Geophysical survey

Geophysical survey

 

  • Geophysical survey activities stipulated in the MOU using Time Domain Electromagnetic (TDEM) method, and the implementation completed of seventy five (75) TDEM points.
  • Received and evaluation of the final report including calibrations, measurements and all technical results.
  • The main goal of this study is to determine:
    • Subsurface layering;
    • Layer thickness (overburden and oil shale).
    • Water table and
    • Subsurface structural Geology.

Field procedure for TEM:-The Transient Electromagnetic (TEM) was used in order interpret the subsurface information in terms of resistivity for determination of the thickness of the overburden rocks as well as the thickness of the oil shale.

The field geophysical works was started with the execution of 75 TEM soundings with coincident loop (100m×100m) in order to reach a target depth of 300m . The location co-ordinates of the loop corners were recorded with a Global Positioning System (GPS) with a total of 75 soundings were carried out over the entire study area.

The preliminary processing of the TEM data; show a good depth of penetration and discrimination between different geoelectrical layers as well. The retuned signal are of good quality data which enabling the penetration of a depth of more 250m depth in most sites. Consequently, depending on the initial and recovered models it is expected to resolve the subsurface lithological models of overburden and oil shale thicknesses and depths. 

 

Data analysis and interpretation of TEM 

The ”TEM-FAST 48” data were processed with the TEM-RESEARCHER (TEM-RES,ver. 2015) package developed by the Applied Electro - Magnetic Research in the Netherlands and delivered with the equipment. The TEM-RES program offers several data processing possibilities. Among them is the possibility of inversion of the field data in an eight layered horizontally uniform.

Details on the TEM-RES program are discussed in the TEM-RESEARCHER manual (AEMR, 2015). The following are the processing steps of the TDEM field data in the TEM-RES program. The program offers the opportunity to visualize five TEM sounding data in one graph. These data are displayed with the program’s theoretical curve in a graph with time in μs on the horizontal axis and the apparent resistivity on the (Rho) in Ohm-m on the vertical scale. All values of the measured process E(t) which are less than 0, are ignored automatically and cleared from the screen