Underground optical cable splicing equipment and splicing scheme thereof

Abstract

The invention discloses underground optical cable splicing equipment and a splicing scheme thereof, and relates to the technical field of underground optical cable splicing of oil and gas wells. The underground optical cable splicing equipment comprises an extended stainless steel tube, a modified nut and a Swagelok joint, a protective aluminum tube is arranged in the extended stainless steel tube, a welding protective stainless steel tube is arranged in the protective aluminum tube, a telescopic aluminum tube is mounted in the extended stainless steel tube, and an optical cable aluminum tube and an optical cable protective stainless steel tube are mounted on the extended stainless steel tube. A welding connecting pipe is fixedly connected to the outer wall of the extension stainless steel pipe, a Swagelok connector is installed in the welding connecting pipe, a first sealing ring, a second sealing ring and a third sealing ring are installed in the welding connecting pipe, eight-claw chucks are installed at the two ends of the welding connecting pipe, and a test hole locking piece is installed on the welding connecting pipe.

Description

Technical Field

[0001] The present invention relates to the technical field of optical cable splicing in oil and gas wells, and in particular to an optical cable splicing device and a splicing solution thereof. Background Art

[0002] The splicing of optical cables in oil and gas wells generally refers to the fusion splicing of downhole sensors and transmission optical cables through optical fibers, and the use of heat shrink tubing to protect the fusion points to achieve smooth light transmission; the outside of the optical cable is sealed with the well environment and the inside of the optical cable through the threaded joints and sealing rings of the junction box, and the junction box must be provided with an installation base called a support tube. At present, the temperature of most oil wells is 150℃ or above. In this solution, the heat shrink tubing cannot meet some high-temperature requirements (above 100℃) in the well. The heat shrink tubing will soften at high temperatures and will not play a protective role; the heat shrink tubing is generally fixed with tape in the junction box, which is not reliable; and the junction box is large in size and has a long production cycle, and the installation requires the support tube to cooperate more complicatedly.

[0003] This patent provides a splicing method that can achieve the optical fiber fusion protection point to withstand 300°C underground. The fusion point is fixed with a mechanical structure, which is more reliable. The splicing adopts tubular splicing to achieve the advantages of small size, convenient downhole, and easy fixation. The new optical cable joint design can achieve double airtightness and fixation of the optical cable, and the joint point can be pressure tested. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a downhole optical cable splicing device and a splicing solution thereof, which can solve the above-mentioned problem.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a downhole optical cable splicing device, comprising an extended stainless steel tube, a modified nut and a Swagelok joint, a protective aluminum tube is arranged inside the extended stainless steel tube, a fusion-bonded protective stainless steel tube is arranged inside the protective aluminum tube, a telescopic aluminum tube is installed inside the extended stainless steel tube, an optical cable aluminum tube and an optical cable protective stainless steel tube are installed on the extended stainless steel tube, a welded connecting tube is fixedly connected to the outer wall of the extended stainless steel tube, the Swagelok joint is installed inside the welded connecting tube, a first sealing ring, a second sealing ring and a third sealing ring are installed inside the welded connecting tube, eight-jaw chucks are installed at both ends of the welded connecting tube, and a test hole locking piece is installed on the welded connecting tube.

[0006] Preferably, a downhole optical cable splicing device splicing solution comprises the following steps:

[0007] S1 puts the fused optical fiber in the middle of the open 60mmφ1*0.2mm stainless steel tube, and adjusts the position so that the bare optical fiber is in the center of the open tube;

[0008] S2 uses UV glue to temporarily fix both ends of the optical fiber on the stainless steel tube;

[0009] S3 applies high temperature resistant silicone inside the open stainless steel tube to cover the optical fiber, and ensure the fullness of the glue.

[0010] S4 puts the 60mmφ1.8*0.3mm stainless steel tube on the φ1mm stainless steel tube and fixes it with high temperature resistant glue at both ends;

[0011] S5 uses a 60mmφ4*1mm open aluminum tube to cover a φ1.8mm stainless steel tube and fix it with high-temperature glue;

[0012] S6 puts the spliced ​​optical fiber and the fusion protection tube into a 340mm long open φ4*1mm aluminum tube, and fills the open tube with high temperature resistant silicone;

[0013] S7 uses a 6mm steel tube to cover the 340mm long open φ4*1mm aluminum tube and the aluminum tube inside the sensor and optical cable, and fixes it with a hydraulic clamp;

[0014] S8 pulls the optical cable joint tube out from one end of the optical cable and overlaps it with the other end of the optical cable to cover the fusion area;

[0015] S9 uses a wrench to lock the optical cable connector and the optical cable;

[0016] S10 sealing rings 1, 2, 3 and metal sealing ferrules form a closed space after the threads are tightened;

[0017] The S11 pressure measuring device pressurizes the confined space, and the pressure leakage is less than 0.5Mpa in 30 minutes at 20Mpa, which means that the metal sealing ferrule is sealed normally;

[0018] S12 seals the pressure measuring space to form a double seal for the optical cable connection point.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The downhole optical cable splicing equipment and its splicing solution. The high-temperature resistant fusion protection method of the solution allows the sensor to be used in a wider range and for a longer time in the downhole. The anti-vibration mechanical method effectively fixes the fusion protection tube to protect the optical fiber. The use of tubular splicing reduces the space occupied in the downhole, facilitates going down the well, and reduces costs. The splicing head design of the splicing tube increases the optical cable fixing points, forming a double fixing protection for the optical cable, and ensures that the airtight point is not subject to external force. After installation, the joint can be pressure tested to ensure the effectiveness of the splicing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0022] Figure 1This is a schematic diagram of the cross-sectional structure of a downhole optical cable splicing device of the present invention;

[0023] Figure 2 This is a schematic diagram of a downhole optical cable splicing device of the present invention;

[0024] Figure 3 This is a schematic diagram of a pressure measuring device installed in a downhole optical cable splicing device of the present invention.

[0025] Figure numerals: 1. Extended stainless steel tube; 2. Protective aluminum tube; 3. Welded protective stainless steel tube; 4. Telescopic aluminum tube; 5. Optical cable aluminum tube; 6. Optical cable protective stainless steel tube; 7. Modified nut; 8. Octopus chuck; 9. Swagelok connector; 10. Welded connecting tube; 11. First sealing ring; 12. Second sealing ring; 13. Octopus chuck pressure cover; 14. Pressure measuring hole locking piece; 15. Third sealing ring. DETAILED DESCRIPTION

[0026] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0027] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0028] In the description of the present invention, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0029] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0030] See also Figure 1-3The present invention provides a technical solution: a downhole optical cable splicing device and a splicing solution thereof, comprising an extended stainless steel tube 1, a modified nut 7 and a Swagelok joint 9, a protective aluminum tube 2 is arranged inside the extended stainless steel tube 1, a fusion protection stainless steel tube 3 is arranged inside the protective aluminum tube 2, a telescopic aluminum tube 4 is installed inside the extended stainless steel tube 1, an optical cable aluminum tube 5 and an optical cable protection stainless steel tube 6 are installed on the extended stainless steel tube 1, a welding connection tube 10 is fixedly connected to the outer wall of the extended stainless steel tube 1, a Swagelok joint 9 is installed inside the welding connection tube 10, a first sealing ring 11, a second sealing ring 12 and a third sealing ring 15 are installed inside the welding connection tube 10, eight-claw chucks 13 are installed at both ends of the welding connection tube 10, and a test hole locking piece 14 is installed on the welding connection tube 10;

[0031] Among them, an eight-claw chuck for fixing the optical cable is arranged inside the welding connection tube 10;

[0032] The first sealing ring 11, the second sealing ring 12 and the third sealing ring 15 correspond to Figure 3 Middle sealing ring 1, sealing ring 3 and sealing ring 3.

[0033] A downhole optical cable splicing device splicing solution comprises the following steps:

[0034] S1 puts the fused optical fiber in the middle of the open 60mmφ1*0.2mm stainless steel tube, and adjusts the position so that the bare optical fiber is in the center of the open tube;

[0035] S2 uses UV glue to temporarily fix both ends of the optical fiber on the stainless steel tube;

[0036] S3 applies high temperature resistant silicone inside the open stainless steel tube to cover the optical fiber, and ensure the fullness of the glue.

[0037] S4 puts the 60mmφ1.8*0.3mm stainless steel tube on the φ1mm stainless steel tube and fixes it with high temperature resistant glue at both ends;

[0038] S5 uses a 60mmφ4*1mm open aluminum tube to cover a φ1.8mm stainless steel tube and fix it with high-temperature glue;

[0039] S6 puts the spliced ​​optical fiber and the fusion protection tube into a 340mm long open φ4*1mm aluminum tube, and fills the open tube with high temperature resistant silicone;

[0040] S7 uses a 6mm steel tube to cover the 340mm long open φ4*1mm aluminum tube and the aluminum tube inside the sensor and optical cable, and fixes it with a hydraulic clamp;

[0041] S8 pulls the optical cable joint tube out from one end of the optical cable and overlaps it with the other end of the optical cable to cover the fusion area;

[0042] S9 uses a wrench to lock the optical cable connector and the optical cable;

[0043] S10 sealing rings 1, 2, 3 and metal sealing ferrules form a closed space after the threads are tightened;

[0044] The S11 pressure measuring device pressurizes the confined space, and the pressure leakage is less than 0.5Mpa in 30 minutes at 20Mpa, which means that the metal sealing ferrule is sealed normally;

[0045] S12 seals the pressure measuring space to form a double seal for the optical cable connection point.

[0046] For example, see Figure 3 , before pressure measurement

[0047] Install the fastening nut, the octagonal chuck, the sealing ring 2, the optical cable connector, and the metal sealing ferrule on the optical cable in sequence;

[0048] Through the torque wrench, the optical cable connector squeezes the metal sealing sleeve to deform and seal with the optical cable, and the sealing ring 3 forms a seal with the optical cable connector;

[0049] Use a torque wrench to tighten the fastening nut to deform the octagonal chuck to lock the optical cable and squeeze the sealing ring 2 to form a seal;

[0050] Install the sealing ring 3 and the pressure measuring equipment on the pressure measuring hole, pressurize the metal sealing ferrule, and test the sealing performance of the metal ferrule;

[0051] After the pressure test, remove the pressure equipment and seal the pressure measuring holes with convex nails.

[0052] Furthermore, the high-temperature resistant fusion protection method of this solution allows the sensor to be used in a wider range and for a longer time underground. The anti-vibration mechanical method effectively fixes the fusion protection tube and protects the optical fiber. The use of tubular joints reduces the space occupied underground, facilitates going down the well, and reduces costs. The joint head design of the joint tube increases the optical cable fixing points, forming a double fixed protection for the optical cable and ensuring that the airtight point is not subject to external forces. After installation, the joint can be pressure tested to ensure the effectiveness of the joint.

[0053] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A downhole optical cable splicing device, characterized in that: The invention comprises an extended stainless steel tube (1), a modified nut (7) and a Swagelok joint (9); a protective aluminum tube (2) is arranged inside the extended stainless steel tube (1); a fusion-welded protective stainless steel tube (3) is arranged inside the protective aluminum tube (2); a telescopic aluminum tube (4) is installed inside the extended stainless steel tube (1); an optical cable aluminum tube (5) and an optical cable protective stainless steel tube (6) are installed on the extended stainless steel tube (1); a welding connecting tube (10) is fixedly connected to the outer wall of the extended stainless steel tube (1); a Swagelok joint (9) is installed inside the welding connecting tube (10); a first sealing ring (11), a second sealing ring (12) and a third sealing ring (15) are installed inside the welding connecting tube (10); eight-claw chucks (13) are installed at both ends of the welding connecting tube (10); and a test hole locking piece (14) is installed on the upper side of the welding connecting tube (10); An eight-claw chuck for fixing the optical cable is arranged inside the welding connection tube (10).

2. A downhole optical cable splicing device splicing solution, characterized in that: The following steps are involved: S1 puts the fused optical fiber in the middle of the open 60mmφ1*0.2mm stainless steel tube, and adjusts the position so that the bare optical fiber is in the center of the open tube; S2 uses UV glue to temporarily fix both ends of the optical fiber on the stainless steel tube; S3 applies high temperature resistant silicone inside the open stainless steel tube to cover the optical fiber, and ensure the fullness of the glue. S4 puts the 60mmφ1.8*0.3mm stainless steel tube on the φ1mm stainless steel tube and fixes it with high temperature resistant glue at both ends; S5 uses a 60mmφ4*1mm open aluminum tube to cover a φ1.8mm stainless steel tube and fix it with high-temperature glue; S6 puts the spliced ​​optical fiber and the fusion protection tube into a 340mm long open φ4*1mm aluminum tube, and fills the open tube with high temperature resistant silicone; S7 uses a 6mm steel tube to cover the 340mm long open φ4*1mm aluminum tube and the aluminum tube inside the sensor and optical cable, and fixes it with a hydraulic clamp; S8 pulls the optical cable joint tube out from one end of the optical cable and overlaps it with the other end of the optical cable to cover the fusion area; S9 uses a wrench to lock the optical cable connector and the optical cable; S10 sealing rings 1, 2, 3 and metal sealing ferrules form a closed space after the threads are tightened; The S11 pressure measuring device pressurizes the confined space, and the pressure leakage is less than 0.5Mpa in 30 minutes at 20Mpa, which means that the metal sealing ferrule is sealed normally; S12 seals the pressure measuring space to form a double seal for the optical cable connection point.

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