CN109115669B - A water cycle test device and method for long-term automatic measurement of rock variable permeability - Google Patents

Abstract

The invention discloses a water circulation test device and method for long-term automatic measurement of rock variable permeability. The test device includes: a rock sample clamping and loading system, including a core holder and a confining pressure control system. The rock sample to be tested is placed on a rock In the core holder; circulating fluid injection and drainage system, this system controls the liquid flowing through the rock sample, and forms a circulation loop; time switch system, this system controls the startup and shutdown of the fluid injection and drainage system at a specified time , no need for operator on-duty control; data acquisition and recording system, this system includes three pressure transmitters, two quality sensors, a paperless recorder and a computer set in the test device. The invention solves the problem that the long-term water erosion effect cannot be studied in the prior art, and the measurement range of the instrument is small, so it cannot be applied to the situation of a sudden change in permeability and the test problem of large permeability change, and at the same time solves the need for testing instruments in the prior art. Testers monitor and manually operate technical issues throughout the process.

Description

A water cycle test device and method for long-term automatic measurement of rock variable permeability

technical field

The invention relates to the test of rock permeability, in particular to a water circulation test device and a test method for long-term automatic measurement of rock variable permeability.

Background technique

Permeability refers to the ability of rock to allow fluid to pass under a certain pressure difference. Long-term water erosion will change the permeability of rock mass. In order to reduce the disaster loss caused by erosion, it is very important to study the long-term change of rock permeability. Most of the existing testing instruments for measuring rock permeability require operators to be on duty all the time. Each test requires a lot of time, effort and expense. Most of the existing instruments for measuring rock seepage have a small measurement range, and cannot study the test problem of large permeability changes caused by long-term water erosion. It is especially difficult to apply to the situation where the permeability changes suddenly in the water inrush test.

Contents of the invention

Purpose of the invention: Aiming at the above prior art, to provide a water cycle test device and test method for long-term automatic measurement of rock variable permeability, which solves the problem that the long-term water erosion effect cannot be studied in the prior art, and the measuring range of the instrument is too small to be applicable It solves the problem of large-change permeability testing, and at the same time solves the technical problem that testing instruments in the prior art require full monitoring and manual operation by testers.

Technical solution: A water cycle test device for long-term automatic measurement of rock variable permeability, including:

A rock sample clamping and loading system, the rock sample clamping and loading system includes a core holder and a confining pressure control system, and the rock sample to be tested is placed in the core holder;

Circulating fluid injection and drainage system, the circulation fluid injection and drainage system is used to inject fluid into the core holder and discharge fluid from the core holder system to form a closed loop system;

A timing switch system, the timing switch system is used to control the time when the circulation injection and drainage system starts working and ends working;

A data collection and recording system, the data collection and recording system is used to receive test data.

Further, the circulating liquid injection and liquid drainage system includes a third water tank, a filter, a water pump, a pressure reducing valve, a throttle valve, an accumulator, a first shut-off valve, a first pressure transmitter, and a second shut-off valve , a second pressure transmitter, a check valve, several solenoid valves, a first water tank and a second water tank; the third water tank is sequentially connected to a filter, a water pump, a pressure reducing valve, a throttle valve, and an accumulator through a communication pipeline 1. The first shut-off valve, the other end of the first shut-off valve is connected to the lower end of the rock core holder, and the first pressure transmitter is arranged between the rock core holder and the first shut-off valve; the upper end of the rock core holder is connected with a connecting pipe Connect the second cut-off valve and check valve in turn. The output end of the check valve is divided into two circuits, which are respectively connected to the first solenoid valve and the second solenoid valve. The outlets of the first and second solenoid valves are respectively placed in the first water tank, The second water tank, the second pressure transmitter is set between the core holder and the second shut-off valve; the first water tank and the inner bottom of the second water tank are respectively provided with a first drain solenoid valve and a second drain solenoid valve , the first drain solenoid valve and the second drain solenoid valve are connected to the water inlet of the third water tank through the drain pipe.

Further, the confining pressure control system includes a servo hydraulic cylinder, a third stop valve and a third pressure transmitter, the core holder is connected to the servo hydraulic cylinder, and a first Three pressure transmitters and a third shut-off valve.

Further, the circulating liquid injection and draining system also includes a flushing device, the flushing device includes two float switches, the two float switches are respectively located on the upper part of the inner wall of the first water tank and the second water tank, and the float switches are connected to the electromagnetic Valve controller, the power output of each solenoid valve is controlled by the solenoid valve controller; when the water level in the first water tank reaches the set height, the float switch in the first water tank is activated, and the solenoid valve controller closes the first solenoid valve power supply and the second electromagnetic drain valve power supply, open the second electromagnetic valve power supply and the first electromagnetic drain valve power supply at the same time; when the water level in the second water tank reaches the set height, the float switch in the second water tank starts, and the solenoid valve controller Turn off the power supply of the second solenoid valve and the power supply of the first drain valve, and simultaneously turn on the power supply of the first solenoid valve and the power supply of the second drain solenoid valve.

Further, the timing switch system includes a power supply and a timer switch socket, the timer switch socket is connected to a power supply, and the power plug of the water pump is inserted into the timer switch socket.

Further, the data acquisition and recording system includes a first mass sensor and a second mass sensor, a paperless recorder, a computer, the second water tank and the third water tank are suspended under the first mass sensor and the second quality sensor respectively, and the first The third pressure transmitter and the first and second quality sensors are all connected to the paperless recorder, and the paperless recorder is connected to a computer.

Further, the first water tank, the second water tank and the third water tank are all made of transparent glass, and the top of the third water tank has a transparent glass cover.

A long-term water cycle test method for automatically measuring rock variable permeability, when water is used as the penetration medium test, includes the following steps:

Step 1: Connect the test device, check the tightness of the device, close all valves, ensure that the three water tanks are clean and free of impurities, and pour clean water into the third water tank;

Step 2: Put a metal tube with the same diameter and height as the rock sample into the core holder 34, and confirm the sealing state of the core holder;

Step 3: Connect the working circuit, and connect the data of each pressure transmitter and quality sensor to the paperless recorder;

Step 4: Open the third stop valve, open the servo hydraulic cylinder, and increase the confining pressure to the working confining pressure;

Step 5: Open the first shut-off valve and the second shut-off valve, and turn on the water pump to provide power for the circulating injection and drainage system;

Step 6: By observing the records of the paperless recorder, adjust the pressure reducing valve and throttle valve to obtain the required water pressure and flow rate, and obtain the pressure loss along the test device under different flow rates without a sample, and draw the corresponding Curve, bring the corresponding data into the computer program;

Step 7: Disconnect the working power of the water pump, reduce the confining pressure to zero, close the first shut-off valve, the second shut-off valve and the third shut-off valve, and take out the metal pipe;

Step 8: Load the sample to be tested, repeat steps 4-5, and set the timer switch as needed to determine the penetration cycle. Change the confining pressure value, adjust the pressure reducing valve and throttle valve to obtain the required water pressure and flow, and wait for the device to complete the setting task;

Step 9: Repeat step 8 under different confining pressure and water pressure conditions;

Step 10: Disconnect the working power of the water pump, reduce the confining pressure to zero, take out the sample, put it into a metal tube and pressurize it, and then the water pump sucks clean water to rinse the entire test device;

Step 11: Close the first shut-off valve, the second shut-off valve and the third shut-off valve, and the test ends.

Beneficial effects: 1. This device creatively uses the change of the quality of the seepage liquid to reflect the change of its flow rate. This method expands the measurement range of the flow rate to several times that of the existing instrument. For the limit change of the permeability of the rock mass under the condition of water inrush research has significant advantages.

2. This device has a timing automatic start and stop switch, which can conduct periodic rock seepage tests without being guarded, and realize digital control.

3. In addition, the test permeation medium of this test device is in a head-to-tail closed pipeline system, which can continuously perform seepage tests for several months without manual operation by operators.

4. All data of this device can be automatically entered into the paperless recorder and loaded into the computer software to obtain high-precision data and process relevant data in real time, without the need for observation readings and manual recording.

Description of drawings

Fig. 1 is the structural representation of a kind of long-term automatic measurement rock variable permeability water circulation testing device of the present invention;

Fig. 2 is a schematic diagram of the working circuit of the present invention.

Detailed ways

The present invention will be further explained below in conjunction with the accompanying drawings.

As shown in Figure 1, a water cycle test device for long-term automatic measurement of rock variable permeability includes a rock sample clamping and loading system, a circulating fluid injection and drainage system, a timing switch system, and a data acquisition and recording system. The rock sample clamping and loading system includes a core holder 34. The rock sample to be tested is placed in the core holder 34, and the surrounding pressure of the rock to be tested is loaded by the servo hydraulic cylinder 35 in the rock sample clamping and loading system. The two ends of the rock sample to be tested are loaded with osmotic pressure difference through the circulation injection and drainage system.

The rock sample clamping and loading system includes a core holder 34 and a confining pressure control system. The rock sample to be tested is placed in the core holder 34, and the confining pressure control system includes a servo hydraulic cylinder 35, a third shut-off valve 23 and a second valve. Three pressure transmitters 13, the core holder is connected with the servo hydraulic cylinder 35, and the third pressure transmitter 13 and the third shut-off valve 23 are arranged between the servo hydraulic cylinder 35 and the core holder.

The circulating fluid injection and drainage system is used to inject fluid into the core holder 34 and discharge the fluid from the core holder system, finally forming a closed circulation system. The circulating liquid injection and liquid discharge system includes a third water tank 43, a filter 31, a water pump 32, a pressure reducing valve 27, a throttle valve 25, an accumulator 33, a first stop valve 21, a first pressure transmitter 11, a first Two shut-off valves 22, a check valve 26, several electromagnetic valves, a first water tank 41 and a second water tank 42. The water outlet of the third water tank 43 is connected successively with filter 31, water pump 32, pressure reducing valve 27, throttle valve 25, accumulator 33, first shut-off valve 21, first shut-off valve 21 output end and rock core through sealed pipeline The lower end of the holder 34 is connected, and the first pressure transmitter 11 is arranged between the core holder 34 and the first stop valve 21 . The upper end of the rock core holder 34 is connected to the second shut-off valve 22 and the check valve 26 in turn with a communication pipeline, and the output end of the check valve 26 is divided into two paths, which are respectively connected to the first solenoid valve 28 and the second solenoid valve 29, The outlets of the first and second electromagnetic valves are respectively placed corresponding to the first water tank 41 and the second water tank 42 , and the second pressure transmitter 12 is arranged between the core holder 34 and the second shut-off valve 22 . The bottom ends of the first water tank 41 and the second water tank 42 are respectively provided with a first drain solenoid valve 210 and a second drain solenoid valve 211, and the first drain solenoid valve 210 and the second drain solenoid valve 211 are connected to the third water tank 43 through a drain pipe. The water inlet of the top cover. The first water tank, the second water tank and the third water tank are all made of transparent glass and can be disassembled to facilitate cleaning, checking water quality and replacing circulating liquid. There is a transparent glass cover on the top of the third water tank to reduce the long-term evaporation of water and avoid the problem of insufficient seepage medium. There are two water inlets on the glass cover to facilitate the flow of seepage liquid into the third water tank.

The circulating fluid injection and drainage system also includes an automatic flushing device, which includes two float switches, the two float switches are respectively located on the upper inner wall of the first water tank 41 and the second water tank 42, and the float switches are connected to the solenoid valve controller 54 , the solenoid valve controller 54 controls the operation of the first solenoid valve 28 , the second solenoid valve 29 , the first drain solenoid valve 210 , and the second drain solenoid valve 211 . When the water level in the first water tank 41 reached the set height, the float switch in the first water tank 41 was activated, and the solenoid valve controller 54 closed the power supply of the first electromagnetic valve 28 and the power supply of the second electromagnetic drain valve 211, and opened the second electromagnetic valve simultaneously. Valve 29 power supply and first electromagnetic drain valve 210 power supply. At this time, the first water tank 41 starts to drain water, and the second water tank 42 starts to continue receiving water flow. In the same way, when the water level in the second tank 42 reaches the set height, the float switch in the second tank 42 starts, and the solenoid valve controller 54 closes the power supply of the second solenoid valve 29 and the power supply of the first drain valve 210, and simultaneously opens the second solenoid valve 29 and the first drain valve 210. A solenoid valve 28 power supply and a second drain solenoid valve 211 power supply. At this moment, the second water tank 42 starts to drain water, and the first water tank 41 starts to continue receiving water flow.

The timing switch system is used to control the time when the circulation injection and drainage system starts working and ends working. Time switch system comprises power supply and timer switch socket 53. The timer switch socket 53 is connected to the power supply, and the power plug of the water pump 33 is connected to the timer switch socket 53. The start-up and shutdown time are set by the timer switch socket 53, thereby controlling the connection and disconnection of the circulating liquid injection and drainage system.

The data acquisition and recording system is used to receive all the data in a water circulation test device for long-term automatic measurement of rock variable permeability. The data acquisition and recording system comprises a first mass sensor 37, a second mass sensor 38, a paperless recorder 52 and a computer 51, and the first to the third pressure transmitters and the two mass sensors are all connected to the paperless recorder 52. The paper recorder 52 is connected to a computer. The second water tank and the third water tank are suspended under the first mass sensor 37 and the second mass sensor 38 respectively, and the flow test unit composed of the first mass sensor 37, the first water tank 41 and the first drain electromagnetic valve 210 is connected with the first electromagnetic valve. 28. The third water tank 43 is not in contact; similarly, the flow test unit composed of the second mass sensor 38 , the second water tank 42 and the second drain solenoid valve 211 is not in contact with the second solenoid valve 29 and the third water tank 43 . The mass change measured by the mass sensor is converted into the water flow change. The paperless recorder directly accepts the data of all transmitters and quality sensors, and processes the test data synchronously and draws images through the spontaneous computer software, and the pressure loss along the device has been eliminated during the calculation process.

In the test with water as the penetration medium, the concrete test method of the present invention is as follows:

Step 1: Connect the test device, check the tightness of the device, close all valves, ensure that the three water tanks are clean and free of impurities, and pour clean water 43 into the third water tank;

Step 2: Put a metal tube with the same diameter and height as the rock sample into the core holder 34, and confirm the sealing status of the core holder 34;

Step 3: Connect the working circuit, and connect the data of each pressure transmitter and mass sensor to the paperless recorder 52;

Step 4: Open the third cut-off valve 23, open the servo hydraulic cylinder 35, and increase the confining pressure to the working confining pressure;

Step 5: Open the first shut-off valve 21 and the second shut-off valve 22, and turn on the diaphragm pump 32 to provide power for the circulating injection and drainage system;

Step 6: By observing the record of the paperless recorder 52, adjust the pressure reducing valve 27 and the throttle valve 25 to obtain the required water pressure and flow rate, and obtain the pressure loss along the test device under different flow rates in the case of no sample, And draw the corresponding curve, and bring the corresponding data into the computer program;

Step 7: Disconnect the working power of the water pump 32, reduce the confining pressure to zero, close the first stop valve 21, the second stop valve 22 and the third stop valve 23, and take out the metal pipe;

Step 8: Load the sample to be tested, repeat steps 4-5, and set the timer switch as needed to determine the penetration cycle. Change the confining pressure value, adjust the pressure reducing valve 27 and throttle valve 25 to obtain the required water pressure and flow, and wait for the device to complete the setting task;

Step 9: Repeat step 8 under different confining pressure and water pressure conditions;

Step 10: Disconnect the working power of the water pump, reduce the confining pressure to zero, take out the sample, put it into a metal tube and pressurize it, and then the water pump sucks clean water to rinse the whole test device to ensure that there is no residual debris in the test device for subsequent testing, and use filter paper Filter the washed-out cuttings in the three tanks for testing and analysis;

Step 11: Close the first shut-off valve 21, the second shut-off valve 22 and the third shut-off valve 23, and the test ends.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (5)

1. A water circulation testing device for automatically measuring rock permeability change for a long period of time, comprising:

the rock sample clamping and loading system comprises a rock core clamp and a confining pressure control system, and a rock sample to be tested is placed in the rock core clamp;

the circulating liquid injection and drainage system is used for injecting liquid into the rock core clamp holder and draining the liquid from the rock core clamp holder system to form a closed circulation system;

the timing switch system is used for controlling the time for starting and ending the operation of the circulating liquid injection and drainage system;

the data acquisition and recording system is used for receiving test data;

the circulating liquid injection and drainage system comprises a third water tank, a filter, a water pump, a pressure reducing valve, a throttle valve, an energy accumulator, a first stop valve, a first pressure transmitter, a second stop valve, a second pressure transmitter, a check valve, a plurality of electromagnetic valves, a first water tank and a second water tank; the third water tank is sequentially connected with a filter, a water pump, a pressure reducing valve, a throttle valve, an energy accumulator and a first stop valve through a communicating pipeline, the other end of the first stop valve is connected with the lower end of the rock core holder, and a first pressure transmitter is arranged between the rock core holder and the first stop valve; the upper end of the rock core holder is sequentially connected with a second stop valve and a check valve through a communicating pipeline, the output end of the check valve is divided into two paths, the two paths are respectively connected with a first electromagnetic valve and a second electromagnetic valve, a first water tank and a second water tank are respectively correspondingly arranged at the outlets of the first electromagnetic valve and the second electromagnetic valve, and a second pressure transmitter is arranged between the rock core holder and the second stop valve; the bottom ends of the first water tank and the second water tank are respectively provided with a first water draining electromagnetic valve and a second water draining electromagnetic valve correspondingly, and drain pipes of the first water draining electromagnetic valve and the second water draining electromagnetic valve are aligned with a water inlet of the third water tank;

the confining pressure control system comprises a servo hydraulic cylinder, a third stop valve and a third pressure transmitter, the core holder is connected with the servo hydraulic cylinder, and the third pressure transmitter and the third stop valve are arranged between the servo hydraulic cylinder and the core holder;

the circulating liquid injection and drainage system further comprises a flushing device, the flushing device comprises two float switches, the two float switches are respectively positioned on the upper parts of the inner walls of the first water tank and the second water tank, the float switches are connected with an electromagnetic valve controller, and the electromagnetic valve controller controls the power output of each electromagnetic valve; when the water level in the first water tank reaches the set height, a float switch in the first water tank is started, the electromagnetic valve controller turns off the first electromagnetic valve power supply and the second electromagnetic drain valve power supply, and simultaneously turns on the second electromagnetic valve power supply and the first electromagnetic drain valve power supply; when the water level in the second water tank reaches the set height, a float switch in the second water tank is started, the electromagnetic valve controller closes the second electromagnetic valve power supply and the first drain valve power supply, and simultaneously opens the first electromagnetic valve power supply and the second drain electromagnetic valve power supply;

surrounding pressure is loaded on the periphery of the rock to be tested through a servo hydraulic cylinder in a rock sample clamping and loading system, and osmotic pressure difference is loaded on two end faces of the rock sample to be tested through a circulating liquid injection and liquid discharge system.

2. The water circulation testing device for automatically measuring rock permeability for a long period of time according to claim 1, wherein the timing switch system comprises a power supply and a timer switch socket, the timer switch socket is connected with the power supply, and a power plug of the water pump is plugged into the timer switch socket.

3. The water circulation testing device for automatically measuring rock permeability for a long time according to claim 2, wherein the data acquisition and recording system comprises a first mass sensor, a second mass sensor, a paperless recorder and a computer, the second water tank and the third water tank are respectively hung under the first mass sensor and the second mass sensor, the first pressure transmitter, the third pressure transmitter, the first mass sensor and the second mass sensor are connected with the paperless recorder, and the paperless recorder is connected with the computer.

4. The water circulation testing device for automatically measuring rock permeability for a long period of time according to claim 2, wherein the first water tank, the second water tank and the third water tank are all made of transparent glass, and a transparent glass cover is arranged on the top of the third water tank.

5. The method for automatically measuring the permeability of rock for a long time according to the device of claim 1, wherein the water circulation test method comprises the following steps when water is used as a permeation medium:

step 1: connecting the testing device, checking the tightness of the device, closing all valves, ensuring that three water tanks are clean and free of impurities, and injecting clear water into a third water tank;

step 2: loading metal pipes with the same diameter and height of the rock sample into a rock core clamp holder (34), and confirming the closing condition of the rock core clamp holder;

step 3: the working circuit is connected, and the data of each pressure transmitter and each quality sensor are connected into the paperless recorder;

step 4: opening a third stop valve, opening a servo hydraulic cylinder, and increasing the confining pressure to the working confining pressure;

step 5: opening the first stop valve and the second stop valve, and opening the water pump to provide power for the circulating liquid injection and drainage system;

step 6: the method comprises the steps of obtaining required water pressure and flow by observing the record of a paperless recorder, adjusting a pressure reducing valve and a throttle valve, obtaining the along-path pressure loss of a testing device under different flow under the condition of no pattern, drawing a corresponding curve, and taking corresponding data into a computer program;

step 7: switching off the working power supply of the water pump, reducing the confining pressure to zero, closing the first stop valve, the second stop valve and the third stop valve, and taking out the metal pipe;

step 8: loading a sample to be tested, repeating the steps 4-5, setting a timing switch according to the requirement, and determining the permeation period; changing the confining pressure value, adjusting the pressure reducing valve and the throttle valve to obtain the required water pressure and flow, and waiting for the device to finish the setting task;

step 9: repeating step 8 under different confining pressure and water pressure conditions;

step 10: switching off the working power supply of the water pump, reducing the confining pressure to zero, taking out the sample, loading the sample into a metal pipe for pressurization, and sucking clear water by the water pump to wash the whole set of testing device;

step 11: and closing the first stop valve, the second stop valve and the third stop valve, and ending the test.

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