SU1233071A1 - Method of geoelectroprospecting - Google Patents

Abstract

The invention relates to geophysical prospecting, in particular to electrical profiling by the method of resistance with grounded and non-grounded lines. The aim of the invention is to increase productivity and measurement accuracy. In order to achieve this goal, in the method of geoelectrical exploration by the method of resistance with low-frequency power supply with excitation of the electric field, polarized in the horizontal plane and measurement of the horizontal components of the electric field gradient, use the supply line in the form of a broken open-loop loop and after measuring the horizontal components of the gradient excite a vertically polarized electric field with the help of two halves of a non-earth loop connected to one pole of a gene Rathore and galvanic grounding connected to the other pole of the generator, and the measured vertical component of the electric field gradient, 6 yl. (Q (lu soo with about

Description

The invention relates to geophysical exploration, and more specifically electrotrophilization using the sapiens method, and is intended to increase the efficiency of geophysical work in the search for mineral deposits.

The purpose of the invention is to increase labor productivity and sensitivity of measurements.

Figure 1 shows the spatial layout of the installation for implementing the method; Fig. 2 shows the current distribution circuit for the ungrounded open-loop multi-polar loop; in FIG. 3, the same for an ungrounded open unipolar loop; Fig. 4-6- are the curves of the relative specific electrical resistance p / p obtained by the proposed method.

Installation for the implementation of the method. contains a supply line in the form of a rectangular loop consisting of two U-shaped insulated wires from the ground; wires 1 and 2; the ends 3 and 4 of wires 1 and 2 are also isolated from the ground, spaced apart by distance 5 and forming a gap in pi melting line. The end 6 of the segment of wire 1 is connected to the switch 8, the end 7 of the segment of wire 2 is connected, the switch 8 to the same generator 1 9. The second generator terminal is connected to the switch 8 and can be connected either to the end 6 of the wire 2 or galvanic grounding 10. The non-grounded receiving line 11 with the meter 12 is located in the central i part of the loop along one of the profiles of the system 13 profiles within the limits of the working plate 14 ...

Received XYZ coordinate system with. the beginning in the middle of the base of an open loop, the axis OX is directed parallel to the base of the loop, the axis is Perpendicular to the base of the earth, the axis 07 is vertically upwards

The method is carried out as follows. .

The supply line is unfolded in the form of an unclosed ungrounded loop and connects its ends 7 and 6 s. generator 9, switch 8 and remote galvanic grounding 10 according to the scheme shown in FIG. 1. Switch 8 is set

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They are turned to the right position and, by the same token, they turn the loop into a multipole mode, where the U-shaped wires are connected to different terminals of the generator and the electric field is polarized in the horizontal plane and perpendicular to the expected extent of the geological object. The receiving line 11 is oriented parallel to the non-closed side of the loop along one of the profiles 13. The horizontal component of the electric field gradient is measured along the direction ((E) along the pointer device gauge 12, moving along profile m 3. Switch 8 is set to the left position and thus, the loop is connected to the unipolar mode, in which both U-shaped segments of the power supply wire are connected to one generator terminal, and remote grounding 10, an electrical circuit is connected to the second generator terminal in the working part-: the tablet 14 is polarized in a vertical plane. The receiving line 11 is oriented in the vertical plane of the earth's surface. The vertical composition is measured by the electric field in the direction. Е (Е) along the dial gauge of the meter 12, moving by profile m I3.

Vertical electrical sections are shown along line 15-15 (Figures 2 and 3). Points 16 in all three figures correspond to the intersection points of line 15-15 and U-shaped segments of supply line wires.

When the loop is turned on in a multipole mode (Fig. 2), the instantaneous currents in unclosed branches and half-loops have a different direction (in Figs. 2 and 3, the direction of the instantaneous currents in the U-shaped sections of the supply line is indicated by + and -), After this, the current lines 17 in the ground and in the central part of the working tablet 14 (FIG. 1) are directed horizontally and the electric field in region 18 is uniform. In FIG. a vertical electrical section is shown corresponding to the case where an ungrounded open loop was turned on in single-pole mode. In this case, the opposite pattern is observed. And: the currents in the ungrounded wires of the U-shaped segments of the supply

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the lines have the same direction, the current lines in the earth 19 are directed vertically and the electric field in region 20 is uniform. Thus, when using a polarized, open-loop, non-grounded loop as a source, the total normal electric field in the central part of the tablet is concentrated near the surface of the earth, uniformly and polarized in the horizontal direction. When using a unipolar open loop grounded as a generator at a remote point as a source, the total normal electric field in the central part of the loop is also uniform, but at the same time concentrated at a much greater depth and polarized in the vertical direction. By using homogeneous electric fields, polarized in two mutually perpendicular directions and concentrated at different depths, and measuring horizontal and vertical electric field gradients perpendicular to each other, it is possible to use a well-developed mathematical apparatus and qualitative interpretation of observations. palettes for uniform potential fields polarized in different directions (for example, magnetic fields caustic). Thereby, the goal of the invention is achieved - labor productivity and measurement accuracy, i.e. geological efficiency of studying the geometric parameters of deep-seated, extended to the depth of the ore bodies.

The interpretation of the observation results is reduced to calculating the values of the electrical resistivity p over the measured E and E, j values using coefficients that take into account the geometry of the installation and the effect of the induction component of the low frequency currents and fluxes x along the wires of the U-shaped segments of the supply lines. Then build a plan of graphs p | according to the system of profiles 13 and produce a quantitative interpretation of the result-.

Commodity observations using mathematical tools or palettes for homogeneous potential fields.

Figure 4 shows an entrapment medium 21 with electrical resistivity p,, high resistivity layer 22 with electrical resistivity p Pi obtained from measurement results E. 23 and E 24. Similar positions 25 and 26 show similar formations having different the depth of the upper KPOMKI-T and various parameters along the strike for depth, and the curves p | ./p ,. From figure 4 it can be seen that if ore body 22 of increased resistance is located mainly in the area of uniform field E, then the anomalous effect

along curve E, 23 considerably exceeds the anomalous effect along E, 24, if the ore body is located in the intersection zone of areas of uniform fields along Ej (and along E, (Figure 5), then the anomalous effects along both components are commensurable with each other 23, 24 If the ore body is located mainly in the homogeneous field of E (6), then the anomalous effect on Е „24 is much larger than the anomalous effect on EX 23, Quantum le ratio of the anomaly of anomalous LI1T on E and by E „, as well as their specificity and absolute intensity values of the anomalies serve as a measure for ety opredele1P1i the geometric pgfametrov searched geological objects.

Using the method of geoelectrical exploration, in comparison with the known methods, the possibility of obtaining by means of one supply line of electric fields, polarized in the horizontal and vertical planes, i.e. labor productivity increases, the efficiency of geophysical work on. the resistance method by increasing the sensitivity to the depth of the upper edge and the dimensions along the strike of the object under study, ensuring that work is carried out in areas where it is impossible to carry out galvanic separations, and increasing labor productivity through the use of ungrounded feeding and receiving lines.

Claims (1)

Invention Formula The method of geoelektrorazdejki method of resistance, in which using a power line connected to the generator, excite an electric field, polarized in a horizontal plane perpendicular to the direction of the strike of the object under study, orient the receiving line parallel to the current lines and measure the horizontal component of the electric gradient field and then orient the electric field along the strike of the object under study and measure the component of the electric field gradient parallel to the current lines and data comparing the two measurements is isolated desired geological objects, characterized in that, in order to increase productivity and ten 15 20 measurement sensitivity, excites a horizontally polarized electric field using an open, ungrounded loop consisting of two, symmetric U-shaped parts connected to alternator terminals of the generator, and measuring the horizontal component of the electric field gradient in the central loop region, then excite a vertically polarized electric field by connecting both parts of the loop to one of the terminals of the generator and the second terminal of the generator to remote grounding, measured in the center The hinge area of the loop is the vertical component of the electric field gradient, which is compared with the horizontal composition of the electric field gradient, and clarifies the position of the geological objects sought. 15 J6 / 7 FIG. 2 Fig.Z 23 2 cpuz.ff / V / g / 77 v - g-Sii. f. (5