JPH01131786A - Method of cut off construction of overflow water by cut off chemical in deep layer boring hole - Google Patents

Abstract

PURPOSE: To surely cut off water by backfilling a recessed hole part deeply dug due to generation of leakage water with granular substance capable of being drilled by a drilling edge, and pouring a water cut-off chemical thereon by a capsule or an injection rod to form a consolidated layer. CONSTITUTION: After forming a recessed hole part 3 by deep digging due to generation of leakage water by a cracked position 2 of a boring pit 1, a drilling rod 4 is lifted, the recessed hole part 3 is backfilled with granular substance 5 having about 3-10 mm diameter and specific gravity about 1.2 or over such as glass balls or baked clay capable of being crushed by a drilling edge. Next a capsule 6 enclosed with a water cut-off chemical is brought down, and the water cut-off chemical is poured into the sedimentary layer of the granular substance 5 to form a consolidated layer with the substance 5 as aggregate. Of course when the cracked position 2 is positioned over the sedimentary layer of the substance 5, or even if it is covered with the sedimentary layer, the water cut-off chemical permeates the cracked position through the gap of the aggregate to blockade it. Next after confirming water cut-off, drilling is again performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This invention relates to a method for stopping lost water in deep boreholes using a water stopping chemical.

[Conventional technology j Boring is used in oil, geothermal and metal exploration, civil engineering, and construction of foundation piles for buildings.

In order to prevent the walls of the borehole from collapsing, the borehole is filled with muddy water during drilling, but during drilling, muddy water escapes into cracks in the bedrock. Particularly in the case of oil, geothermal energy, etc., the drilling depth is deep, at least GL-500 to 5,000 m, and water loss frequently occurs at various locations during boring.

This situation causes leakage of muddy water and compromises the stability of the hole wall.

In this case, there are various methods listed below to stop the water.

(1) A method of stopping water by adjusting the concentration of muddy water.

This is a commonly practiced technique that requires experience.

If the concentration is too low, it will not be effective, and if the concentration is too high, the weight of mud will be applied to the pore walls, which may cause the surface of the pore walls to peel off. Although it is effective for small cracks, it is not effective for large cracks due to leakage.

(2) A method to stop water by injecting cement or mortar.

This method has a poor ability to penetrate into cracks in the ground and rock, making it difficult to inject depending on the location of the hole wall where water is leaking, and because it takes a long time to harden, it flows out into the water without hardening. Sometimes it happens. Therefore, it is not suitable for large cracks.

(3) Water stop method by injection of chemical solution.

This method uses an injection rod, injection hose, or capsule to transport and inject a water stoppage chemical solution to a water leakage point to stop the water.The liquid permeates into the gap and gels there. Therefore, compared to the above two methods, it is an ideal treatment because the hardening of the penetration filling in the cracks is superior.

Furthermore, it is effective in filling even large cracks.

One of the medicinal solutions that can be employed as having the effect on furrows is an isocyanate-based medicinal solution. This is a one-component chemical solution whose main component is a hydrophobic polyisocyanate compound that is insoluble in water, and which reacts with underground water to produce a water-insoluble polyurea gel.

In other words, it reacts with water and turns into a gel, but it is not diluted with water and washed away, and the entire amount of the injected chemical solution is definitely gelled, and it does not dissolve into groundwater or boreholes and contaminate muddy water. It has the following characteristics.

The reaction and gel time of the chemical solution can be controlled by the amount of catalyst. However, this only controls the time at which the reaction begins after contact with moisture; no reaction occurs until it comes into contact with moisture.

Another feature is that when the reaction begins after the chemical solution comes into contact with water, it does not immediately gel, but first generates carbon dioxide gas, becoming a liquid with bubbles, and then gradually gelling.

That is, after a predetermined period of time has passed after contact with moisture, a reaction begins and carbon dioxide gas is generated, and the pressure causes the chemical solution to penetrate into minute cracks in the ground.

Since the reaction proceeds from the leading part of the chemical solution, the leading part gels and seals the crack. Thereafter, subsequent chemical solutions sequentially fill the cracks to ensure that the required range of voids is sealed.

Note that when the surrounding pressure increases, the generation of carbon dioxide gas is suppressed and the bubbles become finer, so the apparent volume of the gel material becomes smaller, but in return, the gel material becomes denser and its strength increases.

When implementing the water stop method by injecting a chemical solution onto the ridges, the cracks that cause water loss were sufficiently exposed, and water loss occurred so that the water loss caused by the cracks could be prevented by - degree of water stop treatment. It is often done to excavate the excavation rond to a depth of more than ten meters before lifting the pipe.

However, there may be cases where the distance between the water outlet and the excavation bottom is 0 to 20 meters.

It would be wasteful to fill such a concave hole with a water-stopping chemical, and if the above-mentioned isocyanate-based chemical liquid reacts with water and hardens, it may be reused if it remains unreacted at the bottom of the hole. It hardens around the excavator blade and causes problems during excavation.

Therefore, conventionally, in order to eliminate empty concave holes, they were backfilled with earth and sand.

``Problems to be Solved by the Invention'' However, with the ridge means, it is difficult to judge how much backfilling should be done when the water leakage site cannot be identified, and there are several water loss canisters. If the excavation is carried out over multiple locations, the surface of some of the cracks may be blocked by earth and sand, resulting in the inconvenience of water leakage when re-excavating.

``Means for Solving Problems'' and ``Operations'' The present invention was made in view of the situation on ridges, and its gist is that the excavation blade The granular material is backfilled with granular material made of a material that can be crushed, and a water-stopping chemical solution is injected into the granular material accumulation layer via an injection rod or capsule, and a solidified material using the granular material as aggregate is injected into the recessed hole. In order to seal the crack while forming a layer, and then re-excavate, a water-stopping chemical solution that has excellent permeability into the gap due to the multi-porous nature of the backfill layer is used, even if the backfill layer is in the crack. The point is that even if the surface is covered, its permeability will not be impaired in any way, and water will be reliably stopped.

"Example" This will be explained in detail below based on the drawings.

Figures 1a to 1e are illustrations of the procedure for implementing the present invention using a capsule, and Figures 2a to 2e are diagrams showing the procedure for implementing the present invention using an injection rod.

FIG. 1 will be explained.

After a concave hole 3 is formed by deep digging due to water loss caused by a crack 2 in a borehole 1, a drilling rod 4 is lifted (a).

The concave hole 3 is backfilled by dropping about 3 to 10 pieces of granular material 5 made of a material 1 that can be crushed with a drilling blade, such as glass balls, fired clay, etc., and having a specific gravity of 1.2 or more (b ).

The capsule 6 containing the water-stopping chemical solution is lowered (C), and the water-stopping chemical solution is injected into the deposited layer of the granular material 5 to form a consolidated layer using the granular material 5 as an aggregate (d).

At this time, if the crack location 2 is located above the deposited layer of granular material 5, the water stop chemical solution penetrates into the crack location 2 as an extension of the hardened layer of the water stop solution formed on the deposited layer, and ．．
When the surface of the crack 2 is covered with a deposited layer of granular material 5, it penetrates into the crack 2 through the gaps in the aggregate to reliably seal it.

After confirming that the water has stopped, excavation will be carried out again (e).

FIG. 2 will be explained.

(a) is the same as Figure 1.

Set the water stop chemical injection rod 7 (b).

The recessed hole 3 is backfilled with the granular material 5 (C).

A water stop chemical solution is injected into the deposited layer of granular material 5 through the injection rod 7 to form a consolidated layer (d).

The sealing action for crack location 2 is the same as in Figure 1.

After confirming that the water has stopped, excavation will be carried out again (e).

Incidentally, the injection of particulate matter onto the ridges may be carried out simultaneously with the injection of the water-stopping chemical solution.

"Effects of the Invention" The present invention having the configuration described above provides various effects as listed below.

(1) In the case of granular materials, unlike sediment, Fischer (
Since the surface of the fissure (crack) is not packed (even if it is packed, there will be gaps because it is a granular material), the water stop chemical solution can easily penetrate into the fisher.

(2) The water-stopping chemical flows down within the granular layer, flows into the fisher area, penetrates, and stops the water (it definitely flows into the fisher part). (3) Unlike earth and sand, it is easier to transport and input. .

(Equivalent in cost) (4) No excess chemical remains in the borehole (recessed hole), water is reliably stopped, and it is economical (cost reduction).

(5) The chemical solution does not remain in the pore hole (recessed hole) in an unreacted state.

[Brief explanation of the drawing]

Figures 1a-e are diagrams showing the implementation procedure of the present invention using a capsule, and Figures 2a''-e are diagrams showing the implementation procedure of the present invention using an injection rod.1...Borehole, 2...Crack location, 3.
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Claims (1)

[Claims] After a water loss occurs, the hole created by deep excavation is backfilled with granular material made of a material that can be crushed with a drilling blade, and a water stop chemical solution is injected into the granular material accumulation layer via an injection rod or capsule. A water-stopping chemical solution for deep boreholes, characterized in that the cracks are sealed while forming a consolidated layer using the granular material as aggregate in the concave portion, and then re-excavation is performed. Water stoppage method for water leakage.