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

MT