JPS6232316B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for supplying muddy water into an underground hole for stably maintaining the excavation wall surface and removing excavation slime.
When excavating and forming an underground hole, when muddy water escapes into the ground, a chemical solution consisting of isocyanate or containing isocyanate as a main component is supplied deep into the underground hole, and the place where the muddy water has escaped is treated with the chemical solution. Concerning a method of sealing with a solidified substance.

Since the above chemical solution is water-insoluble and hydroreactive, it reliably gels without being adversely affected by dilution with running water, and quickly gels at the point where mud is lost while suppressing the solidification reaction in the injection pipe. Even in deep excavation, it is possible to easily and reliably supply the chemical solution to the area where sludge is lost, and to perform reliable treatment in a short time. Since the seal can be strengthened, the seal part is less likely to be destroyed by shocks such as re-excavation.
In addition, since it becomes a solidified material with low strength containing many air bubbles in the excavated hole, it exhibits excellent functions in terms of workability and reliability, such as having no adverse effect on re-excavation.

However, the above chemicals are expensive, and simply supplying the chemicals as in the past would require an unnecessarily large amount of chemicals, especially in cases where large cracks exist deeply, such as in deep bedrock, which would pose a major economic problem. In addition, there were problems such as sometimes requiring a long time to perform the sludge prevention treatment.

In view of the above-mentioned circumstances, the present invention makes it possible to quickly and reliably prevent spillage while suppressing the amount of chemical solution supplied, regardless of the size of the crack, using extremely simple and rational means. To provide a method for preventing mud slippage, which is economically advantageous and can be carried out in a short period of time, and is particularly effective when excavating large-scale and extremely deep underground holes such as oil wells. purpose.

In the above-mentioned method for preventing sludge loss for forming underground hole excavations, the present invention provides that, at the same time as the chemical solution is supplied or prior to the chemical solution supply, muddy water is accumulated in the deep part of the underground hole at the location where the muddy water is lost. It is characterized by supplying a solid filler that becomes a filter layer that reduces the ratio of liquid passing area to inlet area.

In other words, the filler material is intensively intertwined with each other at the entrance of the sludge point or at a location relatively close to the entrance, forming a filter layer, and the increase in flow resistance due to the filter layer reduces the permeation rate of the chemical solution. This effectively prevents a large amount of chemical solution from unnecessarily flowing out from an underground hole to a long distance.
Moreover, when the chemical liquid passes through the filter layer, the flow of the chemical liquid is disturbed, and as a result of this flow disturbance,
The contact area between water such as underground water or muddy water and the chemical solution increases, promoting the hydration reaction of the chemical solution and preventing slippage of the chemical, and the filler is included in the solidified material, making it strong and reliable. It is now possible to perform seals in a highly sensitive state.

The above chemical solution is mainly composed of isocyanate represented by the general formula R-(NCO) _o ,
It is a substance that polymerizes while generating carbon dioxide gas when reacting with water to produce a gel-like polymer that is insoluble in water. In the above general formula, R represents an aliphatic or aromatic group, or an organic group containing both, and n is preferably an integer of 2 or more. Typical isocyanates used in the present invention are exemplified below. That is, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4
and a mixture of 2.3-tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, polymethylene polyphenyl isocyanate, bitolylene diisocyanate, m-phenylene diisocyanate, 1,6-hexamethylene Aromatic or aliphatic polyisocyanates, such as diisocyanate, 0-, m- or p-xylylene diisocyanate, methylene bis-P-phenylene diisocyanate, 2,6-diisocyanate methyl capate, or these isocyanates and polyester graphite. It is a prepolymer containing terminal isocyanate groups derived from a polyol containing active hydrogen such as equol or polyether glycol.

For the above-mentioned various isocyanates, for example, triethylamine, N-methylmorpholine, N-ethylmorpholine, dimethylbenzylamine, triethylenediamine, N,N'-dimethyl-2-methylpiperazine, dimethyllaurylamine, dimethylcoconut tertiary amines such as amines, or reaction accelerators such as organometallic compounds such as dibutyltin laurate and stannath octate, or reaction inhibitors such as benzoyl chloride, chlorinated paraffin, octylic acid, or, e.g. A diluent consisting of an organic solvent such as benzol, xylol, toluene, acetone, methyl ethyl ketone, ethyl acetate, trichloroethylene, or a plasticizer such as dibutyl phthalate, dioctyl phthalate, tricresyl phosphate, dioctyl adipate, or the like; For example, a suitable amount of a suitable agent such as a surfactant such as a silicone nonionic type, or other additives may be added.

The filler may be a substance that does not have active hydrogen, for example, so as not to react with isocyanate.
Fibrous materials such as asbestos tailings, glass fibers, slag wool, and rock wool, granular or powdered materials such as perlite, water slag, slag, vermiculite, coke, clay, and bentonite can be used.

In addition, for fillers, for example, dimensional adjustment,
Treatments such as particle size adjustment, drying, and other various pretreatments can be performed.

Next, an example of the construction method of the present invention will be described with reference to illustrative drawings.

As shown in Fig. 1A, an underground hole 2 is drilled and formed using a drill bit 3a while muddy water 1 such as bentonite is supplied into the underground hole 2 to maintain stability of the excavated wall surface and remove excavated slime. to form oil wells, natural gas wells, etc.

As shown in FIG. A liquid 4, such as liquid paraffin whose specific gravity has been adjusted, that floats in muddy water, is heavier than the chemical solution 5, and does not react with them is supplied as a spacer into the drill rod 3b, and the chemical solution 5 mixed with the filler is subsequently supplied into the drill rod 3b. Then, the muddy water in the drill rod 3b is removed by the spacer liquid 4, and the chemical solution 5 and the muddy water 1 are mixed in the drill rod 3b.
The chemical solution 5 is supplied to the deep part of the underground hole 2 from the drill bit 3a while preventing the chemical solution 5 from being mixed and causing a solidification reaction of the chemical solution 5.

The chemical solution supplied into the hole 2 from the tip of the drill bit 3a comes into contact with moisture for the first time, and the reaction starts at a time corresponding to the amount of the solidification reaction promoting catalyst or reaction inhibitor added. The chemical solution 5 and the filler material during the reaction flow into the sludge removal area A together with the muddy water 1, and as shown in FIG. A filter layer is formed in which the ratio of the liquid passing area to the inlet area of the spillage point A is reduced, and the flow of the chemical solution 5 is suppressed, and the preceding reaction between the chemical solution 5a and water is completed and the reaction occurs. The solidified material is formed sequentially from the tip of the crack, preventing the chemical solution 5 from flowing out further away, and the solidified material grows throughout the crack, including the 6 layers of filler material, as shown in FIG. 2B. Finally, the solidified material 7 seals the muddy spot A.

It should be noted that the filler may be supplied into the underground hole prior to supplying the chemical solution to sufficiently clog the sludge area with the filler material, and then the chemical solution may be supplied, or the filler with a large size may be supplied first. After narrowing the leakage area, filler with a smaller size may be supplied to achieve sufficient clogging. In addition, various changes can be made to the method of supplying the chemical solution and the filler.

Furthermore, the present invention can be applied to the formation of underground hole excavations for various purposes. Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

The drawings show an embodiment of the sludge prevention method for forming underground hole excavations according to the present invention, and FIGS. 1A and 2B are explanatory diagrams of the method, and FIGS. . 1...Muddy water, 2...Underground hole, 5...Medical solution, 6...Filling material, A...Mud water loss location.

Claims (1)

[Claims] 1. When the muddy water 1 is supplied into the underground hole 2 to maintain the stability of the excavated wall surface and remove the excavated slime, when the underground hole 2 is excavated and formed, when the muddy water 1 leaks into the ground, A method of supplying a chemical solution 5 consisting of isocyanate or containing isocyanate as a main component to a deep part of the underground hole 2, and sealing a muddy water loss location A with a solidified product 7 of the chemical solution 5, the method comprising: supplying the chemical solution 5; At the same time or prior to the supply of the chemical solution 5, it accumulates in the deep part of the underground hole 2 at the muddy water loss point A, forming a filter layer that reduces the ratio of the liquid passing area to the entrance area of the muddy water loss point A. A method for preventing mud loss for forming underground hole excavations, which is characterized by supplying a solid filler 6.