JPS60253692A - Method for preventing water loss in deep boreholes - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention is applicable to deep poling hole drilling such as geothermal power generation drilling 2 oil drilling, mineral resource drilling, and various resource exploration drilling, in which circulating mud for drilling is removed from the hole wall. This article relates to a method for preventing water loss in deep polling holes that prevents water from escaping.

``Prior art j'' The state of deep poling is as shown in Figure 3, in which 1 is a casing, 2 is a drill rod that penetrates the inside of the casing 1, and the circulating mud for drilling is circulated through the air core of the drill rod 2. is injected from the tip to the bottom of the hole through the hole 3, filling the hole 3.
It is collected in tank 4 on the ground. Note that arrow 5 in the figure indicates lost water.

Conventional water loss prevention methods include the following.

i) Method by adjusting the concentration of muddy water This method is a method of sealing off lost water N (crack) by increasing the concentration of muddy water.

ii) Method using cement grout This method involves pouring only cement grout or cement grout mixed with wood chips, straw, etc. into deep poling holes to prevent water loss.

iii) Chemical injection method This method uses a drilling rod to inject a water-stopping chemical that gels in water to seal the water leak layer (crack).

iv) Method of injecting water-stopping chemicals using capsules, etc. In this method, the water-stopping chemicals set in a capsule-like substance at a predetermined gel time are lowered to a predetermined depth (water loss layer), and the capsule is ruptured to stop the water. This is a construction method that uses water.

``Problems to be solved by the invention'' However, the conventional construction methods described above have the following problems.

That is, the method i) described above is not effective when the crack width is large or when water loss is severe because the mud particles are not as large as gelled materials. In addition, if the concentration becomes too high, it has the disadvantage of collapsing weak pore walls other than the water leakage tube (because it adheres only to the surface of the pore wall without penetrating into the wall).

In the method 11), it takes a long time for the cement to harden, so it takes time to stop the water, and a series of excavation systems are required.
If water loss is severe from the third day onwards, the system will be shut down for several dozen days. In addition, circulating mud water is wasted and tens of tons of cement are used. Furthermore, since cement has poor permeability, re-excavation will cause collapse as in case 1).

With the method iii), it is difficult to set the gel time depending on depth, temperature, water loss rate, etc., and if gelation occurs in the drilling rod, the rod will be damaged and a large amount of damage will occur. There is danger.

Regarding method iv), this method has the inconvenience that it is difficult to send the capsule to a predetermined depth when the depth is several hundred meters or several thousand meters, and that it is not possible to continuously supply the capsule to a predetermined amount.

``Means for Solving the Problems'' The present invention was made in view of the above-mentioned circumstances, and its gist is that when water leakage occurs, the drilling rod is pulled up to separate it, and the muddy water is removed from the excavation. While pouring from the mouth of the hole, lift and suspend the wire with a weight such as a fixed lead ingot at the tip and suspend the water-stopping chemical injection hose with a flutter to the depth of water leakage in the hole, and connect it through the hose. The main point is that the water can be stopped at the water tank by supplying a water stop chemical solution.

``Operation j, ``Example'' Hereinafter, the operation and Example will be described in detail based on the drawings.

Fig. 1 is a vertical cross-sectional view showing the state of the polling hole 3 in the implementation of the present invention, and 6 in the figure shows a water-stopping chemical solution with a weight 8 such as a lead ingot attached to the tip of the wire 7 for lifting/hanging. It is an injection hose.

Reference numeral 9 denotes a frame on which the drum 10 for removing the wire 7 is assembled.

The weight 8 and wire 7 are shown in enlarged detail in FIG. In other words, the weight 8, which is fixed and placed on the receiving member 11 attached to the end of the hose 6, can be additionally stacked as necessary to achieve a predetermined weight, as shown by the chain line in the figure. It is preferable to make it possible to assemble it from the side by splitting it into two or the like, and to integrate the joint by welding 12 or by fastening a band 13 made of steel wire or the like.

Further, it is preferable that the wire 7 is fixed by adhering to a circumferential groove 14 cut into the weight 8.

As for the injection hose 6, a vinyl chloride cannon is sufficient, but especially in places where the temperature is over 100°C, it is better to use a fiber hose partially mixed with glass fiber or the like.

Next, the procedure for implementing the present invention is as follows.

(1) When the lost water is detected, pull up the drilling rod 2. At this time, the drilling rod does not have to be pulled up completely, but may be pulled up halfway. This is because the size of the injection hose 6 in the present invention is set to such a size that it can be inserted into the clearance between the drilling rod and the casing with sufficient margin.

(2) Mud water is poured from the mouth of the borehole.

(3) Determine the diameter of the injection hose 6 in consideration of the depth of lost water and the amount of lost water.

(4) Determine the weight of the weight 8 in consideration of the depth and the buoyancy of the injection bow 6, and place it on the tip of the bow 6.

(5) Once the injection hose 6 is suspended to a predetermined depth (water leakage point), a water-stopping chemical is supplied to the injection hose 6 from a hopper (not shown) or from a pump and sent into the crack,
Seal this and stop the water.

(6) While injecting the water-stopping chemical, check the water level of the muddy water in the borehole, and if the water level does not drop (or if the check valve shown in Figure 4 operates and the chemical is injected). Once it stops, the infusion is presumed to have had an effect and the infusion is discontinued.

(7) Stop the injection and send air while pulling up the hose 6 to drain the chemical solution inside the hose. In this case, by repeating the process of sending air and water, no unreacted chemical solution remains.

FIG. 4 shows an example of a check valve 15 that is suitable to be attached to the tip of the injection bow 6 when carrying out the present invention. There is a ring 15b for the pole which is pushed toward the upper valve seat 15c by the spring 15a, and the spring 15a connects the intermittent lateral escape port 15d and the horizontal baffle plate 15e, which are installed from the bottom of the cylinder body. Attached nipple 1
It is accepted on the 5th floor.

When using the check valve 15, there is no need to worry about water leakage reaching the water tank, so there is no problem in supplying the water stop chemical solution at the same time as the injection hose 6 is inserted.
When the water reaches the water loss point, the horizontal baffle plate 15e is pulled open by the strong water loss suction force, and the side escape port 15 is opened.
The water stop chemical solution will be diffused and supplied from d.

Figures 5a and 5b show examples of adding the injection hose 6, in which figure a is tightened with a wire 17 using the joint pipe 16 as an intermediary, and figure b is where the tip of the injection hose 6 is attached to the joint fitting 18. A pre-installed base 19 is screwed onto the base.

``Effects of the Invention'' Accordingly, if a flexible hose that can be cut and discarded is used in the chemical liquid injection conduit and the method of the present invention is used, various effects as listed below can be achieved.

(1) The position of the tip of the injection hose 6 can be accurately controlled by measuring the amount of feed of the wire 7, so it is possible to reliably inject water into the designated drainage tube location, and since the supply path is continuous, it is possible to accurately control the position of the tip of the injection hose 6. There is no situation where there is a shortage in quantity.

(2) Even if the depth becomes deeper, each time you add injection BOSE 6, you can cope with it.

(3) It has the unique advantage of being able to cut the hose if the gap is large and water is being sucked in. In addition, the cut marks have an effective effect of sealing the voids, and can be easily cut even during excavation after the water has stopped.

(4) This construction method does not require large equipment. If pumping equipment is required, it can be injected with a conventional injection pump or head pressure compressor.

[Brief explanation of drawings]

Fig. 1 is a vertical view of a poling hole showing an embodiment of the present invention, Fig. 2, Figs. FIG. 4 is a longitudinal sectional view showing an excavation mode, FIG. 4 is a longitudinal sectional view of a check valve preferably employed in the present invention, and FIGS. 5 a and 5 b are explanatory diagrams of an example of hose addition in the present invention. Explanation of symbols 1...Casing, 2...Drill rod, 3...
Polling hole, 4... Tank, 5... Water loss, 6...
・Injection hose, 7... wire, 8... weight, 9...
- Frame, 10... Winding drum, 11... Receiving member, 12... Welding, 13... Band, 14... Circumferential groove, 15... Check valve, 15a... Spring, 15b
... Ball hair ring, 15c... Valve seat, 15d.
...Side escape port, 15e...Horizontal baffle plate, 15F...
・Nipple, 16...Joint pipe, 17...Wire, 1st...Joint fitting, 19...Bag ψβ 2Δ 0,

Claims (1)

[Claims] When water leakage occurs, the drilling rod is pulled up to release it, and the muddy water is poured from the mouth of the borehole and lifted.
Suspend a water stop chemical injection hose with a hanging wire attached to the tip and a weight such as a lead ingot at the tip to the water loss depth in the hole, and supply the water stop chemical solution through the hose. A construction method for preventing water loss in deep polling holes, which is characterized in that water is stopped at the point where water is lost.