JPH06193101A - Method and apparatus for sampling ground water - Google Patents

Abstract

PURPOSE:To efficiently execute sapling under the state of artesian inactivation for ground water existing in a stratum in a great depth without disturbing the surroundings of a sampling area by utilizing a bore. CONSTITUTION:The apparatus is composed of a casing pipe 10 which is equipped with impermeable packers 12, 14 on its upper and lower part and a drainage port 15 on its side, an inner probe 30 which is equipped with an inner packer on its outer circumference and is inserted into the casing pipe and a sampling capsule 60 which is mounted to the bottom end of the casing pipe. Then, the casing pipe is set in a sampling section with both the impermeable packers swelled. Ground water in a sampling area is guided to a capsule main body 61 by operation of a pump 38, and preliminary drainage is made to the outside of the inner probe 30 and is made further to the outside of the casing pipe. The ground water is partially guided into a storage tank 35 for partial sampling by utilizing pore water pressure, and the partial sampling is carried out with a expansion balloon 36 expanded with a high pressure fluid guided therein. At the time when the water by the partial sampling becomes stratum water, the capsule main body is closed tight by operation of a valve of the sampling capsule, and thereby sampling is carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a groundwater sampling technique for sampling groundwater in a pressurized and inactive state without disturbing the environment in the sampling section, and more specifically, it will be described in more detail below. And a casing pipe having an inner packer, an inner probe inserted into the casing pipe having an inner packer, and a ground water sampling device in which a water sampling capsule mounted at the lower end of the inner probe is combined, and a water sampling method using the same. is there. This technique is particularly useful for collecting groundwater that exists in deep layers.

[0002]

2. Description of the Related Art Generally, as a groundwater sampling technique which has been used conventionally, there are a continuous pumping-up sampling system and a batch-type sampling system using a sampling capsule. The continuous water sampling method is a method in which a pump is installed on the probe inserted into the borehole and the groundwater in the water sampling section is continuously pumped up to the ground. On the other hand, the batch water sampling method attaches a depressurized water sampling capsule to the probe inserted into the borehole, and utilizes the pressure difference between the pressure inside the water sampling capsule and the pore water pressure of the stratum in the water sampling section. This is a method of collecting groundwater in a water sampling capsule and collecting it to the ground.

[0003]

With the recent progress in utilization of underground space, it is important to more accurately grasp the characteristics of groundwater existing in deep stratum. For that purpose, it is desirable to collect groundwater in a pressure-inert state (a state in which the pressure at the original position is maintained and there is no contact with the atmosphere). Moreover, it is necessary to collect the formation water (water that originally exists in the voids in the formation). However, drilling water due to drilling of the borehole remains in the borehole and its surrounding strata, or groundwater of different strata exists mixedly.
There is no guarantee that groundwater in the sampling area is formation water.
The above-mentioned conventional methods are also being applied to large depths in recent years, but at present, there are the following problems.

First of all, the continuous water sampling method has better work efficiency than the batch type water sampling method, but since the pumping capacity of the pump is several hundred meters in the existing technology, the groundwater level in the borehole is the pump head. If it falls below the capacity, it will be impossible to collect water. Moreover, it is impossible to structurally collect groundwater in an inactive state.
Further, since the water is continuously sampled for a long time, the load applied to the pump is large and the durability of the pump is significantly reduced.

Next, the batch-type water sampling method has an advantage over the continuous water sampling method in that it does not disturb the in-situ environment. However, since the inside of the water sampling capsule is initially in a depressurized state, strictly speaking, it is inactive under pressure. Do not collect water in the state. In addition, in order to collect the formation water from the water sampling section, it is necessary to discharge several times to several tens of times the groundwater volume in advance, so the groundwater collected in the water sampling capsule must be repeatedly collected to the ground. However, the work efficiency decreases significantly as the depth increases.

An object of the present invention is to provide a technique for efficiently collecting groundwater existing in a deep stratum by using boreholes without disturbing the environment of the water sampling section in a pressurized and inactive state. Is to provide.

[0007]

A groundwater sampling device of the present invention has a casing pipe having an upper water-impervious packer and a lower water-impervious packer and a drain port provided on a side wall, and an inner packer on a lower outer periphery. It is provided with an inner probe to be inserted into the casing pipe and a water collecting capsule to be attached to the lower end of the inner probe. Here, the water sampling capsule is provided with a groundwater introduction portion between the upper and lower water shield packers, a capsule body communicating with the groundwater introduction portion, and a valve mechanism capable of opening and closing the capsule body. The inner probe is a pipe from the water sampling capsule to the outside of the inner probe via a rising pump and a valve, a storage tank for partial water sampling, and a pipe from the water sampling capsule to the storage tank via a valve. An expansion balloon for partial water sampling provided in the storage tank, and a pipe reaching the ground from the storage tank,
A pipe for introducing a high-pressure fluid is provided in the expansion balloon.

In the method of the present invention, the above apparatus is installed in the borehole, and the upper and lower impermeable packers are expanded to define the water sampling section. Next, the inner packer is expanded, and groundwater in the water sampling section is guided from the water sampling inlet to the capsule body, drained to the outside of the inner probe by a pump, and further preliminary drained to the outside of the casing pipe from the drain port. In addition, a part of groundwater is introduced into a storage tank for partial water sampling by using pore water pressure, and a high-pressure fluid is introduced into an expansion balloon to expand the water, and the groundwater in the storage tank is guided to the ground to partially collect water. I do. Then, when it is determined that the groundwater of the partial water sampling is the formation water, the valve mechanism of the water sampling capsule is driven to sample the capsule body in a sealed state.

[0009]

The inner packer shuts off the upper groundwater from flowing into the water sampling section even if the inner surface of the inner probe is pressurized. Preliminary drainage is carried out by discharging the groundwater in the sampling section to the ground, and discharging it from the drainage port of the casing pipe to the outside of the sampling section in the borehole. Partial water sampling is performed by using the pore water pressure of groundwater to introduce the groundwater into the storage tank for partial water sampling and expanding the expansion balloon to pressurize the groundwater inside instead of using a pump. . During drainage and partial water sampling, groundwater flows through the water sampling capsule and is always replaced by new groundwater. Therefore, when it is judged that the partially sampled groundwater is the formation water, the inside of the water sampling capsule is naturally filled with the formation water, and the valve mechanism is closed to perform batch sampling under the pressure-inert condition. The water is complete.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram showing an embodiment of a groundwater sampling device according to the present invention. This device mainly includes a casing pipe 10, an inner probe 30 inserted into the casing pipe 10, and a water sampling capsule 60 attached to the lower end of the inner probe 30. FIG. 2 shows a state in which the casing pipe 10 and the inner probe 30 are separated. Further, FIG. 3 is an overall structural view of the water sampling capsule 60.

In the casing pipe 10, an upper water-impervious packer 12, a strainer 13, and a lower water-impervious packer 14 are arranged in that order below a cylindrical pipe main body 11, and the pipe main body 11 has the same structure. A drain port 15 is provided on the side wall. Further, the upper and lower water-impervious packer pressurizing connection ports 16 are provided on the side wall of the casing pipe 10, and the upper water-impervious packer 1 is connected through the pressurizing connection ports 16.
2 and the upper and lower water-impervious packer expansion pipes 17 reaching the lower water-impervious packer 14 are connected. Casing pipe 10
An upper end opening of the casing pipe can be closed by a casing pipe closing coupler 18, and a first pipe 20 and a first pressure gauge (for air pressure) 21 are provided in a casing pipe pressurizing pipe 19 penetrating the closing coupler 18. To provide.

The inner probe 30 is provided with a first inner packer 32 provided at the center of the outer circumference of a cylindrical probe body 31, second and third inner packers 33, 34 provided at the lower outer circumference, and an upper part. Storage tank 3 for partial water sampling
5 and an expansion balloon 36 provided therein for partial water sampling
Is equipped with. The pipe 37 for preliminary drainage / partial water sampling rises from the water sampling capsule 60 provided at the lower end, and reaches the first inner packer 32 via the water supply / drainage pump 38, the second valve 39, and the second pressure gauge 40. A third valve 42 and a third pressure gauge 43 are provided between the second and third inner packers 33, 34 and the casing pipe pressure transmission port 41 at the upper end.
Connection is made with a casing pipe pressure transmission pipe 44 having. In addition, the pressure transmission pipe 44 is branched to the second and third
A pipe connecting between the inner packers 33 and 34 is connected, and a fourth valve 46 and a fourth pressure gauge 47 are provided to the inner packer 33, 34 to reach the upper / lower impermeable packer pressurizing port 45. Further, a fifth pressure gauge 48 is provided in the middle of the preliminary drainage / partial water sampling pipe 37, branched from the suction side of the water supply / drainage pump 38, and stored via a fifth valve 49 and a sixth pressure gauge 50. Tank 3
Connect to 5. A pipe from the discharge side of the water supply / drainage pump 38 to the storage tank 35 for partial water sampling is connected, and a sixth valve 51 and a three-way valve 52 are provided therein, and a pipe is also connected from the three-way valve 52 to the preliminary drainage port 53. To do. There is a seventh gap between the casing pipe pressure transmission port 41 and the dilatation balloon 36.
The pipe having the valve 54 is connected, and the storage tank 35 and the water sampling port 55 for partial water sampling are connected by the pipe having the eighth valve 56. Reference numeral 57 is a composite cable.

The water collecting capsule 60, as shown in FIG.
Above the capsule body 61, there is a cylindrical portion where the capsule detaching portion 62 and the motor housing 63 are continuous, and a filter 64 located below the cylindrical portion. Capsule body 61
Is airtightly divided by a capsule bottom lid 65 and a capsule upper lid 66, and a water sampling lower shaft 67 slidably penetrates through the center thereof. The lower part of the water sampling lower shaft 67 has a hollow structure, and is fixed to the filter 64 at the lower end. Further, a lower water inlet 68 is formed in the capsule bottom lid 65, an upper water inlet 69 is formed in the lower water sampling shaft 67 near the capsule upper lid 66, and an opening / closing valve is formed in the upper end of the lower water sampling shaft 67. 70 is provided and these serve as a valve mechanism. A valve opening / closing shaft 71 is provided above the opening / closing valve 70, and the valve opening / closing shaft 71 is connected to the lower end of a hollow water sampling upper shaft 72. In the motor housing 63, a motor / gearbox 73 that drives the water sampling upper shaft 72 is incorporated. This water sampling probe 60
The upper end of the is an inner probe connection portion (connection portion to the preliminary drainage / partial water sampling pipe) 74.

Next, an operation procedure for collecting water using the apparatus of the present invention will be described. The operation is usually performed by first inserting the device into the borehole, setting the water sampling section (Figs. 4 to 6), then preliminary drainage (Fig. 7), and partial water sampling during the preliminary drainage period (Figs. 8 and 9). ), And batch-type water sampling with a water sampling capsule (Fig. 1
0), and finally the device recovery. In each valve shown in FIGS. 4 to 9, a white valve symbol indicates an open state, and a black valve symbol indicates a closed state.

[Insertion of Device into Borehole] Casing pipe 10 (in FIG. 2A, the closing coupler 18 at the upper end, the pressurizing pipe 19 and the associated first valve 20 and first pressure gauge 21 are removed. Insert into the borehole, and after reaching the predetermined depth, fix it on the ground. The inner probe 30 (portion B in FIG. 2) is inserted into the casing pipe 10. The inner probe 30 automatically stops at a predetermined depth. At this time, the water level in the casing pipe 10 rises to the groundwater level in the borehole and stabilizes. After the above operations are completed, the closing coupler 18 is airtightly attached to the upper end of the casing pipe 10, and the pressurizing pipe 19, the first valve 20 and the first pressure gauge 21 are attached. By these operations, the insertion of the device is completed and the state shown in FIG. 1 is obtained.

[Setting of Water Collection Section-Part 1] As shown in FIG. 4, the second valve 39 is opened, and the ground water in the borehole is pumped up by using the water supply / drainage pump 38. In this case, the groundwater passes through the strainer 13, the water sampling capsule 60, the preliminary drainage / partial water sampling pipe 37, the fifth pressure gauge 48, the second pressure gauge 40, and the first inner packer 3
Extend 2. The expansion of the first inner packer 32 is confirmed by the second pressure gauge 40. After that, the second valve 39 is closed and the operation of the water supply / drainage pump 38 is also stopped.

[Setting of Water Collection Section-Part 2] As shown in FIG. 5, the first valve 20 and the third valve 42 are opened. Then, the inside of the casing pipe 10 is pressurized with air pressure by the inside casing pressure pipe 19. With the pressurization, the groundwater in the casing pipe 10 expands the second and third inner packers 33, 34 via the third valve 42. The third pressure gauge 43 confirms the packer expansion. Second and third
After the expansion of the inner packers 33 and 34 is completed, the third valve 42 is closed. As a result, both inner packers 33,
A closed section is set between 34. Then, the upper / lower impermeable packer pressurizing port 45 and the upper / lower impermeable packer pressurizing connection port 16 are connected, and the setting of the piping system for expanding the impermeable packer is completed.

[Setting of water sampling section-No. 3] The inside of the casing pipe 10 is already pressurized by the operation shown in the preceding section. As shown in FIG. 6, when the fourth valve 46 is opened, the ground water in the casing pipe 10 causes the casing pipe pressure transmission port 41, the pressure transmission line 44, the fourth valve 46, the fourth pressure gauge 47, and the upper part. The upper impermeable packer 12 and the lower impermeable packer 14 are expanded via the lower impermeable packer pressurizing port 45, the upper / lower impermeable packer pressurizing connection port 16, and the upper / lower impermeable packer extension line 17. Confirmation of expansion of both water shield packers 12 and 14 is 4th
The pressure gauge 47 of FIG. After confirming the expansion of both the water blocking packers 12 and 14, the fourth valve 46 and the first valve 20 are closed,
Pressurization by air pressure from the ground also stops. By the above operation, the water sampling section closed by the water blocking packer can be set at an arbitrary position in the borehole.

[Preliminary Drainage] As shown in FIG. 7, the second valve 39 and the sixth valve 51 are opened. The three-way valve 52 is opened to the side of the preliminary drainage port 53. By this operation, the first inner packer 32 contracts. Further, since the preliminary drainage port 53 is opened by the above operation, the groundwater in the casing pipe 10 is restored to the same level as the groundwater level in the borehole. After the contraction of the first inner packer 32 is completed, the second valve 39 is closed. Operate the water supply / drainage pump 38, and from the water sampling section closed by the upper and lower impermeable packers 12 and 14, the strainer 1
3, preliminary drainage / partial water sampling line 37, fifth pressure gauge 4
The ground water is discharged into the casing pipe 10 via the water supply / drainage pump 38, the sixth valve 51, the three-way valve 52, and the preliminary drainage port 53. Moreover, although the groundwater in the casing pipe 10 rises by the above operation, the preliminary drainage port 1
Since 5 is open, it is discharged into the borehole.

[Partial water sampling-Part 1] Partial water sampling is carried out to temporarily discharge groundwater to the above-ground part in order to confirm the change in groundwater quality during the preliminary drainage period. Therefore, the preliminary drainage is temporarily stopped. The first inner packer 32 is expanded in the same manner as the operation described in the section [Setting of water sampling section-1). On this occasion,
Since it is considered that the pressure in the casing pipe 10 rises, the first valve 20 is opened to let the pressure escape to the ground (see FIG. 8). The fifth valve 49 and the eighth valve 56 are opened, and groundwater is stored in the partial water sampling storage tank 35 by utilizing the potential (pore water pressure) of the water sampling section. At this time, the groundwater passes through the preliminary drainage / partial water sampling line 37, the fifth pressure gauge 48, the fifth valve 49, and the sixth pressure gauge 50. Also the fifth valve 4
It is also possible to store the groundwater in the storage tank 35 by using the water supply / drainage pump 38 by closing 9 and opening the sixth valve 51 and opening the three-way valve 52 to the storage tank 35 side. The sixth pressure gauge 50 confirms the amount of groundwater stored in the partial water sampling storage tank 35. After confirming the storage amount, the fifth valve 49 is closed (or the three-way valve 52 is closed and the water supply / drainage pump 3
Stop 8).

[Partial water sampling-Part 2] The seventh valve 54 is opened. The inside of the casing pipe 10 is pressurized with air pressure from the casing pipe pressurizing pipe 19. Then, the groundwater in the casing pipe 10 is pressurized to expand the partial water sampling expansion balloon 36 via the seventh valve 54 (see FIG. 9). As a result, the volume in the partial water sampling storage tank 35 is reduced, and the ground water in the storage tank 35 is stored in the eighth valve 56.
Water can be sampled from the water sampling port 55 for partial water sampling via.
If the amount of water collected is not sufficient, repeat the above procedure.

In the steps of the preliminary drainage and the partial drainage described above, the water sampling capsule 60 connected to the lower end of the inner probe 30 operates the motor / gearbox 73 to move the upper shaft for water sampling as shown in FIG. 10A. 72, the valve opening / closing shaft 71, each shaft of the water sampling lower shaft 67, and the filter 64 are in a lowered state. This passes through the water sampling lower shaft 67 from the filter 64, the lower water guiding port 68 of the capsule bottom lid 65, the capsule body 61, the upper water guiding port 69, the opening / closing valve 70, the valve opening / closing shaft 71, the water sampling upper shaft 72, The water conduit is connected to the inner probe connection portion (drainage pump pipe connection portion) 74, and the groundwater can flow in. In this state, preliminary drainage and partial water sampling are performed according to the operation procedure described above. The flow of groundwater is indicated by arrows. Preliminary drainage is repeated until it can be determined that it is formation water from the analysis results of the groundwater sampled partially.

[Batch water sampling] When it is determined that the ground water sampled partially is formation water, the motor / gearbox 73
, And pull up each connected shaft. When the water sampling upper shaft 72 is pulled up, the center pin 75 of the valve opening shaft 71 fixed thereto is separated from the opening / closing valve 70. The on-off valve 70 closes the upper portion of the water sampling lower shaft 67 with a built-in spring.
When the water sampling upper shaft 72 is further pulled up, the valve opening / closing shaft 71 is connected to the valve opening housing 76, and the water sampling lower shaft 67 is pulled up. As a result, the water sampling port at the bottom of the water sampling lower shaft 67 becomes
, The shaft stopper 77 contacts the capsule bottom lid 65, and each shaft stops. The inside of the capsule body 61 is sealed by the series of movements of the shaft. The groundwater in the capsule body 61 is in a pressurized and inactive state, and even if it is collected on the ground, the state is maintained.

[Recovery of Device] Each valve in the inner probe is opened, each packer is contracted, and the water sampling capsule is collected on the ground together with the inner probe. One side of the split outer tube of the capsule attaching / detaching portion 62 is removed, and the shaft fixing screw 78 connecting the water sampling upper shaft 72 and the valve opening / closing shaft 71 is removed. Then, the motor / gearbox 73 is operated again, and the upper shaft 7 for water sampling is
2 is pulled up and separated from the valve opening / closing shaft 71. The remaining outer tube of the capsule attaching / detaching part 62 is removed, and the capsule body 61 is removed.
Collect.

In the apparatus of the above-mentioned embodiment, since the casing pipe is used as the expansion water pipe of the water-impervious packer, the inner resistance of the pipe is smaller than that of the conventional hose and the water-impervious packer can be expanded in a short time. By the way, at a depth of several hundreds of meters or more, the conventional method requires about 6 to 24 hours for expansion and contraction of the packer, but the above-mentioned apparatus completes the work in about 1 hour. Since the packer's in-hole expansion / contraction method that utilizes the in-hole water is adopted, the packer can be reliably expanded / contracted even if the groundwater level in the borehole drops. In addition, pollution of groundwater can be minimized. Furthermore, there is no need to install a water supply hose or signal cable on the outside of the casing pipe, and there is no risk of damage to the hose or the like due to contact with the borehole wall.

[0026]

INDUSTRIAL APPLICABILITY In the present invention, the groundwater in the water sampling section divided by the water blocking packer is preliminarily drained through the water sampling capsule.
In the state where the water is partially collected and completely replaced by the formation water, the capsule body is closed by the valve mechanism to confine the formation water, so that the formation water is kept in an inactive state under pressure without changing the environment in the sampling section. Can be collected. Also, since the internal volume of the capsule body can be set to about 5 to 6 liters,
The amount of groundwater required for water quality analysis can be secured with a single water sampling, and the working time can be greatly shortened.

Since the present invention is a partial water sampling system that does not require a pump, it is not necessary to collect groundwater to the ground during preliminary drainage, and the purpose of preliminary drainage can be achieved only by draining through holes. Therefore, the discharge amount per unit time is several times to several tens of times that of the surface drainage, and the working time can be significantly shortened. Since the water supply / drainage pump does not require a high head, the discharge amount of groundwater per unit time is significantly increased, and the load on the motor can be reduced, so that the pump life is greatly extended and it is economical.

In the present invention, after inserting the device into the borehole, preliminary drainage, partial water sampling, and batch type water sampling can be carried out by simple operations, and the work can be efficiently carried out until formation water is collected. You can

[Brief description of drawings]

FIG. 1 is an assembly explanatory view of a water sampling device.

FIG. 2 is an exploded view of the water sampling device.

FIG. 3 is an overall structural diagram of a water sampling capsule.

FIG. 4 is an explanatory diagram of a procedure for setting a water sampling section-Part 1.

FIG. 5 is an explanatory diagram of a procedure for setting a water sampling section-Part 2.

FIG. 6 is an explanatory diagram of a procedure for setting a water sampling section-Part 3.

FIG. 7 is an explanatory diagram of a preliminary drainage procedure.

FIG. 8 is an explanatory diagram of a partial water sampling procedure-part 1.

FIG. 9 is an explanatory diagram of a partial water sampling procedure-part 2.

FIG. 10 is an explanatory diagram of the operation of the water sampling capsule.

[Explanation of symbols]

 10 Casing Pipe 12 Upper Impervious Packer 14 Lower Impermeable Packer 15 Drain Port 18 Casing Pipe Closure Coupler 19 Casing Pipe Pressurizing Pipe 30 Inner Probe 32, 33, 34 Inner Packer 35 Reservoir for Partial Water Collection 36 Partial Water Collection Expansion balloon for use 37 Preliminary drainage / partial water sampling line 41 Casing pipe pressure transmission port 55 Water sampling port for partial water sampling 60 Water sampling capsule 61 Capsule body 64 Filter 68 Lower water inlet 69 Upper water inlet

Claims (2)

[Claims] 1. A casing pipe having an upper water-impervious packer and a lower water-impervious packer and provided with a drain port on a side wall,
An inner probe having an inner packer on the lower periphery and inserted into the casing pipe, and a water sampling capsule attached to the lower end of the inner probe, wherein the water sampling capsule is the groundwater between the upper and lower impermeable packers. Introducing part, a capsule body that communicates with it, and a valve mechanism that is capable of opening and closing the capsule body, the inner probe is a pipe from the water sampling capsule to the outside of the inner probe through a rising pump and a valve, Storage tank for partial water sampling, piping from the water sampling capsule to the storage tank via a valve, expansion balloon for partial water sampling provided in the storage tank, and ground from the storage tank A groundwater sampling device comprising a pipe and a pipe for introducing a high-pressure fluid into the expansion balloon. 2. The apparatus according to claim 1 is installed in a borehole, the upper and lower water-impervious packers are expanded to define a water sampling section, the inner packer is expanded, and ground water in the water sampling section is sampled. The water is introduced from the water introduction part to the capsule body, drained to the outside of the inner probe by a pump and pre-drained from the drain port to the outside of the casing pipe, and part of the groundwater is introduced into the storage tank for partial water sampling using pore water pressure. , A high-pressure fluid is introduced into the expansion balloon to expand it, and the groundwater in the storage tank is guided to the ground for partial water sampling, and when it is determined that the groundwater of the partial water sampling is formation water, the valve mechanism of the water sampling capsule A groundwater sampling method in which the capsule body is sealed by driving.