Abstract: Disclosed is a method and apparatus for enhancing oil and/or gas production from a subterranean well by using high energy, short duration electrical pulses to fracture underground rock formations containing entrapped oil or gas. The invention obviates the large power requirements of the prior art devices by generating a series of constant pulses having different durations into the rock formation to determine its characteristic impedance. Once the characteristic impedance has been determined, a second pulse having an amplitude and duration matching this characteristic impedance is discharged into the rock formation to alter its dynamic characteristics. A third pulse is then discharged into the rock formation to cause its fracture.

Abstract: A method and apparatus for fragmenting a substance by discharging pulsed electrical energy through the substance is disclosed wherein electrodes are placed in contact with the substance and a series of measuring pulses are discharged into the substance to determine the characteristic pulse and the characteristic impedance of the substance. Based upon the series of measuring pulses at least one fragmenting pulse is discharged into the substance through the electrodes to cause the substance to fragment.