Universal type drilling rock mass air tightness detection test device

Abstract

The invention provides a universal drilling rock air tightness detection test device. The test device comprises a detection and control part and a data acquisition system, one end of the detection and control part is provided with an airflow reversing device communicated with the interior of the detection and control part, the airflow reversing device is communicated with a high-pressure air inlet pipe and a high-pressure air outlet pipe which can be opened and closed, and the tail end of the high-pressure air inlet pipe is connected with a high-pressure pump station; a first barometer and a second barometer are arranged on the high-pressure air outlet pipe and the high-pressure air inlet pipe respectively, and the first barometer and the second barometer are electrically connected with the data acquisition system; a packer is arranged on the detection and control part, and a breather pipe is arranged in the middle of the packer to communicate the interior of the packer. According to the invention, airtightness detection of the drilled rock mass can be realized, the accuracy of evaluating the airtightness of the rock mass is improved, and reference and basis are provided for evaluating the airtightness of surrounding rock of an underground gas storage.

Description

Technical Field

[0001] The invention relates to the technical field of gas tightness detection of surrounding rocks of underground gas storage reservoirs, and in particular to a universal borehole rock mass gas tightness detection test device. Background Art

[0002] my country's new energy industry is booming. Compressed air energy storage, as an important part of my country's new energy development plan, is currently in a period of rapid development. Compressed air energy storage (CAES) refers to a storage method that uses electrical energy to compress air during the low load period of the power grid, seals the air at high pressure in the gas storage reservoir, and releases compressed air to drive the steam turbine to generate electricity during the peak load period of the power grid. The gas storage reservoir is an important part of the compressed gas energy storage power station, which can be divided into salt caverns, modified mine caverns, artificial chambers, artificial gas tanks / pipelines, etc. Among them, salt caverns, modified mine caverns, and artificial chambers have high requirements for the air tightness of underground rock masses. The application of gas storage reservoir air tightness detection technology in China is still in the exploratory stage, and the current methods are mostly aimed at the sealing detection of salt cavern gas storage reservoirs, which is time-consuming and labor-intensive. There is a lack of general air tightness detection and evaluation methods for underground rock masses, especially for rock mass air tightness detection and evaluation through drilling. Therefore, it is particularly necessary to carry out research on rock mass air tightness detection test equipment to address these problems.

[0003] At present, the air tightness of the borehole rock mass is mostly measured by first obtaining the permeability of the rock mass through a water pressure test, and then estimating the air tightness of the rock mass. However, there are inevitably certain errors and problems in evaluating the air tightness of the rock mass using this method. Therefore, it is necessary to develop a borehole air tightness detection test device specifically for the air tightness of the rock mass. Summary of the invention

[0004] The purpose of the present invention is to provide a test device for detecting the air tightness of a borehole rock mass so as to improve the accuracy of judging the air tightness of the rock mass.

[0005] To this end, the present invention adopts the following technical solutions:

[0006] A universal drilling rock mass air tightness detection test device, the test device comprises a detection and control part, and a data acquisition system; an airflow reversing device connected to the interior of the detection and control part is arranged at one end, a high-pressure air inlet pipe and a high-pressure air outlet pipe that can be opened and closed are connected to the airflow reversing device, and a high-pressure pump station is connected to the end of the high-pressure air inlet pipe; a first barometer and a second barometer are respectively arranged on the high-pressure air outlet pipe and the high-pressure air inlet pipe, and the first barometer and the second barometer are electrically connected to the data acquisition system; a packer is arranged on the detection and control part, and a ventilation pipe is arranged in the middle part of the packer to connect the interior of the packer; an air bag is arranged on the packer at the same time, so as to form a compressed air test section between the packers and provide effective detection working conditions for the test section; and holes are opened on the wall of the ventilation pipe.

[0007] Furthermore: the test device also includes a control system, which is electrically connected to the high-pressure pump station and the data acquisition system; at the same time, the control system is also electrically connected to the airflow reversing device to form a connected state or a closed state of the internal passage of the airflow reversing device.

[0008] Furthermore, the airflow reversing device includes two passages inside, the first passage is connected to the airbag, and the second passage is connected to the ventilation pipe.

[0009] Furthermore: the cross-sectional area of ​​the packer is greater than or equal to the cross-sectional area of ​​the vent pipe.

[0010] Furthermore: a pressure relief valve is arranged on the high-pressure air outlet pipe downstream of the first barometer, and a pressure regulating valve is arranged on the high-pressure air inlet pipe upstream of the second barometer.

[0011] Furthermore: a flow rate sensor is arranged between the second barometer and the pressure regulating valve.

[0012] Furthermore: a third barometer and a pressure control valve are arranged at the gas outlet of the high-pressure pump station, and the pressure control valve and the third barometer are arranged in sequence along the gas outflow direction.

[0013] Furthermore: the test device is provided with a fixed stand outside the geological borehole, and a pipeline interface which cooperates with the walls of the high-pressure air outlet pipe and the high-pressure air inlet pipe is installed in the fixed stand.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The borehole rock mass air tightness detection test device provided by the present invention can realize the air tightness detection of the borehole rock mass, improve the accuracy of the rock mass air tightness evaluation, and provide a reference and basis for the air tightness evaluation of the surrounding rock of the underground gas storage reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0017] Figure 2 It is a schematic diagram of the internal structure of the airflow reversing device of the present invention.

[0018] The markings in the attached drawings are: 1-geological borehole; 2-gas stop plug; 3-ventilation tube; 4-inflatable air bag; 5-air flow reversing device; 6-high-pressure air inlet pipe; 7-high-pressure air outlet pipe; 8-fixed stand; 9-pipeline interface; 10-first barometer; 11-pressure relief valve; 12-second barometer; 13-flow rate sensor; 14-pressure regulating valve; 15-third barometer; 16-pressure control valve; 17-high-pressure air pump; 18-high-pressure pump station; 19-data acquisition system; 20-control system. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0020] like Figure 1-2 As shown, a universal drilling rock mass air tightness detection test device, the test device includes a detection and control part, and a data acquisition system 19; an airflow reversing device 5 connected to the inside of the detection and control part is arranged at one end, and a high-pressure air inlet pipe 6 and a high-pressure air outlet pipe 7 that can be opened and closed are connected to the airflow reversing device 5, and a high-pressure pump station 18 is connected to the end of the high-pressure air inlet pipe 6; a first barometer 10 and a second barometer 12 are respectively arranged on the high-pressure air outlet pipe 7 and the high-pressure air inlet pipe 6, and the first barometer 10 and the second barometer 12 are electrically connected to the data acquisition system 19; a packer is arranged on the detection and control part, and a vent pipe 3 is arranged in the middle part of the packer to connect the inside of the packer; at the same time, an air bag 4 is arranged on the packer to form a compressed air test section between the packers, and provide the test section with effective detection working conditions to ensure the sealing requirements; and holes are opened on the wall of the vent pipe 3.

[0021] In this embodiment, when the test device performs air tightness detection on the geological borehole 1, only the inspection and control part is extended into the geological borehole 1. At the same time, the sealer in this embodiment adopts a cylindrical air-stopping plug 2, and the number of the air-stopping plugs 2 is optimally divided into upper and lower parts. The air-stopping plugs 2 at both ends are connected by a ventilation pipe 3 and a certain sealing section length is left. The sealing section length can be adjusted or controlled by the ventilation pipe 3. The sealing section is the compressed air test section; a circle of airbag grooves is provided in the cylindrical side of the air-stopping plug 2, and the airbag 4 is loaded in the airbag groove. After the airbag 4 is inflated, the air-stopping plug 2 can fit tightly against the wall of the geological borehole 1 to ensure the air tightness of the compressed air test sealing section.

[0022] like Figure 1As shown, the holes on the wall of the vent pipe 3 can cooperate with and facilitate the pumping and inflation of the sealing section during the compressed air test.

[0023] like Figure 1 As shown, specifically, the test device also includes a control system 20, and the control system 20 is electrically connected to the high-pressure pump station 18 and the data acquisition system 19; at the same time, the control system 20 is also electrically connected to the airflow reversing device 5 to form a connected state or a closed state of the internal passage of the airflow reversing device 5.

[0024] In this embodiment, the control system 20 includes a programmable controller, and the control system 20 is connected to the high-pressure pump station 18, the data acquisition system 19 and the airflow reversing device 5 through connecting lines and communicates with each other, and the entire compressed air test process can be controlled by the control system 20. At the same time, the data acquisition system 19 is respectively connected to the first barometer 10, the second barometer 12, the third barometer 15 and the flow rate sensor 13 through connecting lines.

[0025] like Figure 1-2 As shown, the airflow reversing device 5 includes two passages inside, the first passage is connected to the airbag 4 and is used for pumping and deflation of air in the airbag 4; the second passage is connected to the vent pipe 3 and is used for pumping water and filling and deflation of air in the compressed air test sealing section.

[0026] The cross-sectional area of ​​the packer is greater than or equal to the cross-sectional area of ​​the vent pipe 3, so as to realize the airtightness detection of the sealing section of the compressed air test.

[0027] like Figure 1 As shown, the packer, the vent pipe 3 and the airflow reversing device 5 are sequentially connected from bottom to top and arranged coaxially, and the interiors of the three are hollow to form an internal passage through which air can flow sequentially.

[0028] like Figure 1 As shown, specifically, a pressure relief valve 11 is provided at the downstream of the first barometer 10 in the high-pressure air outlet pipe 7 , and a pressure regulating valve 14 is provided at the upstream of the second barometer 12 in the high-pressure air inlet pipe 6 .

[0029] A flow rate sensor 13 is provided between the second barometer 12 and the pressure regulating valve 14 .

[0030] The intake pressure and intake flow rate can be accurately known and the intake pressure can be adjusted through the second barometer 12, the pressure regulating valve 14 and the flow rate sensor 13. The internal air pressure can be released through the pressure relief valve 11.

[0031] like Figure 1As shown, specifically, the high-pressure pump station 18 includes a high-pressure air pump 17, a third barometer 15 and a pressure control valve 16. The third barometer 15 and the pressure control valve 16 are disposed at the gas outlet of the high-pressure air pump 17, and the pressure control valve 16 and the third barometer 15 are sequentially disposed along the gas outflow direction. Through the third barometer 15 and the pressure control valve 16, the pumping pressure of the high-pressure air pump 17 can be accurately known and adjusted.

[0032] like Figure 1 As shown, this embodiment also provides a detection fixing structure, which fixes the parts of the high-pressure air inlet pipe 6 and the high-pressure air outlet pipe 7 extending to the outside of the geological borehole 1, further ensuring the stability of the test device in the geological borehole 1.

[0033] Specifically, the detection fixed structure includes a fixed stand 8 arranged outside the geological borehole 1, and a pipeline interface 9 matched with the pipe wall of the high-pressure air outlet pipe 7 and the high-pressure air inlet pipe 6 is installed in the fixed stand 8.

[0034] See also Figure 1-2 When the detection device is used to test the air tightness of the borehole rock mass, the specific operation method is as follows:

[0035] First, in the test site area, geological drilling is constructed according to the specification requirements. After the construction is completed and the drilling cleaning work is finished, the air stop plug 2, the vent pipe 3 and the air flow reversing device 5 of the test device are connected from bottom to top in sequence and arranged coaxially, and placed in the predetermined test depth section of the borehole 1, wherein the upper end of the air flow reversing device 5 is respectively connected to the high-pressure air inlet pipe 6 and the high-pressure air outlet pipe 7. The high-pressure air inlet pipe 6 and the high-pressure air outlet pipe 7 are respectively connected to the pipeline interface 9 at the borehole mouth and fixed on the fixed stand 8.

[0036] The pressure relief valve 11 at the end of the high-pressure air outlet pipe 7 is kept in an open state.

[0037] The pressure regulating valve 14 of the outer section of the high-pressure intake pipe 6 and the pressure control valve 16 of the high-pressure pump station 18 are both kept in an open state.

[0038] Before starting the compressed air test, it is necessary to check whether the connections between the various parts of the instrument are tight to ensure the sealing of the test equipment.

[0039] The high-pressure compressed air test requires that the double air-stop plugs 2 of the packer are used to isolate the test section first, and the airflow reversing device 5 is adjusted by the control system 20 to connect the high-pressure air inlet pipe 6 with the inflatable airbag 4. The high-pressure air pump 17 is opened in the positive direction to inflate the airbag 4 and make it fit tightly against the borehole wall to ensure the sealing of the test section.

[0040] The control system 20 adjusts the airflow reversing device 5 to make the high-pressure air inlet pipe 6 communicate with the ventilation pipe 3, and the water in the test section is completely pumped out by the reverse operation of the high-pressure air pump 18.

[0041] After the water in the test section is completely drained, close the pressure relief valve 11 and the pressure regulating valve 14.

[0042] Open the high-pressure air pump 17 forward again, adjust the pumping pressure to the test pressure, and after the third barometer 15 reading reaches the test pressure and remains stable, open the pressure regulating valve 14 and start to inflate the test section, wait for the air pressure in the test section to reach the test pressure, and after the second barometer 12 reading is the same as the test pressure and remains stable (the first barometer 10 reading can be used as a reference to verify with the second barometer 12), first close the pressure regulating valve 14, and then close the high-pressure pump station 18. At this time, record the readings of the first barometer 10 and the second barometer 12 and start timing.

[0043] The whole test system is kept in balance for 60 minutes, and the changes in the readings of the first barometer 10 and the second barometer 12 are recorded, both of which are the test section air pressure.

[0044] Then, based on the recorded data, the gas leakage rate of the rock mass is calculated and the air tightness of the rock mass is evaluated.

[0045] For the gas in the test section, there is an ideal gas state equation (1):

[0046] pV=nRT

[0047] Wherein, p is the gas pressure, in MPa; V is the test section volume, in L; n is the amount of gas, in mol; R is the molar gas constant, R = 8.31 J / (mol·K); T is the gas temperature, in K.

[0048] So the amount of gas leakage is Unit: mol.

[0049] Gas leakage rate of rock mass (2):

[0050]

[0051] Where q is the rock gas leakage rate, which is equal to the gas volume lost per minute per meter of test section length under a test pressure of 1 MPa, and the unit is L / m·MPa·min; Vm is the molar volume of gas under standard conditions, Vm=22.4L / mol; L is the test section length, in m; P is the test pressure, in MPa.

[0052] Substituting the ideal gas state equation into the rock mass gas leakage rate calculation equation, we can obtain (3):

[0053]

[0054] The gas leakage rate of the borehole rock mass can be calculated by formula (3), thereby judging and evaluating the gas tightness of the rock mass.

[0055] The above embodiment is only a preferred technical solution of the present invention. Those skilled in the art should understand that the technical solutions or parameters in the embodiments can be modified or replaced without departing from the principle and essence of the present invention, and all should be covered within the protection scope of the present invention.

Claims

1. A universal drilling rock mass air tightness detection test device, characterized in that: The test device comprises a control part and a data acquisition system (19); an airflow reversing device (5) connected to the interior of the control part is arranged at one end of the control part, a high-pressure air inlet pipe (6) and a high-pressure air outlet pipe (7) which can be opened and closed are connected to the airflow reversing device (5), and a high-pressure pump station (18) is connected to the end of the high-pressure air inlet pipe (6); a first barometer (10) and a second barometer (12) are arranged on the high-pressure air outlet pipe (7) and the high-pressure air inlet pipe (6), respectively, and the first barometer (10) and the second barometer (12) are electrically connected to the data acquisition system (19); A packer is arranged on the inspection part, and a vent pipe (3) is arranged in the middle part of the packer to connect the inside of the packer; at the same time, an air bag (4) is arranged on the packer to form a compressed air test section between the packers and provide effective detection working conditions for the test section; and a hole is opened on the wall of the vent pipe (3).

2. A universal drilling rock mass air tightness detection test device according to claim 1, characterized in that: The test device further comprises a control system (20), wherein the control system (20) is electrically connected to the high-pressure pump station (18) and the data acquisition system (19); At the same time, the control system (20) is also electrically connected to the airflow reversing device (5), thereby forming a connected state or a closed state of the internal passage of the airflow reversing device (5).

3. A universal drilling rock mass air tightness detection test device according to claim 1, characterized in that: The airflow reversing device (5) comprises two passages therein, the first passage being connected to the air bag (4), and the second passage being connected to the ventilation pipe (3).

4. A universal drilling rock mass air tightness detection test device according to claim 1, characterized in that: The cross-sectional area of ​​the packer is greater than or equal to the cross-sectional area of ​​the vent pipe (3).

5. A universal drilling rock mass air tightness detection test device according to claim 1, characterized in that: The high-pressure air outlet pipe (7) is provided with a pressure relief valve (11) downstream of the first barometer (10), and the high-pressure air inlet pipe (6) is provided with a pressure regulating valve (14) upstream of the second barometer (12).

6. A universal drilling rock mass air tightness detection test device according to claim 5, characterized in that: A flow rate sensor (13) is provided between the second barometer (12) and the pressure regulating valve (14).

7. A universal drilling rock mass air tightness detection test device according to claim 1, characterized in that: A third barometer (15) and a pressure control valve (16) are arranged at the gas outlet of the high-pressure pump station (18), and the pressure control valve (16) and the third barometer (15) are arranged in sequence along the gas outflow direction.

8. A universal drilling rock mass air tightness detection test device according to claim 1, characterized in that: The test device is provided with a fixed stand (8) outside the geological borehole (1), and a pipeline interface (9) is installed inside the fixed stand (8) and matches with the pipe wall of the high-pressure air outlet pipe (7) and the high-pressure air inlet pipe (6).

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