Industry

Using microgravity to monitor groundwater storage and usage in an urban woodland environment – Kings Park, Western Australia

Alan Aitken, UWA 

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.

'Next week we have a talk by visiting Senior Research Geoscientist Dr Clive Foss from CSIRO Mineral Resources, speaking about 'Paragon Bore – a special place in the South Australian magnetic field.'

This event will be held on Level 7 of 101 Grenfell St, Adelaide in Training Room 1 at 12 pm till 1 pm on Friday 6th July. Bring along a gold coin donation, with a light lunch provided.

Please send through an email to sa-ntpresident@aseg.org.au if you are thinking about coming along, to give us a rough idea of numbers for catering purposes. Don't forget to include any dietary requirements

The 2018 Professional Scientist Remuneration Survey (conducted by Professionals Australia in conjunction with Science & Technology Australia) is currently underway and open to all science professionals.

Please take a few minutes to assist the scientific community by completing the questionnaire. All survey participants have the opportunity to enter the survey competition to win one of two $500 JB-HiFi vouchers. To enter, complete the entry form available once you complete the survey.

The answers will be aggregated to compile a major report on prevailing market rates and workplace conditions for employees in positions requiring qualifications in a branch of science.

A summary of the survey results will be available on the Professionals Australia website later in the year.

The closing date for the submission of completed survey questionnaires is the 24th of June, 2018. No identifying details are required. All responses are confidential and will be handled in accordance with Professionals Australia's privacy policy.

The survey can be completed here.

EAGE Australasian Workshop on Continuous Improvement in 4D Seismic

4D seismic is well established for monitoring of conventional reservoirs during production. Approaches vary from occasional repeat streamer surveys to frequent monitoring by means of permanent surface or seabed arrays of receivers. The industry has had most success to date with oil fields, but application of 4D seismic to gas fields is also becoming the norm. Successful 4D programs add substantial value by allowing multi-discipline subsurface teams to update their models, optimise the field drainage plan, and avoid drilling unnecessary or poorly-sited wells. However, the demands of increasingly complex reservoirs, and the imperative to contain costs in the current industry climate, require continuous improvement in 4D surveying, processing and evaluation technologies.

The workshop will update on the latest ideas, technologies and industry practice in 4D seismic reservoir monitoring, especially related to industry challenges in the Asia-Pacific region. It will be a perfect avenue to exchange experiences through networking, share dynamic discussions on theoretical aspects, best practices and case studies.

The EAGE calls upon geoscientists and engineers interested in planning, executing and evaluating reservoir monitoring programs using 4D seismic to contribute to the technical programme. Speakers interested to present at the workshop are welcome to contact Event Manager, Ruth Dass with a title and brief abstract before Friday, 27 July 2018.

More details here

The Benefit of Broadband Technology for Reservoir Characterization and Imaging – the End-User Value

Course description

The main aim of this course is to provide a very accessible overview of the many concepts behind broadband seismic (primarily offshore) and its implication for the reservoir focused asset based geoscientist. This will be done through the a very comprehensive set of case study material from all regions of the world and for various stages of the exploration, appraisal and development asset life cycle. The course aims to objectively discuss the various broadband seismic technologies and commercial offerings available today and their respective merits with regards to quantitative reservoir characterization and reservoir imaging using real world application examples. The course will further attempt to identify possible pitfalls and issues with regards to the treatment of broadband data that might lead to flawed or erroneous QI.

Course objectives

Upon completion of the course, participants will be able to understand the value of broader bandwidth seismic data in general and for quantitative reservoir analysis from interpretation to rock property estimation in particular. The course is intended to be very applied and hands on and will only review the very basic concepts of inversion based rock property analysis and quantitative interpretation but will otherwise focus on examples to illustrate the benefit of extended bandwidth seismic.

Course outline

• What is broadband seismic?
• Potential benefits
• Exploration case studies
• Appraisal development case studies
• What next?

Participants' profile

The course is designed for geoscientists with a basic level of geophysical knowledge, including a general knowledge of towed streamer acquisition and processing methods but the content is designed to be accessible for most geoscientists working with or interested in using broadband seismic in their day-to-day working life. In other words, definitely no requirement for expert knowledge.

More details here

Rock Physics for Quantitative Seismic Reservoir Characterization

Course description

This course covers fundamentals of Rock Physics ranging from basic laboratory and theoretical results to practical “recipes” that can be immediately applied in the field. We will present quantitative tools for understanding and predicting the effects of lithology, pore fluid types and saturation, saturation scales, stress, pore pressure and temperature, and fractures on seismic velocity. We will present case studies and strategies for quantitative seismic interpretation and, suggestions for more effectively employing seismic-to-rock properties transforms in reservoir characterization and monitoring, with emphasis on seismic interpretation for lithology and subsurface fluid detection.

Course outline

• Introduction to Rock Physics, motivation, introductory examples
• Parameters that influence seismic velocities - Conceptual Overview
• effects of fluids, stress, pore pressure, temperature, porosity, fractures
• Bounding methods for robust modeling of seismic velocities
• Effective media models for elastic properties of rocks
• Gassmann Fluid substitution – uses, abuses, and pitfalls
• derivation, recipe and examples, useful approximations
• Partial saturation and the relation of velocities to reservoir processes
• The importance of saturation scales and their effect on seismic velocity
• Shaly sands and their seismic signatures
• Granular media models, unconsolidated sand model, cemented sand model
• Velocity dispersion and attenuation; Velocity Upscaling
• Rock Physics of AVO interpretation and Vp/Vs relations
• Quantitative seismic interpretation and rock physics templates.
• Example case studies using AVO and seismic impedance for quantitative reservoir characterization

Participants' profile

The course is recommended for all geophysicists, reservoir geologists, seismic interpreters, and engineers concerned with reservoir characterization, reservoir delineation, hydrocarbon detection, reservoir development and recovery monitoring.

More details here

Finding and exploiting correlations between 3D seismic, log, and engineering data using machine learning or

The future requirements of integrated E&P: Shallow learning – but deep thinking!

Kurt Marfurt's SEG DISC will tour Australia between 11 and 25 July. After each day-long course, Kurt will speak at selected branch technical nights. These talks may be attended by members and non-members alike as with any technical night.

Please check this page for updates on course locations and times in your city. Some of these talks will talk place over lunch.

The day-long course is aimed at:

• Seismic interpreters who want to extract more information from their data.
• Seismic processors and imagers who want to learn how their efforts impact subtle stratigraphic and fracture plays.
• Sedimentologists, stratigraphers, and structural geologists who use large 3D seismic volumes to interpret their plays within a regional, basin-wide context.
• Reservoir engineers whose work is based on detailed 3D reservoir models and whose data are used to calibrate indirect measures of reservoir permeability.
• Team leaders who wish to identify advances in machine learning technology that promise improved efficiency and accuracy in the integration of large data volumes.

Modelling Microgravity for Groundwater Storage, Kings Park

Mentoring program meeting