JP3506902B2 - Water injection method in condensing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water injection method in a condensate method for injecting water into the ground.

[0002]

2. Description of the Related Art The condensate method is a method of injecting water into the ground for the purpose of preventing ground subsidence caused by pumping and preserving the surrounding groundwater environment such as depletion of wells. Figure 5
Fig. 1 shows a schematic diagram showing an example of the water injection method in the conventional condensate method. In the figure, G is the ground, P1 is a water injection pipe for water injection, P2 is a well (pipe), P2a is a strainer section for water injection into the ground, and F is the water table at the time of water injection. . When water is injected from well P2, well P2
Due to the clogging of the ground around the filtration section P2a, the amount of water that can be injected decreases with the passage of time, making it difficult to continue the condensate. Therefore, as a measure to prevent the well P2 from being clogged, the following two methods have been conventionally devised.

One is a method of controlling the water injection pressure, generally setting the liquid level below the upper end of the water injection well, and controlling the water injection pressure as low as possible to perform the water injection. This method is intended to prevent the migration of fine grains in the soil, which is one of the causes of clogging, and avoid clogging of wells by reducing the water injection pressure. This is one of the water methods. The other is to restore the water injection capacity of the well by performing well cleaning (for example, pumping) in this water injection well when clogging progresses in the water injection well.

[0004]

However, the above-mentioned measures for preventing clogging have the following problems. First, in the method of lowering the water injection pressure, there is a problem that the decision of the water injection pressure must be taken into consideration. Originally, the water injection pressure should be determined in consideration of the particle size distribution of the ground, the water permeability, etc., but the current situation is that a specific method for determining the water injection pressure has not been established. Further, even if the optimum injection pressure is set, it is impossible to completely eliminate the clogging from the hydraulic characteristics of the well, and only the effect of delaying the progress speed of the clogging can be expected.

Next, in the method of performing well cleaning, since water cannot be injected from the well when cleaning the well, water must be injected from another well and it is necessary to set up a spare well. is there. In addition, it is the actual situation that the water injection capacity cannot be completely restored by well cleaning.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to recover the water injection capacity while continuing to inject water from a well and to increase the total amount of water injection as compared with the conventional one. The purpose is to provide a water injection method in the condensate method.

[0007]

To solve the above object, according to an aspect of, the invention of claim 1, wherein, in the water injection process in condensate method of performing injection into the ground via a provided in the ground tube, injection By pressurizing water to a high pressure and performing the water injection,
It is characterized by causing splitting in the ground and injecting water.
To do .

In general, groundwater rarely penetrates into the ground uniformly, but rather concentrates on the naturally formed water channels in the ground in many cases. Therefore, according to the invention described in claim 1, a new split is generated in the ground by pressurizing the injected water, and a new water channel is created by the split of the ground, and further water injection can be performed. I can. In other words, according to this water injection method, water injection is not only dependent on infiltration, but water is also injected using the fissure of the ground, so even if the infiltration capacity is reduced due to clogging, the water injection capacity is restored by the fissure of the ground. It can be done. Further, since the conventional method of performing only osmotic water injection is now performed by both osmotic water injection and split water injection, it is possible to reliably improve the water injection capacity.

[0009] Here, the pressure value for causing the splitting in the ground varies depending on the driving depth of the pipe body, the strength of the ground, and the like. For example, the water pressure at the depth at which water is flooded. It can be calculated as the pressure when exceeds the strength of the ground. Further, the high pressure may be applied by gradually increasing the pressure until the water injection capacity is recovered.

According to a second aspect of the present invention, in the water injection method of the condensate method according to the first aspect, when the water injection capacity decreases during the water injection period, the injected water is pressurized to a high pressure and split into the ground.
To recover the water injection capacity by
To collect .

According to the invention of claim 2, in addition to the effect of the invention of claim 1, the timing of the pressurizing process can be optimized, and the pressurizing process is performed at this timing. , It is possible to restore the water injection capacity without stopping the water injection function and continue water injection. Therefore, in the past, a spare pipe (water injection well) was required to restore the water injection capacity, but in the present invention, the spare pipe is unnecessary, and the cost can be reduced.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings of FIGS. Figure 1
FIG. 3 is a schematic diagram showing a condensing device for carrying out the water injection method in the condensing method according to the embodiment of the present invention. In the figure, G indicates the ground. This condensing device is composed of a casing 1 as a pipe body that is cast in the ground, a water injection pipe 3 for injecting water into the casing 1, a pressure water tank 2 connected to the water injection pipe 3, and the like. . The casing 1 has a water blocking part on the upper side and a strainer (filtration) part 1a on the lower side, which allows water to pass through, and the water injection pipe 3 and the upper end part of the casing 1 have a pressure It is sealed by the sealing means 4 so as not to escape.

2 to 4 are explanatory views for explaining the flow of steps of the water injection method in the condensing method according to the embodiment of the present invention, and show, in order, the first step to the third step. It is a thing. In these figures, the arrows shown around the water paths S1 to S7 and the casing 1 indicate the permeation of water into the ground. The length of the arrow indicates the size of the penetrating ability.

The water injection method in the condensing method according to the embodiment of the present invention is performed by sequentially repeating the following first to third steps. That is, first, as the first step,
A process of injecting injected water by performing a predetermined pressurization in the cast casing 1 is performed. The pressure value here is a low pressure where the liquid level is equal to or lower than the upper surface of the ground G as in the conventional case, or
The pressure may be low enough not to cause splitting in the ground using the pressure water tank 2. By this water injection, water is injected into the ground from the strainer portion 1a of the casing 1, and for example, water may enter the water paths S1 and S2 that are naturally formed in the ground, or the water path S1. , Water penetrates into the ground from S2. The injected water is, for example, pumped groundwater.

Next, as a second step, the water injection amount (water injection capacity) is monitored during the water injection in the first step, and the state where the water injection amount is below a predetermined amount is detected. Substances that cause clogging such as fine particles in soil enter the injected water and injected water in the first step, and these move to move the strainer portion 1a of the casing 1 and the walls of the water channels S1 and S2. Clog. Due to this clogging, the amount of water injected from the water injection pipe 3 also decreases, and it is detected that the amount of injected water is below a predetermined amount. And based on this detection, it transfers to a 3rd process.

In the third step, the pressure of the pressure water tank 2 is increased to increase the pressure of injected water. By this pressurization, new splits are generated in the ground, and new splits S3 to S7 are generated by the splits. New water street S3-
When S7 is generated, the water injection capacity is increased by the infiltration of water into these water channels S3 to S7 and the infiltration from the new water channels S3 to S7 into the ground.

The pressure treatment performed in the third step is performed, for example, until a predetermined time elapses or until an increase in the water injection amount is detected. After that, the increase of the pressurization is stopped, the pressure value in the first step is returned to, and the processes from the first step are repeated. Note that the above-described high-pressure pressurization process may be applied not only by continuous pressurization but also by intermittent pressurization. This pressure vibration can easily cause cracks in the ground even if the ground has high strength.

As described above, according to the water injection method in the condensing method of this embodiment, a new split is generated in the ground by pressurization of the water injection pressure, and the water injection capacity is restored by the split of the ground. Since it is possible to continue the water injection for a long time, it is possible to increase the total amount of water injection. Further, it is possible to reduce the cost because a spare pipe body or the like is not required to restore the water injection capacity.

The present invention is not limited to the condensate method of this embodiment. For example, pressurization for injecting water to a high pressure is not carried out only when the water injection capacity is lowered, For example, it may be performed every predetermined time or may be performed constantly. In addition to the casing, the tubular body
For example, various configurations such as a water injection well can be used, and water injection from the pipe body into the ground does not need to be performed via a strainer, for example, without providing a strainer section in the pipe body,
Water may be injected from the lower end of the pipe body. Other,
The detailed structure shown concretely, such as the structure of the casing as the tubular body and the means for pressurizing the injected water, can be appropriately changed without departing from the spirit of the invention.

[0020]

As described above, according to the water injection method of the condensate method of the present invention, a new crack is generated in the ground by pressurization of the water injection pressure, and a new water channel is created by the crack of the ground. Therefore, further water injection can be performed. That is,
According to this construction method, water injection does not depend only on infiltration,
Since water injection using ground splitting is also performed, a large amount of water can be injected compared to the conventional water injection method.

Further, even if the permeation capacity is reduced due to clogging or the like, the water injection capacity is restored by the splitting of the ground, so that the water injection can be continued for a long time. Therefore,
It is possible to reduce the cost because no extra pipe is required to restore the water injection capacity.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a condensing device for carrying out a condensing method according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a first step of the process for explaining a process flow of the condensing method in the same manner.

FIG. 3 is an explanatory diagram showing a second step of the same.

FIG. 4 is an explanatory diagram showing a third step of the same.

FIG. 5 is a schematic diagram showing an outline of a conventional condensing method.

[Explanation of symbols]

1 tube 1a strainer section 2 pressure water tank 3 water injection pipes G ground

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) E02D 3/10 E02D 19/10

Claims (2)

(57) [Claims] 1. In a water injection method in a condensate construction method in which water is injected into the ground through a pipe provided in the ground, the ground is obtained by pressurizing injected water to a high pressure to perform the water injection.
A water injection method in the condensate method, which is characterized by splitting water inside and injecting water. 2. When the water injection capacity declines during the water injection period,
Pressurize the injected water to a high pressure to cause the split in the ground
The water injection method in the condensing method according to claim 1, wherein the water injection capacity is restored by doing so .