JPH0344619B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a method for confirming the effectiveness of a chemical solution of an isocyanate compound in preventing water loss in a deep borehole.

"Conventional Technology" For example, in oil, geothermal and metal exploration, drilling wells are drilled.

However, since the well is at least 500 to 5,000 meters deep, water is lost during drilling.

When this happens, the circulating mud for drilling in the borehole escapes into the ground from the hole wall, making it impossible to maintain the head of the mud and causing the hole wall to collapse.

Therefore, a chemical solution having the effect of filling the water gap is supplied to this water loss location.

As such water-stopping chemicals, chemical agents such as water glass-based and cement milk, as well as urethane-based chemicals with quick coagulation and high water-stopping properties, have come to be used.

This trend is a progression from a "two-component system" that utilizes the gelation reaction that occurs between two different aqueous solutions to a "one-component system" that uses hydrochemical injection methods. , is a water-reactive type, can be injected with one liquid, and has a water-stopping effect even with a small amount.

Specifically, when the isocyanate compound, which is the main component of grout, comes into contact with pore water underground, it reacts as shown in the following formula, generating carbon dioxide gas and forming an insoluble polyurea gel in the water. make.

This polyurea is a hydrophobic, non-hydrated gel with a three-dimensional structure that strongly bonds between soil particles, creating a strong compacted soil that cannot be expected with a two-part system.

In addition, the carbon dioxide gas generated during the water addition reaction is dispersed in the grout as minute bubbles, and the grout actively expands and penetrates into the soil while expanding its apparent volume. to create a much larger volume of compacted soil.

In addition, by this active expansion and infiltration, even if the groundwater is in a flowing state, the ground at the target location can be reliably consolidated while eliminating its influence. The method of confirming the effectiveness of deep boreholes in preventing water loss was to wait for the water level in the borehole to rise as a result of water stoppage. That is, repeat the injection several times,
Water stoppage effectiveness was determined by repeatedly waiting for water to condense and then injecting if water did not condense.

``Problems to be solved by the invention'' However, with the confirmation method described above, the deeper the depth, the longer the injection time and condensation time.
We had to wait several hours or a day to find out whether the water leakage area had been sealed off or stopped.

"Means for Solving the Problems" and "Operation" The present invention was made in view of the above circumstances, and the gist thereof is to apply electricity to the upper part of the water loss area prior to supplying the chemical solution of the isocyanate compound. The sensor is set to hang, and a de-energized signal is detected when the expanded layer of chemical solution in the borehole due to the injection, expansion, and water stoppage of the chemical solution at the point where water is lost reaches the level of the energized sensor. The point is that it eliminates the inefficiency of sealing off water leakage points and confirming that the water has stopped, which takes the same amount of time as water condensation.

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

FIG. 1 is a longitudinal sectional view of a deep borehole 1 showing the gist of the method of the present invention. In the figure, reference numeral 2 denotes a winding drum 4 for connecting the wire line and cable of the energization sensor 3 installed on the ground, and the energization sensor 3 is suspended above the water loss location 5 when water loss occurs. If the distance A between the water loss point 5 and the current sensor 3 is approximately 10 to 20 meters, reliable water stoppage can be achieved. The energization sensor 3 only needs to be able to notify the de-energized state; for example, a commercially available water level measuring device that energizes and sounds a buzzer when immersed in water or a type that activates an ammeter may be used as an improved sensor. You may.

In the figure, reference numeral 6 denotes a pump for supplying a chemical solution of an isocyanate compound, and in the illustrated example, a rod 7 connected to the pump 6 is used to inject water into the water loss location 5.
Furthermore, when the borehole becomes deeper than 500 to 700 m, there are problems with the rod's strength and it takes too much time to raise and lower the rod, so recently a method has been adopted in which capsules filled with chemical liquid are introduced. There is.

The means for dispersing the drug solution from the capsule that has reached the hole bottom includes a method of destroying the entire capsule, or a method of destroying a part of the capsule by colliding a destruction weight against an easily breakable wall to form an injection hole. A method has been proposed in which a valve attached to the tip is opened by sending a messenger from the ground.

As described above, the chemical solution injected into the water leakage point 5 expands due to the addition of water and stops the water, but the expanded filled layer 8 also occupies the inside of the borehole 1 (if it does not occupy the area, the water stoppage is incomplete). ), rises and reaches the level of the energization sensor 3.

Since the charged layer 8 is non-energized, the energization sensor 3 reports that its level is in a non-energized state. In other words, the state in which the filled layer 8 is formed in the borehole 1 can be detected by utilizing the fact that the filled layer 8 is non-conducting.

This state is a stage where the water has been sufficiently shut off, and it is possible to know with almost no time lag that the water has been shut off at the water loss location 5 without waiting for water to condense.

"Effects of the Invention" As described above, according to the method of the present invention, water stop state can be determined in a short period of time, and unnecessary injection is not performed. Furthermore, since the determination can be made in a short time, the construction time is also significantly shortened.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a deep borehole showing the gist of the method of the present invention. 1... Borehole, 2... Winding drum, 3...
Current sensor, 4...Connection of wire line and cable, 5...Water loss location, 6...Pump, 7...
Rod, 8...full layer.

Claims (1)

[Claims] 1. Prior to supplying the isocyanate compound chemical solution, an energization sensor is suspended and set above the water loss location, and the expanded and filled layer of the chemical solution in the borehole becomes energized by the injection, expansion, and water stop of the chemical solution to the water loss location. A method for preventing water loss in deep boreholes using a chemical solution of an isocyanate compound, which is characterized in that a non-energized signal is detected at the level of a sensor to confirm that the water loss point has been sealed and stopped. How to check the effect.