WO2021077397A1

WO2021077397A1 - Portable rock core multi-parameter comprehensive testing apparatus and testing method

Info

Publication number: WO2021077397A1
Application number: PCT/CN2019/113259
Authority: WO
Inventors: 张平松; 李圣林; 刘畅; 孙斌杨; 欧元超
Original assignee: 安徽理工大学
Priority date: 2019-10-21
Filing date: 2019-10-25
Publication date: 2021-04-29
Also published as: LU102275A1; CN110595905A; LU102275B1; ZA202007391B

Abstract

A portable rock core multi-parameter comprehensive testing apparatus and testing method. The testing apparatus comprises a rock core wrapper and a parameter testing host machine; the rock core wrapper comprises a wrapping belt and parameter testing elements (8, 9, 10, 13) provided on the wrapping belt, the wrapping belt for wrapping a rock core comprises an inner layer and an outer layer, a sealed pressurizing air bag is provided between the inner layer and the outer layer of the wrapping belt, and the pressurizing air bag is connected to an inflating device by means of a rubber tube (1); the testing elements (8, 9, 10, 13) comprise a resistivity testing element (8), wave velocity testing elements (9, 10), and a strain testing element which are in signal connection with the parameter testing host machine. The apparatus can implement the multi-state geophysical parameter testing of rock cores having different diameters, wherein resistivity testing and wave velocity testing can be performed in the free state of the rock core and also in the axial compression state of the rock core, and strain testing is performed when the rock core is damaged by rock deformation under axial compression.

Description

Portable rock core multi-parameter comprehensive testing device and testing method

Technical field

The invention relates to the technical field of rock physical parameter testing, in particular to a portable rock core multi-parameter comprehensive testing device and testing method.

Background technique

Coal will still be one of my country's main energy sources in the future. Improving the transparency of the geological conditions of coal mining is the top priority for future mine production development. Among them, it is necessary to strengthen the testing and understanding of the physical mechanics and geophysical parameters of the rock, and to accurately grasp the core test parameters of the coal-measure strata, which is the basis for constructing the transparent geological conditions of mining.

Resistivity, strain, and wave velocity are important geological and geophysical parameters, which are indispensable in exploration data interpretation and model forward parameter selection. In addition, multi-parameter comprehensive testing and the automation of the experimental process are the key to core analysis, and it is also the development trend of core testing and analysis.

Summary of the invention

The purpose of the present invention is to provide a portable core multi-parameter comprehensive test device and test method to solve the above-mentioned problems in the prior art, and realize the portable core analysis device, the multi-state full-diameter core analysis, and the accurate test method. High efficiency and fine integration of test parameters.

In order to achieve the above objectives, the present invention provides the following solutions: The present invention provides a portable core multi-parameter comprehensive test device, including a core wrapper and a parameter test host, the core wrapper includes a wrapping belt and is arranged at The parameter test element on the wrapping belt, the wrapping belt used to wrap the core includes an inner layer and an outer layer, a sealed pressurized airbag is arranged between the inner and outer layers of the wrapping belt, and the pressurized airbag It is connected with an inflatable device through a rubber tube, and the test element includes a resistivity test element, a wave velocity test element and a strain test element that are signal-linked with the parameter test host.

Preferably, the wrapping tape is made of a material that is not easy to stretch, and the wrapping tape is a rectangle with a width of ≥100 mm and a length of ≥450 mm; the two ends of the wrapping tape are bonded by velcro fasteners.

Preferably, the resistivity test element includes electrode sheet A, electrode sheet M, electrode sheet N, and electrode sheet B. The outer surfaces of the four electrode sheets are provided with needle probes where the outer surfaces of the four electrode sheets are attached to the rock core. The top of the probe is provided with a water-absorbable sponge; the four electrode sheets are vertically arranged on the left side of the inner surface of the wrapping belt, and the distance from the outer side is 10mm, and the positions of the four electrode sheets are fixed.

Preferably, the wave velocity test element includes an excitation probe and a receiving probe, both probes are ultrasonic probes, and the excitation probe is arranged between the electrode sheet M and the electrode sheet N; Sliding rail, the receiving probe is slidably arranged on the sliding rail.

Preferably, the slide rail is made of a material that can be bent laterally, the length of the slide rail is greater than or equal to 175 mm, and the distance between the left end of the slide rail and the excitation probe is not greater than 39 mm; One side is provided with a scale for controlling the distance between the excitation probe and the receiving probe.

Preferably, the strain test element is a distributed optical fiber, and the optical fiber distributed in the vertical range on the inner surface of the wrapping tape is laid out in a circle around the core, and the upper end C of the optical fiber is located above the electrode sheet A, and the lower end is The vertical distance between D and the upper end C is 100mm, and the lateral distance is 68mm.

Preferably, a rectangular steel ring is provided on one side edge of the wrapping tape close to the resistivity test element, and the other side of the wrapping tape passes through the steel ring and is fixed by a Velcro tape.

Preferably, the parameter test host includes a resistivity test module, a wave velocity test module, and a strain test module, and each test module is connected to each parameter test element through a multi-parameter integrated cable, and the cable passes inside the wrapping belt.

The present invention also provides a portable core multi-parameter comprehensive test method, which is applied to the above-mentioned portable core multi-parameter comprehensive test device, and includes the following steps:

1) Rock core wrapping: According to the size of the core, adjust the distance between the excitation probe and the receiving probe, add water to the sponge on the four electrode sheets in the resistivity test element, and then wrap the core with a wrapping tape, and Adhere tightly through Velcro; use an inflatable device to pressurize the pressurized airbag to make the resistivity test element, wave velocity test element and strain test element on the inner wall of the wrapping belt couple with the core;

2) Resistivity test: The test host is connected to the four electrode sheets of the resistivity test element on the core holder through a cable, and the resistivity test module in the test host sends a load current command through electrode sheet A and electrode sheet B Continuous current is automatically applied to the tested rock core, and the resistivity test module in the test host starts data collection, recording the power supply current I between electrode sheet A and electrode sheet B and the potential difference between electrode sheet M and electrode sheet N △U, the resistivity value of each core sample

3) Wave speed test: The test host is connected to the ultrasonic probe on the core holder through a cable. The wave speed test module in the test host controls the pulse generator to emit a high-voltage pulse. The high-voltage pulse excites an ultrasonic signal in the excitation probe. The ultrasonic signal is received by the receiving probe after passing through the tested rock core, and then the data is collected by the test host. The test host performs analog-to-digital conversion of the data signal and records the time information. According to the ultrasonic travel time t given in the time information, it is calculated Wave speed of the measured core

Where D is the core diameter;

4) Strain parameter background value test: the core is tested in the free state of the strain background value. After the core is wrapped by the wrapping tape, the distributed optical fiber is tightly coupled with the core, and the test host will obtain a series of strain sampling points according to the core size. A sampling point corresponds to a spatial coordinate on the core. The distributed optical fiber is connected to the test host. The strain test module in the test host controls the transmission of optical signals to the optical fiber. After the optical signal is transmitted, the strain test module measures the Rayleigh scattering signal information, so as to analyze the background data on the strain sampling point;

5) Strain parameter test under loading: Axial compression is used to apply axial pressure to the core. During this dynamic process, strain data is continuously collected to capture the strain value generated when the rock is broken until the core specimen is completely destroyed.

Compared with the prior art, the present invention has achieved the following technical effects:

The present invention can realize multi-state geophysical parameter testing of cores with different diameters. Among them, the resistivity test and the wave velocity test can be carried out in the free state of the core or in the state of the core under axial compression; the strain test is carried out in It is carried out when the rock core is deformed and damaged under axial compression. The test device of the present invention is light, stable, reliable, sturdy and durable, suitable for laboratories and the field, and portable; it realizes the comprehensive test of the core resistivity, wave velocity, and strain parameters, and the test method is scientific and effective; Testing of geophysical parameters of full-diameter cores; realizing fine testing of core strains, with high visualization of the test results, strong anti-interference ability, stable output, and the ability to obtain changes in core strain before and after failure, and the results can be used to analyze the rock The mechanism of deformation and failure under load; improves the work efficiency of indoor core testing, and obtains the geological and geophysical parameters of the core under different conditions.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the embodiments. Obviously, the drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, without creative work, other drawings can be obtained based on these drawings.

Figure 1 is a schematic diagram of the overall structure of a portable core multi-parameter comprehensive testing device;

Figure 2 is a schematic diagram of the layout of test elements for parameters such as resistivity, wave velocity and strain;

Figure 3 is a schematic diagram of the location of the magic hook and loop fastener of the wrapping tape;

Among them, 1-Hose; 2-Male buckle Velcro; 3-Female buckle Velcro; 4-Integrated cable; 5-Steel ring; 6-Outer surface of wrapping tape; 7-Inner surface of wrapping tape; 8-Resistor Rate test element; 9-excitation probe; 10-receiving probe; 11-slide rail; 12-ruler; 13-strain test element.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

In order to make the above objectives, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figures 1-3, the present invention provides a portable core multi-parameter comprehensive testing device, which includes a core wrapper and a parameter testing host.

1. Core wrap holder. The core holder is mainly composed of a wrapping belt and test elements for resistivity, wave speed and strain parameters set on the wrapping belt (Figure 1).

(1) Wrapping belt. The wrapping tape is made of materials that are not easy to stretch. It consists of two layers, an inner and an outer layer, and a sealed pressurized airbag is arranged inside; the inner surface 7 of the wrapping belt is equipped with test elements for resistivity, wave velocity, and strain parameters; the outer surface 6 of the wrapping belt is provided with magic hooks.

According to the standards of the Society of Rock Mechanics, the standard size of the core for parameter testing is a cylinder with a diameter of 25mm, and according to the basic size of the drill bit and core tube in the basic regulations of drilling quality, the full diameter core diameter is 28mm ~ 136mm. In addition, as well as the rock quality index RQD parameter (the ratio of the cumulative length of the columnar core equal to or greater than 10cm in each footage to the footage of each drilling return) and other requirements, in order to achieve various sizes (standard size and full diameter size) ) For core testing requirements, the wrapping belt is designed to be a rectangle with a width of ≥100mm and a length of ≥450mm.

(2) The resistivity test element 8 is an electrode sheet, which is provided with four pieces (electrode sheet A, electrode sheet M, electrode sheet N, electrode sheet B), and a needle probe is designed where the outer surface of the electrode sheet and the core are attached , The top of the needle probe is designed with a water-absorbable sponge. Water is added to the sponge when testing the core resistivity parameters to increase the conductivity between the electrode sheet and the core and improve the test accuracy. The four electrode sheets are vertically arranged and fixed, and are arranged on the left side of the inner surface of the wrapping belt 7 at a distance of 10 mm from the outer side, as shown in FIG. 2 (the inner surface of the wrapping belt 7 is upward).

(3) The wave velocity test element is an ultrasonic probe, including an excitation probe 9 and a receiving probe 10. The excitation probe 9 is used to generate ultrasonic signals, and the receiving probe 10 is used to receive ultrasonic signals. The excitation probe 9 is fixed and arranged between the electrode plates M and N of the resistivity test element 8; the middle part of the inner wall of the wrapping belt is provided with a slide rail 11 transversely. The slide rail 11 is made of transversely bendable material, and the length is ≥175mm. 11 The distance between the left end (the inner surface of the wrapping belt 7 upwards) and the excitation probe 9 is not more than 39mm. The receiving probe 10 is set on the slide rail 11, can move left and right, and has a certain frictional resistance between the slide rail 11, and controls the receiving probe 10 can be in a static state without moving; a ruler 12 is provided on one side of the slide rail 11 to control the distance between the excitation probe 9 and the receiving probe 10 (

D is the core diameter), and the layout is shown in Figure 2.

(4) The strain test element 13 is a distributed optical fiber. A total of 1 optical fiber is routed, which is designed to be laid around the core. The upper end C of the optical fiber is located directly above the electrode sheet A of the resistivity test element 8. It is evenly distributed in the vertical range, and the layout is shown in Figure 2 (the inner surface of the wrapping belt 7 is upward).

(5) A pressurized airbag with internal sealing inside and outside the wrapping belt. The airbag is connected to an external inflator (inflated pressurized latex ball) through the hose 1 to be pressurized, and the resistivity, wave velocity, and strain parameter test elements on the inner wall of the control wrap belt are tightly coupled with the core.

(6) 6 magic hooks on the outer surface of the wrapping tape. A rectangular steel ring 5 is provided on the edge of the right side of the wrapping belt (the outer surface 6 of the wrapping belt is upward), and the inner diameter size allows only the left side of the wrapping belt to pass through. The outer surface 6 of the wrapping belt is provided with a magic hook and loop fastener on the left side, which can be set as one or multiple layers, usually set as a female buckle; the outer surface 6 of the wrapping belt is provided with a male buckle in addition to the male buckle magic buckle 3. Buckle Velcro 2. During the parameter test, the female buckle on the left side of the parcel belt passes through the steel ring 5 on the right (the inner surface of the parcel belt 7 is inward) and is stretched to the male buckle for quick sticking, controlling the parcel belt to tightly wrap the core ,As shown in Figure 3.

2. The parameter test host is mainly composed of resistivity test module, wave velocity test module and strain test module. Each test module is connected to each parameter test element through a multi-parameter integrated cable 4, and the cable passes through the inside of the wrapping belt.

The portable core multi-parameter comprehensive testing method includes the following steps:

1. The core is wrapped and held.

According to the size of the core, adjust the distance between the excitation probe 9 and the receiving probe 10, add water to the electrode sheet, and wrap the core with a wrapping tape; stick the male buckle hook and loop fastener 2 and the female buckle hook and loop fastener 3 tightly ; Use an inflatable device (inflated pressurized latex ball) to pressurize the internally sealed pressurized airbags of the inner and outer layers of the wrapping belt through the hose 1 to promote the resistivity, wave velocity, strain parameter test elements and the core on the inner wall of the wrapping belt Tightly coupled.

2. Test of resistivity and wave speed parameters.

(1) Resistivity test.

During the resistivity test, the test host is connected to the electrode sheet on the core holder through the integrated cable 4, and the resistivity test module in the test host sends a load current command, and the test core is automatically loaded continuously through electrode sheets A and B. Current, the resistivity test module in the test host starts data collection, recording the power supply current I (A) between the electrode sheets A and B and the potential difference ΔU (V) between the electrode sheets M and N. According to the formula for each core:

The test host calculates the resistivity value of each core sample.

(2) Wave speed test

The test host is connected to the ultrasonic probe on the core holder through a cable. The wave speed test module in the test host controls the pulse transmitter to emit a high-voltage pulse. The high-voltage pulse excites an ultrasonic signal in the excitation probe 9, and the ultrasonic signal passes After the tested rock core is received by the receiving probe 10, the test host performs data collection, and the test host performs analog-to-digital conversion of the data signal and records the time information. According to the ultrasonic travel time t given in the time information, according to the formula:

Then calculate the wave velocity of the tested core.

3. Test the background value of strain parameters.

The core is tested for the strain background value in the free state. After the core is wrapped by the wrapping belt, the distributed optical fiber is tightly coupled with the core. According to the core size, the test host will obtain a series of strain sampling points. One sampling point corresponds to a spatial coordinate (x, y, z) on the core. The distributed optical fiber is connected to the test host. The strain test module in the test host controls the transmission of optical signals to the optical fiber. After the optical signal is transmitted, the strain test module measures the Rayleigh scattering signal information in the optical fiber and analyzes a series of strain sampling points Background data on.

4. Strain parameter test under load.

The axial pressure loading device is used to apply axial pressure to the core. During this dynamic process, strain data is continuously collected to capture the strain value generated when the rock ruptures until the core specimen is completely destroyed. After starting the test, the axial pressure loading device gradually applies axial pressure to the core, and the strain test module in the test host controls the strain condition of the core tested by the optical fiber. The strain test module analyzes the strain values at a series of strain sampling points, and The background data is compared, and the strain value α corresponding to each sampling point due to axial compression is obtained. In the mapping software, the three-dimensional model of the core and the spatial coordinates and strain values of several sampling points are used to construct the core under compression. The strain distribution three-dimensional model is used to express the core strain test results in a refined manner.

In the present invention, specific examples are used to illustrate the principle and implementation of the present invention. The description of the above examples is only used to help understand the method and core idea of the present invention; at the same time, for those of ordinary skill in the art, according to this The idea of the invention will change in the specific implementation and the scope of application. In summary, the content of this specification should not be construed as a limitation of the present invention.

Claims

A portable core multi-parameter comprehensive testing device, which is characterized in that it comprises a core holder and a parameter test host. The core holder includes a wrapping belt and a parameter testing element arranged on the wrapping belt. The wrapping tape that wraps the core includes an inner layer and an outer layer. A sealed pressurized airbag is arranged between the inner and outer layers of the wrapping tape. The pressurized airbag is connected to an inflator through a hose, and the test element It includes a resistivity test element, a wave velocity test element and a strain test element connected with the parameter test host signal.
The portable core multi-parameter comprehensive testing device according to claim 1, wherein the wrapping tape is made of a material that is not easily stretched, and the wrapping tape is a rectangle with a width ≥ 100 mm and a length ≥ 450 mm; the wrapping tape The two ends are glued together by velcro.
The portable rock core multi-parameter comprehensive test device according to claim 1, wherein the resistivity test element includes electrode sheet A, electrode sheet M, electrode sheet N, and electrode sheet B, and the outer surfaces of the four electrode sheets A needle probe is arranged at the joint with the rock core, and the top of the needle probe is provided with a water-absorbable sponge; the four electrode sheets are arranged vertically on the left side of the inner surface of the wrapping belt, and are 10mm away from the outer side, And the positions of the four electrode sheets are fixed.
The portable rock core multi-parameter comprehensive test device according to claim 3, wherein the wave velocity test element includes an excitation probe and a receiving probe, both probes are ultrasonic probes, and the excitation probe is arranged on the electrode sheet. Between M and electrode sheet N; a sliding rail is arranged transversely in the middle of the inner wall of the wrapping belt, and the receiving probe is slidably arranged on the sliding rail.
The portable rock core multi-parameter comprehensive test device according to claim 4, wherein the slide rail is made of a material that can be bent laterally, the length of the slide rail is greater than or equal to 175 mm, and the left end of the slide rail is connected to The distance between the excitation probes is not greater than 39 mm; one side of the slide rail is provided with a ruler for controlling the distance between the excitation probe and the receiving probe.
The portable core multi-parameter comprehensive testing device according to claim 3, characterized in that: the strain test element is a distributed optical fiber, and the optical fibers distributed in the vertical range on the inner surface of the wrapping belt are arranged around the core. The upper end C of the optical fiber is located above the electrode sheet A, and the vertical distance between the lower end D and the upper end C is 100 mm, and the lateral distance is 68 mm.
The portable rock core multi-parameter comprehensive testing device according to claim 1, wherein a rectangular steel ring is provided on the side edge of the wrapping belt close to the resistivity test element, and the other side of the wrapping belt After the side passes through the steel ring, it is fixed by Velcro.
The portable core multi-parameter comprehensive test device according to claim 1, wherein the parameter test host includes a resistivity test module, a wave velocity test module, and a strain test module, and each test module communicates with each other through a multi-parameter integrated cable. The parameter test element is connected, and the cable passes through the inside of the wrapping belt.
A portable core multi-parameter comprehensive test method, applied to the portable core multi-parameter comprehensive test device according to any one of claims 1-8, characterized in that it comprises the following steps:

1) Rock core wrapping: According to the size of the core, adjust the distance between the excitation probe and the receiving probe, add water to the sponge on the four electrode sheets in the resistivity test element, and then wrap the core with a wrapping tape, and Adhere tightly through Velcro; use an inflatable device to pressurize the pressurized airbag to make the resistivity test element, wave velocity test element and strain test element on the inner wall of the wrapping belt couple with the core;

2) Resistivity test: The test host is connected to the four electrode sheets of the resistivity test element on the core holder through a cable, and the resistivity test module in the test host sends a load current command through electrode sheet A and electrode sheet B Continuous current is automatically applied to the tested rock core, and the resistivity test module in the test host starts data collection, recording the power supply current I between electrode sheet A and electrode sheet B and the potential difference between electrode sheet M and electrode sheet N △U, the resistivity value of each core sample

3) Wave speed test: The test host is connected to the ultrasonic probe on the core holder through a cable. The wave speed test module in the test host controls the pulse generator to emit a high-voltage pulse. The high-voltage pulse excites an ultrasonic signal in the excitation probe. The ultrasonic signal is received by the receiving probe after passing through the tested rock core, and then the data is collected by the test host. The test host performs analog-to-digital conversion of the data signal and records the time information. According to the ultrasonic travel time t given in the time information, it is calculated Wave speed of the measured core

Where D is the core diameter;

4) Strain parameter background value test: the core is tested in the free state of the strain background value. After the core is wrapped by the wrapping tape, the distributed optical fiber is tightly coupled with the core, and the test host will obtain a series of strain sampling points according to the core size. A sampling point corresponds to a spatial coordinate on the core. The distributed optical fiber is connected to the test host. The strain test module in the test host controls the transmission of optical signals to the optical fiber. After the optical signal is transmitted, the strain test module measures the Rayleigh scattering signal information, so as to analyze the background data on the strain sampling point;

5) Strain parameter test under loading: Axial compression is used to apply axial pressure to the core. During this dynamic process, strain data is continuously collected to capture the strain value generated when the rock is broken until the core specimen is completely destroyed.