Exploring with Airborne Gravity Gradiometry
|Dr Asbjørn Nørlund Christensen (Nordic Geoscience, Melbourne, Australia)|
|Engineering – Airborne Exploration|
|5 CPD points|
2D 3D DEPOSITS EXTRAPOLATION INTERPRETATION INVERSION MAPPING MARINE MINERALS SALT
The course combines a series of presentations on airborne gravity gradiometry (AGG) with hands-on exercises and class discussions. The objective of the course is to introduce attendees to AGG with a particular emphasis on its application to exploration for hydrocarbons and mineral resources.
Upon completion of the course, participants will have a deeper understanding of:
- The differences and similarities between AGG and conventional gravity;
- The current AGG technologies (FTG and FALCON) as well as the emerging new AGG technologies that may become available in the near future;
- The sensitivity of the AGG technologies — what may and may not be detected — and how to design an AGG survey to deliver maximum value to their exploration programme;
- The ways to interpret AGG data and how to integrate the interpretation with seismic and other geophysical data;
- A number of case studies ranging from base metals to hydrocarbon exploration plays.
- Fundamentals of Airborne Gravity Gradiometry (AGG)
- Basic theory of AGG
- How AGG differ from ground-, marine-, and airborne-gravity.
- Current and future AGG instruments
- AGG data acquisition and processing
- Sensitivity and detectability of AGG surveys
- How to design an AGG survey
- How AGG surveys are processed and what is delivered to you
- Interpretation of AGG data
- Regional mapping and qualitative interpretation
- Inversion of AGG data and quantitative interpretation
- Case Studies: AGG in petroleum exploration
- Basin studies
- Salt and sub-salt
- 3D extrapolation of 2D seismic
- Transition zones
- Thrust zones
- Case Studies: AGG in minerals exploration
- Iron ore
- Iron Oxide Copper Gold (IOCG) deposits
The course is presented with a minimum use of mathematics and is intended for any exploration geophysicist/geologist interested in learning about airborne gravity gradiometry.
About the instructor
Asbjorn Norlund Christensen is owner of Nordic Geoscience Pty. Ltd., consulting world-wide on ground and airborne geophysics.
Working for BHP Billiton in the late 1990’s Asbjorn was actively involved in the initial development and deployment of the FALCON AGG system. He was worked on minerals exploration projects in Australia, Asia and Africa, and has managed research teams and technology companies.
His areas of interest are: geophysical technology development and deployment, potential fields, and the integrated interpretation of geophysical data for minerals and petroleum exploration. He has an MSc in Geophysics from University of Aarhus, Denmark and a PhD in Geophysics from Colorado School of Mines, USA. He is a member of EAGE, SEG, PESA and he is the Victoria Branch President of the ASEG. He is based in Melbourne, Australia.
Explore other courses under this discipline:
Instructor: Mr Jaap Mondt (Breakaway)
Although in the search for hydrocarbons seismic plays the dominant role, complementary data can be very useful. A clear example is that seismic can clearly determine reservoir geometries based on acoustic impedance changes but is less sensitive to the pore-fluids. Electromagnetic measurements, such as Controlled Source EM (CSEM) measures resistivity directly and hence can discriminate between brine and hydrocarbon fill.
You might wonder about the poorer resolution of EM compared with seismic. Indeed, that is the case, but by combining the two independent sources of information, then seismic will give the structure (container) which then can be used as a constraint for the inversion of EM. Another application is in the realm of determining the shape of allochthone salt bodies below which hydrocarbons can be present.
Numerous applications can be mentioned in relation to shallow seismic. An obvious one is the use of Ground Penetrating Radar (GPR) for investigating archaeological sites or determining the depth to upwelling deep salt-water due to severe pumping of fresh water for irrigation.
Instructor: Dr Asbjørn Nørlund Christensen (Nordic Geoscience)
In the past fifteen years airborne gravity gradiometry (AGG) has gained acceptance as a cost effective exploration tool in a variety of minerals and petroleum exploration programs. This one-day course is intended for all explorers considering using AGG in their exploration efforts.
Instructor: Dr Yaoguo Li (Colorado School of Mines)
Gravity and magnetic data are among the oldest geophysical data acquired for the purpose of resource exploration and exploitation. They currently also have the widest areal coverage on the Earth, span a great range of scales, and play important roles in mineral, energy, and groundwater arenas. This course will focus on the methodology, numerical computation, solution strategy, and applications of 3D physical property inversions of gravity and magnetic data sets. The course is designed to have two tracks in order to meet the different needs of EAGE community in mineral exploration and in oil & gas exploration and production. We achieve this by dividing the course into two parts, and cover the methodologies common in potential-field methods in Part-I and discuss tools and applications specific to mineral exploration or oil & gas reservoir monitoring in Part-II.
Instructor: Dr Bruce Hobbs (University of Edinburgh)
Following a brief summary of electromagnetic methods for exploration, the theoretical basis of the MTEM method is presented together with practical methods of data acquisition and processing. Modelling and inversion for this method are described and land and marine case studies are presented.
Instructor: Dr Alessandro Ferretti (Tele-Rilevamento Europa (TRE))
Satellite radar data for surface deformation monitoring are gaining increasing attention, and not only within the oil and gas community. They provide a powerful tool for remotely measuring extremely small surface displacements over large areas and long periods of time, without requiring the installation of in-situ equipment. However, apart from remote sensing and radar specialists, only a relatively small number of geoscientists and engineers understand how a radar sensor orbiting the Earth at about 7 km/s from 700km above the Earth's surface can actually measure ground displacements of a fraction of a centimetre. This course provides a step-by-step introduction to satellite radar sensors, SAR imagery, SAR interferometry and advanced InSAR techniques. Rather than a tutorial for remote sensing specialists, the course starts from very basic concepts and explain in plain language the most important ideas related to SAR data processing and why geoscientists and engineers should take a vested interest in this new information source.
Instructor: Dr Laura Valentina Socco (Politecnico di Torino)
The use of surface wave analysis for near surface characterisation has dramatically increased in the last decade thanks to the possibility offered by this technique for shear wave velocity estimation. New tools and approaches have been developed for surface wave data acquisition and analysis to make the method robust and suitable to complex systems.