Underground optical cable connector

Abstract

The underground optical cable connector comprises a semicircular connector body and a semicircular pipe clamp which can be arranged in a butt joint mode, and after the semicircular connector body and the pipe clamp are in butt joint, a containing cavity used for containing a heat preservation inner pipe body is formed in the semicircular connector body and the pipe clamp; the connector body comprises a first connecting section, a mounting section and a second connecting section which are integrally connected; an optical cable installation cavity with the open top end is formed in the installation section in the axial direction, the two ends of the connector body are connected with a first straight-through connector and a second straight-through connector which are the same in structure respectively, and a first center through hole communicated with the optical cable installation cavity is formed in the first straight-through connector. And a second central through hole communicated with the optical cable mounting cavity is formed in the second straight joint. The heat preservation inner pipe body can be sleeved with the heat preservation inner pipe body, sufficient optical fiber allowance is reserved in the optical cable installation cavity, and the problem of optical fiber breakage caused by optical cable length change due to too large temperature difference in the heating period can be effectively solved.

Description

Technical Field

[0001] The invention belongs to the technical field of geothermal energy development and application, and specifically relates to a downhole optical cable connector. Background Art

[0002] The formation temperature measurement in geothermal wells is mainly achieved by laying armored optical fibers or copper core optical cables with armor and temperature measurement components on the outer surface of the buried pipeline. The temperature measurement of the heat transfer medium in the buried pipeline is mainly completed by inserting a temperature measuring optical cable or a temperature measuring instrument into the central channel of the buried pipe. Among them, when measuring the formation temperature in the geothermal well by laying an armored temperature measuring optical cable on the outer surface of the buried pipeline, it is necessary to lower the armored temperature measuring optical cable into the well along with the buried pipeline and install it in the annular gap between the buried pipeline and the production casing. During the well construction process of the geothermal well, the wellbore trajectory cannot be absolutely vertical, and there is always a well inclination. The well inclination may even be artificially increased to design a directional well, resulting in the production casing that was previously lowered into the well and consolidated in the well also being in an inclined state. When the underground pipeline with optical cable laid on the outer surface is lowered later, due to the effect of gravity, the underground pipeline in a free state and the production casing fixed in the well cannot be in a coaxial state, resulting in the temperature measuring optical cable in the gap between the underground pipeline and the production casing being easily squeezed and broken by the underground pipeline and the production casing. In order to avoid loss and reconnect the temperature measuring optical cable in the well, a downhole optical cable connector is required.

[0003] The structural dimensions and use conditions of existing ground optical cable connectors cannot meet the requirements of underground wells. In particular, the optical fiber in the connector has no margin or very little margin. During the heating period of the geothermal well, especially the intermittent heating period, the temperature of the heat transfer medium varies greatly. The optical fiber is affected by the temperature change and the length changes greatly, which makes the optical fiber in the connector easy to be broken. Ultimately, the underground optical cable may fail at any time during the heating period and cannot work normally. In addition, ordinary optical cable connectors cannot meet the temperature and pressure requirements of medium and deep geothermal wells, and cannot ensure that the connector can work reliably and seal without leakage. Summary of the invention

[0004] In view of the defects and shortcomings in the prior art, the present invention provides a downhole optical cable connector to solve the technical problem that the prior art lacks an optical cable connector suitable for medium-deep geothermal wells.

[0005] To achieve the above object, the present invention adopts the following technical scheme:

[0006] A downhole optical cable connector, comprising a semicircular connector body and a semicircular pipe clamp that can be butted together, wherein a receiving cavity for receiving a heat-insulating inner pipe body is formed inside the semicircular connector body and the pipe clamp after being butted together;

[0007] The connector body includes a first connection section, an installation section, and a second connection section that are integrally and connectedly arranged; an optical cable installation cavity with an open top is axially arranged in the installation section, and first and second straight-through connectors with the same structure are respectively connected to both ends of the connector body. A first central through hole communicating with the optical cable installation cavity is arranged in the first straight-through connector, and a second central through hole communicating with the optical cable installation cavity is arranged in the second straight-through connector.

[0008] The present invention also has the following technical features:

[0009] Specifically, the number of the pipe clamps is at least two, and one end of each pipe clamp is hinged to the connector body, and the other end is movably connected by means of fastening bolts and nuts.

[0010] Furthermore, the number of the pipe clamps is two, and the two pipe clamps are respectively arranged at both ends of the connector body.

[0011] Furthermore, a top cover is detachably arranged on the optical cable installation cavity, and a sealing gasket is arranged between the top cover and the connector body.

[0012] Furthermore, concave-shaped flow-through grooves are axially arranged on the outer walls of the first connection section and the second connection section.

[0013] Furthermore, locking components are detachably connected to the first straight-through connector and the second straight-through connector.

[0014] Furthermore, the locking component includes a locking sleeve provided with a third central through hole, and a ferrule assembly coaxially sleeved in the locking sleeve. The ferrule assembly includes a first ferrule provided with a fourth central through hole and a second ferrule provided with a fifth central through hole. A first outer conical surface is arranged on the outer wall of the first ferrule, and a first inner conical surface is arranged on the inner wall of the second ferrule. The first outer conical surface and the first inner conical surface are connected by extrusion fit. A second outer conical surface is arranged on the outer wall of the second ferrule, and a second inner conical surface is arranged at the head end of the first straight-through connector; the second outer conical surface and the second inner conical surface are connected by extrusion fit;

[0015] The third central through hole, the fourth central through hole, and the fifth central through hole are coaxially and communicatively arranged.

[0016] Furthermore, a first limiting step and a second limiting step are sequentially arranged in the third central through hole from front to back.

[0017] Furthermore, an external thread is arranged on the outer wall of the head end of the first straight-through connector, and an internal thread matching the external thread is arranged on the inner wall of the tail end of the locking sleeve.

[0018] Compared with the prior art, the present invention has the following technical effects:

[0019] (1) The downhole optical cable connector provided by the present invention, through structural design, especially the semi-circular connector body and the semi-circular pipe clamp arranged in butt joint, can be sleeved outside the heat preservation inner pipe, and there is sufficient optical fiber allowance reserved in the optical cable installation cavity, which can effectively avoid the problem of optical fiber breakage caused by the change of optical cable length due to excessive temperature difference during the heating period.

[0020] (2) The present invention adopts an arc-shaped design and is applicable to the downhole channel. The concave-shaped flow-through groove is used to increase the flow-through cross-section between the hole wall and the heat preservation inner pipe. The structural dimensions are reasonable, the flow resistance of the heat transfer medium is small, and thus the energy consumption of the ground circulation water pump is reduced, and the energy-saving effect is remarkable.

[0021] (3) The structure of the present invention is simple and convenient to use, and is worthy of popularization. Description of the Drawings

[0022] Figure 1 is the overall structural schematic diagram of the present invention;

[0023] Figure 2 is the exploded view of the present invention;

[0024] Figure 3 is the sectional view I of the present invention;

[0025] Figure 4 is the sectional view II of the present invention;

[0026] Figure 5 is the connection schematic diagram of the first straight-through joint and the locking assembly.

[0027] The reference numerals in the drawings represent:

[0028] 1 - connector body, 2 - pipe clamp, 3 - accommodation cavity, 4 - optical cable installation cavity, 5 - first straight-through joint, 6 - second straight-through joint, 7 - fastening bolt, 8 - nut, 9 - top cover, 10 - sealing gasket, 11 - locking assembly, 12 - first limiting step, 13 - second limiting step;

[0029] 101 - first connection section, 102 - installation section, 103 - second connection section; 111 - locking sleeve, 112 - ferrule assembly; 1121 - first ferrule, 1122 - second ferrule. Detailed Embodiments

[0030] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and any equivalent transformation made on the basis of the technical solution of the present application falls within the protection scope of the present invention.

[0031] When the present invention describes directions, it should be understood that the directions or positional relationships indicated by terms such as "upper", "lower", "front", "rear", "left", "right", etc. are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be construed as a limitation to the present invention.

[0032] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0033] Unless otherwise specified, all components of the present invention are commercially available.

[0034] Embodiment

[0035] Following the above technical solution, as Figure 1 and Figure 2 shown, this embodiment provides an underground optical cable connector, which includes a semi-circular connector body 1 and a semi-circular pipe clamp 2 that can be butt-jointed. The two horizontal end faces of the connector body 1 are butt-joint faces, and the two horizontal end faces on both sides of the pipe clamp 2 are butt-joint faces. After the connector body 1 and the semi-circular pipe clamp 2 are butt-jointed along the butt-joint faces, a receiving cavity 3 with a circular cross-section is formed for receiving the heat-insulating inner pipe. The inner diameter of the receiving cavity matches the outer diameter of the heat-insulating inner pipe, and the connected connector body 1 and semi-circular pipe clamp 2 can be tightly fitted and clamped outside the heat-insulating inner pipe. The installation is firm and reliable, and the occupied space is smaller.

[0036] The connector body 1 includes a first connection section 101, an installation section 102, and a second connection section 103 that are integrally and connectedly arranged; an optical cable installation cavity 4 with an open top is axially arranged in the installation section 102, and a certain length of optical fiber can be coiled in the optical cable installation cavity to prevent the direct-connected optical fiber from breaking due to the length expansion and contraction during the alternating change of heat and cold because there is no margin.

[0037] The optical cable installation cavity 4 is used for receiving the optical cable; and a first through joint 5 and a second through joint 6 are respectively connected to both ends of the connector body 1. A first central through hole communicating with the optical cable installation cavity 4 is arranged in the first through joint 5, and a second central through hole communicating with the optical cable installation cavity 4 is arranged in the second through joint 6. The optical cable can pass through the first through joint 5 and enter the optical cable installation cavity 4, and then pass through the second through joint 6 and exit.

[0038] As a preferred solution of this embodiment, one end of the pipe clamp 2 is hinged to the connector body 1, and the other end is movably connected by means of a fastening bolt 7 and a nut 8; in other embodiments, both ends of the pipe clamp 2 and the connector body 1 can also be movably connected by means of a fastening bolt 7 and a nut 8.

[0039] As a preferred solution of this embodiment, the number of pipe clamps 2 is two, and the two pipe clamps 2 are respectively arranged at both ends of the connector body 1. In other embodiments, the number of pipe clamps 2 can also be selected according to the length of the heat-insulating inner pipe.

[0040] As a preferred solution of this embodiment, a top cover 9 is detachably arranged on the optical cable installation cavity 4, and a sealing gasket 10 is arranged between the top cover 9 and the connector body 1. The sealing gasket 10 and the top cover 9 in this embodiment are both arc-shaped and are both made of metal material, which can reliably seal the optical fiber cavity and enable the optical fiber cavity to have sufficient pressure resistance.

[0041] As a preferred solution of this embodiment, concave flow grooves 10 are axially arranged on the outer walls of the first connection section 101 and the second connection section 103. The concave flow grooves 10 can increase the transition channels of the heat transfer medium while ensuring the strength and reduce the flow resistance. The heat transfer medium enters from the annulus and flows out from the heat-insulating inner pipe. The concave flow grooves 10 reduce the thickness of the semi-circular connector body 1, that is, reduce its cross-sectional area, increase the flow cross-section between the hole wall and the heat-insulating inner pipe, and thus reduce the flow resistance of the heat transfer medium.

[0042] As a preferred solution of this embodiment, locking components 11 are detachably connected to the first straight-through joint 5 and the second straight-through joint 6.

[0043] As a preferred solution of this embodiment, the locking component 11 includes a locking sleeve 111 provided with a third central through hole, and a ferrule assembly 112 coaxially sleeved inside the locking sleeve 111. The ferrule assembly 112 includes a first ferrule 1121 provided with a fourth central through hole and a second ferrule 1122 provided with a fifth central through hole. A first outer conical surface is provided on the outer wall of the first ferrule 1121, and a first inner conical surface is provided on the inner wall of the second ferrule 1122. The first outer conical surface and the first inner conical surface are connected by extrusion fit. A second outer conical surface is provided on the outer wall of the second ferrule 1122, and a second inner conical surface is provided at the head end of the first straight-through joint 5; the second outer conical surface and the second inner conical surface are connected by extrusion fit; after the inner conical surfaces and the outer conical surfaces are butted, a conical sealing area is formed.

[0044] The third central through hole, the fourth central through hole and the fifth central through hole are coaxially and communicatively arranged.

[0045] As a preferred solution of this embodiment, a first limiting step 12 and a second limiting step 13 are sequentially arranged in the third central through hole from front to back. The first limiting step 12 is used to limit the axial displacement of the first ferrule 1121, and the first limiting step 12 is used to limit the axial displacement of the first straight-through joint 5.

[0046] As a preferred solution of this embodiment, an external thread is provided on the outer wall of the head end of the first straight-through joint 5, and an internal thread matching the external thread is provided on the inner wall of the tail end of the locking sleeve 111. After the first straight-through joint 5 and the locking sleeve 111 are threadedly connected, the ferrule will be pressed to ensure that the optical cable is locked, reliably sealed, and no heat transfer medium will leak.

[0047] When the present invention is in use, the first central through hole in the first straight-through joint 5 of the optical cable well is penetrated into the optical cable installation cavity 4, and a certain length of optical fiber is coiled in the optical cable installation cavity 4, and then the optical cable passes through the second central through hole in the second straight-through joint 6; the downhole optical cable connector is sleeved on the outer wall of the heat preservation inner tube, and the semi-circular connector body 1 and the semi-circular pipe clamp 2 that are already hinged at one end are fixed outside the heat preservation inner tube by means of the fastening bolts 7 and nuts 8.

[0048] The downhole optical cable connector provided in this embodiment, through structural design, especially the butt-jointed semi-circular connector body and semi-circular pipe clamp, can be sleeved outside the heat preservation inner tube body, and there is sufficient optical fiber margin reserved in the optical cable installation cavity, which can effectively avoid the problem of optical fiber breakage caused by the change of the optical cable length due to excessive temperature difference during the heating period.

[0049] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention; for those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An underground optical cable connector, characterized in that, it includes a semi-circular connector body (1) and a pipe clamp (2) that can be butt-jointed. After the semi-circular connector body (1) and the semi-circular pipe clamp (2) are butt-jointed, an accommodation cavity (3) for accommodating the body of the heat-insulating inner pipe is formed inside; The connector body (1) includes a first connection section (101), an installation section (102) and a second connection section (103) that are integrally connected. An optical cable installation cavity (4) with an open top is axially arranged inside the installation section (102), and a first through connector (5) and a second through connector (6) are respectively connected to both ends of the connector body (1). A first central through hole communicating with the optical cable installation cavity (4) is arranged inside the first through connector (5), and a second central through hole communicating with the optical cable installation cavity (4) is arranged inside the second through connector (6).

2. The underground optical cable connector according to claim 1, characterized in that, one end of the pipe clamp (2) is hinged to the connector body (1), and the other end is movably connected by means of a fastening bolt (7) and a nut (8).

3. The underground optical cable connector according to claim 1, characterized in that, the number of the pipe clamps (2) is two, and the two pipe clamps (2) are respectively arranged at both ends of the connector body (1).

4. The underground optical cable connector according to claim 1, characterized in that, a top cover (9) is detachably arranged on the optical cable installation cavity (4), and a sealing gasket (10) is arranged between the top cover (9) and the connector body (1).

5. The underground optical cable connector according to claim 1, characterized in that, concave-shaped flow-through grooves (10) are axially arranged on the outer walls of the first connection section (101) and the second connection section (103).

6. The underground optical cable connector according to claim 1, characterized in that, locking components (11) are detachably connected to the first through connector (5) and the second through connector (6).

7. The underground optical cable connector according to claim 6, characterized in that, the locking component (11) includes a locking sleeve (111) provided with a third central through hole, and a ferrule assembly (112) coaxially sleeved inside the locking sleeve (111). The ferrule assembly (112) includes a first ferrule (1121) provided with a fourth central through hole and a second ferrule (1122) provided with a fifth central through hole. A first outer conical surface is arranged on the outer wall of the first ferrule (1121), and a first inner conical surface is arranged on the inner wall of the second ferrule (1122). The first outer conical surface and the first inner conical surface are connected by extrusion fit. A second outer conical surface is arranged on the outer wall of the second ferrule (1122), and a second inner conical surface is arranged at the head end of the first through connector (5); the second outer conical surface and the second inner conical surface are connected by extrusion fit; the third central through hole, the fourth central through hole and the fifth central through hole are coaxially and communicatively arranged.

8. The underground optical cable connector according to claim 7, characterized in that, A first limiting step (12) and a second limiting step (13) are sequentially arranged from front to back in the third central through hole.

9. The downhole optical cable connector according to claim 7, characterized in that, an external thread is provided on the outer wall of the head end of the first straight connector (5), and an internal thread matching the external thread is provided on the inner wall of the tail end of the locking sleeve (111).

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