Industry

The initial geophysics conference “Looking into Our World”, provided us with a platform to develop and learn from. As such, this year’s event will come under the banner of “Latin Geophysics Explore 2021” which better reflects nature of the conference since the science is not dictated by political boundaries but by geoscientific ones.

Building on from last year we wish to grow the event to include a half day training course to complement the speaker program maintaining a similar structure to last year.

A programme can be accessed here.

https://chilexploregroup.cl/en/latin-geophysics-explore-2021-en/

Title: Basin-wide and multi-scenario modeling of rock property and AVO feasibility volumes

Presenter: Dr. Per Avseth

Please see the Zoom link for the 18th May webinar: https://us02web.zoom.us/webinar/register/WN_-9wBWxOITtOYopFbRpVYpA

Summary:

One of the key tasks within the field of geoscience is to obtain a better understanding of the subsurface rock properties using remote sensing techniques (e.g., seismic and CSEM) and/or selected modelling tools. In mature areas with many wells and good quality seismic data, a data-driven approach can be used to predict rock properties between wells. In areas with limited well control and/or complex geology, we still rely on models to understand expected changes in rock properties between/away from wells, even though the seismic data is of good quality. Integration of geology and geophysics is a key to optimally select, constrain, and calibrate rock physics models. Lack of well log data can make it challenging to quantify uncertainties, but a scenario-based modeling with alternative geological scenarios and sensitivity testing of key input parameters can help us to better understand and possibly reduce the uncertainties away from well control.  In this presentation, I will demonstrate how a scenario-based feasibility modelling of rock physics properties, constrained by local geological inputs (mineralogy, facies, temperature, burial history, etc.) can give valuable information, that can be utilized before new seismic data are acquired (e.g., to decide whether certain types of data like AVO will be beneficial or not), or they can be used to guide the quantitative seismic interpretation of existing seismic data. 

Bio:

Per Avseth is a geophysical advisor and CTO of Dig Science in Oslo, Norway, and a part-time researcher at the Dept. of Electronic Systems at the Norwegian University of Science and Technology (NTNU) in Trondheim.  Per received his M.Sc. in Applied Petroleum Geosciences from NTNU in 1994, and his Ph.D. in Geophysics from Stanford University, California, in 2000. Per worked as a research geophysicist at Norsk Hydro in Bergen, Norway (2001-2006), a consultant at Rock Physics Technology (2006-2008) and Odin Petroleum (2008-2012) in Bergen, and as a geophysical advisor at Tullow Oil in Oslo (2012-2016). He held a position as an adjunct professor in reservoir geophysics at the Dept. of Petroleum and Geoscience at NTNU from 2008-2020. Per was the SEG Honorary Lecturer for Europe in 2009. He is a co-author of the book Quantitative Seismic Interpretation (Cambridge University Press, 2005), and has published extensively in the fields of rock physics and AVO analysis. His current research focuses on basin-scale rock physics and integration of basin modeling, sedimentology and rock physics.

The AGM of the ASEG Queensland Branch will be held on Tuesday 27 April at the XXXX Brewery in Milton from 1715.

QLD ASEG members interested in joining the branch committee should email james.alderman@riotinto.com before Friday 23 April.

Nominations are open for President, Secretary, Treasurer, Communications Representative and general committee.

For the technical talk, we’re pleased to welcome Peter Fullagar back to Brisbane. Peter will present the first of a two part talk on fast TEM inversion using conductive ellipsoids. More details on the talk can be found at the Eventbrite registration link.

Peter Fullagar - Fullagar Geophysics Pty Ltd

Beyond plates – fast TEM inversion using conductive ellipsoids

Part 1: Forward modelling

Interpreting TEM data in terms of conductive rectangular plates is effective in many situations. However, not all conductors are planar. Triaxial ellipsoid conductors are an attractive alternative: geometrically simple (corner-free), mathematically tractable at early and late time limits, and able to encompass shapes ranging from plates to elongate lenses to equi-dimensional pods. Accordingly a fast magnetostatics-based algorithm has been developed to compute ellipsoidal conductor responses in both resistive and inductive limits. Inversion of measured data then entails adjustment of ellipsoid parameters. The methodology is suitable for downhole, ground, or airborne TEM, either impulse or step response.

The event is free for members and $15 for non-members who are welcome to join prior to the meeting. Please register through Eventbrite here.

In this first of two presentations, the forward modelling algorithm is described and illustrated. 

Title: Shallow mantle convection beneath West Africa and source to sink at continental margins: A novel approach to reservoir prediction in offshore deep-water settings

Presenter: Dr Bhavik Harish Lodhia (UNSW)

Abstract:

Deep-water settings are prevalent in many of the world’s frontier basins. To better focus exploration spend in today’s challenging environment and predict reservoirs, a novel approach to close the loop between onshore denudation and offshore sediment deposition is required. Sedimentary flux measurements, regional subsidence patterns, tomographic models and simple isostatic calculations are combined to constrain the history of offshore solid sedimentary flux and sub-plate support of the Mauritanian Basin. We combine seismic reflection and well data along the West African margin with shear wave tomography and the uplift and magmatic history of the Cape Verde Rise to constrain thermal, spatial and temporal scales of upper mantle convection. Predictions of solid sedimentary flux to the Mauritanian Basin calculated by inversion of continental drainage are compared to observations in the Chinguetti field of the Mauritanian Basin.

Bio: Bhavik moved to Australia from the United Kingdom earlier this year and is currently a Postdoctoral Fellow in Energy Technology and Geophysics at UNSW. Bhavik graduated with a PhD in Geology and Geophysics at Imperial College London in 2019 and completed a masters/bachelors degree in Earth Sciences at St. Anne's College, University of Oxford in 2014. His work has focused on basin dynamics, geodynamics, sediment source to sink and petroleum systems modelling.

Register: https://us02web.zoom.us/webinar/register/WN_-_AXVmqGT5GGGUrJw-VODA

Attend in-person

Time:                    5:30 for 6pm start

Address:              Level 2, Club York (99 York St, Sydney. Room 'York 2')

Meeting registration:      https://www.surveymonkey.com/r/2V6JM9F by Sunday 18th April - due to COVID restrictions we require a registration for in-person meetings. If you have trouble registering please email nswsecretary@aseg.org.au 

Title: Learning to learn about the earth, using Bayesian inference

Presenter: Anandaroop Ray (Geoscience Australia)

Abstract: To understand earth processes, geoscientists infer subsurface earth properties such as electromagnetic resistivity or seismic velocity from surface observations such as magnetotelluric data or seismograms. These properties are used to populate an earth model vector, and the spatial variation of properties sheds light on the underlying earth structure and phenomena, from groundwater aquifers to plate tectonics. I will show that in order to make accurate inferences about earth properties, inferences can first be made about the underlying length scales of these properties. From a mathematical point of view, the length scales can be conveniently thought of as “properties” of earth properties. This can be treated in an “infer to infer” paradigm analogous to the “learning to learn” paradigm which is now commonplace in the machine learning literature. A non-stationary trans-dimensional Gaussian Process (TDGP) is used to parameterise earth properties, and a multi-channel stationary TDGP is used to parameterise the length scales. Using non-stationary kernels, i.e., kernels with spatially variable length scales, earth models with sharp discontinuities can also be represented within this framework. As GPs are multi-dimensional interpolators, the same theory and computer code can be used to solve geophysical problems in 1D, 2D and 3D. This is demonstrated through a combination of 1D and 2D non-linear regression examples and a controlled source electromagnetic field example.

Biography: Anandaroop Ray (“Anand”) started his career as a non-seismic geophysicist with Shell Exploration and Production in 2007. In 2010 he joined the PhD programme in marine electromagnetics at the Scripps Institution of Oceanography in San Diego, California. In 2014 he completed his thesis focusing on uncertainty estimation in electromagnetic inversion for marine hydrocarbon exploration. From 2012-19, he worked for Chevron R&D on various problems – controlled source electromagnetics (CSEM), seismic full waveform inversion (FWI), reservoir properties from seismic (RPFS), airborne electromagnetics (AEM), statistical hydrocarbon exploration lookback analyses, and the role of machine learning in geophysics. The question most asked through his work is “how credibly can we interpret our inversion model(s),” the answering of which often requires the use of high-performance computing (HPC) techniques. He currently co-advises a PhD student at Columbia University on Bayesian geophysical inversion and has been active in convening and organizing the Uncertainty in Geophysical Inversion session at the American Geophysical Union’s Fall Meeting. In March 2019 he joined the Minerals, Energy and Groundwater Division at Geoscience Australia, where he continues to work on inverse uncertainty, model representation and geostatistics.

Register: https://us02web.zoom.us/webinar/register/WN_j_B7TWtMQvOSxy9zTLj5Iw

You are invited to join online with GSA  -- 31 March 2021 – 6.30pm

Speaker: Brad Pillans, Chair of the National Rock Garden Steering Committee

Topic: The thrill of the chase: Finding (and funding) 100 iconic rocks for the National Rock Garden

Zoom link:  click here to watch

Abstract: When the National Rock Garden was officially launched in 2010 at the Australian Earth Sciences Convention in Canberra, it seemed a straightforward task to bring in a bunch of rocks from all around the country and tell the story of Australian geology. Are we there yet? Not quite, but the thrill of the chase remains as we build our national collection of 100 or more iconic rocks. In this presentation, Brad will reveal some of the great rocks we already have and some that we don’t have (but would like to have).

ASEG Victoria is pleased to announce the restart of in-person branch events starting with the first technical meeting night of 2021. You are cordially invited to join us for a talk by Mr. Warren Gray from Seisintel on Thursday April 22nd at 6pm at The Kelvin Club.  Admission to this event is free for members only, so please ensure you have renewed your membership for 2021 before registering.

THREE YEARS IN THE MARINE SEISMIC EXPLORATION WORLD

The last three years have been a whirlwind for the offshore marine seismic survey industry. Through 2018-2019 Shearwater had bought WesternGeco’s fleet of 10 seismic vessels and then acquired 7 vessels from CGG. In 2018 Axxis Geo Solutions entered the Ocean Bottom Seismic market with the largest OBN survey conducted in the North Sea. Ocean Bottom Seismic companies Magseis and FairfieldNodal merged. Suriname and Guyana were the new hot spots and West Coast Africa was as busy as ever. Optimism was tentatively returning to discussion at the big exploration conferences. And then 2020 brought about the challenges of COVID-19 with plunging oil prices, slashed exploration budgets, halted projects and challenges in crew and vessel movements. A number of players entered bankruptcy protection or had their banks withdraw support of ongoing vessel operations right in the middle of projects. Using some tools from the Seisintel, we will discuss where the most recent proprietary and multiclient seismic survey activity has been, the latest technologies and acquisition methods being deployed by the industry and look forward to discussing some bright spots of the coming year.

BIO

Warren Gray completed a Bachelor of Surveying at Melbourne University in 1996. Offshore work was always of interest and after cold calling one company in Singapore and a brief ten-minute phone interview, Warren was on the plane one week later. Work was as a navigator and navigation data processor for Western Geophysical on their 3D seismic vessel M/V Western Legend. After three years and during the oil price downturn of 1999 where oil was US$12-barrel, Warren made another cold call from a ship off Angola in West Africa to Veritas (now CGG) in Singapore and was lucky to be offered another job straight away. After six years mostly on the 2D and 3D vessel Pacific Sword around the Asia-Pacific and being married during that period, onshore life was calling in order to start a family. Warren worked as a Survey Officer and later as Environmental Monitoring Manager for the Port of Melbourne during the channel deepening dredging project to deepen the shipping lanes into Melbourne. This brought about a steep learning curve into the GIS and desktop mapping world. The work in the GIS arena proved to be critical to his next role in 2009 where he was geodetic support for Fugro-Geoteam and then CGG. Tasked with design, mapping and planning of marine seismic surveys for tenders and operations, the insight into all facets of the industry were continually compounding. When the opportunity came up late in 2016, Warren jumped at the chance to work with Searcher Seismic and is now Technical Director of their Seisintel product range.

Please register your interest in attending this technical meeting night by using the following link:

https://www.eventbrite.com.au/e/aseg-victoria-technical-meeting-night-tickets-148513609203

Light refreshments will be provided on the evening.  The committee looks forward to this long overdue reunion with fellow members.  We hope to see you all there once again!

Survey Design and Seismic Acquisition for Land, Marine, and In-between in Light of New Technology and Techniques

Registration: SEG DISC registration

ASEG members get the member price of $250US, and registration comes with free copy of the e-book.

Day 1 – August 10th

Start time: 8:00am – 12:00pm PERTH time

Day 2 – August 11th

Start time: 8:00am – 12:00pm PERTH time

Description

Seismic surveys are subject to many different design criteria, but often the parameters are established based on an outdated view of how data can be acquired, and how it will be processed. This course is designed to highlight what is possible using modern methods, and how they impact seismic survey design.

Survey designs are subject to a limited set of operational and geophysical considerations. What frequencies do we require (in the source), and what will or can we detect? What geometry will be utilized, and what record length will be recorded?

However, new techniques and processing methods require that we understand and answer a new and different set of questions:

• Are classic survey geometries outdated? What geometry is optimum given almost limitless availability of channels, and how are these best deployed if they are not constrained to be connected together?
• How do you QC data from a system that doesn’t permit real time views of data?
• How do compressive sensing methodologies fit into classical geometry requirements, and can these significantly impact how data is acquired and processed? Is random “optimum” and is optimum unique?
• Do offset and sampling requirements change if processing will utilize FWI and/or least squares migration?
• Can very low frequencies be generated, detected and used for improved inversion?
• How should simultaneous sources be utilized, and can subsequent data be separated from the continuous records that will be required if this technique is used? If two sources are better than one, are four better than two?
• What should we expect of seismic data five or ten years from now?

This course is designed to cover some of the fundamentals of survey design, but will highlight the changes in technology that we have seen in the past five years, and those that are likely to develop in the next five years with a view to allowing seismic surveys to be designed and acquired to optimize technology efficiencies and interpretation requirements in light of new technology.

Goals

This course will not describe specific survey designs for particular geologic objectives, but after attending this course, the participant should:

• Understand the basic geophysical requirements of a seismic survey, based on geologic objectives
• Have a much-improved knowledge of the differences between classic survey design, and what is required for modern high-end processing techniques including FWI 
• Understand the concepts of simultaneous sources, compressive sensing, node acquisition, and broadband data, and see how these fit into survey design techniques
• Understand that there is a relationship between acquisition parameters and seismic image quality
• Understand how the basic requirements tied to modern acquisition and processing ideas can fundamentally change the data that is presented to an interpreter, and why final data volumes can look significantly different from legacy data

Who should attend?

All those interested in seismic surveys should attend. Geophysicists involved in acquisition may discover new techniques and concepts which with they are unfamiliar. Geophysicists involved in processing seismic data will better understand the shortcomings of the data that they are given to process, and better understand what techniques will, and will not, work for a particular survey. The interpreter may better understand the difference between modern seismic volumes presented for interpretation, and the legacy data that he is accustomed to interpreting. For those directly involved in survey design, the concepts will open up the potential for acquiring better images of the subsurface more efficiently, and at less cost.

The course does not require extensive mathematical knowledge or background. Concepts will be explained in a way that the layman or manager can understand. Students will be able to follow and understand the course from the basics to the level of asking knowledgeable questions of those actually involved in seismic acquisition and processing.

Survey Design and Seismic Acquisition for Land, Marine, and In-between in Light of New Technology and Techniques

Registration: SEG DISC registration

ASEG members get the member price of $250US, and registration comes with free copy of the e-book.

Day 1 – August 10^th

Start time: 8:00am – 12:00pm PERTH time

Day 2 – August 11^th

Start time: 8:00am – 12:00pm PERTH time

Description

Seismic surveys are subject to many different design criteria, but often the parameters are established based on an outdated view of how data can be acquired, and how it will be processed. This course is designed to highlight what is possible using modern methods, and how they impact seismic survey design.

Survey designs are subject to a limited set of operational and geophysical considerations. What frequencies do we require (in the source), and what will or can we detect? What geometry will be utilized, and what record length will be recorded?

However, new techniques and processing methods require that we understand and answer a new and different set of questions:

• Are classic survey geometries outdated? What geometry is optimum given almost limitless availability of channels, and how are these best deployed if they are not constrained to be connected together?
• How do you QC data from a system that doesn’t permit real time views of data?
• How do compressive sensing methodologies fit into classical geometry requirements, and can these significantly impact how data is acquired and processed? Is random “optimum” and is optimum unique?
• Do offset and sampling requirements change if processing will utilize FWI and/or least squares migration?
• Can very low frequencies be generated, detected and used for improved inversion?
• How should simultaneous sources be utilized, and can subsequent data be separated from the continuous records that will be required if this technique is used? If two sources are better than one, are four better than two?
• What should we expect of seismic data five or ten years from now?

This course is designed to cover some of the fundamentals of survey design, but will highlight the changes in technology that we have seen in the past five years, and those that are likely to develop in the next five years with a view to allowing seismic surveys to be designed and acquired to optimize technology efficiencies and interpretation requirements in light of new technology.

Goals

This course will not describe specific survey designs for particular geologic objectives, but after attending this course, the participant should:

• Understand the basic geophysical requirements of a seismic survey, based on geologic objectives
• Have a much-improved knowledge of the differences between classic survey design, and what is required for modern high-end processing techniques including FWI 
• Understand the concepts of simultaneous sources, compressive sensing, node acquisition, and broadband data, and see how these fit into survey design techniques
• Understand that there is a relationship between acquisition parameters and seismic image quality
• Understand how the basic requirements tied to modern acquisition and processing ideas can fundamentally change the data that is presented to an interpreter, and why final data volumes can look significantly different from legacy data

Who should attend?

All those interested in seismic surveys should attend. Geophysicists involved in acquisition may discover new techniques and concepts which with they are unfamiliar. Geophysicists involved in processing seismic data will better understand the shortcomings of the data that they are given to process, and better understand what techniques will, and will not, work for a particular survey. The interpreter may better understand the difference between modern seismic volumes presented for interpretation, and the legacy data that he is accustomed to interpreting. For those directly involved in survey design, the concepts will open up the potential for acquiring better images of the subsurface more efficiently, and at less cost.

The course does not require extensive mathematical knowledge or background. Concepts will be explained in a way that the layman or manager can understand. Students will be able to follow and understand the course from the basics to the level of asking knowledgeable questions of those actually involved in seismic acquisition and processing.

Date: 30th March 2021

Time: 5:30 - 6:30pm AEDT

Register: https://us02web.zoom.us/webinar/register/WN_J6zK4TXCTbCI1PxCI4uF9g

Richard retired from Geoscience Australia after more than a 30 year career of developing new geological understanding to open up provinces for exploration investment. Applied geophysics played a key component throughout his career, and this seminar will be a personal reflection on the key ‘geophysical-aha’ moments that have changed his understanding of a region’s geology and, through this new knowledge, Australia’s mineral potential.

The 30-year story begins in the field as a young geologist using geophysics to map Cape York, Pilbara and Yilgarn and seismic transects across a number of Proterozoic orogens, through the UNCOVER formulation to the lead designer of the Exploring for the Future programme.