Course Summary

The electrical resistivity tomography (ERT) and transient electro-magnetic (TEM) methods are widely used for hydrological, environmental, engineering and mining surveys to map the subsurface resistivity. This course provides basic training on practical field survey techniques and data interpretation for 2-D and 3-D ERT surveys to professionals in the earth sciences. It includes a review of the resistivity method followed by instrumentation, survey techniques, data processing and interpretation methods. A brief review of topics such as time-lapse and I.P. surveys with case histories will also be covered. The course will also give an insight into the ideas and theories behind the TEM method, the processing and inversion of TEM data, and in principal how the instruments work. The focus will be on ground-based data and it will be demonstrated how processing, inversion and visualization of TEM data and is carried out in practice. 

Why do you think this course should be included into the EAGE portfolio?

In some less developed areas of the world the older 1-D electrical surveys are still being used despite the limitations of the method. This is due partly to lack of proper equipment, and inadequate knowledge of modern 2-D and 3-D ERT surveys. The TEM is a newer and complimentary technique to measure the subsurface resistivity that can be used in areas where it is difficult to carry out ERT surveys, such as dry regions with poor electrical ground contact or for deep surveys with limited line length. This course provides practical guidelines on choosing the proper survey parameters and modelling techniques of the field data. This course also covers the integration of the electrical survey information with other geodata for a more comprehensive interpretation.

What does this course add to the existing courses and how is it different?

This course covers the ERT and TEM methods in detail which is not possible in a more general course. It is intended to complement such general courses for practising field surveyors that are currently involved in resistivity surveys as well as in academic research. It also covers integration with other types of geodata and 3D visualization commonly used in modern surveys.

Short Course Description

This course covers the theoretical and practical developments in 2-D, 3-D and 4-D ERT (Electrical Resistance Tomography) and TEM (Transient-Electromagnetic) surveys, data processing, interpretation and integration with other geophysical and geographical information. In recent years, the 1-D vertical sounding method has been increasingly replaced by 2-D and 3-D ERT surveys due to developments in resistivity meter equipment and automatic computer modelling techniques.  These ERT surveys are now widely used throughout the world. The TEM method can be used in areas where it is not practical to carry out ERT surveys, such as dry regions or for deep surveys with limited accessible survey area. However, in parts of Asia and Africa practical knowledge of such surveys is not as widespread as in Europe and North America. This course will cover the practical aspects of carrying out the survey and the interpretation of the data using modern computer inversion techniques.

Motivation

In some areas of the world, particularly in parts of Asia and Africa, the older 1-D electrical surveys are still being used despite the limitations of the method. This is due partly to lack of proper equipment, and inadequate knowledge of such modern 2-D and 3-D ERT surveys. Even where they are widely used, mistakes in field surveys and interpretation are common. This course provides practical guidelines on choosing the proper survey parameters and modelling of the results. The TEM method is a relatively newer technique which also measures the ground resistivity and complements the ERT technique as it can be used in areas where it is difficult to carry out ERT surveys. Practical knowledge in the use of the TEM technique is limited and this course will help to popularise its use in field survey.

Meet the Instructors