JPH05195684A - Chemical grouting tube fitting structure for geothermal steam well - Google Patents

Abstract

PURPOSE:To simply lift or lower a pipe in a geothermal well. CONSTITUTION:A lubricator 4 is fitted to the tip of a rise pipe 2 on the pit mouth of a geothermal steam well 1 via an auxiliary valve 3, and a line wiper 5 is fitted to its tip. A chemical grouting tube 6 is constituted of a coil tube 7 and a nozzle 8, the coil tube 7 is inserted from the center section of the line wiper 5, and it is inserted into an air lift pipe 9 fitted at the lower end of the auxiliary valve 3 and suspended in the geothermal well 1. The coil tube 7 of the chemical grouting tube 6 is wound on a winch 13 so that it can be freely lifted or lowered in the geothermal well 1 by the rotation of the winch 13. The nozzle 8 is finely formed at the tip section via a step section 11, and multiple grooves 12 are formed along the axis on the step section 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting a chemical injection pipe in a geothermal steam well, and more particularly to a structure for mounting a chemical injection pipe in a hot water type geothermal steam well accompanied by hot water.

[0002]

2. Description of the Related Art In a hot water type geothermal steam well, a considerable amount of alkaline earth metal is dissolved in the underground high temperature and high pressure geothermal fluid. Alkaline earth metal precipitates as carbonates and the like, which adheres to the geothermal steam well as a scale, which results in insufficient collection of geothermal fluid, and in extreme cases, the geothermal steam well may be blocked.

In order to prevent the scale from adhering, the applicant of the present invention extends a chemical injection pipe having an upper portion fixed by a seal flange in a geothermal steam well to a position below the flushing point to inject a chemical for scale prevention, We proposed a method to prevent alkaline earth metals in hot water from precipitating as carbonates by diffusing the scale-preventing agent directly into the underground geothermal fluid from the tip of the injection pipe ( Japanese Patent Fair 1-1952
No. 0).

[0004]

When the above-mentioned chemical injection pipe is constructed in a geothermal steam well, the production of steam in the geothermal steam well is stopped and the pipe for the chemical injection pipe (for example, the outer diameter; 33.4 mm, length: 9.3 m / piece, weight: 6.5 kg / piece) were connected one by one, and the pipe was lowered to an arbitrary depth.

Further, it is necessary to periodically log the temperature and pressure of the geothermal steam well, and in such a case, it was necessary to remove one by one while pulling up the chemical injection pipe.

However, the work of raising and lowering the chemical injection pipe in the geothermal steam well has poor workability and the production of steam in the geothermal steam well must be stopped, resulting in a stable supply of steam for geothermal power generation. As a result, there was a problem that it hindered the steady operation of geothermal power generation. The present invention is to solve the problems that the conventional chemical injection pipes have as described above.

[0007]

According to the present invention, a chemical injection pipe hung from the upper part of a well of a geothermal steam well into the well comprises a nozzle having a coil tube and a step having a narrow tip. The nozzle is inserted inside the air lift pipe attached below the sub valve, and the narrow part of the nozzle tip can protrude below the tip of the air lift pipe. On the other hand, the coil tube is inserted into the well through the line wiper at the top of the geothermal steam well, the lubricator and the sub valve, and the nozzle is suspended vertically in the well. It has a structure of being.

[0008]

The present invention has the above-described structure. The coil tube is a flexible hollow tube, which is appropriately wound around a drum or the like, and the nozzle attached to the tip thereof also serves as a weight. When inserting the present invention into a geothermal steam well, after removing the rubber packing of two or more parts of the line wiper at the wellhead, passing the nozzle through the line wiper, and then once putting it in the lubricator longer than the nozzle. Attach the rubber packing of the line wiper to seal the coil tube. Therefore, the jetted steam is doubly blocked by the sub valve and the line wiper at the bottom of the lubricator.

When the chemical injection pipe is lowered through the air lift pipe attached to the lower portion of the sub-valve, the sub-valve is opened, but the jetted steam is blocked by the line wiper. , No steam will blow out. Further, the chemical injection pipe of the present invention can be automatically lowered by the self-weight of the nozzle and the coil tube in the well if the coil tube wound in a coil on the winch is continuously fed out. When pulling up, the coil tube can be easily pulled up by rewinding it to the winch.

When the chemical injection pipe is pulled up, the sub valve is opened and pulled up. At this time, since the vapor is sealed by the line wiper, it is possible to pull up the chemical injection pipe without ejecting the vapor. It is safe because it can.

When the nozzle connected to the tip of the coil tube reaches the tip of the air lift pipe at a predetermined depth below the flushing point, the thin portion of the nozzle tip protrudes from the tip of the air lift pipe, and the nozzle has an air lift at the thick portion. The coil tube is fixed and suspended by the tube grip, which is locked at the lower end of the tube and is separately attached to the outside of the geothermal steam well.

On the other hand, in the air lift pipe, since the plurality of grooves formed in the step portion of the nozzle play a role for air circulation, there is no problem in applying the air lift method.
The air lift pipe can also serve as a protection pipe for protecting the chemical injection pipe from the jetted geothermal fluid.

The flushing point is the point at which the geothermal fluid is vaporized by decompression, and when hot water boils at this flushing point, the alkaline earth metal ions contained in the hot water become carbonate, etc. In order to form and precipitate, it is necessary to inject a scale inhibitor.

On the other hand, geothermal steam wells require so-called logging to regularly examine the temperature, pressure and composition of hot water of the geothermal fluid. Therefore, a temperature sensor, a pressure sensor or a hot water sampler must be installed. It is necessary to descend to the well, and therefore the measuring instrument must be raised and lowered or the chemical injection pipe must be raised and lowered each time logging is performed.

According to the present invention, since the nozzle of the chemical injection pipe is suspended from the coil tube, and the coil tube is wound around the winch, the nozzle of the chemical injection pipe can be easily raised and lowered. .. Further, when repeating the raising and lowering of the chemical injection pipe, the coil tube may be cut and dropped in the middle due to metal fatigue, but the nozzle of the present invention is caught on the tip of the air lift pipe and drops deep inside the well. Since it does not occur, there is no risk of impeding the ejection of geothermal fluid.

Further, in the present invention, since the line wiper, the lubricator and the sub valve are attached to the geothermal well pit, steam is not ejected when the chemical injection pipe is lifted and lowered, and the safety is high.

[0017]

1 to 3 show one embodiment of the present invention, the present invention will be described below with reference to these drawings. A rising pipe 2 is attached on the wellhead of the geothermal steam well 1 along the axis of the geothermal steam well 1, and a lube lubricator 4 is attached to the tip of the rising pipe 2 via a sub valve 3. A line wiper 5 is attached to the tip of the briquette 4.

On the other hand, the chemical injection pipe 6 is composed of a coil tube 7 and a nozzle 8 connected to the tip of the coil tube 7, and the coil tube 7 is inserted from the central portion of the line wiper 5 and the sub valve 3 is inserted. The tube grip 1 which is inserted into the air lift pipe 9 attached to the lower end of the geothermal steam well 1 reaches a predetermined depth below the flushing point in the geothermal steam well 1 and is attached to the outside of the geothermal steam well 1.
Suspended by 0.

The tip of the nozzle 8 attached to the lower end of the chemical injection pipe 6 has an outer diameter smaller than the outer diameter of the upper portion through the step portion 11, and the nozzle 8 is attached to the step portion 11. A plurality of grooves 12 are formed along the axis of. In addition, in FIG.
Reference numeral 13 is a winch around which the coil tube 7 is wound,
Reference numeral 14 is a main valve attached to the wellhead of the geothermal steam well 1, which is always in a fully open state, 15 is a steam pipe for transporting steam, and 16 is a sub valve attached to the steam pipe 15. Is.

To lower the medicine injection pipe 6, a winch 13 is used.
Is rewound, the coil tube 7 is drawn out, and the nozzle 8 at the tip is lowered into the well. Further, the winch 13 may be rotated in the reverse direction to wind up the coil tube 7 in order to raise the chemical injection pipe 6, the operation is simple, and the efficiency of the geothermal extraction work can be improved.

Further, since the nozzle 8 has a thin tip portion protruding from the air lift pipe 9, the chemical liquid in the chemical injection pipe 6 can be surely injected into the well. Further, since the plurality of grooves 12 are formed along the axis in the step portion 11 of the nozzle 8, there is no problem in applying the air lift method.

[0022]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, it is easy to raise and lower the chemical injection pipe into the geothermal well, and the air lift method can be easily applied. Further, the line wiper and the sub valve attached to the wellhead are provided. As a result, it is possible to prevent the geothermal fluid from being ejected when the chemical injection pipe is raised or lowered, which is advantageous in that the safety is high.

[Brief description of drawings]

FIG. 1 is an explanatory view of a well to which the present invention is attached.

FIG. 2 is an enlarged cross-sectional view of a main part of a nozzle tip portion.

FIG. 3 is a sectional view taken along line AA in FIG.

[Explanation of symbols]

 1: Geothermal steam well 2: Rise pipe 3: Sub valve 4: Lubricator 5: Line wiper 6: Chemical injection pipe 7: Coil tube 8: Nozzle 9: Air lift pipe 10: Tube grip 11: Step part 12: Groove 13 : Winch

Claims (1)

[Claims] 1. A chemical injection pipe that hangs down from the upper part of a well of a geothermal steam well into the well comprises a coil tube and a nozzle having a stepped structure with a narrow tip, and the nozzle is located under a sub valve. While being inserted into the attached air lift pipe, the thin portion of the nozzle tip can protrude below the air lift pipe tip, and a plurality of cut grooves are formed on the outer periphery of the step portion of the nozzle in the nozzle axial direction. On the other hand, the coil tube is inserted into the well through the line wiper at the top of the geothermal steam wellhead, the lubricator, and the auxiliary valve, and the nozzle is suspended vertically in the well. Geothermal steam well injection pipe mounting structure.