JP2004243229A - Method of removing contaminant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remove a contaminant more effectively and efficiently by virtue of an appropriate and exact heating. <P>SOLUTION: When removing at least one of volatile contaminant, non-volatile water soluble contaminant, non volatile and water insoluble contaminant which are all maintained underground, a pouring well PW and a suction well SW are separately provided within a range from an area in which the removing is carried out to its adjacent area, thereby pouring a heated fluid G from the pouring well PW and performing a suction through the suction well SW, thus removing the contaminant. The heated fluid G is poured to the removing area from a pouring position which is a specified position in the depth direction of the pouring well PW, with such pouring position being sealed with a packer 6, 6 fore and aft. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for on-site removal of volatile contaminants, non-volatile water-soluble contaminants, and non-volatile non-water-soluble contaminants retained in soil or groundwater.
[0002]
[Prior art]
Conventionally, as a method of removing volatile contaminants, non-volatile water-soluble contaminants, non-volatile non-water-soluble contaminants, etc. retained in the ground, on the one side in the horizontal direction of the area to be removed, A method of providing an injection well along the direction and a suction well along the vertical direction on the other side, injecting steam from the injection well while performing suction from the suction well, and passing the vapor horizontally through the removal target area. It has been proposed (for example, see Patent Document 1).
[0003]
In addition, a technique using high-temperature water instead of steam has been proposed to facilitate removal of non-aqueous phase liquid (NAPL) in groundwater (for example, see Patent Document 2).
[0004]
Further, in order to facilitate the removal of contaminants immediately below the structure, a technique has been proposed in which injection wells and suction wells are respectively formed along the horizontal direction on the upper and lower sides of a region to be removed, and vapor is passed along the vertical direction. I have. (For example, see Patent Document 3).
[0005]
[Patent Document 1]
Japanese Patent No. 2660307
[Patent Document 2]
JP-A-2002-11456
[Patent Document 3]
JP-A-2002-239524
[0006]
[Problems to be solved by the invention]
However, in the above-mentioned prior arts, since the injection is performed under the same injection condition from the entire injection well to the entire target region, for example, when the formation characteristics are different in the depth direction of the injection well, , The injection cannot be performed under the injection conditions suitable for each layer, the desired heating effect and heating efficiency cannot be obtained due to the local distribution of the heating fluid, and the removal level is not uniform in the depth direction of the injection well. Or the removal efficiency is low.
[0007]
Therefore, a main object of the present invention is to enable more effective and efficient removal of pollutants.
[0008]
[Means for Solving the Problems]
The present invention that has solved the above problems is as described below.
<Invention according to claim 1>
In removing contaminants retained in the ground, injection wells and suction wells are respectively provided at intervals in a range from the removal target area to the vicinity area, and while the heating fluid is injected from the injection well, suction is performed. In the method of taking out contaminants by sucking from the well,
A method for removing contaminants, wherein a predetermined position in the depth direction of an injection well is defined as an injection site, and a heating fluid is injected from the injection site into the removal target region with the front and rear of the injection site sealed.
[0009]
(Effect)
As described above, when a predetermined position in the depth direction of the injection well is set as the injection site and the heating fluid is injected from the injection site in a state where the front and rear of the injection site are sealed, the injection range in the well depth direction is limited. Injection can be performed under conditions suitable for the formation characteristics in the depth range. Therefore, it is possible to more effectively and efficiently remove contaminants.
[0010]
<Invention according to claim 2>
A plurality of packers provided at intervals in the axial direction are provided on the outer surface, an injection pipe having an injection port between the packers is inserted into the injection well, and the adjacent packers are swelled so that the front and rear spaces between the packers are expanded. The method for removing contaminants according to claim 1, wherein the heating fluid is injected from an injection port between the packers in a state in which the packing is sealed.
[0011]
(Effect)
As a means for sealing before and after the injection site, a packer is preferable.
[0012]
<Invention of Claim 3>
As the injection pipe, one having a packer at at least three places spaced apart in the axial direction, and having an injection port between each packer,
3. The method for removing contaminants according to claim 2, wherein the injection is performed sequentially or simultaneously from the injection ports between the packers, and at this time, the injection is performed under independent injection conditions for each of the packers.
[0013]
(Effect)
As described above, the injection is performed sequentially or simultaneously from the injection port between the packers, and at this time, the injection is performed under the independent injection conditions for each of the packers, so that the formation characteristics are different in the depth direction of the injection well. In such a case, implantation can be performed under implantation conditions suitable for each layer, the removal level becomes uniform in the depth direction of the implantation well, and uniform contaminant removal can be efficiently performed.
[0014]
<Invention of Claim 4>
The contamination according to any one of claims 1 to 3, wherein the contaminant is at least one of a volatile contaminant, a non-volatile water-soluble contaminant, and a non-volatile non-water-soluble contaminant. Material removal method.
[0015]
(Effect)
The present invention is particularly suitable for removing such contaminants.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
(Basic configuration)
FIG. 1 conceptually shows the basic principle of the method for removing contaminants according to the present invention. In this method, the injection well PW and the suction well SW are provided at intervals, and while the heating fluid is injected from the injection well PW, suction is performed from the suction well SW to remove contaminants.
[0017]
In other words, when the heating fluid is injected into the injection well PW and suction is performed from the suction well SW (a negative pressure is applied to the suction well), the injected heating fluid passes through the ground toward the suction well SW and turns around. Heat. This allows volatile pollutants to evaporate and other non-volatile pollutants to move through the ground by heating. As a result, these contaminants P1, P2, and P3 move to the suction well PW with the heating fluid, the liquid, or moisture in the ground, and can be taken out from the suction well SW.
[0018]
When the injection and the suction are simultaneously stopped, the injected heating fluid remains in the ground containing the pollutants P1, P2, and P3, depending on the processing time. Therefore, performing suction while the injection is stopped, for example, stopping the injection and continuing the suction after injection and suction for a predetermined period of time is a preferable mode in some cases. Depending on the degree of heating, even after the injection of the heating fluid is stopped, the temperature in the ground is at a level effective for removing contaminants. The heat stored in the cell facilitates the transfer and removal of pollutants. There is also an advantage that the injection region can be dried by suction while the injection is stopped. This advantage is particularly remarkable when the heating fluid is a gas such as steam.
[0019]
The pollutants targeted by the present invention are at least one of volatile pollutants held in the ground, non-volatile water-soluble pollutants and non-volatile non-water-soluble pollutants, These are P1 retained in the ground above the groundwater level, P2 existing at the groundwater level, P3 existing below the groundwater level, and as a pollutant zone occupying a certain area, or between soil particles. Exists in a state held in the very small area. Examples of specific pollutants include trichloroethylene, tetrachloroethylene, volatile organic pollutants such as benzene, nonvolatile water-soluble pollutants, and nonvolatile non-water-soluble pollutants such as, The present invention is not limited to these.
[0020]
The depth of the injection well PW and the suction well SW can be appropriately determined according to the depth and the existence form of the target pollutant. For example, when targeting a depth range above the groundwater level, the depths of the wells PW and SW can be set above the groundwater level, and from the range above the groundwater level to the range below the groundwater level. When the whole is to be treated, the depth of the wells PW and SW can be set below the groundwater level.
[0021]
On the other hand, the number and arrangement of the wells PW and SW can be appropriately determined according to the construction area, construction depth, heating efficiency, suction efficiency, removal efficiency (processing time), type of the substance to be removed, type of the heating fluid, and the like. it can. The injection wells PW and the suction wells SW are removed at appropriate intervals at which contaminants can be removed in accordance with the above-described principle in consideration of ground conditions and injection conditions (type, temperature, processing time, etc. of a heating fluid). And at least one of them is provided in a range extending from to the vicinity thereof. More specifically, when the construction area is small, there is not much difference in length and width, and when importance is placed on heating efficiency, a suction well 3W is provided only at the center of the construction area and surrounds the periphery of the construction area. If a plurality of injection wells PW, PW are provided at intervals, or if the suction efficiency is emphasized without emphasizing the heating efficiency, the injection well is provided only at the center of the construction area and surrounds the periphery of the construction area. A plurality of suction wells can be provided at intervals as described above. When the construction area is wide or elongated, a plurality of injection wells and a plurality of suction wells can be arranged regularly or irregularly according to the width and length. As a simple embodiment, an injection well may be provided on one side of the removal target region, and a suction well may be provided on the other side.
[0022]
The heating fluid in the present invention is basically applicable regardless of the temperature, if it can heat the substance to be removed in the ground, and can be used regardless of the state of gas and liquid. For example, if the temperature at the underground position where the pollutant exists is 15 ° C., a sufficient effect is exhibited even if room temperature water or room temperature air having a higher temperature is used. As a specific heating fluid, steam is preferable. However, depending on the construction area, the construction depth, the temperature of the target substance, the heating efficiency, the suction efficiency, the removal efficiency (processing time), and the type of the removal target substance, Normal-temperature air, high-temperature or normal-temperature water, steam, or a mixed fluid of at least two of these can be used, and the temperature is usually 15 ° C. or higher in a normal case, 30 ° C. or higher depending on the type of pollutant, In consideration of the heating efficiency, the temperature is preferably set to 60 to 100 ° C. For example, when the contaminants are present as a non-aqueous solution in groundwater as described above, only high-temperature water or a mixed fluid of the high-temperature water with another steam or high-temperature or normal-temperature air can be used. When volatile contaminants are the main target, when it is desired to ensure underground drying properties, or when emphasis is placed on the ability of fluids to pass through the ground, air above the ground is mainly used, It is also preferable to use a mixed fluid whose temperature is adjusted by mixing steam in consideration of the type, the temperature in the ground, and the like. Further, in the present invention, any other fluid that can be injected into the ground and can heat contaminants can be basically used.However, since it is inexpensive and does not pollute the environment, steam, water, Air is preferred.
[0023]
(1st Embodiment)
The present invention has a point in a method of injecting a heating fluid, in which a predetermined position in a depth direction of an injection well is set as an injection site, and injection of the heating fluid from the injection site to the removal target region is performed with the front and rear of the injection site sealed. Is what you do.
[0024]
As an injection means with such a seal, for example, a so-called double-tube packer type injection pipe used for injecting a chemical solution into the ground as shown in FIG. 2 can be applied. Normal double-tube packer-type injection pipes are not designed for injecting high-temperature fluids, so it is necessary to select materials that take heat resistance into consideration, but the basic structure and principle are the same as those for chemical liquid injection. Can be used.
[0025]
To explain the illustrated example in more detail, the injection device of this example has an outer injection tube and an inner injection tube 20, and the outer injection tube is constituted by an outer tube 10. The outer tube 10 has a first tube 1, a second tube 2, and a third tube 3. A through-hole 4 is formed in the wall surface of the first pipe 1, and a flexible sleeve 5 such as rubber that can be deformed to cover the through-hole 4 is provided. A flexible packer 6 such as rubber, which is liquid-tightly sealed, is attached to the second tube 2 and the third tube 3 screwed to the first tube 1.
[0026]
As shown in FIG. 3, the outer tube 10 is prepared as a unit tube, and the second tube 2 of the unit tube and the third tube 3 of the other unit tube are screwed and connected to each other to form a long injection outer tube. It can be.
[0027]
In the case of a connection-type injection outer tube, a plurality of, for example, three or more packers 6 can be mounted on the outer surface at an axial interval. Furthermore, an inlet 7 is formed in the third pipe 3 between the adjacent packers 6 and 6, respectively. As shown in FIG. 2, in addition to one injection port 7, a plurality of injection ports 7 can be formed, for example, 4 steps, and 16 steps can be formed at 90 ° intervals in each step. It is desirable that these injection ports 7, 7,... Adopt means for preventing sand particles from entering from the surrounding ground. As means for preventing sand particles from entering, as shown in FIG. It is possible to adopt a mode of covering with a flexible sleeve 8 or covering each step or the whole with a film made of, for example, vinyl chloride, which is broken by the supply pressure of the heating fluid.
[0028]
On the other hand, as shown in FIG. 2, the injection inner tube 20 can be inserted into the outer tube 10, the front and rear of the discharge port 22 are in close contact with the inner surface of the outer tube 10 in a liquid-tight manner, and the heating fluid is pressure-fed inside. Although there is no particular limitation, examples of the structure include a structure in which packing members 23 and 24 such as rubber are provided before and after a discharge port 22 of an inner pipe main body 21 having a heating fluid supply path. The structure shown in FIG. 4 of JP-A-63-44893 can be used as it is.
[0029]
The dimension between the packers 6 and 6 can be about 10 cm to 2 m, particularly preferably about 25 to 50 cm. In addition, as shown in FIG. 7, it is preferable that the total length of the dimensions between the packer 6 and the packers 6, 6 substantially coincides with the range to be heated (for example, about 5 to 6 m).
[0030]
When construction is performed using such an injection device, a suction well and an injection well are respectively formed at predetermined positions set with respect to the removal target region. That is, first, as shown in FIG. 3, the target ground 30 is excavated to a predetermined depth to form the insertion hole 31. In this case, it is desirable to drill holes using the casing 50 in order to prevent the insertion holes 31 from collapsing. The order of forming the suction wells SW and the injection wells PW may be determined as appropriate. Either of them may be performed first, or they may be performed simultaneously using a plurality of drilling machines.
[0031]
If the insertion hole 31 is formed, a strainer 51 is provided as shown in FIG. 4 at least for the suction well SW and preferably also for the injection well PW, depending on the depth of the well and the properties of the ground, It is preferable to protect the hole wall and ensure the communication between the hole and the ground.
[0032]
Thereafter, as shown in FIG. 5, a means for suctioning the inside of the well is inserted into the suction well SW, for example, by inserting a suction device 60 including a suction pipe 61 and a water pump 62 connected to the tip thereof. Provide. The outer tube 10 is inserted into the injection well PW. The casing 50 is preferably removed after the insertion of these devices or, if the strainer 51 is installed, after the installation. The outer injection tube 10, the suction device 60, and the strainer 51 can be built directly or together with the casing 50.
[0033]
Prior to the contaminant removal step, at least for the suction well SW, and preferably also for the injection well PW, the gap between the suction device 60 or the injection outer tube 10 and the hole wall at the mouth is jacket 52 (rubber or the like). (A flexible sealing material).
[0034]
When the outer injection tube 10 is installed, prior to injection of the heating fluid, the inner injection tube 20 is inserted as shown in FIG. 6, the discharge port 22 is positioned at the position of the packer 6, and the through hole 4 of the packer 6 is formed. In a state where the fluid and the discharge port 22 are communicated with each other, a swelling fluid, preferably a solidifying material such as cement or cement bentonite, is pumped through a flow path in the injection inner pipe 20, and the adjacent packers 6 and 6 are compressed. The packers 6 and 6 are fed into the respective insides to expand these packers 6 and 6 so as to be in close contact with the wall surfaces of the insertion holes 31. As the fluid for swelling the packer, in addition to cement bentonite, water and air can also be used. However, in the case of cement bentonite, this hardens eventually, and the packer 6 is firmly adhered to the hole wall surface of the insertion hole 31. It is preferable in that it can be performed.
[0035]
When the swelling fluid 40 is fed, as described above, in addition to discharging the swelling fluid 40 from the discharge port 22 through the internal flow path using the injection inner tube 20, other appropriate means can be used. In any case, the swelling fluid 40 passes through the through hole 4 and the sleeve 5 is deformed by the feed pressure. For example, the swelling fluid 40 is sent into the packer 6 while separating both ends of the sleeve 5 from the outer surface of the first pipe 1. It is. When the packer 6 has swelled sufficiently, the feeding of the swelling fluid 40 is stopped. Then, the sleeve 5 is restored and the through hole 4 is sealed. The swelling of the packer 6 may be performed at least in the adjacent packers 6, 6, but if necessary, all of the target packers may be sequentially swelled.
[0036]
When the swelling fluid is fed, as described above, in addition to discharging the fluid from the discharge port 22 through the internal flow path using the injection inner pipe 20, other appropriate means can be used. In any case, the swelling fluid passes through the through hole 4 and deforms the sleeve 5 by the feed pressure. For example, the swelling fluid is sent into the packer 6 while separating both ends of the sleeve 5 from the outer surface of the first pipe 1. It is. When the packer 6 has swelled sufficiently, the feeding of the swelling fluid is stopped. Then, the sleeve 5 is restored and the through hole 4 is sealed. The swelling of the packer 6 may be performed at least in the adjacent packers 6, 6, but if necessary, all of the target packers may be sequentially swelled.
[0037]
When the setup is completed, as shown in FIG. 7, with the packers 6 and 6 being operated, the inner tube 20 is inserted into the outer tube 10 or the inner tube 20 is expanded. If it is to be used for feeding the injection fluid 40, the injection inner pipe 20 is inserted as it is to a predetermined position, and a heating fluid is pressure-fed to the injection inner pipe 20 in place of the swelling fluid 40 to be discharged from the discharge port 22. , 7,... While the flexible sleeve 8 is deformed or the coating is broken, and the heating fluid G penetrates into the surrounding ground from the injection well PW.
[0038]
When injecting the heating fluid G, it is preferable to insert the injection inner tube 20 to the deepest portion of the outer tube 10 and to expand the adjacent packer or all the packers as described above, and It is preferable that the injection ports 7, 7,. Conversely, a step-down method from the upper part to the deepest part, or a method of moving up and down in an appropriate selection position order can be adopted.
[0039]
At the same time as this injection, or before or after a predetermined time has elapsed after the injection, suction is performed via the suction well SW. In the present invention, it is desirable to continuously change the injection point while performing suction continuously, but it is also possible to stop suction when changing the injection point.
[0040]
By the suction, as described above, the injected heating fluid G heats the surroundings while passing through the ground toward the suction well SW. Then, volatile pollutants are volatilized, and other non-volatile pollutants are easily moved underground by heating. As a result, these contaminants move toward the suction well SW with the heating fluid G, the liquid, or moisture in the ground, and are taken out from the suction well SW. In the present embodiment, since the suction position is not limited to the depth direction of the suction well SW, the heating effect works effectively not only on the area being heated but also on the heated area as shown in the drawing. While the suction is being performed, the movement and removal of the contaminants from the region to the suction well SW are continued. The aspirated material can be purified by a purifying device (not shown) after gas-liquid separation or the like as necessary, or can be stored in a storage tank or the like after the purifying treatment or unpurified.
[0041]
In the injection device of the first embodiment, as shown in FIG. 8, the space between the adjacent packers 6 and 6, the wall surface of the insertion hole 31, and the outer surface of the injection outer tube 10 is defined as a space without filler, and The heating fluid G can be injected. In this case, the heating fluid G injected through the injection ports 7, 7,... Is filled in the ground 30 between the adjacent packers 6, 6 while the heating fluid G is filled in the wide space. Is injected into. Therefore, since the whole of the insertion hole 31 facing the space is permeated and injected with the permeation target area, a large amount of the heating fluid G can be injected from one injection zone, and the heating fluid G permeated into the ground is Injected far into the distance.
[0042]
The injection speed and injection pressure of the heating fluid G are preferably determined according to the permeation permissible speed and permissible pressure of the ground.
[0043]
And, in this way, when the heating fluid is injected from the injection site in a state where the front and rear of the predetermined position in the depth direction of the injection well is sealed with a packer, the injection range in the well depth direction can be limited, Injection can be performed under conditions suitable for the formation characteristics in the depth range. Therefore, for example, the geological structure, types of contaminants, their locations, and the like are known in advance by a known geological survey method such as a boring survey, and appropriate injection conditions in each depth range are determined based on the survey results. By performing the injection under independent injection conditions for each packer, even if the formation characteristics are different in the depth direction of the injection well, the injection conditions (injection pressure, injection speed, injection Volume, type of heating fluid, etc.).
[0044]
More specifically, when the injection conditions are slid as described above, the injection pressure and the type of the heating fluid are important factors in consideration of the type of the stratum (sand and the like). It is desirable to change it. Focusing on the type of pollutant, for example, when removing a non-aqueous solution existing below the groundwater level, it is possible to use high-temperature water below the groundwater level and use steam at other locations. As described above, according to the present invention, since limited injection can be performed under appropriate injection conditions for each injection position, uniform contaminant removal can be efficiently performed.
[0045]
By the way, in the illustrated embodiment, since the injection system of the injection inner tube 20 is a single system, simultaneous injection at a plurality of positions is impossible. However, by providing a plurality of injection systems, the injection conditions can be maintained independently. Also allows simultaneous injection at a plurality of locations. For example, although not shown, a plurality of discharge ports of the injection inner pipe are provided in the longitudinal direction at intervals corresponding to the injection holes 7 of the outer pipe, supply paths for the respective discharge ports are individually provided, and individual injection conditions are set for each discharge port. (If they are independent, they may be different or they may be the same). In this case, an independent supply path for each discharge port can be formed by using a multiple pipe structure such as a double pipe or a parallel pipe structure in which a plurality of pipes are bundled.
[0046]
On the other hand, as a second method, the injection range is partially overlapped (wrapped) in the well depth direction (axial direction) as shown in FIG. 7, and the heating fluid is injected into a continuous range. As shown in FIG. 9, the heating fluid may be injected into a plurality of ranges spaced apart in the depth direction of the injection well, in other words, the injection range may be discontinuous in the depth direction of the well. Others are the same as the first method.
[0047]
Further, as a third technique, the heating fluid can be injected into only one area in the depth direction of the well per one injection location, if necessary, for example, when the depth range of the processing target is narrow. At this time, as shown in FIG. 10, the injection tube 10 having the packer 6 on the outer surface portion on the base side from the tip and the injection port 7 on the tip side of the packer 6 is relatively inserted into the insertion hole 31. Then, the packer 6 is swelled and brought into close contact with the wall surface of the insertion hole 31, and at this time, the space surrounded by the packer 6, the wall surface of the insertion hole 31, and the outer surface of the injection pipe 10 is a space, and the heating fluid G May be injected. Others are the same as the first method.
[0048]
Furthermore, it is of course possible to use other types of double-tube packer-type injection devices and injection methods within the scope of the present invention.
[0049]
(Second embodiment)
As another form of the injection means with a seal, an injection method using a seal grout, such as a well-known sleeve injection method, can be applied. FIG. 11 shows an application example of the sleeve injection method. That is, firstly, after the insertion hole 31 is formed and the inside thereof is first filled with seal grout S (cement bentonite filler), the sleeve pipe 60 is immediately inserted and installed, and a curing period is taken until the seal grout S is solidified. Thereafter, the inner injection pipe 20 (having an injection hole between the double packers, like the injection inner pipe of the first embodiment) was inserted into the sleeve pipe 60, and positioned at 61 desired rubber sleeves. In this state, the heating fluid G is discharged from the discharge gap of the rubber sleeve 61 through the injection inner pipe 20, and the heating fluid G is injected into the ground while the seal grout S is split by the supply pressure of the heating fluid.
[0050]
As a simpler form, as shown in FIG. 12, the sleeve pipe 60 may be omitted, and the injection inner pipe 20 may be directly inserted into the seal grout S to perform injection.
[0051]
In this case, the cracking site of the filler S becomes a pinpoint, the heating fluid G is injected only from the cracking site, and the permeation area to the ground is the sum of the areas facing the splitting site. Unlike the embodiment, the permeation area is extremely small. The choice between the second embodiment and the first embodiment may be determined as appropriate, but in the former case, the injection range in the well depth direction becomes too narrow, resulting in the occurrence of splitting in the ground. Therefore, the injection heating range tends to be extremely narrow, and the heating efficiency may be reduced. Therefore, the latter injection mode is generally preferred.
[0052]
The other points such as the construction procedure are the same as those in the first embodiment, so that the description is omitted.
[0053]
(Third embodiment)
Although the above embodiment forms a linear injection well and a suction well along the vertical direction, for example, when removing contaminants held in the lower ground of an existing structure, the surrounding ground is directed toward the lower ground. There is a limit to digging a straight well diagonally downward.
[0054]
In addition, the wells along the vertical direction can cover a wide range in the vertical direction, but no matter how deep the wells are, the horizontal cover range does not become wide.
[0055]
Therefore, in these cases, as shown in FIG. 13, a well W composed of a curved portion A1 extending from the ground surface to a target depth and a linear portion A2 passing laterally (substantially horizontally) from the tip thereof is formed. It is desirable to form. As shown in the figure, when targeting the lower ground of the existing structure C, a curved portion A1 is provided from the ground surface around the existing structure C to the depth below the existing structure C, and the lower part of the existing structure C is provided. A straight portion A2 can be provided so as to pass through.
[0056]
The well having such a shape can be formed by JP-A-2002-194990, JP-A-2002-194951, JP-A-2002-250029, and the like by the present applicant. The following is a brief description of this drilling method. That is, when the drilling shaft 70 to which the tapered bit 71 having the pressure receiving surface inclined with respect to the axial direction is attached is used, and the curve propulsion is performed, as shown in FIG. 14A, the inclined surface 71S of the tapered bit 71 is used. The rotation of the drilling shaft 70 is stopped in a state in which the tip of the hole is located on the side to be bent with respect to the rotation axis, and only the propulsion force is applied to the drilling shaft 70 in the state as it is. At this time, the propulsion direction of the taper bit 70 is gradually changed by the force applied to the pressure receiving surface 71S of the taper bit 71, and the drilling shaft 70 can be propelled into the ground in a curved manner. In other words, the tapered bit 71 advances while deflecting to the side to release the force received by the pressure receiving surface 71S. In addition, this curved propulsion can be performed in a three-dimensional curved propulsion. In the illustrated example, the propulsion is bent in the vertical plane direction, but can be bent in the horizontal plane direction. On the other hand, when linear propulsion is performed, as shown in FIG. 14B, a turning force and a propulsion force are applied to the drilling shaft 5, and the drilling shaft 70 is drilled by the tapered bit 71 at the tip to dig in the ground. To promote. At this time, although the tip of the tapered bit 71 has the inclined surface 71S, it advances while rotating around the axis, so that the effect of the pressure received by the inclined surface 71S is canceled out, and it is possible to drill holes linearly. .
[0057]
Thus, as shown in FIG. 13, for example, the drilling shaft 70 can be advanced in a curved shape from the ground surface to the target layer, and thereafter can be advanced in the target layer along the horizontal direction. In addition to stopping at the underground position, such drilling may be performed at a position separated from the insertion position by a predetermined distance (a position opposite to the insertion side when targeting the lower ground of the existing structure) or at the ground portion or in advance. The present invention can be applied to the case where the drilling is performed so as to penetrate the provided shaft. Of course, holes formed of such linear portions and curved portions can be formed by other known methods.
[0058]
When a well composed of such a curved portion A1 and a linear portion A2 is applied, as shown in FIG. 15, the injection well PW and the suction well SW are arranged at intervals in the vertical direction, and the heating fluid G is arranged in the vertical direction. In addition, it is preferable to carry out the transfer of contaminants. In this case, it is preferable that the injection well PW is on the lower side and the suction well SW is on the upper side, because the movement of the heating fluid G and the contaminants becomes easier, and the contaminant removing ability becomes higher. You can also. In this case, as shown in FIG. 16, by arranging a plurality of such pairs of vertical wells PW and SW at intervals in the horizontal direction, a wider planar direction range can be covered.
[0059]
On the other hand, as shown in FIG. 17, the injection wells PW and the suction wells SW can be arranged at intervals in the horizontal direction to supply the heating fluid and move the contaminants in the horizontal direction. In this case, as shown in FIG. 18, by arranging a plurality of sets of the wells PW and SW in the horizontal direction at intervals in the vertical direction, it is possible to perform the construction covering a wider depth range.
[0060]
On the other hand, although not shown, in the present invention, the injection well and the suction well can be constructed by arc drilling using an arc drilling axis.
[0061]
Note that the other points such as the construction procedure in the third embodiment are the same as those in the first embodiment, and thus description thereof will be omitted.
[0062]
(Other forms)
Like the injection, the suction can be performed only in a limited range. In this case, a device having the same structure as the injection device of the above embodiment can be used for suction. Further, in this case, suction is performed by adjusting the suction position to the same depth position as the injection position (the suction device is also moved when the depth position of the injection pipe is moved), or the suction fluid is inclined at a different depth position. It can also pass in the direction.
[0063]
In addition, as described above, as the form of the well, a linear one, a one composed of a curved part and a linear part, and an arc-shaped one can be adopted, but these are appropriately selected within one construction area, They can be combined. For example, in one construction area, a linear injection well and a suction well, and an injection well and a suction well each including a curved portion and a linear portion are provided. May be a well composed of a curved portion and a straight portion.
[0064]
【The invention's effect】
As described above, according to the present invention, it is possible to more effectively and efficiently remove contaminants.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an outline of contaminant removal.
FIG. 2 is a sectional view showing an outline of a double tube packer type injection device.
FIG. 3 is a cross-sectional view showing an outline of a drilling step.
FIG. 4 is a sectional view showing an outline of a strainer installation process.
FIG. 5 is a cross-sectional view showing an outline of an installation process of an injection device and the like.
FIG. 6 is a sectional view showing an outline of a packer swelling step.
FIG. 7 is a sectional view showing an outline of a heating fluid injection step.
FIG. 8 is an enlarged sectional view of a main part in a heating fluid injection step.
FIG. 9 is a cross-sectional view showing an outline of another injection mode.
FIG. 10 is a sectional view showing still another outline.
FIG. 11 is a sectional view showing an outline of a second embodiment.
FIG. 12 is a sectional view showing an outline of a second embodiment.
FIG. 13 is a sectional view showing an outline of a third embodiment.
FIG. 14 is a sectional view showing the principle of drilling.
FIG. 15 is a sectional view showing an outline of a well arrangement mode.
FIG. 16 is a sectional view showing an outline of another well arrangement mode.
FIG. 17 is a sectional view showing an outline of still another well arrangement mode.
FIG. 18 is a sectional view showing an outline of another well arrangement mode.
[Explanation of symbols]
6: Packer, 10: Outer tube, 12: Inner tube, SW: Suction well, PW: Injection well, G: Heated fluid.

Claims (4)

In removing contaminants retained in the ground, injection wells and suction wells are respectively provided at intervals in a range from the removal target area to the vicinity area, and while the heating fluid is injected from the injection well, suction is performed. In the method of taking out contaminants by sucking from the well,
A method for removing contaminants, wherein a predetermined position in the depth direction of an injection well is defined as an injection site, and a heating fluid is injected from the injection site into the removal target region with the front and rear of the injection site sealed. A plurality of packers provided at intervals in the axial direction are provided on the outer surface, an injection pipe having an injection port between the packers is inserted into the injection well, and the adjacent packers are swelled so that the front and rear spaces between the packers are expanded. The method for removing contaminants according to claim 1, wherein the heating fluid is injected from an injection port between the packers in a state in which the sealing material is sealed. As the injection pipe, one having a packer at at least three places spaced apart in the axial direction, and having an injection port between each packer,
3. The method for removing contaminants according to claim 2, wherein the injection is performed sequentially or simultaneously from the injection ports between the packers, and at this time, the injection is performed under independent injection conditions for each of the packers. The contamination according to any one of claims 1 to 3, wherein the contaminant is at least one of a volatile contaminant, a non-volatile water-soluble contaminant, and a non-volatile non-water-soluble contaminant. Material removal method.

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