Magneto-Telluric methods
Jaap Mondt
40 hours
Business context
Various kinds of geophysical data are available. They are
usually separated into Seismic and Non-Seismic data. Seismic is,
without any doubt, the main method used in the oil and gas
industry. But Non-Seismic data (gravity, magnetics, electrical,
electromagnetics, spectral, etc.) is the main source of information
in shallow subsurface applications (engineering, mapping pollution,
archaeology, etc.). It is also used at the early reconnaissance of
hydrocarbon plays and in mapping prospects below salt. However,
seismic has its limitations and therefore also non-seismic methods
are used successfully as complementary tools in subsurface
evaluation. In combination with seismic data, they can
significantly reduce the uncertainty of subsurface models as they
measure different physical properties of the subsurface. Controlled
Source EM (CSEM) and Magneto Telluric (MT)for example responds to
reservoir resistivity and play a major role in detecting resistive
and conductive layers. Especially MT can be used to "look" below
salt and basalt.
Course content
The Course Topics
- Geophysical data
- Magnetics
- Electrical methods
- Electromagnetics
- Land Electro-Magnetic methods (GPR)
- Marine Electro-Magnetic methods (CSEM)
- Magneto-Telluric methods (MT)
- Joint Inversion of non-seismic and seismic data
- Value of Information for MT projects
- Machine Learning Applications
- Case Studies
The course
As the name Magneto-Telluric (MT) already suggests, it involves
Magnetic as well as Telluric (Earth current) measurements.
Therefore, we start with considering the Earth's magnetic field,
modeling the response of magnetized bodies, followed by studying
electrical currents related to the response of resistive bodies.
Then we will dive into understanding Electro-Magnetism (EM) and
learn about the various ways EM is measured and used. The use of
source-controlled EM (CSEM, TDEM) and natural-source generated
fields in the earth (MT). Processing these data to derive Earth
properties using inversion. Inversion involves starting with an
approximate model of the subsurface and iteratively update the
model parameters to make the forward calculated (modelled) response
fit the observations. In the course you will study relevant
chapters of a book, presentations, look at videos and make many
practical exercises. Multiple-choice quizzes are provided to
enhance the learning. Each possible answer of a quiz to the
questions can be tried and might invite you to go back to the
course material.
Learning, methods and tools
At the end of the course participants will have a clear idea of
the strength and weaknesses of MT methods. This will be evident
from the examples discussed. The course uses self-study, videos and
many practical exercises and participant involvement in video
conferencing
Day by day programme
