SU1287079A1 - Method of recording variations of apparent electric specific resistance of rock mass - Google Patents

Abstract

The invention relates to geophysics, and more specifically to geoelectrical exploration, and can be applied in the study of napaMetpoB media that vary over time for prediction of land surveys. The purpose of the invention is to increase efficiency by simplifying measurements and processing results. To this end, a series of sequences of current rectangular pulses with a varying switching period from one sequence to another are passed through the mountain range. Record the value of the EMF of the transition process. Measured in k-each sequence, the amplitude of the process of formation, on the basis of which the apparent electrical resistivity is calculated. SS

Description

The invention relates to geophysics, and more specifically to electrical exploration, and can be applied in the study of time-varying electrical environmental parameters for the prediction of earthquakes.

The purpose of the invention is to increase efficiency by simplifying measurement and processing,

The method is implemented by passing N sequences of current pulses into the ground, each of which is generated by current polarity switching with a predetermined switching period At (n is the sequence number). Current pulse sequences differ in switching periods u.t, which are chosen to be smaller than the transition time from a single pulse T, Switching period amp t in each sequence of current pulses n found, according to the formula

the geometrical coefficient of the installation calculates the magnitude of the apparent resistance p, by varying between individual, individual probing or within one sequence of current pulses, the electrical conductivity of rocks is judged over time.

fO F

formula of invention

The method of recording variations in the apparent electrical resistivity of a rock mass, in which the time parameters of the process of the formation of a magnetic field that occurs in a rock mass when passing a sequence are measured

rectangular current pulses after switching the polarity of rectangular current pulses with a specified switching period in a radiating grounded dipole, I distinguish

.t -fg (C).

Where T is the transition time.

single pulse; n is the sequence number

current pulses (1 p N); q - coefficient, q 1,2 ... 1,5. The registration of parameters, for example, the EMF of the process of formation, is carried out by a standard installation of sounding by the formation of a magnetic field (ESM). The EMF recording is carried out, for example, on an oscillographic tape with a low speed of through V; (sweep)

V 0.2 ... 0.5 mm / s.

For each sequence, the amplitude of the formation process at time At is measured. Taking into account the sensitivity of the equipment, the magnitude of the amplitude of the current pulse and

So that, in order to increase efficiency by simplifying measurements and processing the results of observations, a series of N sequences of current pulses with different switching periods ut is formed, and the period is set in each sequence of current pulses

switching neither

based on utotj35

  about

(n-i) / „,

q / s / 5

where T is the transition time of a single pulse, s;

p - sequence number (1 p N) |

q - Coefficient, q 152 ... 1.5; in this case, the magnitude of the EMF of the transient process is recorded; in each sequence, the amplitude of the process of formation is measured, the magnitude of which leads to the apparent electrical resistivity.

Claims (1)

10 claims A method of recording variations in the apparent resistivity of a rock mass at 15 which measures the temporal parameters of the process of formation of magnetic pulses differ in switching periods Kt _n , which are chosen less than the transition time from a single pulse T. The switching period in each sequence of current pulses is 20 η are found by the formula ^bt n ⁼ 7δ ^qin ' ^{1 (s)} ' ⁷⁵ where T is the transient time of a single pulse; η is the sequence number jq of current pulses (1 ί η ίΝ); q is the coefficient, q = 1.2 ... 1.5. Registration of parameters, for example, • EMF of the formation process, is carried out by a standard installation of sounding by the formation of a magnetic field ^ 5 field (ZSM). EMF recording is carried out, for example, on an oscilloscope tape with a low speed V; (sweep) V = 0.2, ..., 0.5 mm / s. For each sequence, the amplitude of the formation process at time At _{n is} measured. Taking into account the sensitivity of the equipment, the magnitudes of the amplitudes of the current pulse and the field occurring in the rock mass when passing a sequence of current rectangular pulses after switching the polarity of the current rectangular pulses with a given switching period in a radiating grounded dipole differ in that, in order to increase efficiency by simplifying measurements and processing the results of observations, form a series of N sequences of current pulses with different switching periods At _n , while in each sequence of current pulses set the switching period based on the ratio T (n-v),, At _h = - ~ q / С /, where Т is the transient process of a single pulse, s; η is the sequence number C1 <η <N); q-coefficient, q = 1.2 ... 1.5, while the magnitude of the emf of the transient is recorded, the amplitude of the formation process is measured in each sequence, the magnitude of which calculates the apparent electrical resistivity.