Overview of EM Methods with a Focus on the Multi-Transient Electromagnetic (MTEM) Method
|Dr Bruce Hobbs (University of Edinburgh, United Kingdom)|
|Near Surface – Non-Seismic Methods|
|5 CPD points|
2D 3D INVERSION MARINE MULTI‑TRANSIENT NEAR SURFACE OCEANOGRAPHY RECIPROCITY RESISTIVITY SATURATION
Reservoir rocks contain water, hydrocarbons or a mixture of both. The resistivity of those rocks is a sensitive indicator of hydrocarbon saturation levels and may be determined remotely by electromagnetic (EM) methods. The multi-transient electromagnetic method (MTEM) is a technology with sufficient resolving power to delineate potential reservoirs and to monitor hydrocarbon movements in a commercial context.
The objective of this course is to provide an understanding and appreciation of the technology and its capabilities so that geoscientists will feel confident in incorporating the method into their appraisal and decision-making workflows. Another objective is to understand the contribution that MTEM technology can make to appraisals and work-flow in exploration and monitoring.
The course is divided into four sections. The first gives a brief summary of EM methods and introduces the new MTEM technology. Following sections provide details of the method, its practical realisation for land and marine surveys and some case studies.
1. EM Methods and Introduction to MTEM
- Resistivity and its importance in the oil industry
- Overview of EM and electrical methods
- Introduction to the MTEM method
- Overview of applications
2. The MTEM method: Acquisition and Processing
- Step and impulse response functions
- Step and pseudo-random binary sequence (PRBS) source functions
- Repeatability and reciprocity
- Layout and acquisition parameters
- Processing and quality control
- In-field results - real time appraisal (RTA) of subsurface prospects
3. Modelling and Inversion
- 1D modelling of step and impulse response functions
- 3D modelling of complex structures
- Extraction of dipole-dipole DC resistivity as a by-product of MTEM
- 2D inversion of DC resistivity
- 1D inversion of step and impulse response functions
- Collation of 1D inversions
4. Equipment and applications
- Three generations of field equipment for land surveys
- Marine Equipment
- Case studies including surveys in France, Canada, Central America and the North Sea
Participants should have knowledge of basic science.
About the instructor
Bruce Hobbs is Visiting Professor at the University of Edinburgh and is co-founder, with Anton Ziolkowski, David Wright and Leon Walker, of the company MTEM Ltd. He was Director of Pentland Geophysics.
Bruce graduated from Exeter University with B.Sc (1965) and Ph.D (1968) in mathematics and his 41 years of research have mainly involved electromagnetic induction studies, inversion theory and near surface geophysics. Academic positions include faculty positions at Laurentian University, Ontario and The University of Edinburgh, Scotland, a research fellowship at Cambridge University and sabbaticals at Scripps Institute of Oceanography as a Green Scholar, the Lunar and Planetary Laboratory at the University of Arizona (twice) as Adjunct Professor and the University of Paris (twice) as Visiting Professor.
Bruce has held posts as Geophysical Secretary and Vice-President of the Royal Astronomical Society, London; Chairman, Joint Association for Geophysics, UK; Chairman, Working Group 3, Division 1 of the International Association of Geomagnetism and Aeronomy and has organised and run many workshops on electromagnetic induction and resistivity.
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