Geophysical methods and apparatus for determining the hydraulic conductivity of porous materials

A geotechnical method of determining the in-situ hydraulic conductivity of a porous material under test (PMUT) by electrically probing said porous material's surface, comprising the steps of:

• a) analyzing a standard sample of a material (SSM) with geotechnical characteristics similar to those of the PMUT, said SSM, after evaluation by independent methods, having known hydraulic conductivity "K.sub.md ", known saturation levels "S" of its pore filling fluid, known irreducible water saturation "Sw.sub.irr ", known permeant resistivity "R.sub.w ", known material resistivity "R",
• b) solving for SSM, equation system:
• ##EQU5## where an iterative approach makes four unknowns converge to final values for the formation factor "a", the water saturation variable "n", the cementation exponent "m", and constant "C.sub.k ", of the SSM;
• c) measuring in-situ the resistivity "R" of the PMUT with an electrical probe;
• d) measuring by independent means, the moisture saturation "S" for the PMUT;
• e) solving, for porosity ".phi.", and hydraulic conductivity "K.sub.md " for PMUT, equation system ##EQU6## where S and R are obtained in steps c) and d) and R.sub.w, a, n, m, Sw.sub.irr, and C.sub.k, are those of SSM.