JPS6361473B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a flow line device that is attached to a drilling machine that excavates a geothermal well using muddy drilling fluid and that separates drilling waste from the drilling fluid.

(Conventional technology) In facilities that utilize geothermal energy such as geothermal power plants, geothermal fluids (hot water and steam) ejected from geothermal wells drilled into good underground geothermal reservoirs are used as the energy source. It is said that

Conventionally, as a means of excavating this geothermal well, a method of excavating while using muddy water and discharging drilling waste has been used. Furthermore, air mud drilling methods using mud and compressed air have been developed in recent years. The air mud drilling method is a method in which excavation waste scraped by a bit is discharged to the outside of the excavation pit using a high-pressure air flow along with muddy water pumped into the excavation pit. The drilling fluid (mud water and compressed air) containing the discharged drilling waste is led to the flow line device, where the compressed air is separated by a mud separator and released into the atmosphere, after which the drilling waste is separated by a sierre shaker. Separated and removed from muddy water. The muddy water from which the drilling waste has been removed is sent to the drilling hole again through the muddy pit and is reused as drilling fluid.

(Problems to be Solved by the Invention) However, in the above-mentioned flow line equipment used in the air mud drilling method, all of the processing steps are performed in a path open to the atmosphere, so the tip of the bit may be damaged during excavation. If a crack in the stratum containing a sufficient amount of geothermal fluid is encountered, the high temperature and high pressure geothermal fluid will self-gush due to the pressure.
The mud flows through the muddy water circulation route and erupts with great force near the mud separator of the flow line equipment.
This poses a danger to surrounding equipment and workers, making it impossible to continue excavation to the desired depth.
There was a problem that work had to be interrupted.

In order to solve the above problem and continue drilling even in situations where geothermal fluid is gushing out, it is possible to install a drilling muffler in the flow line equipment. A drilling muffler is a device that separates muddy water and compressed air and also serves as a muffler, replacing the mud separator described above, but when geothermal fluid self-sprays, its force can be weakened to some extent. However, in order to withstand the force of geothermal fluid that violently ejects at high temperature and high pressure, and to obtain the effect of weakening the force to the extent that it does not affect drilling, the drilling muffler must be sufficiently large and sturdy. The problem remains that it requires a great deal of cost and work to manufacture, transport and install it to a predetermined location.

The present invention was made in view of the above circumstances, and in the air mud drilling method, even when geothermal fluid is spouted out, there is little impact on the surroundings.
The purpose of the present invention is to provide a simple and inexpensive flow line device that allows safe continuation of excavation.

(Means for Solving the Problems) The present invention guides drilling fluid discharged from an excavator through a pipe, and connects a discharge section provided in the pipe that discharges the drilling fluid with a sufficient amount of water. It is installed underwater in a pit.

(Function) The flow line device according to the present invention functions as follows when excavating in a situation where geothermal fluid self-gushes.

The self-spouting geothermal fluid is guided from the excavator along with drilling fluid and excavation waste through a pipe, and is ejected into the water from a discharge part in the pit water. This allows the sufficient amount of water in the pit to cool the geothermal fluid.
Moreover, since the head pressure counteracts the ejection pressure of the geothermal fluid and weakens its force, the influence on the surroundings can be significantly suppressed compared to when the geothermal fluid is ejected directly into the atmosphere.

At the same time, compressed air, which is the drilling fluid discharged, floats above the water and is released into the atmosphere, muddy water is diffused into the water, and drilling debris settles and accumulates at the bottom of the pit, and is discharged from the pit by appropriate means. Ru.

(Example) An example of the present invention and an excavation system using the same will be described with reference to FIGS. 1 to 3.

FIG. 3 is a schematic diagram of the entire drilling system for drilling a geothermal well using the flow line device according to the present invention, and the system configuration and drilling method will be explained using this diagram. (The arrows in the figure indicate the circulation route of muddy water.) In the figure, reference numeral 1 is an excavation pit. An excavation hole 1 is excavated by a bit 4 provided at the tip of a drill pipe 3 of an excavator 2.

Mud water and compressed air are pumped into the drill pipe 3 from above by a mud water pump 5 and a compressor 6, and these drilling fluids (mud water and compressed air) descend inside the drill pipe 3 and are pumped from the bit 4. It is sent to the excavation shaft 1, where it ascends inside the excavation shaft 1 along with the excavation waste, and is normally discharged from the excavation fluid outlet 8 provided in the bungeo box 7.

A flow line device 9 is connected to the drilling fluid outlet 8 . The flow line device 9 is composed of a valve 10, a pipe line 11, and a mud separator 12, and is conventionally used in the air mud excavation method. In the flow line device 9, compressed air is separated from the drilling fluid guided through the conduit 11 by the mud separator 12 and released into the atmosphere. Next, the muddy water is separated from drilling waste by the shaker 13, the separated drilling waste is discharged into the waste mud pit 14, and the muddy water falls into the muddy water pit 15, during which suspended solids are removed. and is led to the muddy water suction pit 16. The muddy water accumulated in the muddy water suction pit 16 is sent to the drill pipe 3 by the aforementioned muddy water pump 5, and is used again as drilling fluid.

As mentioned above, while drilling while circulating drilling fluid using the conventional flow line device 9, the bit 4 at the tip of the drill pipe 3 encounters a crack in the stratum where geothermal fluid exists, As described above, when the geothermal fluid violently spouts out from the pine separator 12, the flow line device 17 according to the present invention is immediately switched to continue excavation.

The flow line device 17 according to the invention comprises a conduit 1
8, a discharge part 19, and a pit 20, one end of which is connected to the drilling fluid outlet 22 of the bungeo box 21 via a valve 23, and when the valve 23 is opened, the above-mentioned normal condition is established. By closing the valve 10 provided in the drilling fluid path, the conventional flow line device 9 is switched to the flow line device 17 of the present invention. A discharge portion 19 is provided at the other end of the pipe line 18 . The discharge part 19 is connected to a pit 20 which is provided at an appropriate position near the excavator 2 and which has a sufficient amount of water.
is placed underwater. Further, as shown in FIGS. 1 and 2, the discharge section 19 is formed by combining perforated tubes 24, 24, 24 having a large number of holes into an H-shape, and a pedestal 25 placed at the bottom of the pit 20. ,25
is held by weights 26, 26, 26, 26 above. In addition, the pipe line 18, the discharge part 1
9 and the like are made of a heat-resistant and pressure-resistant material such as a steel pipe. In addition, the shape and dimensions of each part of the discharge part 19, the diameter of the perforated pipe 24, the size and number of holes, the dimensions of the pit 20, the amount of water held, and the water depth, and the position where the discharge part 19 is arranged in the pit 20 ( That is, the distance between the discharge part 19 and the bottom of the pit 20 and the water surface is determined by taking into consideration the expected ejection pressure and ejection amount of the artesian geothermal fluid.

With the above configuration, the flow line device 17 can:
The self-gushing geothermal fluid is guided to the pit 20, and the discharge part 1
By ejecting water into the water from numerous holes,
The geothermal fluid is finely dispersed to weaken its momentum, the water cools the geothermal fluid, and the discharge part 19
Since the head pressure of the water applied to the geothermal fluid counteracts the ejection pressure of the geothermal fluid, the force of the geothermal fluid can be sufficiently weakened compared to when the geothermal fluid is ejected directly into the atmosphere, and the impact on the surroundings can be reduced. Further, since the excavated waste simultaneously discharged from each hole of the discharge portion 19 settles and accumulates at the bottom of the pit 20, it can be discharged from the pit 20 by appropriate means.

Note that when drilling is performed using the flow line device 17 of the present invention, the muddy water of the drilling fluid is sent into the drill pipe 3 by the muddy water pump 5 as in normal times, but the muddy water is recycled to the muddy water suction pit 16. Therefore, water is supplied by the water supply device 27 to ensure the amount of muddy water necessary for excavation. In addition, the capacity of the pit 20 should be sufficient to accommodate the amount of geothermal fluid (hot water) and drilling fluid (mud water) flowing into it, or overflow should be prevented by appropriate means such as installing a drainage pump. It's fine if you do this.

Thus, the flow line device 1 according to the present invention
In a drilling system using a conventional flow line device 9, even when geothermal fluid comes out
By switching to the flow line device 17 of the present invention, excavation can be continued as usual.

Although one embodiment of the present invention and an excavation system using the same have been described above, the present invention is not limited to the above embodiment, and the shape etc. of the discharge portion 19 may vary depending on the pressure of the ejected geothermal fluid, Various applications are possible depending on temperature, amount, etc. or,
Regarding the excavation system using the present invention, if a pump suction pit is provided in a part of the pit 20 and the supernatant water of the mud flows into it (that is, the function of the conventional mud water pit 15 and mud water suction pit 16). ), the flow line device 17 of the present invention can be used even during normal excavation, and devices such as the pine separator 12 and the shear shaker 13 can be made unnecessary.

(Effects of the Invention) As described above in detail, in the drilling of geothermal wells, according to the present invention, a device with a simple configuration and low cost can prevent the ejection of geothermal fluid even in a situation where the geothermal fluid self-injects. This has the effect of weakening the force and reducing the impact on the surrounding area, allowing excavation to continue safely.

[Brief explanation of drawings]

1 and 2 are schematic configuration diagrams of an embodiment of the present invention, in which FIG. 1 is a plan view thereof, and FIG. 2 is a front sectional view thereof. FIG. 3 is an overall schematic system diagram of a drilling system for drilling a geothermal well using an embodiment of the present invention. 17...Flow line device, 18...Pipe line, 1
9...Discharge part, 20...Pit.

Claims (1)

[Claims] 1 Attached to a drilling machine that excavates while discharging drilling fluid such as mud from a wellbore along with drilling waste,
In a flow line device that guides drilling fluid discharged from a drilling well through a pipe and separates drilling waste from the drilling fluid, a pit that holds water is provided,
A flow line device for artesian drilling of a geothermal well, characterized in that a discharge section for discharging drilling fluid provided in the conduit is provided underwater in the pit.