FURTHER DEVELOPMENT AND TESTING OF THE MAGNETOTELLURIES REMOTE REFERENCE TECHNIQUE

Información del proyecto

Identificador del acuerdo de subvención: TH.-01027-81

Proyecto cerrado

Fecha de inicio 1 Septiembre 1982

Fecha de finalización 31 Marzo 1986

Financiado con arreglo a

• Programme (EEC) of Community projects in the hydrocarbons sector, 1973-1985

Coste total

€ 1 011 650,00

Aportación de la UE

€ 301 046,00

Coordinado por

BGR HANNOVER
Germany

Objetivo

The Magnetotelluric Remote Reference Technique (RRMT) is to be developed further for routine application to hydrocarbon exploration. An increase in the reliability of the data is obtained with RRMT by reduction of the influence of noise level.
The work is concentrated on two areas :
(a) further development of the measuring equipment, the data processing programs, and the interpretation techniques;
(b) development and testing of an exploration strategy for specific types of geological structures.
Values for parameters have been established on the basis of measurements and processing results obtained so far. By standardisation of the processing methods, the program processes the data four times faster than the earlier versions. Software to calculate confidence limits was developed for the single and Remote Reference processing program package.
Extensive measurements in three highly industrialised test areas of FRG showed that the quality of the sounding curves is significantly improved by the RRMT technique relative to the single-site magnetotelluric technique.
RRMT makes it possible to obtain usable results in areas where the sounding curves obtained with "classical" MT methods cannot be interpreted or only with a great expenditure of time and effort.
The testing of the RRMT technique yielded the following conclusions:
- Electromagnetic noise that correlates over large distances must be
expected in the period range of T < 10 s. Therefore, the distance
between the base and reference stations should be at least 20 km.
- The two stations should be sited consecutively along the profile or along
neighbouring profiles and survey time must be as short as possible.
- In some parts of the North German basin, good-conducting sediments were
found but thickness resulted in periods as high as 10000 s., in order
to determine basement depths.
- "H" solution is preferable for the processing of the data.
- Period range T < 10 s must be given careful attention during measuring and processing. Sorting out poor data requires great number of measurements.
Furthermore exploration, geophysical and geological data were obtained for the study areas.
In the Eastern Holstein test area, a very good-conducting layer was found in the Mesozoic. In the pre-Permian no good-conducting layers of significant thickness were found, but structures with relatively high resistivities are prominent.
In contrast to the East Holstein area, the RRMT results in large parts of the Nienburg-Versmold-Lippstadt study area show a thick, good-conducting layer in the pre-Permian. The depth to the basement decreases from 15 km at Hodenhagen to about 10 km in the Wiehen mountains to the south-west. Large lateral changes in conductivity were observed along a profile between Duemmer and Lippstandt.
The RRMT data for the Alpine study area shows low resitivities for the Molasse basin and high resistivities for the Calcereous Alps. The good-conducting Molasse layers can be traced below the Alpine nappe.
The RRMT method uses two precisely synchronised MT equipments placed at two sites A and B: the data of site A are processed together with those of site B for improving the results for site A and vice-versa.

This method is routinely applied in hydrocarbon exploration. The improvements granted by the RRMT method are tested in such areas as volcanic or alpine layers or thick evaporite beds. These activities are accompanied by the development of the corresponding hard and software.

RRMT measurements are carried out along
- 1 profile in the study area of East Holstein (W-GERMANY)
- 2 profiles in the study area of Nienburg-Versmold-Lippstadt (W-GERMANY)
- 2 profiles in the study area of the Alps (W-GERMANY/AUSTRIA)

Ámbito científico (EuroSciVoc)

Este proyecto aún no se ha clasificado con EuroSciVoc.
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Programa(s)

• ENG-HYDROCARB 1C - Programme (EEC) of Community projects in the hydrocarbons sector, 1973-1985

Tema(s)

• 1.4 - GEOPHYSICS AND PROSPECTING

Convocatoria de propuestas

Datos no disponibles

Régimen de financiación

DEM - Demonstration contracts

Coordinador

BGR HANNOVER

• Aportación de la UE: Sin datos
• Dirección: ALFRED-BENTZ-HAUS POSTFACH 510153 ; 3000 Hannover ; Alemania
• Coste total: Sin datos