Central circulating pipe of mid-deep geothermal well

Abstract

The utility model discloses a central circulating pipe of a mid-deep geothermal well, and belongs to the technical field of geothermal energy exploitation equipment. A central circulating pipe of a mid-deep geothermal well comprises a pipe body, the pipe body is of a hollow cylindrical tubular structure, threaded connectors are arranged at the two ends of the pipe body respectively, a groove is spirally formed in the outer wall of the pipe body, and the included angle between the groove and the axis of the pipe body is 30 degrees. A bayonet area and a buffer area are arranged on the groove; the bayonet areas and the buffer areas are arranged at intervals; the number of the bayonet areas on each groove is at least two; the width of the bayonet area is greater than that of the groove; the diameter of the buffer area is larger than the width of the groove. According to the utility model, the temperature measuring optical fiber can be more effectively protected, the temperature measuring optical fiber is prevented from being damaged in the working process, and the stability and reliability of the geothermal well temperature measuring system are improved at the same time.

Description

Technical Field

[0001] The utility model relates to the technical field of geothermal energy mining equipment, in particular to a central circulation pipe for a medium-deep geothermal well. Background Art

[0002] Geothermal wells are devices that generate electricity from geothermal energy at depths of approximately 3,500 meters or from hot spring water with a temperature greater than 30°C. Geothermal energy is categorized into three types: high-temperature, medium-temperature, and low-temperature. High-temperature geothermal energy is defined as steam above 150°C; medium-temperature geothermal energy is defined as a mixture of water and steam between 90°C and 150°C; and low-temperature geothermal energy is defined as warm water, lukewarm water, or hot water, above 25°C and below 90°C.

[0003] With the increasing development and utilization of geothermal energy, the operational efficiency and stability of geothermal wells, as key facilities for geothermal energy extraction, have attracted increasing attention. Accurately monitoring the well's temperature is a key factor in ensuring its proper operation. Therefore, temperature-sensing optical fibers are widely used in geothermal wells to enable real-time temperature monitoring.

[0004] However, the traditional geothermal well central circulation pipe design presents several technical challenges. Specifically, it typically utilizes thick-walled tubing, with the temperature-sensing optical fiber wrapped around the outside of the pipe. While this design achieves a certain degree of well temperature monitoring, due to limitations such as the well diameter, the temperature-sensing optical fiber is susceptible to compression or scraping during lowering and operation, resulting in breakage and damage. This not only impacts the operation of the geothermal well temperature measurement system but also adds unnecessary financial and time costs associated with replacing the temperature-sensing optical fiber.

[0005] In order to solve the above problems, a new type of geothermal well central circulation pipe design is needed to more effectively protect the temperature measuring optical fiber and avoid damage during operation. Utility Model Content

[0006] The utility model is aimed at the above-mentioned problems and makes up for the shortcomings of the existing technology, and provides a central circulation pipe for a medium-deep geothermal well, including a pipe body, which is a hollow cylindrical tubular structure, with threaded connection ports provided at both ends of the pipe body, and a spiral groove provided on the outer wall of the pipe body, and the angle between the groove and the axis of the pipe body is 30°; a bayonet area and a buffer zone are provided on the groove; the bayonet area and the buffer zone are spaced apart; the number of bayonet areas on each groove is at least two; the width of the bayonet area is greater than the width of the groove; and the diameter of the buffer zone is greater than the width of the groove.

[0007] Preferably, the cross section of the groove is in the shape of a Chinese character "凵", the depth of the groove is 5mm-10mm, and the width of the groove is 5mm-10mm.

[0008] Preferably, it further comprises a metal clip, the outer wall of the metal clip is arc-shaped, an accommodating groove is provided inside the metal clip, and the metal clip is installed in the clip area by a metal adhesive.

[0009] Preferably, there are three grooves, and the three grooves are parallel to each other.

[0010] Preferably, it further comprises a temperature measuring optical fiber, which is arranged in the groove.

[0011] The beneficial effects of the utility model are as follows:

[0012] This utility model optimizes the structure of the central circulation pipe in medium-deep geothermal wells. By spirally forming grooves on the outer wall of the pipe body and simultaneously providing a bayonet area and a buffer zone within the grooves, it effectively protects the temperature-measuring optical fiber and prevents damage to the temperature-measuring optical fiber. Furthermore, this utility model optimizes the arrangement of the temperature-measuring optical fiber, thereby preventing damage to the temperature-measuring optical fiber and improving the stability and reliability of the geothermal well temperature measurement system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is one of the structural schematic diagrams of a central circulation pipe of a medium-deep geothermal well in the utility model.

[0014] Figure 2 This is the second structural schematic diagram of a central circulation pipe of a medium-deep geothermal well in the utility model.

[0015] Figure 3 This is one of the schematic diagrams of the cross section of a central circulation pipe of a medium-deep geothermal well in the utility model.

[0016] Figure 4 It is a partial schematic diagram of the cross section of a central circulation pipe of a medium-deep geothermal well according to the present invention.

[0017] Figure 5 The utility model is a structural schematic diagram of a centralizer in a central circulation pipe of a medium-deep geothermal well.

[0018] Figure 6 It is a cross-sectional schematic diagram of a temperature measuring optical fiber in a central circulation pipe of a medium-deep geothermal well according to the present invention.

[0019] Figure 7 This is one of the structural diagrams of the temperature measuring optical fiber set in the buffer zone.

[0020] Figure 8 This is the second structural diagram of the temperature measuring optical fiber arranged in the buffer zone.

[0021] Figure 9 is a schematic diagram of the diameter of the buffer zone.

[0022] Figure 10 It is a schematic diagram of the width of the bayonet area.

[0023] Markings in the figure: 1 is the tube body; 2 is the groove; 3 is the bayonet area; 4 is the temperature measuring optical fiber; 5 is the buffer zone; 6 is the internal threaded opening; 7 is the centralizer; 8 is the external threaded opening; 9 is the metal clip; 401 is the metal shell; 402 is the protective layer; 403 is the optical fiber bundle; 701 is the bow bridge support; 702 is the buckle; W1 is the width of the groove; D1 is the depth of the groove; W2 is the width of the bayonet area; D2 is the depth of the bayonet area; R is the diameter of the buffer zone. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0025] Figure 1 、 Figure 2 The overall structure of the utility model is shown, which is a central circulation pipe for a medium-deep geothermal well, including a pipe body 1. The pipe body 1 is a hollow cylindrical tubular structure. Threaded connection ports are respectively provided at both ends of the pipe body 1, one end of which is an internal threaded port 6 and the other end is an external threaded port 8. The threaded connection ports are used for interconnecting the central circulation pipes.

[0026] Figure 2 The layout of the groove 2, the bayonet area 3, and the buffer zone 5 is shown in detail. The groove 2 is spirally arranged on the outer wall of the tube 1, forming a 30° angle with the central axis of the tube 1. This design ensures that the temperature measurement optical fiber 4 measures more comprehensive and complete data within the geothermal well.

[0027] The groove 2 is provided with a bayonet area 3 and a buffer area 5; the bayonet area 3 and the buffer area 5 are spaced apart; the number of the bayonet areas 3 is at least two; Figure 9 and Figure 10 As shown, the width W2 of the bayonet area is greater than the width W1 of the groove; the diameter R of the buffer zone is greater than the width W1 of the groove. The bayonet area 3 is shaped like an inwardly concave rectangular parallelepiped. The bayonet area's width W2 is greater than the groove's width W1 to better secure the temperature-measuring optical fiber 4 within the groove 2. The buffer zone 5 is shaped like an inwardly concave cylindrical or elliptical cylinder. The buffer zone's diameter R is greater than the groove's width W1 to better accommodate the temperature-measuring optical fiber 4.

[0028] The buffer zone 5 is used to reserve a portion of the length of the temperature measuring optical fiber 4 , which can effectively prevent the deformation of the tube body 1 from pulling the temperature measuring optical fiber 4 , thereby further protecting the temperature measuring optical fiber 4 .

[0029] Specifically, the cross-section of the groove 2 is shaped like a Chinese character "凵". The dimensions of the groove 3 are determined by the size of the temperature-measuring optical fiber 4. The preferred groove depth D1 is 5 mm to 10 mm, and the groove width W1 is 5 mm to 10 mm. The depth D2 of the bayonet area is the same as the groove depth D1, and the width W2 of the bayonet area is greater than the groove width W1, and the bayonet area width W2 is 10 mm to 20 mm. The depth of the buffer zone 5 is the same as the groove depth D1, and the diameter R of the buffer zone is greater than the groove width W1, and the buffer zone diameter R is 10 mm to 30 mm.

[0030] Specifically, if Figure 4 As shown, the metal clip 9 also includes a metal clip 9, which is shaped to match the bracket area 3. The outer wall of the metal clip 9 is arc-shaped, and the metal clip 9 is provided with a receiving groove inside. The temperature measuring optical fiber 4 is placed in the receiving groove. The metal clip 9 is installed in the bracket area 3 using a metal adhesive. The metal clip 9 is used to fix the temperature measuring optical fiber 4 to prevent it from being squeezed or scraped against the well wall or the centralizer 7 during the lowering process.

[0031] Specifically, there are three grooves 2, and the three grooves 2 are parallel to each other. Such a layout and design can measure data more comprehensively.

[0032] like Figure 1 and Figure 5 As shown, a centralizer 7 is provided on the outside of the pipe body 1 , and ring buckles 702 are provided at both ends of the centralizer 7 , and the two ring buckles 702 are connected by a plurality of arch bridge supports 701 .

[0033] Specifically, if Figure 3 and Figure 4 As shown, a central circulation pipe of a mid-deep geothermal well further includes a temperature measuring optical fiber 4, which is arranged in the groove 2. Figure 6 As shown, the outer side of the temperature measuring optical fiber 4 is set as a metal shell 401, and a protective layer 402 is set inside the metal shell 401. The protective layer 402 is made of rubber, and an optical fiber bundle 403 is set inside the protective layer 402; the optical fiber bundle 403 has poor bending and ductility, and is prone to breakage, thereby causing failure of temperature data transmission.

[0034] Other optical fiber sensors, such as pressure sensors, can also be placed in the groove 2 of the present invention to measure changes in the pressure in the well.

[0035] The utility model optimizes the structure of the central circulation pipe of the deep geothermal well, realizes the orderly arrangement and effective fixation of the temperature measuring optical fiber 4, and at the same time provides a buffer zone 5 to prevent the temperature measuring optical fiber 4 from being pulled when the pipe body 1 is deformed, thereby improving the stability and service life of the temperature measuring optical fiber 4.

[0036] During use, the temperature measuring optical fiber 4 is laid along the groove 2, and the metal clip 9 is installed in the clip area 3 with a metal adhesive to fix the temperature measuring optical fiber 4. When laying, the shape of the temperature measuring optical fiber 4 in the buffer area 5 is as follows: Figure 8 As shown, when the tube body 1 falls and deforms due to weight, it tears the temperature measuring optical fiber 4, and the temperature measuring optical fiber 4 is tightened into a straight line (as shown in FIG. Figure 7 As shown), the length of the temperature measuring optical fiber 4 reserved in the buffer zone 5 will protect the temperature measuring optical fiber 4.

[0037] It can be understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Ordinary technicians in this field should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the scope of protection of the present invention.

Claims

1. A central circulation pipe for a medium-deep geothermal well, characterized by: It includes a tube body (1), the tube body (1) is a hollow cylindrical tubular structure, both ends of the tube body (1) are provided with threaded connection ports, a groove (2) is spirally arranged on the outer wall of the tube body (1), and the angle between the groove (2) and the axis of the tube body (1) is 30°; a clamping area (3) and a buffer area (5) are arranged on the groove (2); the clamping area (3) and the buffer area (5) are arranged at intervals; the number of clamping areas (3) on each groove (2) is at least two; the width (W2) of the clamping area is greater than the width (W1) of the groove; the diameter (R) of the buffer area is greater than the width (W1) of the groove.

2. The central circulation pipe for a medium-deep geothermal well according to claim 1, characterized in that: The cross-section of the groove (2) is in a "U" shape, the depth (D2) of the groove is 5 mm - 10 mm, and the width (W2) of the groove is 5 mm - 10 mm.

3. The central circulation pipe for a medium-deep geothermal well according to claim 1, characterized in that: It further includes a metal clip (9), the outer wall of the metal clip (9) is arc-shaped, an accommodation groove is arranged inside the metal clip (9), and the metal clip (9) is installed in the clamping area (3) through a metal binder.

4. The central circulation pipe for a medium-deep geothermal well according to claim 1, characterized in that: The number of the grooves (2) is three, and the three grooves (2) are parallel to each other.

5. The central circulation pipe for a medium-deep geothermal well according to claim 1, characterized in that: It further includes a temperature measurement optical fiber (4), and the temperature measurement optical fiber (4) is arranged in the groove (2).

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