The electrical signature of rock samples exposed to hydrostatic and triaxial pressures
| Autor: | Georg Nover, H. Heikamp |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2001 |
| Předmět: |
fracturing
Hydrostatic pressure lcsh:QC801-809 lcsh:QC851-999 Signature (logic) law.invention chemistry.chemical_compound Capacitor carbonate amphibolite pressure lcsh:Geophysics. Cosmic physics Geophysics chemistry law Electrical resistivity and conductivity Mechanical stability Electrical impedance spectroscopy Carbonate Sedimentary rock Geotechnical engineering lcsh:Meteorology. Climatology Composite material Hydrostatic equilibrium Geology |
| Zdroj: | Annals of Geophysics, Vol 44, Iss 2 (2001) |
| ISSN: | 1593-5213 |
| Popis: | The electrical signature of sedimentary (carbonate) and crystalline rock samples was studied in hydrostatic and triaxial pressure experiments up to 300 MPa. The aim was to establish a relation between an electrical signal stimulated by an external pressure acting on the sample and the mechanical stability of the rock. Natural open fractures tend to be closed under hydrostatic pressure conditions, whereas in triaxial pressure experiments new fractures are generated. These contrary processes of either decrease or increase in crack density and geometry, cause a decrease or increase in the inner surface of the sample. Such pressure induced variations in pore geometry were investigated by an interpretation and modelling of the frequency dependence of the complex electrical conductivity. In a series of hydrostatic pressure experiments crack-closure was found in the electrical signature by a decrease of the model capacitor C being related to crack geometry. This capacitor increases in the triaxial experiments where new fractures were formed. |
| Databáze: | OpenAIRE |
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