KR101223473B1 - System and Apparatus for measuring transmissibility of underground structure - Google Patents

Abstract

The present invention relates to an airtight property measuring apparatus and system.
The airtightness characteristic measuring apparatus according to the present invention is inserted into a borehole formed in a region to be subjected to airtightness characteristic measurement, and is disposed in each test section along the depth direction of the borehole, and an injection hole for injecting fluid into the test section, and a test. A plurality of test tubes are formed on both sides of the plurality of test tubes, the plurality of test tubes formed with a measuring hole for transferring the pressure of the fluid filled in the section, and the expansion and contraction is possible to close the test section in close contact with the borehole wall when inflated It includes a packer, a fluid flow line connected to the injection hole through the inside of the packer and the test tube and a pressure measuring line connected to the measuring hole through the inside of the packer and the test tube.

Description

System and Apparatus for measuring transmissibility of underground structure

The present invention relates to an apparatus for measuring airtight characteristics such as water permeability and air permeability, and more particularly, to an airtight characteristic measuring system and apparatus for evaluating the hermeticity of natural gas storage and compressed air storage using underground spaces.

Underground space is used as a reservoir for storing compressed air or compressed natural gas (CNG). Underground spaces can be formed by excavating cavities or using rock salt or aquifers. It is realistic to excavate and use the cavity as underground storage in geological environment in Korea.

One of the most important technical problems in storing compressed air in a cavern formed in the basement is securing airtightness so that the stored air does not leak.

Air can flow out from the cavity can be divided into three categories. First, after excavating the rock, the concrete lining for airtightness is installed on the excavation surface, because the concrete lining is constructed by section, construction joints occur between sections. Air may flow out through these construction joints. Secondly, air can leak through the contact surface between the concrete lining and the rock, and finally, through the cracks in the rock, air can be released.

Therefore, the possibility of air leakage by the above three structures should be estimated and evaluated quantitatively before air storage. In addition, the airtightness characteristics of the above structures depend on the construction quality of the concrete lining cast in the field and various site conditions (temperature, humidity, curing, and surrounding geological conditions). It should be measured and evaluated through

Conventionally, in order to evaluate the field confidentiality characteristics of the three structures, it was generally necessary to excavate several boreholes and perform a field test. This is because the above three structures have spatial positions and different directions. That is, the boreholes for testing the joints, the boreholes for testing the contact surface of the rock and the concrete lining, and the boreholes for the cracking in the rock, were separately formed, and the permeability and permeability were measured for each borehole. Therefore, in order to grasp the airtight characteristics of the entire cavity, it was difficult to test through a large number of boreholes.

In addition, the leakage characteristics of the concrete medium and the rock medium, which are weak compared to the leak rates of the three structural parts but should be added to the total leak amount, should also be evaluated. However, in the conventional airtight property measuring device, the airtight property was identified using only water, but there is no problem in the high leaking structure, but in the low leaking structure such as concrete and rock media, Precise judgment was not easy.

In order to solve the above problems, it is an object of the present invention to provide an airtightness characteristic measuring device and system whose structure is improved to improve workability by identifying the airtightness characteristic of a plurality of sections in one borehole.

In order to achieve the above object, the airtightness characteristic measuring system according to the present invention includes an airtightness characteristic measuring device inserted into a borehole formed in a region subject to the hermetic characteristic measurement, and a fluid storage connected to the fluid flow line and storing fluid. The pressure measuring line is connected to the flow rate meter and the pressure measuring line, which is installed in the fluid flow line between the tank, the fluid storage tank and the test tube, and calculates a flow rate of the transferred fluid. It includes a pressure gauge for measuring the pressure transmitted through.

In addition, the airtightness characteristic measuring apparatus according to the present invention is disposed in each test section along the depth direction of the borehole, the injection hole for injecting fluid into the test section, and the measuring hole for delivering the pressure of the fluid filled in the test section A plurality of test tubes formed on the side of the plurality of test tubes, the plurality of packers disposed on both sides of the plurality of test tubes, the plurality of packers sealing the test section by being in close contact with the borehole wall when inflated; It includes a fluid flow line connected to the injection hole through the inside of the pressure measurement line connected to the measurement hole through the inside of the packer and the test tube.

According to the present invention, at least three test tubes may be arranged to measure airtight characteristics of at least three test sections, and three test sections may include a construction joint of a concrete lining constructed on an inner wall of a rock, And a contact surface between the rock and the concrete lining, and a crack inside the rock.

In addition, an insertion tube is detachably coupled between the at least one test tube of the plurality of test tubes and the packer so that the length of the test tube is extended, and between the test tube and the packer, as well as a plurality of insert tubes Insertion tubes can be inserted and the length can be adjusted as needed to meet site conditions.

In addition, the insertion tube is fitted to the test tube and the packer, the insertion tube is inserted into the test tube and the screws are fastened together to overlap each other, the insertion tube is inserted into the packer and the screws are fastened together to the overlapping parts, An insertion tube is detachably coupled between the test tube and the packer. That is, the test tube, the insertion tube and the packer are all formed in a prefabricated manner, and the number of test tubes and the length of each test tube can be freely adjusted.

According to an embodiment of the present invention, the packer is coupled to the test tube and has a through-hole formed therein, through which the fluid can flow in and out, is attached to surround the outer circumferential surface of the tube body and flows out through the through-hole. And an expandable member that is expandable and retractable by the fluid. Accordingly, the expansion member is expanded by the fluid injected through the inflow and outflow line connected to the through hole of the packer through the inside of the packer and the test tube, and is in close contact with the borehole wall.

On the other hand, in the airtight characteristic measurement system according to an embodiment of the present invention, the fluid storage tank is composed of a water storage tank and a gas storage tank, the fluid flow line is a first line connected to the water storage tank and the gas storage And a second line connected to the tank and a main line connected to the test tube, and further comprising a valve for selectively connecting the first line and the second line to the main line.

And a pressurizing line connected to the water storage tank from the gas storage tank so that the gas discharged from the gas storage tank is injected into the water storage tank so that water is discharged through the first line.

In addition, the flow meter may perform a function as a flow controller for adjusting the flow rate of the fluid to be conveyed.

In the present invention, it is possible to simultaneously measure the airtight property for a plurality of test intervals by using the airtight property measuring device, there is an advantage that the airtightness evaluation can be performed very quickly and easily.

In addition, the airtightness characteristic measuring device can be freely variable in the length of the test tube by selectively assembling the insertion tube, there is an advantage that can be used in a variety of conditions and sizes of the test section.

In addition, the airtightness measurement system according to the present invention has the advantage that the accuracy of the measurement is improved by selectively using water and gas as a medium for measuring the airtightness characteristics according to the permeation characteristics of the medium.

1 is a schematic configuration diagram of a gas tight characteristic measuring system according to an embodiment of the present invention.
FIG. 2 is a schematic exploded perspective view of the airtightness characteristic measurement device shown in FIG. 1.
3 is a schematic perspective view of the coupled state of FIG.
4 is a schematic cross-sectional view taken along the line IV-IV of FIG. 3.
FIG. 5 is a schematic view for explaining the hydraulic container shown in FIG. 1.
FIG. 6 is a view for explaining an operating state of the airtight characteristic measuring apparatus shown in FIG. 2.
7 to 9 are graphs showing the pressure change according to the flow rate in the test section.

Hereinafter, with reference to the accompanying drawings, it will be described in more detail with respect to the airtightness characteristic measuring system and apparatus according to an embodiment of the present invention.

1 is a schematic configuration diagram of a gas tight characteristic measuring system according to an embodiment of the present invention, FIG. 2 is a schematic separated perspective view of the gas tight characteristic measuring apparatus shown in FIG. 1, and FIG. 3 is a schematic view of the combined state of FIG. 2. It is a perspective view, and FIG. 4 is schematic sectional drawing along the III-III line | wire of FIG.

1 to 4, the airtightness characteristic measuring system 100 according to an embodiment of the present invention, the airtightness characteristic measuring apparatus 50, the fluid storage tank (61, 62), the flow meter 70 and the pressure gauge (90) ).

The airtightness characteristic measuring apparatus 50 is for quantitatively measuring and evaluating the airtightness of a target area, more specifically, air permeability and water permeability. Here, the target area may be various areas requiring sealing, for example, may be an oil reservoir, a compressed air reservoir for energy storage, a natural compressed gas reservoir, or the like. Hereinafter, the airtightness characteristic measuring apparatus 50 according to the present invention will be described by taking a cavity formed underground to store compressed air among various target areas as an example.

The airtightness characteristic measuring apparatus 50 is formed in the rod shape as a whole, and inserted into the borehole b of the target region to measure the airtightness of the target region, and includes a plurality of test tubes 11, 12, 13 and a plurality of packers. 20 is provided.

Each test tube (11, 12, 13) is formed in a hollow and spaced apart from each other. In addition, two holes penetrating between the inner circumferential surface and the outer circumferential surface are formed in the test tubes 11, 12, and 13, one of which is an injection hole 14 for injecting fluid into the test section of the target region, and the other is a test section. Measuring hole 15 for measuring the pressure of the fluid in the inside.

When the test tubes 11, 12, and 13 are inserted into the bore holes b, they are disposed in the test section in the bore holes b. The test section is arbitrarily determined as a section for the user to test the sealing, but as described in the background art, three sections are the main targets in the cavity in which the concrete lining is constructed for storing compressed air to which the present embodiment is applied. That is, as shown in Figure 6, the structure that greatly affects the sealability in the compressed air storage cavity is the construction joints (a1) of the concrete lining, the interface (a2) between the concrete lining and the excavation surface and cracks in the rock (a3).

In this embodiment, three test tubes (11, 12, 13) are provided to measure the sealing performance together for the three test intervals affecting the sealability of the cavity, and each test tube (11, 12, 13) Are placed in each of the three test intervals (a1, a2, a3).

Of course, the number of test tubes is three in the present embodiment, for example, if cracks are continuously found by depth in a rock, four or more test tubes may be arranged, and only two may be arranged in another place. The number of arrangements may vary depending on the nature of the area.

In order to measure the tightness of a test section, the test section must first be closed, and Packer plays this role. In other words, the packer is installed at both ends of the test tube and expanded to close the test section in which the test tube is placed in close contact with the borehole wall. In the present embodiment, three test tubes 11, 12, and 13 are disposed, and thus four packers 21, 22, 23, and 24 are installed to seal both sides of each test tube.

In the present embodiment, each packer 21 to 24 includes a tube body 26, a mounting part 27, and an expansion member 28. Tube body 26 is a portion connected to the test tube, it is formed in a hollow shape. The mounting portion 27 is formed in a ring shape along the outer circumferential surface of the tube body 26, and is disposed in the upper and lower portions of the tube body 26 to form a pair. The mounting portion 27 functions as a coupling member for coupling the expansion member 28 to the tube body 26 to be described later.

The expansion member 28 is made of an expandable material that expands as pressure is applied, such as rubber, and is elastically restored and contracted when the pressure is removed, and both ends of the expansion member 28 are constrained to the pair of mounting portions 27. (26) is wrapped around and combined. Accordingly, the space formed between the outer circumferential surface of the tube body 26 and the mounting portion 27 and the expansion member 28 is completely sealed.

The tube body 26 is formed with a through hole 26a penetrating between the inner circumferential surface and the outer circumferential surface, and the inflow and outflow line 49 is connected to the through hole 26a. Outflow line 49 extends outward through the tube body 26 and the interior of the test tube. When the fluid is injected between the tube body 26 and the expansion member 28 through the inlet and outlet line 49, the expansion member 28 is inflated outward and in close contact with the borehole wall w. When the packers 21 to 24 disposed on both sides of each test tube 11, 12, and 13 are all inflated, the three test sections are completely closed.

In the present invention, unlike a conventional method, a plurality of test tubes are disposed to simultaneously measure the sealing property for a plurality of test sections, and the depth of the test sections may be different for each borehole or for each target region. That is, the production position of the construction joint (a1), the interface (a2) of the concrete lining and the rock crack (a3) is different depending on the cavity or even in the same cavity.

Therefore, if the position and length of the plurality of test tubes 11, 12, 13 are fixed in the airtight characteristic measuring apparatus 50, it cannot be used under the condition that the depth of the test section is changed every time. Or multiple boreholes should be drilled.

Therefore, in this embodiment, in consideration of the depth of the test section is variable, the length of the test tubes (11, 12, 13) can also be varied, for this purpose, a hollow insertion tube is to be assembled between the packer and the test tube To make it possible. In other words, the length of the test tube is increased by the length of the insertion tube. In addition, if a plurality of insertion tubes are inserted between the packer and the test tube, the length of the test tube is extended by the number of the insertion tubes to be inserted. The insertion tube is detachably assembled between the packer and the test tube because it must be able to freely modify the numbers to be assembled.

In this embodiment, a total of five insertion tubes 31, 32, 33, 34, 35 are assembled. That is, no insertion tube is installed in the first test tube indicated by the reference numeral 11, and one insertion tube 31 and 32 is inserted into each side of the second test tube indicated by the reference numeral 12, and the reference tube 13 Two (33, 34) and one (35) insertion tube is inserted into one side of the third test tube shown.

In the present embodiment, the insertion tube is not inserted into the first test tube 11 and the insertion tube is inserted into the second and third test tubes 12 and 13, and the coupling structure between the test tube and the packer, the test tube and the insertion tube The coupling structure between the tube and the coupling structure between the insertion tube is exactly the same.

That is, the packer, the test tube and the insertion tube are all formed with an insertion groove (g) at one end, and the fitting portion (i) is installed at the other end. And the fitting portion (i) is a structure that is fitted into the insertion groove (g). A plurality of screw grooves n are formed along the outer circumferential surface of the fitting portion i, and a plurality of fastening holes h are formed on the outer wall of the insertion groove g so as to correspond to the plurality of screw grooves n. The screw s is fastened to the screw groove n through the fastening hole h so that the packer, the test tube, and the insertion tube are coupled to each other.

In addition, an O-ring (o) is interposed between the fitting portion (i) and the insertion groove (g) to prevent the fluid such as gas filled in the test section through the insertion portion (i) and the insertion groove (g). prevent.

The lower cover 28 is coupled to the packer 21 at the lower end of the airtightness characteristic measuring device 50, and the upper cover 29 is coupled to the packer 24 at the upper end. The upper cover 27 and the lower cover 28 are also coupled to the packers 21 and 24 by screws s, and are sealed with O-rings (o).

A plurality of through holes are formed in the upper cover 27 to allow the inflow and outflow line 49 and the fluid flow line and the pressure measurement line 42 to be described later to be discharged to the outside. The o-ring (o) is sandwiched between the lines 49, 42 and 45.

However, the upper cover 27 is not necessarily required, and the upper cover 27 may be opened without the upper cover. That is, since the inside and the outside of the airtightness characteristic measuring apparatus 50 are mutually sealed, it is not necessary for the inside of the airtightness characteristic measuring apparatus 50 to necessarily be sealed. If there is no upper cover 27 there is an advantage that the installation of a plurality of lines (49, 42, 45) is easy.

Meanwhile, a fluid flow line is connected to the injection holes 14 formed in the test tubes 11, 12, and 13, respectively, and a pressure measuring line 42 is connected to the measurement hole 15. The fluid flow line and the pressure measurement line 42 extend outward through the upper cover 28 and are connected to the fluid storage tank and the pressure gauge 90, respectively. Since three test tubes are provided in this embodiment, three fluid flow lines and three pressure measuring lines are also provided.

The fluid storage tank is for storing the fluid injected into the test section. In this embodiment, the water storage tank 61 and the gas storage tank 62 are provided as the fluid storage tank. That is, in this embodiment, water and gas (nitrogen) are selectively injected into the test section. In the case of high porosity or large cracks, the airtightness can be measured precisely even by injecting water with a relatively small flow rate. It cannot be measured. In this case, the gas tightness of the test section can be measured more precisely by using a gas having high fluidity such as nitrogen.

On the other hand, the flow meter 70 is installed in the fluid flow line to measure the amount of fluid supplied or recovered from the water storage tank 61 and the gas storage tank 62. In addition, the flow meter 70 may perform a flow control function to adjust the flow amount of the fluid. Since the flow meter with the flow rate adjustment function is already known device, a detailed description thereof will be omitted.

In addition, when impurities are included in the water flowing into the flow meter 70 from the water storage tank 61, an error may occur in the flow rate integration, and the flow meter 70 may be damaged. Install Si) to filter the ball impurities.

And a valve 43 is provided to selectively supply water and gas. That is, in the present embodiment, the fluid flow line includes a first line 46 connecting between the water storage tank 61 and the valve 43 and a second connection between the gas storage tank 62 and the valve 43. The main line 45 is connected to the line 47 and the valve 43 and the airtightness characteristic measuring device 50. By selective opening and closing of the valve 43, the first line 46 or the second line 47 is selectively connected to the main line 45.

Since the gas storage tank 62 is filled with high-pressure gas, the gas storage tank 62 can be filled directly into the test section by opening the gas storage tank 62. However, in the case of the water storage tank 61, a separate pump or the like is required for water transfer. As described above, although a driving means such as a pump may be separately provided in the water storage tank 61, the present embodiment provides a driving force for transferring water by using a high-pressure gas filled in the gas storage tank 62.

That is, as shown in Figure 5, after connecting the pressure line 48 through which the gas can be transferred between the gas storage tank 62 and the water storage tank 61, the water storage from the gas storage tank 62 Water may be transferred through the first line 46 by injecting gas into the tank 61 and pressurizing the gas.

The pressure measuring line 42 extends from the measuring hole 15 and is connected to the pressure gauge 90. Since the end of the pressure measuring line 42 is closed by the pressure gauge 90, the fluid discharged from the main line 45 and filling the test section finally fills the pressure measuring line 42. Therefore, the pressure of the fluid in the pressure measuring line 42 is transmitted to the pressure gauge 90, and since the pressure is the same as the pressure in the test section, the pressure in the test section can be quantitatively measured.

Both the pressure gauge 90 and the flow meter 70 are connected to a controller (not shown) through a wired or wireless communication network, and transmits a pressure value and a flow rate value to the controller, and the user checks the measured values through a display panel provided in the controller. Can be.

On the other hand, the inflow line 49 connected to the packer is connected to the pump 63, by injecting fluid through the pump 63, as shown in Figure 6, the expansion member 28 to the borehole wall (w) Closely seal the test section.

In the drawings, the fluid flow line, the pressure measurement line, and the fluid injection line are shown as single lines for convenience of description, but as mentioned above, each line is provided with three lines in this embodiment. Similarly, flowmeters and pressure gauges connected to each fluid flow line and pressure measurement line are also arranged according to the number of lines.

Hereinafter, the usage example of the airtightness characteristic measurement system 100 which consists of said structure is demonstrated.

In order to quantitatively measure the airtightness of the target region, a borehole b is first formed in the target region. After that, in consideration of the depth and arrangement of the joint (a1), the contact surface (a2) of the concrete lining (1) and the rock (r) and the crack (a3) in the rock (r), each test tube (11, 12, 13) is assembled by inserting the insertion tube into the airtightness characteristic measuring device 50 so that it can be placed in the test section.

Thereafter, when the airtightness characteristic measuring device 50 is inserted into the borehole b and the pump 63 is operated to expand the plurality of packers 21 to 24 to closely contact the borehole wall w, all test sections are closed. .

When the fluid of water or gas is injected into the test section in the above state, the test section is filled with the fluid and completely filled up to the pressure measuring line 42. In this process, the flow meter 70 and the pressure gauge 90 continuously measure the flow rate and the pressure value.

Subsequently, when the injection of the fluid is stopped, the fluid flows out through the construction joint a1 or the crack in the rock a3 to decrease the pressure in the test section. The airtight characteristics of the test section can be quantitatively identified.

The way of injecting fluid into the test section is divided into pulse injection test, constant rate injection test and constant pressure injection test. 7 to 9 show the response curves of the flow rate and the pressure according to each method.

In the instantaneous shock injection method shown in FIG. 7, the injection of the fluid is stopped immediately after injecting the fluid at one instant (t1), and the rectified amount injection method shown in FIG. 8 is between a predetermined period (t1 to t2). Injecting fluid is a method of maintaining a constant injection amount, the constant pressure injection method shown in Figure 9 is a method of injecting while gradually reducing the flow rate to maintain a constant pressure in the test section.

As above, inject and stop the fluid in the test section in the above three ways, observe the pressure response, and select the method that best matches the theoretical pressure-flow response curve and the measured pressure-flow response curve. .

In the present invention, it is possible to simultaneously measure the airtight property for a plurality of test intervals by using the airtight property measuring device, there is an advantage that the airtightness evaluation can be performed very quickly and easily.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation and that those skilled in the art will recognize that various modifications and equivalent arrangements may be made therein. It will be possible. Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

100 ... hermetic measuring system 11,12,13 ... test tube
21,22,23,24 ... packer 27,28 ... upper and lower covers
31,32,33,34,35 ... Insertion pipe 42 ... Pressure measuring line
45,46,47 ... Fluid flow line 50 ... Air tightness measuring device
61 ... water storage tank 62 ... gas storage tank
63 ... Pump 70 ... Flow Meter
90 ... pressure gauge

Claims (12)

Inserted into the borehole formed in the area to be measured for airtightness characteristics,
A plurality of test tubes disposed in each test section along the depth direction of the borehole, and formed with an injection hole for injecting fluid into the test section, and a measurement hole for transmitting pressure of the fluid filled in the test section;
A plurality of packers disposed at both sides of the plurality of test tubes, the plurality of packers sealing and expanding the test section in close contact with the inner wall of the borehole when inflated and contracted;
A fluid flow line connected to the injection hole through an inside of the packer and a test tube; And
And a pressure measurement line connected to the measurement hole through the inside of the packer and the test tube.
The packer is connected to the test tube and has a through-hole formed therein, through which the fluid can flow in and out. With a member,
An airtightness characteristic measuring device further comprising an inflow and outflow line connected to the through hole of the packer through the inside of the packer and the test tube. The method of claim 1,
At least three test tubes are arranged, and the airtightness characteristic measuring apparatus, characterized in that it is possible to measure the airtightness characteristics for at least three test intervals together. The method of claim 2,
The three test sections include a construction joint of a concrete lining constructed on the inner wall of the rock, a contact surface between the rock and the concrete lining, and a crack inside the rock. The method of claim 1,
An airtightness characteristic measuring device, characterized in that the insertion tube is detachably coupled between the test tube and the packer of the plurality of test tubes to extend the length of the test tube. 5. The method of claim 4,
The insertion tube is fitted to the test tube and the packer,
The insertion tube is inserted into the test tube and the screws are fastened together to overlap each other, and the insertion tube is inserted into the packer and the screws are fastened together to the overlapping parts,
The airtightness measuring device, characterized in that the insertion tube is detachably coupled between the test tube and the packer. delete The method of claim 1,
The fluid injection characteristic measuring apparatus, characterized in that the fluid injected into the test section is water or gas. An airtightness characteristic measuring device according to any one of claims 1 to 5 and 7, which is inserted into a borehole formed in a region to be subjected to the airtightness characteristic measurement;
A fluid storage tank connected to the fluid flow line and storing fluid;
A flow meter for calculating a flow rate of the fluid being installed and transferred in the fluid flow line between the fluid storage tank and the test tube; And
And a pressure gauge connected to the pressure measuring line and measuring a pressure transmitted through the pressure measuring line from the fluid filled in the test section. 9. The method of claim 8,
The fluid storage tank is composed of a water storage tank and a gas storage tank,
The fluid flow line includes a first line connected to the water storage tank, a second line connected to the gas storage tank, and a main line connected to the test tube,
And a valve for selectively connecting the first line and the second line to the main line. 10. The method of claim 9,
The gas tightness measuring system characterized in that it further comprises a pressure line connected to the water storage tank from the gas storage tank. 9. The method of claim 8,
The flow meter is a hermetic properties measuring system, characterized in that together with the function to adjust the flow rate of the fluid to be conveyed. 9. The method of claim 8,
And a filter for filtering impurities in the fluid flow line between the fluid storage tank and the flow meter.

Images