Method of prospecting for geological formations and apparatus for implementing the method

摘要

When prospecting for geological formations, a feeding electrode 2 is grounded in the centre of a circle formed by uniformly grounded feeding electrodes 3. The feeding electrodes 3 are connected by lengths of supply lines 4 to current generators 1 via regulators 5. A first stage of investigations involves a preliminary sounding. Current pulses are applied from the generators 1 to the lengths of supply lines 4 which are connected to diametrically opposite feeding electrodes 3. A current pulse period is synchronized with a reference signal received by a receiver 7 from the global radio navigation system. Upon turning the current off, a signal of a field magnetic component transient is measured by a meter 8 that is coupled to a magnetic component sensor 9. Using the measurement results, a geoelectric section of country medium is constructed, and expected values of the field electric and magnetic components are determined for the case when the constructed geoelectric section incorporates a geoelectric model of the geologic formation being sought. A basic sounding of the studied medium is then performed by applying equal currents to the supply line lengths 4 and measuring signals of electric and magnetic component transients along the profiles radiating from the centre of said circle. The calculated and measured values of the field electric and magnetic components are compared and a decision on a presence of a geological formation in the studied medium is made based on the results of the comparison.