阅读说明：本技术 一种伞状地热井除垢装置及其除垢方法 (Umbrella-shaped geothermal well descaling device and descaling method thereof ) 是由 郤保平 何水鑫 董赟盛 辛国旭 杨欣欣 曹钰 尚思远 于 2021-07-08 设计创作，主要内容包括：本发明涉及一种伞状地热井除垢装置及其除垢方法,属于地热能开发领域。本伞状地热井除垢装置主要包括三部分：井下除垢系统,管道系统和地面辅助系统,井下除垢系统主要包括骨架、高强度透水布、弹簧机构及可替换的刀头；管道系统包括空心钻杆、注药主管道、注药支管道和由注药管道与空心钻杆之间的环状空隙组成的抽采通道；地面辅助系统包括钻机、注药泵、抽采泵和过滤装置。本发明将化学除垢方法与机械除垢方法进行结合,提高了钙垢清除的效率,采用伞状结构和抽采通道的有机组合实现了钙垢碎渣的抽采,避免了由于钙垢自由沉积导致的井段堵塞,具有较高实用价值与经济效益。(The invention relates to an umbrella-shaped geothermal well descaling device and a descaling method thereof, belonging to the field of geothermal energy development. The umbrella-shaped geothermal well descaling device mainly comprises three parts: the underground descaling system mainly comprises a framework, high-strength permeable cloth, a spring mechanism and a replaceable cutter head; the pipeline system comprises a hollow drill rod, a main medicine injection pipeline, a branch medicine injection pipeline and an extraction channel consisting of an annular gap between the medicine injection pipeline and the hollow drill rod; the ground auxiliary system comprises a drilling machine, a medicine injection pump, an extraction pump and a filtering device. The invention combines the chemical descaling method and the mechanical descaling method, improves the efficiency of calcium scale removal, realizes the extraction of calcium scale broken slag by adopting the organic combination of the umbrella-shaped structure and the extraction channel, avoids well section blockage caused by the free deposition of the calcium scale, and has higher practical value and economic benefit.)

1. The utility model provides an umbelliform geothermal well scale removal device, it includes underground scale removal system, pipe-line system and ground auxiliary system, its characterized in that:

the pipeline system (200) comprises a hollow drill rod (201), a main injection pipeline (202), a branch injection pipeline (203), an extraction channel (204), a lower annular joint (205) and an upper annular joint (206), wherein the upper end opening position of the hollow drill rod (201) is movably connected with a closed end head (207) through the upper annular joint (206), a plurality of extraction holes (208) are formed in the lower end face of the hollow drill rod (201), and the lower annular joint (205) is arranged below the hollow drill rod (201); the main medicine injection pipeline (202) sequentially penetrates through the closed end (207) and the hollow drill rod (201) from top to bottom, the axis direction of the main medicine injection pipeline (202) is collinear with the axis direction of the hollow drill rod (201), the main medicine injection pipeline (202) is fixedly connected with the closed end (207), the main medicine injection pipeline (202) and the closed end (207) are kept static when the hollow drill rod (201) rotates, the main medicine injection pipeline (202) outside the hollow drill rod (201) is communicated with the lower annular joint (205), and an annular gap part between the main medicine injection pipeline (202) and the hollow drill rod (201) is set as an extraction channel (204);

the underground descaling system (100) comprises frameworks (101), spring mechanisms (102), high-strength permeable cloth (103) and tool bits (104), wherein the frameworks (101) are uniformly distributed at the bottom of a hollow drill rod (201) along the circumferential direction, the root of the framework (101) is hinged with the bottom of the hollow drill rod (201), the framework (101) is arranged obliquely upwards, a medicine injection branch pipeline (203) is arranged in the framework (101) along the axial direction of the framework, and the medicine injection branch pipeline (203) is communicated with a main medicine injection pipeline (202) through a lower annular joint (205); the tool bit (104) is respectively installed at the free end of the framework (101), the tool bit (104) is provided with a medicine spraying hole (105), the medicine spraying hole (105) is communicated with the medicine injection branch pipe (203), a fan-shaped area between adjacent frameworks (101) is provided with high-strength permeable cloth (103), the spring mechanisms (102) are respectively arranged between the hollow drill rod (201) and the corresponding frameworks (101), and the spring mechanisms (102) drive the tool bit (104) through the frameworks (101) to always press the inner wall of the geothermal well (1);

the ground auxiliary system comprises a drilling machine (301), a medicine injection pump (302), an extraction pump (303) and a filtering device (304), wherein the medicine injection pump (302) is communicated with the upper end of a main medicine injection pipeline (202) through a pipeline, the extraction pump (303) is communicated with the upper part of an extraction channel (204) through a pipeline, and the filtering device (304) is arranged on the pipeline through which the extraction pump (303) is communicated with the extraction channel.

2. An umbrella-shaped geothermal well descaling device according to claim 1, wherein: the length L of the framework (101) is not less than the radius of the geothermal well (1).

3. An umbrella-shaped geothermal well descaling device according to claim 1, wherein: the cutting edge of the cutter head (104) is obliquely and upwards arranged, and a saw-toothed notch is formed in the position of the cutting edge.

4. The descaling method for the umbrella-shaped geothermal well descaling device according to claim 1, comprising the following steps of:

s1, stopping production of the geothermal well (1), determining the maximum depth H of a well wall calcium scale attachment area (2) in the geothermal well (1) by using a logging camera, manufacturing a pipeline system (200) according to the maximum depth H, enabling the lengths of a hollow drill rod (201), an extraction channel (204) and a main drug injection pipeline (202) in the pipeline system (200) to be not less than 1.2 times of H, averagely dividing the hollow drill rod (201) and the main drug injection pipeline (202) into N sections according to actual conditions, and performing main pipeline section prefabrication on hollow drill rod monomers and drug injection pipeline monomers according to the length of each section as 1.2H/N, wherein 10m is not more than 1.2H/N and not more than 20m, a threaded interface is reserved at the connection position of adjacent hollow drill rod monomers, and a threaded interface is reserved at the connection position of adjacent main drug injection pipeline monomers;

s2, firstly, hinging the framework (101) to the lower part of the first section of hollow drill rod monomer, and communicating the first section of main drug injection pipeline monomer with a branch drug injection pipeline (203); then, the drilling machine (301) grips the first section of the hollow drill rod single body to ensure that the central shaft of the first section of the hollow drill rod single body, the central shaft of the underground descaling system (100) and the central shaft of the geothermal well (1) are collinear; finally, the drilling machine (301) grips the first section of hollow drill rod monomer to move downwards, so that the first section of hollow drill rod monomer, the first section of main medicine injection pipeline monomer and the underground descaling system (100) enter the geothermal well (1) from the well mouth;

s3, hoisting the main medicine injection pipe and the hollow drill rod:

A. hoisting the second section of the main drug injection pipeline monomer prefabricated in the step S1 to the position above the first section of the main drug injection pipeline monomer, connecting the second section of the main drug injection pipeline monomer and the first section of the main drug injection pipeline monomer through a threaded interface in a threaded manner, and sealing the joint;

B. hoisting the second section of hollow drill rod monomer prefabricated in the step S1 to the position above the first section of hollow drill rod monomer, connecting the second section of hollow drill rod monomer and the first section of hollow drill rod monomer through a threaded connector, and sealing the joint; then, the drilling machine (301) loosens the first section of hollow drill rod monomer, moves upwards and grips the second section of hollow drill rod monomer, and drives the underground descaling system (100) to move downwards;

C. the steps A-B are sequentially and repeatedly executed, the remaining main medicine injection pipeline monomers and the hollow drill rod monomers are sequentially connected end to end, the preparation of the pipeline system (200) is completed, and meanwhile, the underground descaling system (100) and the pipeline system (200) are moved to preset positions;

s4, in the process that the underground descaling system (100) and the pipeline system (200) are gradually descended in the geothermal well (1) in the step S3: firstly, when the underground descaling device (100) just starts to enter the geothermal well (1), the cutting tool bit (104) clings to the well wall to descend; then, the cutting tool bit (104) descends into the calcium scale generation area (2), the calcium scale compresses the spring mechanism (102) through the compression framework (101), and the high-strength water-permeable cloth (103) retracts inwards; finally, the tool bit (104) crosses the calcium scale generation area (2), the spring mechanism (102) resets and moves to drive the framework (101) and the high-strength water-permeable cloth (103) to expand outwards and restore to the initial state, the tool bit (104) is tightly attached to the well wall again, and the underground descaling system (100) reaches a preset position;

s5, completing the connection of the injection pump (302), the extraction pump (303), the filtering device (304) and the closed end (207) with the pipeline system (200), preparing a chemical descaling agent on the ground in advance, and starting the ground auxiliary system (300); firstly, a chemical descaling agent is pumped into a main drug injection pipeline (202) by a drug injection pump (302), transported along a branch drug injection pipeline (203) and sprayed out from a spraying hole (105) to a calcium scale generation area (2) on a well wall; then, a drilling machine (301) drives the underground descaling system (100) to rotate and ascend through a hollow drill rod (201), a tool bit (104) cuts and removes calcium scale at the position of a calcium scale generation area (2) in the process of rotating and ascending along the well wall, meanwhile, an extraction pump (303) is started, the cut calcium scale broken slag is upwards discharged out of a shaft along an extraction channel (204) under the action of the extraction pump (303), the calcium scale broken slag is filtered by a filtering device (304) and then is subjected to centralized harmless treatment, and tail water is poured back into the geothermal well (1);

s6, the drilling machine (301) lifts the underground descaling system (100) to leave the geothermal well (1) through the hollow drill rod (201), the calcium scale removing operation is completed, the ground auxiliary system (300) is closed, the umbrella-shaped geothermal well descaling device is removed, and the normal production of the geothermal well (1) is recovered.

Technical Field

The invention belongs to the technical field of geothermal energy development, and particularly relates to an umbrella-shaped geothermal well descaling device and a descaling method thereof.

Background

Geothermal energy is clean energy with great reserves and wide distribution range, and has very high utilization value. The hot dry rock geothermal resource is one of geothermal resources, and compared with a hydrothermal geothermal resource, the hot dry rock geothermal resource is more stable and higher in temperature, and is more suitable for realizing the design of stable power generation. But the defect is that the buried depth is large, and the current main development means is to drill a production well and an injection well according to a certain distance and manufacture an artificial heat reservoir by means of hydraulic fracturing and the like. After the cold water injected from the injection well is heated by the heat reservoir, high-temperature water and steam can be produced in the production well for power generation and heating.

In the process of extracting geothermal energy, the well wall is easy to generate calcium scale, and the principle that the well wall generates calcium scale is as follows: when the geothermal fluid rises to the position near the wellhead of the production well, the pressure is rapidly reduced, the flash evaporation phenomenon occurs, and CO dissolved in the fluid₂Quickly released into air and Ca in fluid²⁺Concentration and CO₃ ^2-The product of the concentrations being greater than CaCO₃Solubility product of (C) so that CaCO₃Calcium scale is precipitated from the fluid and attached to the well wall to form calcium scale, and the depth of the calcium scale is generally within the range of 100m below the well head through principle analysis.

The large amount of calcium scale is attached to the surface of the well wall, so that the diameter of the well shaft of the production well is reduced, the temperature of high-temperature water is reduced, the flow is reduced, and the production well is blocked and even scrapped. The current conventional method for removing calcium scale from well walls is to inject chemicals into the production well or to remove the scale by physical methods. However, since the position of the generated calcium scale is far away from the earth surface, the efficiency of removing the deep calcium scale by using a mechanical descaling method is low, and the calcium scale removed from the inner wall of the production well can continue to deposit downwards, possibly plugging part of the well section of the production well. Meanwhile, the generation position of the calcium scale is far away from the earth surface, when the scale is removed by adopting a method of injecting chemical drugs, the uniformity of drug distribution is largely uncontrolled, and the dosage of the injected drugs is increased to increase extra economic cost. Therefore, it is urgent to find a new device and method for removing calcium scale from geothermal well, which can rapidly complete the descaling operation of geothermal well and will not cause the blockage of well section.

Disclosure of Invention

The invention provides an umbrella-shaped geothermal well descaling device and a descaling method thereof, aiming at overcoming the defects of the prior art and solving the technical problem of mechanical descaling in a geothermal well.

The invention is realized by the following technical scheme.

An umbelliform geothermal well scale removal device, it includes scale removal system, piping system and ground auxiliary system in the pit, wherein:

the pipeline system comprises a hollow drill rod, a main medicine injection pipeline, a branch medicine injection pipeline, an extraction channel, a lower annular joint and an upper annular joint, wherein the open position at the upper end of the hollow drill rod is movably connected with the closed end through the upper annular joint; the main medicine injection pipeline sequentially penetrates through the closed end and the hollow drill rod from top to bottom, the axis direction of the main medicine injection pipeline is collinear with the axis direction of the hollow drill rod, the main medicine injection pipeline is fixedly connected with the closed end, the main medicine injection pipeline and the closed end are kept static when the hollow drill rod rotates, the main medicine injection pipeline outside the hollow drill rod is communicated with the lower annular joint, and an annular gap part between the main medicine injection pipeline and the hollow drill rod is arranged as an extraction channel;

the underground descaling system comprises a framework, a spring mechanism, high-strength permeable cloth and a tool bit, wherein the framework is made of high-strength steel, a plurality of frameworks are uniformly distributed at the bottom of the hollow drill rod along the circumferential direction, the root of the framework is hinged with the bottom of the hollow drill rod, the framework is obliquely and upwards arranged, the framework is driven to synchronously rotate by the rotation of the hollow drill rod, a medicine injection branch pipeline is arranged in the framework along the axis direction of the framework, and the medicine injection branch pipeline is communicated with a main medicine injection pipeline through a lower annular joint, so that the overall sealing effect of the pipeline is ensured, and meanwhile, the main medicine injection pipeline and the medicine injection branch pipeline can relatively rotate; the tool bit is respectively arranged at the free end of the framework, the tool bit is connected with the framework in an assembling way and can be replaced, the tool bit is provided with a pesticide spraying hole which is communicated with the pesticide injection branch pipeline, and when a pesticide injection pump is adopted to pump chemical descaling agent into the pesticide injection main pipeline, the chemical descaling agent can be sprayed upwards from the pesticide spraying hole on the tool bit and towards the well wall; the fan-shaped area between the adjacent frameworks is provided with high-strength permeable cloth, the edges of the high-strength permeable cloth are fixedly connected with the upper surfaces of the frameworks at two sides, and when the frameworks are in a contraction state, the high-strength permeable cloth is folded and contracted to a certain extent; when the framework is opened, the high-strength water-permeable cloth is also opened, and the projection area of the high-strength water-permeable cloth on the horizontal plane is basically the same as the area of the shaft. Therefore, the calcium scale stripped from the well wall falls on the high-strength water permeable cloth, so that the subsequent extraction treatment is facilitated, and the well section blocking phenomenon possibly caused by free sinking of the calcium scale is avoided. The spring mechanisms are respectively arranged between the hollow drill rods and the corresponding frameworks, the spring mechanisms drive the tool bits to always press the inner walls of the geothermal wells through the frameworks, and the spring mechanisms can ensure that the frameworks and the high-strength water-permeable cloth are fully opened after the umbrella-shaped geothermal well descaling device is lowered to a specified position in a shaft, so that the tool bits are tightly attached to the wall of the shaft;

the ground auxiliary system comprises a drilling machine, a medicine injection pump, an extraction pump and a filtering device, wherein the drilling machine can hold the hollow drill rod tightly, so that the drilling machine and the hollow drill rod are tightly combined, and the vertical movement and power output of the pipeline system and the underground descaling system are realized. The hollow drill rod can also be loosened, so that the hollow drill rod and the drilling machine can move relatively, and the pipeline system can be prolonged. The extraction pump is connected with the extraction channel through a filtering device, and the extraction pump, the filtering device and the extraction pipeline are connected to pump out and filter the removed calcium scale from the geothermal well.

Further, the length L of the framework is not less than the radius of the geothermal well.

Furthermore, the cutting edge of the cutter head is obliquely and upwards arranged, and a saw-toothed notch is formed in the position of the cutting edge.

A descaling method of an umbrella-shaped geothermal well descaling device comprises the following steps:

s1, stopping production of the geothermal well, determining the maximum depth H of a well wall calcium scale attachment area in the geothermal well by using a logging camera, manufacturing a pipeline system according to the maximum depth H, enabling the lengths of a hollow drill rod, an extraction channel and a main drug injection pipeline in the pipeline system to be not less than 1.2 times of H, averagely dividing the hollow drill rod and the main drug injection pipeline into N sections according to actual conditions, and performing pipe section prefabrication on a hollow drill rod monomer and a main drug injection pipeline monomer according to the length of each section as 1.2H/N, wherein the length of each section is not less than 10m and not more than 1.2H/N and not more than 20m, reserving a threaded interface at the joint of adjacent hollow drill rod monomers, and reserving a threaded interface at the joint of adjacent main drug injection pipeline monomers;

s2, firstly, hinging the framework to the lower part of the first section of hollow drill rod monomer, and communicating the first section of main drug injection pipeline monomer with a branch drug injection pipeline; then, the drilling machine grips the first section of the hollow drill rod single body tightly to ensure that the central shaft of the first section of the hollow drill rod single body, the central shaft of the underground descaling system and the central shaft of the geothermal well are collinear; finally, the drilling machine grips the first section of hollow drill rod monomer to move downwards, so that the first section of hollow drill rod monomer, the first section of main medicine injection pipeline monomer and the underground descaling system enter the geothermal well from the well mouth;

s3, hoisting the main medicine injection pipe and the hollow drill rod:

A. hoisting the second section of the main drug injection pipeline monomer prefabricated in the step S1 to the position above the first section of the main drug injection pipeline monomer, connecting the second section of the main drug injection pipeline monomer and the first section of the main drug injection pipeline monomer through a threaded interface in a threaded manner, and sealing the joint;

B. hoisting the second section of hollow drill rod monomer prefabricated in the step S1 to the position above the first section of hollow drill rod monomer, connecting the second section of hollow drill rod monomer and the first section of hollow drill rod monomer through a threaded connector, and sealing the joint; then, the drilling machine loosens the first section of hollow drill rod monomer, moves upwards and grips the second section of hollow drill rod monomer, and drives the underground descaling system to move downwards;

C. sequentially and repeatedly executing the steps A-B, sequentially connecting the rest main medicine injection pipeline monomers and the hollow drill rod monomers end to end, completing the preparation of a pipeline system, and simultaneously moving the underground descaling system and the pipeline system to preset positions;

s4, in the process that the underground descaling system and the pipeline system are gradually descended in the geothermal well in the step S3: firstly, when the underground descaling device just starts to enter a geothermal well, a cutting tool bit is tightly attached to a well wall to descend; then, the cutting tool bit is lowered into a calcium scale generation area, the calcium scale compresses a spring mechanism through a compression framework, and the high-strength water-permeable cloth is retracted inwards; finally, the cutter head crosses a calcium scale generation area, the spring mechanism resets to move to drive the framework and the high-strength water-permeable cloth to expand outwards and restore to an initial state, the cutter head is tightly attached to the well wall again, and the underground descaling system reaches a preset position;

s5, completing connection of the injection pump, the extraction pump, the filtering device and the closed end head with a pipeline system, preparing a chemical descaling agent on the ground in advance, and starting a ground auxiliary system; firstly, pumping a chemical descaling agent into a main drug injection pipeline by a drug injection pump, transporting the chemical descaling agent along a branch drug injection pipeline, and spraying the chemical descaling agent to a calcium scale generation area on a well wall from a drug spraying hole; then, the drilling machine drives the underground descaling system to rotate and rise through the hollow drill rod, the cutter head cuts and removes calcium scale at the position of a calcium scale generation area in the process of rotating and rising along the well wall, meanwhile, the extraction pump is started, the cut calcium scale broken slag is upwards discharged out of the shaft along the extraction channel under the action of the extraction pump, the calcium scale broken slag is filtered by the filtering device and then is subjected to centralized harmless treatment, and tail water is back-poured into the geothermal well;

s6, the drilling machine lifts the underground descaling system to a position away from the geothermal well through the hollow drill rod, the calcium scale removing operation is completed, the ground auxiliary system is closed, the umbrella-shaped geothermal well descaling device is removed, and normal production of the geothermal well is recovered.

Compared with the prior art, the invention has the beneficial effects that:

1. the method can improve the descaling speed of the geothermal well, improve the descaling effect of the geothermal well, and simultaneously can avoid the damage to the shaft of the geothermal well caused by the pure mechanical descaling;

2. the invention can collect the calcium scale stripped from the well wall and discharge the calcium scale out of the geothermal well, thereby avoiding the consequences that the stripped calcium scale is freely deposited downwards and even blocks part of the well section due to the adoption of a common mechanical descaling method;

3. the device has a simple structure, and can be suitable for the descaling work of geothermal wells with different sizes.

Drawings

FIG. 1 is a schematic top view of an umbrella-shaped geothermal well descaling device;

FIG. 2 is a schematic sectional view taken along the line A-A in FIG. 1;

FIG. 3 is a schematic cross-sectional view taken along the plane B-B in FIG. 1;

FIG. 4 is a perspective view of the assembly structure of the cutter head and the frame;

FIG. 5 is a schematic view of the opening of the bottom of the hollow drill rod;

FIG. 6 is a schematic view of the connection of the lower annular joint with the main drug injection pipe and the branch drug injection pipe;

FIG. 7 is a schematic view of the connection of the upper annular adaptor to the closed end and the hollow drill rod;

FIG. 8 is a flow chart of the process of using the umbrella-shaped geothermal well descaling device;

in the present application, all the figures are schematic drawings, which are only intended to illustrate the inventive principle and are not drawn to scale.

In the figure, 100 downhole descaling systems, 200 piping systems, and 300 surface auxiliary systems are shown; 1 is a geothermal well; 2 is a calcium scale adhesion area of the well wall;

101 is a framework; 102 is a spring device; 103 is high-strength permeable cloth; 104 is a cutter head; 105 is a spraying hole;

201 is a hollow drill rod; 202 is a main medicine injection pipeline, and 203 is a branch medicine injection pipeline; 204 is an extraction channel; 205 is a lower annular joint; 206 is an upper annular joint; 207 is a closed end, and 208 is an extraction hole;

301 is a drilling machine; 302 is a drug injection pump; 303, an extraction pump; 304 is a filter device.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention. Unless otherwise specified, the examples follow conventional experimental conditions.

An umbrella-shaped geothermal well descaling device as shown in fig. 1 to 7 comprises a downhole descaling system, a pipeline system and a surface auxiliary system, wherein:

the pipeline system 200 comprises a hollow drill rod 201, a main injection pipeline 202, a branch injection pipeline 203, an extraction channel 204, a lower annular joint 205 and an upper annular joint 206, wherein the open position of the upper end of the hollow drill rod 201 is movably connected with a closed end 207 through the upper annular joint 206, a plurality of extraction holes 208 are formed in the lower end face of the hollow drill rod 201, and the lower annular joint 205 is arranged below the hollow drill rod 201; the main medicine injection pipeline 202 sequentially penetrates through the closed end 207 and the hollow drill rod 201 from top to bottom, the axial direction of the main medicine injection pipeline 202 is collinear with the axial direction of the hollow drill rod 201, the main medicine injection pipeline 202 is fixedly connected with the closed end 207, the main medicine injection pipeline 202 and the closed end 207 are kept static when the hollow drill rod 201 rotates, the main medicine injection pipeline 202 outside the hollow drill rod 201 is communicated with the lower annular joint 205, and an annular gap part between the main medicine injection pipeline 202 and the hollow drill rod 201 is set as an extraction channel 204;

the underground descaling system 100 comprises frameworks 101, a spring mechanism 102, high-strength permeable cloth 103 and a cutter head 104, wherein a plurality of frameworks 101 are uniformly distributed at the bottom of a hollow drill rod 201 along the circumferential direction, the root parts of the frameworks 101 are hinged with the bottom of the hollow drill rod 201, the frameworks 101 are obliquely and upwards arranged, a chemical injection branch pipe 203 is arranged in the frameworks 101 along the axial direction of the frameworks, and the chemical injection branch pipe 203 is communicated with a chemical injection main pipe 202 through a lower annular joint 205; the tool bits 104 are respectively arranged at the free ends of the frameworks 101, the tool bits 104 are provided with medicine spraying holes 105, the medicine spraying holes 105 are communicated with the medicine injection branch pipes 203, the sector areas between the adjacent frameworks 101 are provided with high-strength water-permeable cloth 103, the spring mechanisms 102 are respectively arranged between the hollow drill rods 201 and the corresponding frameworks 101, and the spring mechanisms 102 drive the tool bits 104 to always press the inner walls of the geothermal wells 1 through the frameworks 101;

the ground auxiliary system comprises a drilling machine 301, a medicine injection pump 302, an extraction pump 303 and a filtering device 304, wherein the medicine injection pump 302 is communicated with the upper end of a main medicine injection pipeline 202 through a pipeline, the extraction pump 303 is communicated with the upper part of an extraction channel 204 through a pipeline, and the filtering device 304 is arranged on the pipeline through which the extraction pump 303 is communicated with the extraction channel.

Fig. 4 illustrates only one form of the cutting head 104, and any cutting head that can effect the cutting of calcium scale while releasing chemical descaling agents into the well wall is within the scope of the present invention.

Further, the length L of the framework 101 is not less than the radius of the geothermal well 1.

Further, the cutting edge of the cutter head 104 is disposed obliquely upward, and a saw-toothed notch is disposed at the cutting edge.

Fig. 8 shows a descaling method of the umbrella-shaped geothermal well descaling device, which comprises the following steps:

s1, stopping production of the geothermal well 1, determining the maximum depth H of a well wall calcium scale adhesion area 2 in the geothermal well 1 by using a logging camera, manufacturing a pipeline system 200 according to the maximum depth H, enabling the lengths of a hollow drill rod 201, an extraction channel 204 and a main drug injection pipeline 202 in the pipeline system 200 to be not less than 1.2 times of H, averagely dividing the hollow drill rod 201 and the main drug injection pipeline 202 into N sections according to actual conditions, and performing pipe section prefabrication on of a hollow drill rod monomer and a main drug injection pipeline monomer according to the length of each section as 1.2H/N, wherein 10m is not more than 1.2H/N is not more than 20m, a threaded interface is reserved at the joint of adjacent hollow drill rod monomers, and a threaded interface is reserved at the joint of adjacent main drug injection pipeline monomers;

s2, firstly, hinging the framework 101 to the lower part of the first section of hollow drill rod monomer, and communicating the first section of main drug injection pipeline monomer with the branch drug injection pipeline 203; then, the drilling machine 301 grips the first section of the hollow drill rod single body to ensure that the central shaft of the first section of the hollow drill rod single body, the central shaft of the underground descaling system 100 and the central shaft of the geothermal well 1 are collinear; finally, the drilling machine 301 grips the first section of hollow drill rod monomer to move downwards, so that the first section of hollow drill rod monomer, the first section of main medicine injection pipeline monomer and the underground descaling system 100 enter the geothermal well 1 from a well mouth;

s3, hoisting the main medicine injection pipe and the hollow drill rod:

A. hoisting the second section of the main drug injection pipeline monomer prefabricated in the step S1 to the position above the first section of the main drug injection pipeline monomer, connecting the second section of the main drug injection pipeline monomer and the first section of the main drug injection pipeline monomer through a threaded interface in a threaded manner, and sealing the joint;

B. hoisting the second section of hollow drill rod monomer prefabricated in the step S1 to the position above the first section of hollow drill rod monomer, connecting the second section of hollow drill rod monomer and the first section of hollow drill rod monomer through a threaded connector, and sealing the joint; then, the drilling machine 301 loosens the first section of hollow drill rod monomer, moves upwards and grips the second section of hollow drill rod monomer, and drives the underground descaling system 100 to move downwards;

C. sequentially and repeatedly executing the steps A-B, sequentially connecting the rest main medicine injection pipeline monomers and the hollow drill rod monomers end to end, completing the preparation of the pipeline system 200, and simultaneously moving the underground descaling system 100 and the pipeline system 200 to preset positions;

s4, in the process that the downhole descaling system 100 and the pipeline system 200 are gradually lowered in the geothermal well 1 in the step S3: firstly, when the underground descaling device 100 just starts to enter the geothermal well 1, the cutting tool bit 104 is tightly attached to the well wall to descend; then, the cutting bit 104 is lowered into the limescale production area 2, the limescale compresses the spring mechanism 102 through the compression framework 101, and the high-strength water-permeable cloth 103 is retracted inward; finally, the cutter head 104 crosses the calcium scale generation area 2, the spring mechanism 102 resets and moves to drive the framework 101 and the high-strength water-permeable cloth 103 to expand outwards and restore to the initial state, the cutter head 104 is tightly attached to the well wall again, and the underground descaling system 100 reaches a preset position;

s5, completing the connection of the injection pump 302, the extraction pump 303, the filtering device 304 and the closed end 207 with the pipeline system 200, preparing a chemical descaling agent on the ground in advance, and starting the ground auxiliary system 300; firstly, a chemical descaling agent is pumped into the main chemical injection pipeline 202 by the chemical injection pump 302, is transported along the branch chemical injection pipeline 203 and is sprayed out of the spray holes 105 to the well wall calcium scale generation area 2; then, the drilling machine 301 drives the underground descaling system 100 to rotate and ascend through the hollow drill rod 201, the cutter head 104 cuts and removes calcium scale at the position of the calcium scale generation area 2 in the process of rotating and ascending along the well wall, meanwhile, the extraction pump 303 is started, the cut calcium scale broken slag is upwards discharged out of the shaft along the extraction channel 204 under the action of the extraction pump 303, the calcium scale broken slag is filtered by the filtering device 304 and then is subjected to centralized harmless treatment, and tail water is back poured into the geothermal well 1;

s6, the drilling machine 301 lifts the underground descaling system 100 to leave the geothermal well 1 through the hollow drill rod 201, the calcium scale cleaning operation is completed, the ground auxiliary system 300 is closed, the umbrella-shaped geothermal well descaling device is removed, and normal production of the geothermal well 1 is recovered.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.