SU115130A1 - The method of electrical fossil shielded three-electrode installation - Google Patents

Description

Electrical prospecting methods using electrical probing, electric profiling and electric logging are carried out with the help of three-electrode installations, the fields of which are composed of the fields of the component electrodes. A common disadvantage of these installations is the relatively small anomalous effect they have on various bodies.

Installations with multielectromagnetic power supply systems, in which the floor is of a different type compared to conventional installations, allow for a certain placement of electrodes to increase the relative magnitude of the anomalies produced, are very cumbersome and cannot be used for bilateral research.

To eliminate this drawback and increase the sensitivity of electrical exploration, it is proposed to use point electrodes in a shielded three-electrode installation. One of these electrodes is referred to "infinity," and a part of the current from this electrode branches into a shielding electrode located between the supply and measuring electrodes.

The essence of the proposed invention is the use of electrical screening methods of electrical sounding, electrical profiling and electric logging of a shielded three-electrode installation during electrical exploration. The drawing shows a schematic diagram of an installation for carrying out the proposed exploration method.

The installation consists of a main supply electrode 1, measuring electrodes 2 and 3, as well as a shielding electrode 4 located between the electrodes / and 2. The electrodes I, 2, 3 and 4 are point and are on the same straight line; In addition, electrode 5 is located in the so-called "infinity." During the logging work, this electrode is installed at the wellhead 6.

A constant current of a known magnitude from the power supply 7 is passed through the electrode. The opposite pole for the current flowing into the earth is A. The electrodes 4 and 5, connected by an automatic regulating device 5, are connected to each other.

This device provides a current (-A /) through the electrode 4, and a current (Ip) 1 through the electrode 5. The number n indicates how much of the total current goes through electrode 4 and can vary between 0 and 1.

Measurement and recording of the emf induced in the electrodes 2 to 3 is carried out by the registered device 9.

Subject invention

A method of electrical prospecting of fossil shielded three-electrode installation, characterized in that in order to increase the efficiency of electrical exploration, point electrodes are used, one of which is referred to infinity, and part of the current from this electrode is coupled to the shield electrode located between the supply and measuring electrodes.