Optical fiber replacement method and replacement device

Abstract

The invention discloses an optical fiber replacement method and device. The optical fiber replacement method comprises the steps that first pressure information of a built-in pipe in a well based on the pressure building condition and old optical fiber detection information are obtained to determine whether an optical fiber needs to be replaced or not; if replacement is needed, when the new optical fiber and the old optical fiber are connected, fluid is controlled to be pumped into the well built-in pipe, so that the old optical fiber is moved out of the well built-in pipe and the new optical fiber is moved into the well built-in pipe, and when the new optical fiber is moved to a designated installation position of the well built-in pipe, connection between the new optical fiber and the old optical fiber is disconnected; and acquiring communication information of the new optical fiber to determine the installation condition of the new optical fiber in the process of gradually moving the new optical fiber into the underground pipe. According to the replacement method, the pressure of the built-in pipe in the well can be detected before replacement, whether the optical fiber needs to be replaced or not is determined by combining the old optical fiber detection information, and the risk that replacement is conducted only based on the old optical fiber detection information is avoided; the new optical fiber installation condition can be determined according to the new optical fiber communication information during replacement, and the replacement risk and cost are reduced.

Description

Technical Field

[0001] The present invention relates to the field of technical optical fiber monitoring, and more particularly to an optical fiber replacement method. In addition, the present invention also relates to a replacement device capable of performing the above optical fiber replacement method. Background Art

[0002] Long-term monitoring technology using optical fiber outside the pipe can monitor the entire process and life cycle of oil and gas field development, and provide real-time and continuous understanding of the distribution and flow status of oil and gas downhole. However, due to the long-term exposure of optical fiber to high temperature, high pressure, and high hydrogen sulfide content, it will be damaged over time and requires timely replacement with new optical fiber to continue monitoring operations.

[0003] In related technologies, an insertion tube is placed inside an oil and gas well, and an optical fiber is placed inside the tube. If a problem with the optical fiber's measurement data indicates a need for replacement, fluid is introduced through one end of the tube to allow the damaged optical fiber to move out of the tube. A new optical fiber is then injected into the tube along with the fluid to complete the replacement. This method directly replaces the optical fiber, ignoring the effect of tube pressure on the movement of the optical fiber. If the tube pressure is high, directly injecting fluid and moving the optical fiber in and out is risky, and components can easily be damaged during the insertion process. Damage to components during the insertion process cannot be detected in a timely manner, resulting in high replacement costs.

[0004] In summary, how to provide a low-risk, low-cost replacement method is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] In light of this, the present invention aims to provide a fiber replacement method that can detect the pressure of the wellbore insertion tube before replacement and, combined with the detection information of the old fiber, determine whether the fiber needs to be replaced, thus avoiding the risk of replacing based solely on the detection information of the old fiber. During replacement, the installation status of the new fiber can be determined based on the communication information of the new fiber, thereby reducing the replacement risk and cost. Another object of the present invention is to provide a replacement device capable of performing the above-mentioned fiber replacement method.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for replacing an optical fiber, comprising:

[0008] obtaining first pressure information of the well-entered pipe under a pressure-holding condition and detection information of the old optical fiber, and determining whether the optical fiber needs to be replaced based on the first pressure information and the detection information of the old optical fiber;

[0009] If replacement is required, when the new optical fiber is connected to the old optical fiber, fluid is pumped into the well insertion tube to move the old optical fiber out of the well insertion tube and the new optical fiber into the well insertion tube, and the connection between the new optical fiber and the old optical fiber is disconnected when the new optical fiber moves to a designated installation position of the well insertion tube;

[0010] During the process of gradually moving the new optical fiber into the designated installation position of the in-well insertion tube, communication information of the new optical fiber is obtained to determine the installation status of the new optical fiber.

[0011] Preferably, after the new optical fiber is moved into the designated installation position of the in-well insertion tube, the method further comprises:

[0012] Controlling the discharge of fluid from the well into the pipe until it is empty;

[0013] Second pressure information of the in-well insertion pipe under a pressure-holding condition is obtained, and a sealing condition of the in-well insertion pipe is determined based on the second pressure information.

[0014] Preferably, determining the sealing condition of the in-well landing pipe based on the second pressure information includes:

[0015] determining a sealing condition of the in-well insertion pipe based on the second pressure information and the first pressure information;

[0016] And / or, the sealing condition of the in-well injection pipe is determined based on the second pressure information and preset pressure information, wherein the preset pressure information is a theoretical pressure range of the in-well injection pipe in a pressure-holding state.

[0017] Preferably, after determining the sealing condition of the in-well landing pipe based on the second pressure information, the method further includes:

[0018] Controlling the injection of a high-temperature resistant filler into the space between the new optical fiber and the in-well insertion tube until the space is filled to a full state;

[0019] The new optical fiber is controlled to connect to a ground detection instrument to detect the performance of the optical fiber.

[0020] Preferably, controlling the injection of a high-temperature resistant filler into the space between the new optical fiber and the in-well insertion tube until the space is filled to a full state comprises:

[0021] The in-well insertion pipe includes an input end, a connecting end and a removal end. The connecting end connects the input end and the removal end. The ports of the input end and the removal end are arranged flush with each other, and the high-temperature resistant filling body is controlled to be injected from the input end until the high-temperature resistant filling body flows to the removal end.

[0022] Preferably, before obtaining the first pressure information of the wellbore insertion pipe under the pressure holding condition, the method further includes:

[0023] When sealing the wellhead, the removal end and the entry end are sealed and the head end of the new optical fiber is simultaneously sealed in the well entry tube, and the tail end of the new optical fiber is sealed;

[0024] Gas is pumped into the wellbore injection pipe until the wellbore injection pipe is in a pressure-holding state.

[0025] Preferably, controlling the pumping of fluid into the well into the inlet pipe comprises:

[0026] The first power element is controlled to pump fluid into the in-well pipe at a gradually increasing pumping speed. When the first power element is at a maximum pumping speed, the pumping force is less than the maximum tensile strength of the new optical fiber and the old optical fiber.

[0027] The present invention also provides a replacement device, comprising:

[0028] Pipe inserted into the well;

[0029] a first power element connected to the in-well injection pipe and the fluid circulation system, the first power element being used to pump the fluid into the in-well injection pipe;

[0030] a second power element, connected to the well inlet pipe, for controlling the gas to flow into the well inlet pipe to achieve pressure holding and fluid recovery relative to the fluid circulation system;

[0031] A control element, signal-connected to the first power element and the second power element, is used to execute any of the above-mentioned optical fiber replacement methods.

[0032] Preferably, the well insertion pipe comprises an inlet end, a communication end and an outlet end which are connected in sequence, and the communication end is arc-shaped and protrudes relative to the outlet end and the inlet end;

[0033] The connecting end includes a first part and a second part connected thereto. Both the first part and the second part first expand outward away from a first direction and then contract toward the first direction. The first direction is the axial direction of the wellbore insertion pipe.

[0034] Preferably, it further comprises a sealing member and a stopper, and a protective sleeve is provided on the periphery of the said moving-in end and the said moving-out end;

[0035] The sealing member is provided at a position of the protective sleeve away from the communication end to form a seal between the ports of the inlet end and the outlet end;

[0036] The stopper is arranged at a position of the protective sleeve close to the communicating end, and is used to prevent the moving-in end and the moving-out end from being withdrawn from the protective sleeve.

[0037] The optical fiber replacement method provided by the present invention determines whether the optical fiber needs to be replaced by obtaining first pressure information of the well-mounted injection pipe under a pressure-holding condition and old optical fiber detection information, thereby avoiding the distortion of the old optical fiber detection information due to the pressure problem of the well-mounted injection pipe, ensuring that the optical fiber replacement is carried out on the premise that there is indeed a problem with the optical fiber, and ensuring the reliability of the optical fiber replacement; if the optical fiber needs to be replaced, then, under the premise that the new optical fiber and the old optical fiber are connected, fluid is pumped into the well-mounted injection pipe, so that the old optical fiber can be moved out of the well-mounted injection pipe and the new optical fiber can be moved into the well-mounted injection pipe, until the new optical fiber moves to the designated installation position, at which time the connection between the new optical fiber and the old optical fiber is disconnected, and the replacement of the new optical fiber is completed; and in the process of the new optical fiber gradually moving into the designated installation position, the installation status of the new optical fiber is determined by obtaining the communication information of the new optical fiber, thereby ensuring the reliability of the new optical fiber moving-in process and the reliable replacement of the optical fiber.

[0038] The beneficial effects of the present invention are: through the pressure detection information of the well-inserted pipe under the pressure-holding condition and the old optical fiber detection information, it is determined whether the optical fiber is damaged, avoiding the old optical fiber detection problem caused by the pressure information of the well-inserted pipe, and obtaining communication information during the new optical fiber moving in, ensuring the reliability of the moving in, ensuring the accuracy, reliability and effectiveness of the optical fiber replacement process, and reducing the replacement cost and replacement risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0040] Figure 1 A flow chart of the optical fiber replacement method provided by the present invention;

[0041] Figure 2 A schematic structural diagram of the replacement device provided by the present invention;

[0042] Figure 3 This is a schematic diagram of the replacement device provided by the present invention in use;

[0043] Figure 4 This is a schematic structural diagram of the well insertion pipe provided by the present invention.

[0044] Figures 1-4 , the reference numerals include:

[0045] 1-in-well insertion tube; 2-optical fiber; 3-high-temperature resistant filling body; 4-gas storage element; 5-first power element; 6-fluid circulation system; 7-second power element; 8-sealing element; 9-stopper; 10-protective sleeve; 11-moving end; 12-connecting end; 13-moving end; 01-bottom end of the well. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0047] The core of this invention is to provide a fiber replacement method. Using pressure information from a wellbore drop tube under pressure-holding conditions and detection information from the old fiber, the method determines whether the fiber is damaged, avoiding problems with detecting the old fiber due to the drop tube's pressure information. Furthermore, communication information is obtained during the insertion of the new fiber, ensuring the reliability of the insertion and the accuracy, reliability, and effectiveness of the fiber replacement process, thereby reducing replacement costs and risks. Another core of this invention is to provide a replacement device capable of performing the aforementioned fiber replacement method.

[0048] The optical fiber replacement method provided by the present invention is used to complete the replacement between the new optical fiber and the old optical fiber. Specifically, when the old optical fiber is damaged, the old optical fiber in the well tube 1 is replaced with the new optical fiber to ensure the reliability of long-term optical fiber monitoring. Figure 3 The in-well pipe 1 is a pipe arranged in an oil and gas well, with its port located at the wellhead end and its bottom located at the well bottom end 01, which may specifically include but is not limited to a steel pipe.

[0049] Among them, please refer to Figure 1 The specific replacement method includes: obtaining first pressure information of the wellbore drop tube 1 under a held-down pressure condition and detection information of the old optical fiber, and determining whether the optical fiber needs to be replaced based on the first pressure information and the detection information of the old optical fiber. The first pressure information here is used to verify the sealing of the wellbore drop tube 1 and the continuity of the optical cable. The specific verification method is to compare the first pressure information with a preset pressure range. If it is within the preset pressure range, it indicates that the seal is good. At this time, if the detection information of the old optical fiber determines that the optical fiber measurement has shortened or the measurement data has drifted and distorted, it is determined that the optical fiber needs to be replaced.

[0050] If the first pressure information is not within the preset pressure range, such as lower than the preset pressure, it means that the pressure in the wellbore insertion tube 1 affects the detection of the optical fiber. At this time, it cannot be directly considered that the old optical fiber needs to be replaced based on the detection information, so as to ensure the accuracy of determining that the optical fiber needs to be replaced and the reliability of the replacement.

[0051] The acquisition of specific first pressure information can be achieved through sensors. The detection of the sensor and the detection of the old optical fiber are relatively independent. A more reliable downhole common sensor is used to ensure the accuracy of pressure detection, avoiding the direct use of old optical fiber detection which may cause data errors, ensuring the accuracy of the first pressure information detection, and ensuring the reliability of the sealing detection of the well-insulated pipe 1.

[0052] If it is determined based on the first pressure information and the detection information of the old optical fiber that a replacement is required, then when the new optical fiber is connected to the old optical fiber, a fluid is pumped into the wellbore insertion tube 1 to move the old optical fiber out of the wellbore insertion tube 1 and the new optical fiber into the wellbore insertion tube 1. When the new optical fiber moves to the designated installation position of the wellbore insertion tube 1, the connection between the new optical fiber and the old optical fiber is disconnected. The component for pumping the fluid here can be a fluid pump. Specifically, the fluid is an environmentally friendly, non-toxic, non-corrosive liquid that does not chemically react with the pipe material. It can provide a pumping force by pumping, so that the old optical fiber can be pulled more easily at the wellhead position. While the old optical fiber is being pulled, due to the connection between the new optical fiber and the old optical fiber, the new optical fiber enters the wellbore insertion tube 1, completing the replacement.

[0053] The designated installation position of the specific in-well insertion pipe 1 can be any marked position in the pipe, which can determine the position of the new optical fiber. It can be defined in combination with the on-site installation requirements.

[0054] As the new optical fiber is gradually moved into its designated installation position within the wellbore insertion tube 1, communication information from the new optical fiber is captured to determine its installation status. The new optical fiber has one end connected to the old optical fiber and another end located above ground. This end provides feedback to determine whether the new optical fiber has been successfully inserted into the wellbore insertion tube 1, ensuring the reliability of the replacement. This "smooth" process implies that the new optical fiber could be damaged or broken during insertion. By capturing the new optical fiber's communication information, the replacement process can be monitored, ensuring reliability.

[0055] The new optical fiber communication information specifically refers to the new optical fiber connection and attenuation information, which can be monitored at regular intervals or in real time over a long period of time.

[0056] It should be noted that after confirming that the new optical fiber has been installed in place, disconnect the new optical fiber from the old optical fiber, remove the old optical fiber, and then proceed with the treatment.

[0057] In this embodiment, the outer periphery of the new optical fiber can be connected to a steel wire armor layer to reliably protect the optical fiber, ensure that the new optical fiber is monitored for a longer time, avoid damage during the insertion process, and ensure the reliability of the optical fiber insertion.

[0058] The above replacement method, before replacement, determines through the first pressure information and the old optical fiber detection information that it is the old optical fiber that is damaged, rather than being affected by the in-well insertion pipe 1, thereby ensuring accurate judgment before replacement, reducing the risk of replacement, and ensuring the reliability of replacement; during the replacement process, the installation status can be determined through the new optical fiber detection information, and it can be known in time whether the new optical fiber is successfully installed during the installation process, thereby reducing the risk of replacement and reducing the cost of replacement.

[0059] In addition to the above embodiment, after the new optical fiber is moved into the designated installation position of the well feed tube 1, the method further includes: controlling the discharge of fluid from the well feed tube 1 until it is empty. The empty state herein means that all the fluid in the well feed tube 1 is discharged. The specific discharge method can be to pump the fluid or to pneumatically push the fluid out. The discharged fluid can enter a circulation tank for subsequent use or can be directly discharged into a storage tank, without limitation.

[0060] Specifically, whether the new optical fiber has been moved into the designated installation position of the in-well entry tube 1 can be determined by the process of removing the old optical fiber or by the process of moving the new optical fiber in, without limitation. Specifically, the determination is made based on the movement path during the in-and-out process. For example, if a detection device is provided at the designated installation position of the in-well entry tube 1, the detection device can detect a detection point on the new optical fiber. If the detection device detects the detection point, it indicates that the new optical fiber has arrived at the designated installation position.

[0061] In the emptying state, gas can be introduced into the wellbore insertion tube 1 under the premise of ensuring the sealing of the wellbore insertion tube 1, and the second pressure information of the wellbore insertion tube 1 based on the pressure holding condition is obtained, and the sealing condition of the wellbore insertion tube 1 is determined based on the second pressure information. The determination of the sealing condition here is to test the sealing inside the tube again after installing the new optical fiber. Only when it is determined that the sealing inside the tube is intact can other operations be performed to avoid the situation where the sealing inside the tube has problems and the detection is incorrect even if the optical fiber is intact, thereby ensuring the reliability of the new optical fiber replacement process, realizing multi-directional monitoring of the replacement process, and ensuring the reliability and effectiveness of the replacement.

[0062] On the basis of the above-mentioned embodiment, determining the sealing condition of the in-well injection pipe 1 based on the second pressure information includes: determining the sealing condition of the in-well injection pipe 1 based on the second pressure information and the first pressure information; and / or determining the sealing condition of the in-well injection pipe 1 based on the second pressure information and the preset pressure information, the preset pressure information being the theoretical pressure range of the in-well injection pipe 1 in the pressure-holding state.

[0063] After obtaining the second pressure information, a judgment needs to be made to determine the sealing condition of the insertion pipe 1 in the well, and the specific determination can be made by comparing the second pressure information with the first pressure information. Here, it is specifically based on the first pressure information and also based on the detection of the pressure in the pipe under the pressure-holding state. Therefore, a direct comparison can be made. If the two are the same or the difference between the two is within a reasonable range, it means that the pipe is still well sealed after the new optical fiber is placed, and the replacement of the new optical fiber is reliable and smooth.

[0064] In addition, the sealing condition of the in-well insertion pipe 1 can be specifically determined through the second pressure information and the preset pressure information. This preset pressure information corresponds to the theoretical pressure range of the in-well insertion pipe 1 when it is in a pressure-holding state. If the second pressure information is within the preset pressure information, it means that the pipe is still well sealed after the new optical fiber is placed, and the replacement of the new optical fiber is reliable and smooth.

[0065] Based on any of the above embodiments, after determining the sealing condition of the wellbore insertion tube 1 based on the second pressure information, the method further includes: controlling the injection of a high-temperature resistant filler 3 between the new optical fiber and the wellbore insertion tube 1 until the tube is filled to a full state. The full state here specifically refers to the high-temperature resistant filler 3 being able to cover the portion of the new optical fiber placed in the wellbore insertion tube 1.

[0066] In this embodiment, the high temperature resistant filler 3 specifically includes but is not limited to special high temperature resistant materials such as polyethylene and fiber. By filling the high temperature resistant filler 3, the high temperature resistance of the inserted new optical fiber can be improved and the performance of use can be guaranteed.

[0067] The specific filling method of the high-temperature resistant filling body 3 can be controlled by controlling the on-off of the pipeline between the in-well injection pipe 1 and the high-temperature resistant filling body storage device, which is not specifically limited.

[0068] After filling the high-temperature resistant filling body 3 to a full state, if the high-temperature resistant filling body 3 requires a certain amount of time to solidify or confirm the filling condition, then set a period of time to verify the solidification. After that, control the new optical fiber to connect to the ground detection instrument to detect the optical fiber performance and confirm again to ensure the reliability and effectiveness of the new optical fiber replacement.

[0069] Based on any of the above embodiments, the well entry pipe 1 includes an entry end 11, a connecting end 12 and an exit end 13. The connecting end 12 connects the entry end 11 and the exit end 13. The ports of the entry end 11 and the exit end 13 are arranged flush. Figure 2 The connecting end 12 of the well-entry tube 1 is protruded relative to the moving-in end 11 and the moving-out end 13. When the optical fiber is passed through the well-entry tube 1, the protruding connecting end 12 can facilitate the passing of the optical fiber, increase the bending angle of the optical fiber, reduce the risk of optical fiber breakage, and facilitate the smooth passing of the optical fiber, thereby ensuring the reliability of optical fiber replacement.

[0070] In this embodiment, since the process of inserting the optical fiber into the well insertion tube 1 is not a completely straight fit, but is in a coiled state, and in view of different well conditions and different well field layouts, the length of the optical fiber needs to have a length margin. Compared with the theoretical calculated value, a certain proportion can be added as a length margin to ensure smooth and reliable replacement of the optical fiber.

[0071] Control the injection of the high-temperature resistant filler 3 between the new optical fiber and the in-well insertion tube 1 until it is filled to a full state, including: controlling the injection of the high-temperature resistant filler 3 from the insertion end 11 until the high-temperature resistant filler 3 flows to the removal end 13. When the high-temperature resistant filler 3 flows to the removal end 13, it indicates that the high-temperature resistant filler 3 has been filled in the in-well insertion tube 1, and the filled high-temperature resistant filler 3 can cover the new optical fiber to improve the high-temperature resistance of the optical fiber.

[0072] Based on any of the above embodiments, before obtaining the first pressure information of the wellbore insertion tube 1 under the pressure-holding condition, the method further includes: when sealing the wellhead, sealing the removal end 13 and the insertion end 11, and simultaneously sealing the head end of the new optical fiber to the wellbore insertion tube 1, and sealing the tail end of the new optical fiber; and pumping gas into the wellbore insertion tube 1 until the wellbore insertion tube 1 is in the pressure-holding state. When gas is pumped into the wellbore insertion tube 1, the wellhead, the removal end 13, the insertion end 11, and the tail end of the new optical fiber are reliably sealed, so that the pressure-holding state of the tube is achieved after the gas is introduced, thereby ensuring reliable and effective testing of the sealing performance of the wellbore insertion tube 1.

[0073] In this embodiment, the removal end 13 and the insertion end 11 are sealed and the head end of the new optical fiber is simultaneously sealed in the well insertion tube 1. This is because when the new optical fiber is replaced, the new optical fiber and the old optical fiber are connected, and the head end of the new optical fiber has been placed at the removal end 11. Therefore, when the removal end 11 is sealed, the head end of the new optical fiber is naturally sealed as well.

[0074] Based on any of the above embodiments, controlling the pumping of fluid into the wellbore tube 1 includes: controlling the first power element 5 to pump fluid into the wellbore tube 1 at a gradually increasing pumping speed, wherein when the first power element 5 is at the maximum pumping speed, the pumping force is less than the maximum tensile strength of the new optical fiber and the old optical fiber. The first power element 5 herein can be a hydraulic pump with a relatively small displacement and can be precisely controlled. When the new optical fiber reaches the designated installation position, a sealing test is performed, specifically by detecting second pressure information in the tube under a pressure-holding state. If the test is determined to be qualified based on the second pressure information, the pumping speed is gradually adjusted by the hydraulic pump. After the speed is adjusted to an appropriate speed, the old optical fiber is gradually pulled out using the thrust of the liquid pump and an external pulling force, and the new optical fiber is introduced.

[0075] Among them, when the first power element 5 is at the maximum pumping speed, the pumping force is less than the maximum tensile strength of the new optical fiber and the old optical fiber, so as to avoid damage or breakage of the new optical fiber and the old optical fiber, and avoid the connection between the new optical fiber and the old optical fiber from breaking in the tube, thereby ensuring the reliability of the placement of the new optical fiber.

[0076] In addition to the above-mentioned optical fiber replacement method, the present invention also provides a replacement device, including: an in-well insertion tube 1, a first power element 5, and a second power element 7. Figure 2 .

[0077] The first power element 5 is connected to the wellbore insertion pipe 1 and the fluid circulation system 6. The first power element 5 is used to pump the fluid into the wellbore insertion pipe 1. Specifically, the first power element 5 extracts the fluid in the fluid circulation system 6 and pumps the fluid into the wellbore insertion pipe 1 at a certain pumping speed, so as to realize the replacement process of the new and old optical fibers by thrust assistance. Figure 2 The optical fiber 2 in can be a new optical fiber or an old optical fiber.

[0078] The second power element 7 is connected to the wellbore injection pipe 1 and is used to control the gas flow into the wellbore injection pipe 1 to achieve pressure holding and fluid recovery relative to the fluid circulation system 6. Specifically, the second power element 7 can be an air compressor, which pressurizes the gas and delivers it to the wellbore injection pipe 1. The specific gas source can be achieved through the gas storage element 4. As for fluid recovery, after the new optical fiber is delivered to the designated installation position through the fluid, the gas is pressurized and delivered to the wellbore injection pipe 1 through the air compressor. The fluid in the wellbore injection pipe 1 is driven by the gas and returned to the fluid circulation system 6. After the return, the fluid can be prevented from flowing into the wellbore injection pipe 1 by closing the switch valve.

[0079] In this embodiment, the gas pressurized and transported by the second power element 7 may be nitrogen or other inert gases.

[0080] The control element is signal-connected to the first power element 5 and the second power element 7, and is used to execute the optical fiber replacement method of any of the above-mentioned embodiments. The control element here can obtain first pressure information of the wellbore insertion tube 1 under the pressure-holding condition and detection information of the old optical fiber, and determine whether the optical fiber needs to be replaced based on the first pressure information and the detection information of the old optical fiber. If necessary, under the premise that the new optical fiber and the old optical fiber are connected, the control element controls the first power element 5 to pump fluid into the wellbore insertion tube 1, so that the old optical fiber is removed from the wellbore insertion tube 1 and the new optical fiber is moved into the wellbore insertion tube 1;

[0081] Afterwards, when it is determined that the new optical fiber has moved to the designated installation position of the in-well insertion tube 1, the connection between the new optical fiber and the old optical fiber is disconnected, and during the movement of the new optical fiber, the control element determines the installation status based on the communication information of the new optical fiber. If the installation is determined to be correct, gas is introduced into the in-well insertion tube 1 by controlling the second power element 7 to discharge the fluid in the tube to the fluid circulation system 6, and then the second pressure information of the in-well insertion tube 1 under the pressure holding condition is obtained, and the sealing condition of the in-well insertion tube 1 is determined based on the second pressure information; if the sealing is good, the control element controls the injection of high-temperature resistant filling body 3 between the new optical fiber and the in-well insertion tube 1 until it is filled to a full state; then the control element controls the new optical fiber to connect to the ground detection instrument to detect the performance of the optical fiber and ensure the reliable filling of the new optical fiber.

[0082] Based on any of the above embodiments, please refer to Figure 2 、 Figure 4 The well insertion tube 1 includes an inlet end 11, a connecting end 12, and an outlet end 13, which are sequentially connected. The connecting end 12 is arc-shaped and protrudes relative to the outlet end 13 and the inlet end 11. The arc-shaped connecting end 12 facilitates the insertion of the optical fiber into the insertion tube, ensures smooth insertion, avoids fiber breakage or damage, and ensures the reliability of optical fiber replacement.

[0083] Specifically, connecting end 12 includes a first portion and a second portion connected thereto. Both the first and second portions initially expand outward in a first direction away from the first portion and then contract in a direction toward the first portion. The first direction is the axial direction of the wellbore insertion tube 1. When an optical fiber passes from the first portion to the second portion, it can reliably pass through the first portion by first expanding outward and then contracting. When entering the second portion, the contraction followed by expansion ensures smooth entry and passage through the removal end.

[0084] Specifically, the connecting end 12 can be viewed as a round gourd shape, or an elliptical shape, or a circle with a notch, etc., and can be flexibly changed to achieve the effect of improving the reliability of optical fiber insertion.

[0085] Based on any of the above embodiments, please refer to Figure 2 、 Figure 4 The replacement device also includes a seal 8, a stopper 9, and a protective sleeve 10 provided around the outer periphery of the insertion end 11 and the removal end 13. The protective sleeve 10 can be made of plastic and is primarily used to protect the portion of the in-well insertion tube 1 close to the wellhead, specifically the insertion end 11 and the removal end 13. This is because these two portions are close to the wellhead and are susceptible to wear or damage during optical fiber replacement. The provision of the protective sleeve 10 protects the insertion end 11 and the removal end 13, thereby ensuring the reliability of optical fiber replacement.

[0086] Please refer to Figure 2The seal 8 is positioned on the protective sleeve 10 away from the connecting end 12 to seal the ports at the entry and exit ends 11 and 13. Specifically, it is connected to the inner wall of the entry and exit ends 11 and 13, and ensures the tightness of the wellbore entry pipe 1 through an interference fit. The seal 8 must undergo temperature and pressure resistance testing, ensuring excellent sealing performance that is no less than the pressure and temperature resistance requirements of the matching optical cable. It must be protected from damage from bumps and repeated twisting and disassembly that may affect the sealing effect.

[0087] The stopper 9 is provided on the protective sleeve 10 near the connecting end 12 to prevent the insertion end 11 and the removal end 13 from being withdrawn from the protective sleeve 10. A plurality of stoppers 9 may be provided, and they can be securely connected to the outer periphery of the insertion end 11 and the removal end 13. In the event that the wellbore insertion tube 1 slips relative to the protective sleeve 10, the stoppers 9 can be used to prevent the wellbore insertion tube 1 from falling directly and causing an operational accident, thereby ensuring safety.

[0088] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0089] The above describes in detail the optical fiber replacement method and replacement device provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above examples is intended only to facilitate understanding of the method and core concepts of the present invention. It should be noted that those skilled in the art may make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for replacing an optical fiber, characterized in that: include: Obtaining the first pressure information of the well insertion pipe (1) under the pressure holding condition and the old optical fiber detection information, and determining whether the optical fiber needs to be replaced based on the first pressure information and the old optical fiber detection information; If replacement is required, when the new optical fiber is connected to the old optical fiber, fluid is pumped into the well insertion tube (1) to move the old optical fiber out of the well insertion tube (1) and move the new optical fiber into the well insertion tube (1), and when the new optical fiber moves to a designated installation position of the well insertion tube (1), the connection between the new optical fiber and the old optical fiber is disconnected; During the process of gradually moving the new optical fiber into the designated installation position of the in-well insertion tube (1), communication information of the new optical fiber is obtained to determine the installation status of the new optical fiber.

2. The optical fiber replacement method according to claim 1, characterized in that: After the new optical fiber is moved into the designated installation position of the in-well insertion tube (1), the method further includes: Controlling the discharge of fluid from the well inlet pipe (1) until it reaches an empty state; Second pressure information of the wellbore insertion pipe (1) under a pressure holding condition is obtained, and a sealing condition of the wellbore insertion pipe (1) is determined based on the second pressure information.

3. The optical fiber replacement method according to claim 2, characterized in that: Determining the sealing condition of the well insertion pipe (1) based on the second pressure information includes: Determining a sealing condition of the wellbore insertion pipe (1) based on the second pressure information and the first pressure information; And / or, the sealing condition of the wellbore insertion pipe (1) is determined based on the second pressure information and pressure preset information, wherein the pressure preset information is a theoretical pressure range of the wellbore insertion pipe (1) in a pressure-holding state.

4. The optical fiber replacement method according to claim 3, characterized in that: After determining the sealing condition of the wellbore insertion pipe (1) based on the second pressure information, the method further includes: Controlling the injection of a high-temperature resistant filler (3) between the new optical fiber and the well insertion tube (1) until the filling reaches a full state; The new optical fiber is controlled to connect to a ground detection instrument to detect the performance of the optical fiber.

5. The optical fiber replacement method according to claim 4, characterized in that: Controlling the injection of a high-temperature resistant filler (3) between the new optical fiber and the in-well insertion tube (1) until the space is filled to a full state, comprising: The well insertion pipe (1) comprises an entry end (11), a connecting end (12) and a removal end (13), wherein the connecting end (12) connects the entry end (11) and the removal end (13), and the ports of the entry end (11) and the removal end (13) are arranged flush with each other, and the high-temperature resistant filling body (3) is controlled to be injected from the entry end (11) until the high-temperature resistant filling body (3) flows to the removal end (13).

6. The optical fiber replacement method according to claim 5, characterized in that: Before obtaining the first pressure information of the well-mounted insertion pipe (1) under the pressure holding condition, the method further includes: When sealing the wellhead, the removal end (13) and the insertion end (11) are sealed and the head end of the new optical fiber is simultaneously sealed in the well insertion tube (1), and the tail end of the new optical fiber is sealed; Gas is pumped into the well inlet pipe (1) until the well inlet pipe (1) is in a pressure-holding state.

7. The optical fiber replacement method according to any one of claims 1 to 6, characterized in that: Controlling the pumping of fluid into the well inlet pipe (1) comprises: The first power element (5) is controlled to pump fluid into the wellbore tube (1) at a gradually increasing pumping speed, and when the first power element (5) is at the maximum pumping speed, the pumping force is less than the maximum tensile strength of the new optical fiber and the old optical fiber.

8. A replacement device, characterized in that: include: Pipe inserted into the well (1); A first power element (5) is connected to the wellbore insertion pipe (1) and the fluid circulation system (6), and the first power element (5) is used to pump the fluid into the wellbore insertion pipe (1); a second power element (7) connected to the well inlet pipe (1) and used to control the gas to flow into the well inlet pipe (1) to achieve pressure holding and fluid recovery relative to the fluid circulation system (6); A control element, signal-connecting the first power element (5) and the second power element (7), for executing the optical fiber replacement method according to any one of claims 1 to 7.

9. The replacement device according to claim 8, characterized in that The well entry pipe (1) comprises an entry end (11), a communication end (12), and an exit end (13) which are connected in sequence, wherein the communication end (12) is arc-shaped and is arranged to protrude relative to the exit end (13) and the entry end (11); The connecting end (12) comprises a first part and a second part connected thereto, wherein both the first part and the second part first expand outwards away from a first direction and then contract toward the first direction, wherein the first direction is the axial direction of the well insertion pipe (1).

10. The replacement device according to claim 9, characterized in that It also includes a sealing member (8) and a stopper (9), and a protective sleeve (10) is provided on the periphery of the moving-in end (11) and the moving-out end (13); The sealing member (8) is arranged at a position of the protective sleeve (10) away from the connecting end (12) to form a seal between the ports of the moving-in end (11) and the moving-out end (13); The stopper (9) is provided at a position of the protective sleeve (10) close to the communication end (12) and is used to prevent the moving-in end (11) and the moving-out end (13) from being withdrawn from the protective sleeve (10).

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