Fig. 1. THz-TDS of sands samples and reference signal

Fig. 2. Schematic diagram of experimental process

Fig. 3. Schematic diagram of experimental device

Fig. 4. THz-TDS of oil A and oil B

Fig. 5. THz-TDS of some samples

Fig. 6. Relationship betweenCand σ/d for sands samples mixed with oil A and oil B

Fig. 7. Experimental (symbols) dielectric constant ε and calculated (lines) dielectric constant ε_eff as a function of P for two-phase systems of two samples.