradient-based regularization function constraining geophysical inversion. Our results demonstrate that this technique allows geophysical inversion to update the model preferentially in geologically less certain areas. It also indicates that inverted models are consistent with both the probabilistic geological model and geophysical data of the area, reducing interpretation uncertainty. The interpretation of inverted models reveals that the recovered greenstone belts may be shallower and thinner than previously thought.

 

Bio

Jérémie studied physics and geosciences at undergraduate level in Grenoble and obtained his MSc. Eng. (geophysics) in Strasbourg (France). Various internships have led him to Canada and Germany working on hydrogeophysics and magnetotellurics in research institutes and on reservoir mapping for industry. He then worked for Schlumberger for about three years where he focussed on reservoir appraisal and characterization using geophysical integration techniques. He was based in Milan, Italy and trained mostly in Houston before moving to Perth to start his PhD at the Centre for Exploration Targeting (Uni. of WA), focusing on multidisciplinary geophysical integration. Jérémie submitted his thesis in September 2018 and is now involved in the MinEx CRC and Loop consortia.

 

Registration (before 20 February)

Eventbrite link

2018 SEG/AAPG Distinguished Lecturer: Satish Singh

Tuesday, August 7, 2018
17:30
19:00

Seismic Full Waveform Inversion for Fundamental Scientific and Industrial Problems.

Seismic waveform inversion is a powerful method used to quantify the elastic property of the subsurface. Although the development of seismic waveform inversion started in the early 1980s and was applied to solve scientific problems, it became popular in industry only about 15 years ago. One of the key elements in the success of seismic waveform inversion has been the increase of the acquisition of long offset seismic data from 3 km in the early 1990s to more than 15 km today. Not only did long offset data provide refraction arrivals, but it also allowed recording of wide-angle reflections, including critical angles, providing unique information about the subsurface geology.

In this talk, I will elaborate on the early development of the seismic full waveform inversion (FWI) and its application to solve fundamental scientific problems. The first big success of FWI was its application to gas hydrate reflections, also known as bottom simulating reflection (BSR), which showed that the
BSRs are mainly due the presence of a small amount of free methane gas, not a large amount of hydrates stored above the BSR, and hence the total amount of methane stored in marine sediments should be much less than previously estimated. A second major success of FWI was its application to quantify the characteristics of the axial melt lens observed beneath ocean spreading centers. The seismic full waveform inversion results show that one can distinguish between pure melt and partially molten mush within a 50 m thick melt lens, allowing to link the melt delivery from the mantle with the hydrothermal circulation on the seafloor. The application of full waveform inversion to spreading center problems has become an important area of research.

Unlike in sedimentary environment, the seafloor in general scientific environment could be very rough and water depth could be deep, making it very difficult to use the conventional method of background velocity estimation. To address this issue, the surface seismic data could be downward continued to the seafloor, as if both streamer and sources were placed on the seafloor, similar to land geometry. This method allows to bring the refraction starting from zero offset to far offset, which is extremely useful for full waveform inversion of first arrivals. The downward continuation also allows to reduce the seafloor diffraction, increase the moveout of reflection arrivals, and enhance wide-angle reflections, all important for seismic full waveform inversion. The application of a combination of downward continuation and FWI has allowed to quantify gas anomalies in sedimentary basins and fluids at subduction fronts. The waveform inversion also has been used to monitor CO 2 sequestration.

I will explain the intricacy of FWI, based on the physics of waves, specifically the role of amplitudes and converted waves in addressing fundamental scientific problems. The presentation should interest professionals working in the oil and gas sectors, or crustal studies and global seismology.

More details and biography.

Date City Address
30 July Brisbane  
1 August Canberra Scrivener Room, Geoscience Australia, CANBERRA
2 August Victoria Kelvin Club, 18-30 Melbourne Place, MELBOURNE
7 August Adelaide Coopers Alehouse, 316 Pulteney St ADELAIDE
8 August Sydney The University of Sydney
14 August Hobart CODES Conference Room, University of Tasmania, Sandy Bay
15 August Perth Ground Floor, 1 Ord St, WEST PERTH

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