CN202903886U - Convenient and fast test probe for resistivity in well - Google Patents

Abstract

The utility model relates to a simple and quick well resistivity testing probe, which comprises an electrode (1), an insulating cylinder (2), and a connecting cable (3). There are four electrodes (1), and the four electrodes are respectively The first electrode (A), the second electrode (M), the third electrode (N), the fourth electrode (A'), the four electrodes (A, M, N, A') in a certain order of spacing It is installed on the outer wall of the insulating cylinder (2) and connected with the wire in the connecting cable (3). Connect the DC constant current power supply at both ends of the power supply electrode, and measure the voltage and current at both ends of the measuring electrode to calculate the resistivity value of the measuring point. The resistivity test probe is reasonable in design, light in weight, high in test efficiency and good in stability.

Description

Simple and fast in-hole resistivity test probe

technical field

The utility model relates to the field of geotechnical engineering testing, in particular to a simple and quick resistivity testing probe in wells.

Background technique

In engineering surveys such as water conservancy and hydropower, municipal engineering, roads and bridges, in order to obtain the resistivity (or conductivity) of rock and soil, it is necessary to conduct in-well resistivity testing.

The existing in-hole resistivity test method generally uses a comprehensive logging tool. Since this device needs to take into account many testing methods such as natural gamma ray, sound wave, well temperature, and well diameter, it is relatively heavy and difficult to carry under complex terrain conditions in mountainous areas. affect test efficiency.

Contents of the invention

The purpose of this utility model is to overcome the shortcomings of the above-mentioned existing background technology, and provide a simple and fast in-well resistivity test probe, which can be conveniently and quickly carried out in-well resistivity testing probe with the help of ordinary resistivity testing instruments (measuring devices). Resistivity (or conductivity) test, the resistivity test probe is reasonable in design, light, high in efficiency and good in stability.

The purpose of this utility model is achieved through the following measures: a simple and quick well resistivity test probe, which is characterized in that it includes electrodes, insulating cylinders, and connecting cables. There are four electrodes, and the four electrodes are respectively the first An electrode, a second electrode, a third electrode, and a fourth electrode, the four electrodes are installed on the outer wall of the insulating cylinder in sequence according to a certain distance and connected with the wires in the connecting cable.

In the above technical solution, the four electrodes are symmetrically arranged, that is, the distance between the first electrode and the second electrode=the distance between the third electrode and the fourth electrode=40cm, the distance between the second electrode and the third electrode The distance between them is 10cm, and the center of the distance between the second electrode and the third electrode is the test point 0.

In the above technical solution, the connection between the electrode and the connecting cable is insulated and sealed with a sealant.

In the above technical solution, the four electrodes are non-polarized lead or copper electrodes.

The electrodes in the utility model are firmly welded to the wires in the four-core connecting cable, and the power supply + and power supply - terminals in the measuring device are connected to a DC constant current power supply, and the voltage and current at the two ends of the measuring device + and - are measured. , the rock-soil resistivity at the measured position in the well can be calculated according to the following formula.

$\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; AM</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; AN</span>}}}{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; MN</span>}}}<span\; class="notranslate">\; \&CenterDot;</span>\frac{{\mathrm{<span\; class="notranslate">\; \&Delta;\; U</span>}}_{\mathrm{<span\; class="notranslate">\; MN</span>}}}{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; K</span>}\frac{{\mathrm{<span\; class="notranslate">\; \&Delta;\; U</span>}}_{\mathrm{<span\; class="notranslate">\; MN</span>}}}{\mathrm{<span\; class="notranslate">\; I</span>}}$

为电极A与电极M之间的距离；

为电极A与电极N之间的距离；

为电极M与电极N之间的距离；ΔU_MN为电极M与N之间的电压；I为电极M与N之间的电流；K为装置系数。In the formula: ρ is the resistivity;

is the distance between electrode A and electrode M;

is the distance between electrode A and electrode N;

is the distance between electrode M and electrode N; ΔU _MN is the voltage between electrodes M and N; I is the current between electrodes M and N; K is the device coefficient.

The present invention adopts four electrodes, wherein when AB supplies power, MN measurement is the first set of data, when A′B supplies power, MN measurement is the second set of data, using two sets of data for comprehensive analysis is conducive to improving the resolution of the resistivity test in the well rate and stratification accuracy of rock and soil mass. The utility model is applicable to the drilling diameter range of 50-150mm.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Fig. 2 is a schematic diagram of the structure of the utility model when testing the resistivity in a simple and fast well.

.第一电极与第二电极之间的距离, .第三电极与第四电极之间的距离, 

.第二电极与第三电极之间的距离。In the figure: 1. Electrode, 2. Insulation cylinder, 3. Connecting cable, 4. Measuring device (resistivity testing instrument), A. The first electrode, M. The second electrode, N. The third electrode, A'. The first four electrodes,

.the distance between the first electrode and the second electrode, .the distance between the third electrode and the fourth electrode,

. The distance between the second electrode and the third electrode.

Detailed ways

The implementation of the present utility model will be described in detail below in conjunction with the accompanying drawings, but they do not constitute a limitation of the present utility model, they are only examples, and the advantages of the present utility model will become clearer and easier to understand.

Referring to the accompanying drawings, it can be seen that the utility model is a simple and fast resistivity test probe in a well, including an electrode 1, an insulating cylinder 2, and a connecting cable 3. There are four electrodes 1, and the four electrodes are respectively the first electrode A and the second electrode A. Electrode M, the third electrode N, the fourth electrode A', the four electrodes A, M, N, A' are mounted on the outer wall of the insulating cylinder 2 in sequence according to a certain distance and connected to the wires in the connecting cable 3 ( As shown in Figure 1).

＝第三电极与第四电极之间的距离

＝40cm，第二电极与第三电极之间的距离

间距为10cm，第二电极与第三电极之间中心点为测试零点。所述电极1与连接电缆3的连接处采用密封胶绝缘灌注密封(防止漏电)。所述的四个电极A、M、N、A’采用不极化的铅或铜电极。The four electrodes A, M, N, A' are symmetrically arranged, that is, the distance between the first electrode and the second electrode

= the distance between the third electrode and the fourth electrode

=40cm, the distance between the second electrode and the third electrode

The distance is 10cm, and the center point between the second electrode and the third electrode is the test zero point. The connection between the electrode 1 and the connecting cable 3 is insulated and sealed with a sealant (to prevent leakage). The four electrodes A, M, N, A' are non-polarized lead or copper electrodes.

During the test, the two ends of the power supply in the measuring device are connected to a DC constant current power supply, among which the power supply + is connected to the positive pole of the power supply, the power supply - is connected to the negative pole of the power supply, and at the same time the power supply - is placed away from the wellbore and grounded, and the electrode A in the probe is connected to the power supply + , electrodes M and N are respectively connected to measurement + and measurement - (or electrode A' in the probe is connected to power supply +, electrodes M and N are respectively connected to measurement - and measurement +), and the current and voltage at both ends of the measurement electrode MN can be calculated and measured Point resistivity value.

Other unspecified parts are prior art.

Claims (3)

1. resistivity measurement is popped one's head in the simple and efficient well, it is characterized in that: comprise electrode (1), insulating cylinder (2), stube cable (3), described electrode (1) has four, four electrodes are respectively the first electrode (A), the second electrode (M), third electrode (N), the 4th electrode (A '), described four electrodes (A, M, N, A ') sequentially are contained in the outer wall of insulating cylinder (2) according to certain spacing and are connected with wire in the stube cable (3); Described four electrodes (A, M, N, A ') are symmetric offset spread, i.e. distance between the first electrode and the second electrode

Distance between third electrode and the 4th electrode

Distance between the second electrode and the third electrode

Spacing is 10cm, the distance between the second electrode and the third electrode

The center for the test 0 point.

2. resistivity measurement probe in the simple and efficient well according to claim 1 is characterized in that the fluid sealant insulated enclosure is adopted in the junction of described electrode (1) and stube cable (3).

3. resistivity measurement probe in the simple and efficient well according to claim 2 is characterized in that lead or the copper electrode of described four electrodes (A, M, N, A ') for not polarizing.

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