JPS6149092A - Flow line apparatus for automatic drilling geothermal well - 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) The present invention relates to a flow line device that is attached to a drilling machine that excavates a geothermal well using a drilling fluid such as mud, and that separates drilling debris from the drilling fluid.

(Conventional technology) In facilities that utilize geothermal energy such as geothermal power plants, the energy source is geothermal fluid (hot water and steam) spouted from geothermal wells drilled into good geothermal reservoirs underground. 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 excavation method is a method of excavating while discharging excavation waste scraped by a pit and muddy water pumped into the excavation hole to the outside of the excavation hole using a high-pressure air flow. The discharged drilling fluid (mud water and compressed air) containing drilling waste is led to a flow line device, where the compressed air is separated by a mud separator and released into the atmosphere. The mud from which the drilling waste has been removed is sent to the drilling hole again through the mud pit V, 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 carried out in a route that is open to the public, so it is difficult to avoid pits during excavation. If the tip encounters a fissure in the stratum that contains a sufficient amount of geothermal fluid, the high-temperature, high-pressure geothermal fluid will self-gush due to the pressure.

The mud flows through the circulation path and sprays out near the mud separator of the flow line equipment with great force.

This poses a danger to surrounding equipment and workers.
Excavation to the desired depth could not be continued.

There was a problem in that work had to be interrupted.

The above problem? In order to solve this problem and continue drilling even in situations where geothermal fluid is gushing out, it is possible to install a drilling muffler on the flow line equipment. A drilling muffler replaces the mud separator described above. This is a muddy water and compressed air separation device that also functions as a silencer, but if 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 has been made in view of the above circumstances, and is an air mud excavation method that has little impact on the surroundings even under conditions where geothermal fluid is gushing out. The purpose is to provide an inexpensive flow line device IIV.

(Means for Solving the Problems) The present invention introduces drilling fluid discharged from an excavator through a pipe, and a discharge section provided in the pipe that discharges the drilling fluid has 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 under conditions where geothermal fluid self-gushes.

The self-gushing 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.

In addition, since the head pressure counteracts the ejection pressure of the geothermal fluid and weakens its force, the influence of the geothermal fluid on the surroundings can be significantly suppressed compared to when the geothermal fluid is ejected directly into the atmosphere.

At the same time, pressurized air, which is the drilling fluid discharged, floats above the water and is released into the atmosphere, muddy water diffuses into the water, and drilling debris settles and accumulates in the pit a section.

It is discharged from the pit by appropriate means.

[Embodiment] An embodiment of the present invention and an excavation system using the same will be described with reference to FIGS. 1 to 3.

The third factor is a schematic system 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 arrow in the middle shows the circulation route of muddy water.

) In the figure, the symbol l is an excavation pit. Drill hole l is excavator 2
The excavation is done by a pit 4 provided at the tip of a drill pipe 3.

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 enter the drilling hole from the pit 4. The drilling fluid is sent to the excavation shaft 1, where it ascends inside the excavation shaft 1 along with the drilling waste, and is discharged from the drilling fluid outlet 8 provided in the punch box 7 during normal times.

A flow line device 9 is connected to the drilling fluid outlet 8 . The flow line device 9 includes a pulp lO1 conduit 11
．． The mud separator 12 is a mud separator 12 that has been commonly used in air mud excavation methods. In the flow line device 9, compressed air is separated by a mud separator 12, which is a drilling fluid, guided by a pipe line 11, and released into the atmosphere. Next, the muddy water is separated from the excavated waste by a Sierre shaker 13 and separated by 1.
r: Excavation (drilling) is discharged to the pigeon pit 14, and the muddy water falls into the muddy pit 15. On the way, suspended solids are removed and guided to the muddy water suction pit 16. The muddy water is sent to the drill pipe 3 by the aforementioned muddy water pump 5 and used as drilling fluid again.

As mentioned above, while drilling without circulating drilling fluid using the conventional flow line device 9, the pit 4 at the tip of the drill pipe encounters a crack in the stratum where geothermal fluid exists. and mud separator 12 as mentioned above.
If the geothermal fluid blows out more violently, the excavation is continued by immediately switching to the inventive flow line device 17.

The flow line device 17 according to the invention includes a conduit 18, a discharge ff119. Consisting of a pit 20, its conduit 1817,
) - Drilling fluid outlet 2 of end cover box 21
2 through a pulp 23, and by opening this pulp 23 and closing the pulp IO provided in the path of the drilling fluid during normal operation, the flow line device 9 of the present invention is connected to the flow line device 9 of the present invention. It is switched to the flow line device 17. A discharge portion 19 is provided at the end of the pipe line 18 .

The discharge part 19 was provided at an appropriate position near the excavator 2. It is placed underwater in a pit 20 which has sufficient water tv. Further, as shown in FIGS. 1 and 2, the discharge section 19 is formed by combining perforated pipes 24, 24, 24 having a large number of holes into an H-shape, and a pedestal 2 placed at the bottom of the pit 20.
5.25 is held by a weight 26.26.26φ26. Note that the pipe line 18. The discharge portion 19 and the like are formed of a material having heat resistance and pressure resistance, such as a steel pipe. In addition, the shape of the discharge part 19 and the dimensions of each part, the diameter of the perforated pipe 24, the size and number of holes, the dimensions of the pit 200, the water depth tJP, and the position where the discharge part 19 is placed in the pit 20. (That is, the distance between the discharge part 19 and the blowing surface of the pit 20 and the water surface) etc. are determined in consideration of the expected ejection pressure, ejection amount, etc. of the artesian geothermal fluid.

With the above configuration, the flow line device 7117 guides the self-spouting geothermal fluid to the t-pit 20 and jets it out into the water from the many holes of the discharge part 19.

In addition to dispersing the geothermal fluid finely and weakening its force,
The water cools the geothermal fluid, and the head pressure of the water applied to the discharge part 19 decreases against the ejection pressure of the geothermal fluid, which sufficiently weakens the force of the geothermal fluid compared to when the geothermal fluid is ejected directly into the atmosphere. In addition, since the excavated debris discharged from each part of the discharge section 9 at the same time 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 pipe 16. Because it doesn't, water supply device 2
Water is replenished by Step 7 to ensure the amount of muddy water necessary for excavation. In addition, the capacity of the pit 20I7) should be sufficient to allow for the amount of geothermal fluid (hot water) and drilling fluid (mud water) that will flow into it, or the overflow should be prevented by appropriate means such as installing a drainage pump. It's fine if you just say.

In this way, when the flowline device 17 according to the present invention is used in an excavation system, even when geothermal fluid self-injects, switching from the conventional flowline device 9 to the flowline device +7 of the present invention can solve the problem normally. Can drill & d at time and colleagues.

Although an embodiment of the IM according to the present invention and an excavation system using the same have been described above, the present invention is not limited to the above-mentioned embodiments (the shape of the discharge lti portion 19, etc. Numerous applications are possible in order to correspond to fluid pressure, temperature, volume, etc.Also, even if the excavation system uses an inventive method, a Bonzo suction pit'iff is provided in a part of the pit 20, and a If it is arranged so that the supernatant water of the muddy water flows in (that is, if the functions of the conventional muddy water pit 15 and muddy water suction pit 16 are added), the flow line device ft+7 of the present invention can be used even during normal excavation. .

Mud separator 12. Devices such as the fail shaker 13 can be made unnecessary.

(Effect of the invention) As explained in detail above, in drilling geothermal wells,
According to the present invention, by using a W4 device that is easy to construct and inexpensive, even in situations where geothermal fluid self-injects, it is possible to weaken the force of the ejection of geothermal fluid and reduce the impact on the surroundings (because it is possible to continue drilling safely. It has effective effects such as:

[Brief explanation of drawings]

1 and 2 are schematic configuration diagrams of an embodiment of the present invention, in which the first figure is a plan view and the second figure is a front sectional view. 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. 19...Discharge part, 20...Pit.

Claims (1)

[Claims] Attached to a drilling machine that excavates while discharging drilling fluid such as mud from a drilling well along with drilling debris, the drilling fluid discharged from the drilling well is guided through a pipe and the drilling debris is separated from the drilling fluid. A flow line device for artesian drilling of a geothermal well, characterized in that a pit for holding water is provided, and a discharge section for discharging drilling fluid provided in the pipe is provided in water in the pit. .