Materi Supreme I - Time Domain Electromagnetic (TDEM) Method

Aceh Training : Fundamental Concepts of Magnetotelluric Technology Dr. Yunus Daud, M.Sc, July 2012

Pemerintah Provinsi Aceh

Dr. Yunus Daud, M.Sc

Banda Aceh, 16 July 2012

Tender Preparation Training : Phase 1

Fundamental Concept of Magnetotelluric Technology


Outline

1. Introduction

2. TDEM Data Acquisition, Processing and Modeling

3. Static Shift MT Data Correction

4. Example of TDEM Data In Geothermal Exploration


Introduction


Basic Principle of TDEM

Time-Domain Electromagnetic (TDEM) methods are based on the principle of using electromagnetic induction to generate measurable responses from sub-surface features.

When a steady current in a cable loop is terminated a time varying magnetic field is generated. As a result of this magnetic field, eddy currents are induced in underground conductive materials.

The decay of the eddy currents in these materials is directly related to their conductive properties, and may be measured by a suitable receiver coil on the surface.


Basic Principle of TDEM


Application of TDEM Exploration

Application of TDEM Exploration:

Groundwater Exploration

Mineral Exploration

Salt Water Intrusion

Geologic Mapping

Static Shift Correction of MT Data

Geothermal Exploration


TDEM Field Configuration

Courtessy of NGA Inc.


TDEM Field Configuration

Record in minutes

Very portable when using batteries

1 to 5 stations/day


Airborne TDEM


TDEM Eddy Curent Flow



TDEM Waveform



Useful Equation of TDEM

Courtessy of Zonge Engineering Inc.


TDEM Sounding and Model



Static Shift Correction Using TDEM

TDEM Data is inverted in 1-D approach to produce resistivity vs depth

The resistivity-depth parameter is then converted to become MT data (resistivity vs period) using 1-D fwd modelling

The resistivity period is then used for shifting of TE/TM MT data


TDEM in Geothermal Exploration

Courtessy of Wameo, 2005

Aceh Training : Fundamental Concepts of Magnetotelluric Technology Dr. Yunus Daud, M.Sc, July 2012 Courtessy of Wameo, 2005


Contact: Dr. Yunus Daud, M.Sc. Mobile: 0812-877-2043

E-mail: [email protected]

Materi Supreme I - Time Domain Electromagnetic (TDEM) Method

Documents

Transcript of Materi Supreme I - Time Domain Electromagnetic (TDEM) Method