Mining, Environmental, Petroleum, and Engineering Industry Applications of Electromagnetic Techniques in Geophysics

Abstract

Electromagnetic (EM) techniques are extremely important as a direct detection geophysical tool utilized in the base metal industry. They were developed in countries such as Canada, whose thin conductive weathering overburden did not hamper the penetration of EM signals and enabled exploration to depths on the order of 300 m. As a result, EM techniques were used widely in North America and Scandinavia for many years before they became common in countries with a thick conductive overburden, such as Australia. The 1980s and 1990s have seen the use of EM methods move from anomaly finding to mapping, as well as the development of better, faster and more accurate computer modelling algorithms. A review of EM papers, for the years 1998 to 2002, showed that most dealt with EM techniques as mapping tools. Airborne, ground and marine EM techniques are still being developed, as are data processing and interpretation software. The advent of robust 2-D and 3-D computer modelling and inversion algorithms has led to the acceptance of EM methods as a mapping tool for many environmental and petroleum industry applications, a trend which is expected to increase.

A Selection Algorithm of Survey Lines and the Interactive Mode of the Sounding Curve

“…As a result of (3), (4) and (5), (1) and (2) can be written as follows: According to (6) and (7), we can concluded that the curves of Ex and Hx are smooth and continuous, and are derivable at any points where the value of frequency is larger than zero (f>0). Fig.2 shows two curves of Ex, which are apparently smooth and continuous.…”

“…It has been successfully used in a series of explorat ion areas, such as metal min ing, petroleum, geothermal resources and groundwater since its inception [3][4][5][6][7] .…”

A novel transient electromagnetic measuring system

“…Under the efforts of a lot of famous geophysics instrument companies, some excellent TEM systems [1][2][3][4] are developed and applied, including PROTEM [1][2][3][4][5] (Geonics, Canada), TerraTEM [6] (Australian Geo Instruments), GDP-16,32 [7] (Zonge, U.S.A), V6 [8] (Phoenix ,Canada), SMARTem [9] (ElectroMagnetic Imaging Technology, Australia). Recently, distributed and pulled TEM systems are developed rapidly.…”

Survey design to maximize the volume of exploration of the InfiniTEM system when looking for discrete targets

“…Such surveys allow for the detection of permafrost and groundwater, the delineation of pollution plumes and saline intrusions in aquifers, the depiction of leakage from tailings dams, and the characterization of acid mine drainage (Keller, 1997;Sheard et al, 2005;Brakni, 2011). Mapping applications have become especially important in shallow environmental surveys (Sheard et al, 2005). The TDEM method also has important applications in the discovery and delineation of ore bodies and the characterization of unexposed conductive objects in civil engineering studies (Brakni, 2011).…”