While-drilling optical fiber communication system and method

Abstract

The invention provides a while-drilling optical fiber communication system and method, and relates to the technical field of drilling engineering, and the while-drilling optical fiber communication system comprises a wellhead mechanism, a connection mechanism and a pay-off mechanism; the wellhead mechanism comprises a wellhead drill floor and a wellhead drill rod section; the connecting mechanism is located above the well mouth mechanism, can move up and down and comprises a fixing frame, a driving rod, a connecting drill rod section, a cable coiling device, a photoelectric sliding ring and a rigid connecting rod. And the upper end of the continuous drill rod section is detachably connected with the driving rod and the lower end is detachably connected with the wellhead drill rod section. A first optical fiber is arranged in the rigid connecting rod, and the rigid connecting rod is connected with a second optical fiber of the pay-off mechanism through a wet joint; the pay-off mechanism comprises a wire bin and an anchoring device, the top of the wire bin is provided with a wet connector connected with the second optical fiber, and the anchoring device fixes the wire bin and the continuous drill rod section. Through a three-stage optical fiber transmission path of'photoelectric composite cable-rigid connecting rod-wire cabin ', optical fiber communication maintenance during drill rod connection is realized, continuity and reliability of optical fiber communication during rotary drilling are ensured, and the problem of communication interruption is solved.

Description

Technical Field

[0001] This application relates to the technical field of drilling engineering, and particularly to a fiber optic communication system and method while drilling. Background Art

[0002] In China, oil and gas exploration is advancing towards complex fields such as low permeability, unconventional, deep and ultra-deep, and deep water. Drilling engineering faces major challenges in terms of efficiency, safety, and quality, and there is an urgent need for new drilling methods and technologies. Automated intelligent drilling and completion is the future trend, and its key lies in downhole measurement, transmission, and automatic control. This involves downhole real-time perception, parameter measurement and transmission, well-ground two-way high-speed communication, etc., which are the core conditions for realizing digital twin and visual drilling while drilling, supporting decision-making analysis such as drilling parameter optimization, risk prediction, and trajectory guidance and control, improving drilling efficiency, and reducing complex operation time. The communication speed of traditional measurement-while-drilling devices is slow, making it difficult to achieve real-time and efficient perception, and improving the real-time perception rate has become a research hotspot.

[0003] During the drilling and production process, the commonly used communication devices while drilling can be divided into two categories: wired transmission and wireless transmission. According to domestic and foreign research results, wired transmission is mostly based on the principle of logging cable transmission. The cable transmission method is one of the most widely used technologies in logging activities. It uses a multi-core cable as the transmission medium and places it inside the drill pipe by embedding method. After connecting each section of the drill pipe, a transmission link is built to achieve two-way communication of signals. However, the cable transmission method has problems such as slow transmission rate, large occupation of the internal space of the drill pipe, and susceptibility to electromagnetic interference, resulting in limitations in the reliability and efficiency of signal transmission.

[0004] Wireless transmission methods such as acoustic wave transmission, electromagnetic transmission, and mud transmission, although they solve some problems of cable transmission to a certain extent, also have deficiencies such as small information transmission volume, large signal attenuation, and poor anti-interference ability, and cannot meet the requirements of real-time and efficient communication in complex drilling environments.

[0005] Fiber optic communication technology while drilling is an advanced communication technology used in the oil and gas industry. Based on the advantages of the fiber optic communication field, fiber optic communication has characteristics such as large capacity, wide bandwidth, low loss, strong anti-interference, and good confidentiality performance, and is suitable for the transmission of high-speed and broadband information. The raw materials for making fiber optic are rich, environmentally friendly, and have a long service life. Fiber optic communication technology while drilling has advantages such as high bandwidth, strong anti-interference, corrosion resistance, high temperature and high pressure resistance, and real-time performance, which greatly improves the real-time monitoring and data transmission rate of the bottom hole conditions during the drilling of oil wells and gas wells.

[0006] However, through practical applications and experimental studies, it is found that during the process of connecting drill pipes during the lowering of the drill pipe, it is difficult for existing fiber optic communication devices while drilling to achieve the vertical docking of the optical fiber inside the original drill pipe and the connected drill pipe; and as the drilling depth continuously increases, the fiber optic communication device while drilling needs to store several kilometers of optical fiber for the upward transmission of downhole measurement signals. In addition, the optical fiber inside the drill pipe needs to continuously withstand the scouring of downhole mud and the strong vibration environment during the drilling process, making it difficult to ensure the reliability of the optical fiber. These factors directly affect the reception of downhole measurement signals at the ground information processing end. Therefore, how to smoothly lower the optical fiber and ensure normal communication during the drill pipe connection process is an important technical problem faced by the current fiber optic communication technology while drilling.

[0007] Application content

[0008] In view of this, the present application proposes a fiber optic communication system and method while drilling to solve the problems of smoothly lowering the optical fiber and ensuring normal communication during the drill pipe connection process.

[0009] The technical solution of the present application is implemented as follows:

[0010] On the one hand, the present application provides a fiber optic communication system while drilling, including:

[0011] A wellhead mechanism, including a wellhead drill floor and a wellhead drill pipe joint, and the wellhead drill pipe joint is installed on the wellhead drill floor;

[0012] A connection mechanism, located above the wellhead mechanism, capable of moving up and down relative to the wellhead mechanism, including a fixed frame, a driving rod, a connected drill pipe joint, a cable coiling device, an optoelectronic slip ring, and a rigid connecting rod. The driving rod is vertically arranged on the fixed frame and can rotate relative to the fixed frame. The upper end of the connected drill pipe joint is detachably connected to the driving rod, and the lower end is detachably connected to the wellhead drill pipe joint. The cable coiling device is arranged on the fixed frame for taking in and paying out the optoelectronic composite cable. The rigid connecting rod is internally provided with a first optical fiber, and a first wet joint is provided at the lower end of the rigid connecting rod. The upper end of the rigid connecting rod is mechanically connected to the optoelectronic slip ring. One end of the first optical fiber is optically coupled to the optoelectronic slip ring, and the other end is connected to the first wet joint. The rigid connecting rod can movably pass through the driving rod and the connected drill pipe joint;

[0013] A wire releasing mechanism, including a wire bin and an anchoring device. The second optical fiber is coiled on the wire bin, and the top of the wire bin has a second wet joint connected to the second optical fiber. The second wet joint is detachably connected to the first wet joint to establish a communication connection between the first optical fiber and the second optical fiber. The anchoring device is arranged on the wire bin for anchoring with the connected drill pipe joint.

[0014] Based on the above technical solution, preferably, the optical and electrical composite cable includes a protective outer sheath and at least one transmission optical fiber encapsulated therein. The protective outer sheath integrates a mechanical strengthening structure, and the load-bearing capacity of the optical and electrical composite cable is configured to be greater than the maximum total load generated by the optical and electrical slip ring, the rigid connecting rod, and the cable pay-off mechanism during downhole operations.

[0015] Based on the above technical solution, preferably, the optical and electrical composite cable further includes at least one power transmission cable encapsulated in the protective outer sheath. A first cable is arranged inside the rigid connecting rod. The upper end of the first cable is electrically connected to the power transmission cable through the optical and electrical slip ring. The lower end of the first cable is connected to the conductive contact of the first wet joint. A second cable is arranged in the cable bin. One end of the second cable is connected to the conductive contact of the second wet joint, and the other end is connected to the anchoring device.

[0016] Based on the above technical solution, preferably, the anchoring device includes an electric drive mechanism, a force transmission component, and a radially expandable anchoring execution component. The electric drive mechanism receives electric energy through the second cable, drives the force transmission component to convert the rotational motion into a linear displacement, and forces the anchoring execution component to radially expand and form a mechanical lock with the inner wall of the drill pipe joint.

[0017] Based on the above technical solution, preferably, a spiral winding groove is arranged on the outer peripheral wall of the cable bin along its axial direction, and the second optical fiber is wound in the winding groove.

[0018] Based on the above technical solution, preferably, the cable pay-off mechanism further includes a cable pay-off frame coaxially and fixedly arranged at the bottom of the cable bin. The anchoring device is arranged on the cable pay-off frame. A plurality of guide wheel groups are arranged outside the cable pay-off frame. The plurality of guide wheel groups are arranged at intervals in a spiral shape along the axial direction of the cable pay-off frame. Each guide wheel group includes two relatively rotatable guide wheels. The rotation axis of the guide wheel is perpendicular to the axis of the cable bin. A guide gap for the second optical fiber to pass through is formed between the two guide wheels.

[0019] Based on the above technical solution, preferably, the cable pay-off mechanism further includes a damper fixedly connected to the release end of the second optical fiber.

[0020] Based on the above technical solution, preferably, the cable coiling device includes a cable coiling shaft and a power source. The cable coiling shaft is rotatably arranged at the top of the fixed frame. The optical and electrical composite cable is coiled around the cable coiling shaft. One end is used to connect to the data acquisition device, and the other end is connected to the optical and electrical slip ring. The power source is used to drive the cable coiling shaft to rotate forward or backward.

[0021] Based on the above technical solutions, preferably, the wellhead mechanism further includes a locking device, which is arranged on the wellhead drill floor and is used to fix the wellhead drill pipe joint on the wellhead drill floor during the connection of drill pipe joints and allow the wellhead drill pipe joint to slide along the wellhead drill floor during drilling; the wire releasing mechanism further includes a support member, which is detachably arranged on the second wet joint and is used to temporarily fix the wire bin at the outlet end of the wellhead drill pipe joint during the connection of drill pipe joints.

[0022] In a second aspect, the present application provides a fiber optic communication method while drilling, which utilizes the fiber optic communication system while drilling described in the first aspect, and includes the following steps:

[0023] S1. Fix the wellhead drill pipe joint on the wellhead drill floor, place the wire releasing mechanism inside the wellhead drill pipe joint, and fix the wire bin at the outlet end of the wellhead drill pipe joint;

[0024] S2. Lift the connection mechanism to a certain height and connect the upper end of the connecting drill pipe joint and the lower end of the driving rod;

[0025] S3. Release the fiber optic composite cable, make the first wet joint pass through the connecting drill pipe joint and connect with the second wet joint, and establish an optical path connection between the first optical fiber and the second optical fiber;

[0026] S4. Cancel the fixation of the wire bin inside the wellhead drill pipe joint, recover the fiber optic composite cable, lift the wire bin into the connecting drill pipe joint, and anchor it to the inner wall of the connecting drill pipe joint through the anchoring device;

[0027] S5. Lower the connection mechanism, connect the lower end of the connecting drill pipe joint and the wellhead drill pipe joint, and release the fixation of the wellhead drill pipe joint on the wellhead drill floor;

[0028] S6. Rotate and lower the drill pipe to carry out drilling;

[0029] S7. When the connecting drill pipe joint enters the wellbore, stop drilling, disconnect the upper end of the connecting drill pipe joint and the lower end of the driving rod, fix the connecting drill pipe joint on the wellhead drill floor, release the anchoring between the wire bin and the inner wall of the connecting drill pipe joint, lift the wire bin to the outlet end of the connecting drill pipe joint, and fix the wire bin at the outlet end of the connecting drill pipe joint, and disconnect the connection between the first wet joint and the second wet joint;

[0030] S8. Lift the connection mechanism a certain height, connect the upper end of the new connecting drill pipe joint and the lower end of the driving rod, and repeat steps S3 - S7 to complete the continuous connection of drill pipes.

[0031] The present application has the following beneficial effects compared with the prior art:

[0032] (1) By providing a connection mechanism including an optoelectronic slip ring and a rigid link, and cooperating with a wire pay-off mechanism with a detachable wet joint, a three-level optical fiber transmission path of "optoelectronic composite cable - rigid link - wire bin" is constructed. The rigid link can pass through the drive rod and the connecting drill pipe joint movably to achieve physical penetration. The optoelectronic slip ring ensures the continuous transmission of optical signals in the rotating state, and the wet joint structure ensures accurate docking during connection, thus synchronously establishing the optical fiber channel and maintaining the communication link during the drill pipe connection process, solving the problems of optical fiber lowering interruption and communication failure caused by drill pipe connection in the traditional solution, and realizing the continuity and reliability of optical fiber communication under the rotating drilling condition.

[0033] (2) By integrating a power transmission channel in the optoelectronic composite cable and carrying out collaborative design with the rigid link - wire bin cable system, the synchronous transmission of optical fiber communication and power supply is realized, enabling the anchoring device to obtain electric control ability, thereby achieving the integrated integration and collaborative optimization of the power supply and communication functions of the communication system while drilling.

[0034] (3) The wire bin is lifted into the connecting drill pipe joint through the optoelectronic composite cable and anchored with the inner wall of the connecting drill pipe joint through the anchoring device. On the one hand, it is to ensure that the wire bin and the drill pipe rotate and lower synchronously. On the other hand, when the lower end of the drive rod is adjacent to the connecting drill pipe joint and drills into the wellbore, at this time the wire bin is just located at the upper part of the connecting drill pipe joint, which is convenient for directly lifting the wire bin into the new connecting drill pipe joint after the new connecting drill pipe joint is connected. The lifting displacement stroke of the wire bin is small and the connection efficiency is high.

[0035] (4) Through the design of the guide wheel group with spiral arrangement and optimized guide clearance, the friction force of the optical fiber during the wire pay-off process can be effectively reduced. At the same time, multiple guide wheel groups arranged at spiral intervals make the guiding of the optical fiber more accurate and not prone to stacking. When the optical fiber passes through the guide wheel group, due to the rotation of the guide wheel and the existence of the guide clearance, the force on the optical fiber is more uniform, avoiding the situation of optical fiber damage or unsmooth lowering caused by excessive friction. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1 is a schematic structural diagram of the communication system with optical fiber while drilling disclosed in the present application;

[0038] Figure 2 is a schematic structural diagram of the rigid link disclosed in the present application;

[0039] Figure 3 Schematic connection diagram of the optical and electrical composite cable, optical and electrical slip ring, and rigid connecting rod disclosed in the present application;

[0040] Figure 4 Schematic plan view of the wire pay-off mechanism disclosed in the present application;

[0041] Figure 5 Schematic plan view of the anchoring device disclosed in the present application;

[0042] Figure 6 Schematic view of the state after the connection drill pipe joint and the drive rod are assembled in the present application;

[0043] Figure 7 Schematic view of the connection state of the first wet joint and the second wet joint disclosed in the present application;

[0044] Figure 8 Schematic view of the state where the wire bin is lifted to the connection drill pipe joint in the present application;

[0045] Figure 9 Schematic view of the drilling state after the connection drill pipe joint and the wellhead drill pipe joint are assembled in the present disclosure;

[0046] Reference numerals:

[0047] 1. Wellhead mechanism; 11. Wellhead drill floor; 12. Wellhead drill pipe joint; 13. Locking device; 2. Connection mechanism; 21. Fixed frame; 22. Drive rod; 23. Connection drill pipe joint; 24. Cable coiling device; 25. Optical and electrical slip ring; 26. Rigid connecting rod; 261. First optical fiber; 262. First wet joint; 27. Optical and electrical composite cable; 271. Protective jacket; 272. Transmission optical fiber; 273. Power transmission cable; 263. First cable; 241. Cable coiling shaft; 242. Power source; 3. Wire pay-off mechanism; 31. Wire bin; 311. Wire winding groove; 32. Anchoring device; 33. Second optical fiber; 34. Second wet joint; 35. Second cable; 321. Electric drive mechanism; 322. Force transmission component; 323. Anchoring execution component; 36. Wire pay-off frame; 37. Guide wheel set; 371. Guide wheel; 38. Damper; 39. Support member. Detailed implementation manners

[0048] Next, in combination with the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0049] As Figure 1 shown, in combination withFigures 6 - 9 As shown in the figure, an embodiment of the present application discloses a fiber optic communication system while drilling, which includes a wellhead mechanism 1, a connection mechanism 2, and a cable releasing mechanism 3.

[0050] Among them, the wellhead mechanism 1 includes a wellhead drilling platform 11 and a wellhead drill pipe joint 12. The wellhead drilling platform 11 serves as the basic platform for drilling, bearing the wellhead drill pipe joint 12 and other upper equipment to ensure the stability and safety of the entire drilling operation. The wellhead drill pipe joint 12 is installed on the wellhead drilling platform 11 and serves as the starting connection part of the drill pipe, providing the initial support and connection point for the drill pipe, enabling the operation while drilling to proceed smoothly from the wellhead.

[0051] The connection mechanism 2 is located above the wellhead mechanism 1 and can move up and down relative to the wellhead mechanism 1. With this setting, a flexible operation space is provided during the drill pipe connection process to ensure the smooth progress of the connection operation.

[0052] In some embodiments, the connection mechanism 2 can be driven to move up and down by a lifting mechanism, such as a winch or an electric hoist.

[0053] The connection mechanism 2 of this embodiment includes a fixed frame 21, a driving rod 22, a connection drill pipe joint 23, and a cable coiling device 24.

[0054] Among them, the fixed frame 21 serves as the support structure of the connection mechanism 2, providing a stable platform to fix other components and ensuring the stability and reliability of the entire connection process.

[0055] The driving rod 22 is vertically arranged on the fixed frame 21 and can rotate relative to the fixed frame 21. In this embodiment, the driving rod 22 is a hollow structure, and the lower part of the driving rod 22 has an interface connected to the connection drill pipe joint 23, facilitating the detachable connection between the upper end of the connection drill pipe joint 23 and the lower end of the driving rod 22. At the same time, the lower end of the connection drill pipe joint 23 is detachably connected to the wellhead drill pipe joint 12.

[0056] In some embodiments, the upper end of the connection drill pipe joint 23 and the lower end of the driving rod 22 can be connected by male-female thread connection, clamp-type quick-release connection, or wet joint method. Correspondingly, the connection method between the lower end of the connection drill pipe joint 23 and the wellhead drill pipe joint 12 is the same. The rotation of the driving rod 22 on the fixed frame 21 can be achieved by a reduction motor in cooperation with a gear transmission method, or by a reduction motor in cooperation with a sprocket chain or pulley transmission method. The rotation of the driving rod 22 can enable the connected drill pipe to perform rotary drilling operations.

[0057] The cable coiling device 24 is arranged on the fixed frame 21 and is used for winding and unwinding the optical electric composite cable 27. Although the optical electric composite cable 27 can be released in the drill pipe, when the drill pipe needs to be connected, the optical electric composite cable 27 cannot be continuously lowered with the drill pipe.

[0058] To this end, the following technical solutions are adopted in this embodiment to achieve the goal.

[0059] Specifically, the connection mechanism 2 of this embodiment is further provided with an optical fiber slip ring 25 and a rigid connecting rod 26, and the wire releasing mechanism 3 is used to cooperate with the fiber optic cable release.

[0060] In this embodiment, a first optical fiber 261 is provided inside the rigid connecting rod 26, a first wet connector 262 is provided at the lower end of the rigid connecting rod 26, the upper end of the rigid connecting rod 26 is mechanically connected to the optical fiber slip ring 25, one end of the first optical fiber 261 is optically coupled to the optical fiber slip ring 25, and the other end is connected to the first wet connector 262. The rigid connecting rod 26 can pass through the driving rod 22 and the connecting drill pipe joint 23 movably.

[0061] The wire releasing mechanism 3 includes a wire bin 31 and an anchoring device 32. A second optical fiber 33 is wound around the wire bin 31. The top of the wire bin 31 has a second wet connector 34 connected to the second optical fiber 33. The second wet connector 34 is detachably connected to the first wet connector 262 so that the first optical fiber 261 and the second optical fiber 33 establish a communication connection. The anchoring device 32 is provided on the wire bin 31 for anchoring with the connecting drill pipe joint 23.

[0062] With such a setting, the cable coiling device 24 can take in and release the optical power composite cable 27, and the rigid connecting rod 26 and the optical fiber slip ring 25 rise or fall with the taking in and releasing of the optical power composite cable 27. At the initial connection, the wire releasing mechanism 3 is placed inside the wellhead drill pipe joint 12, and it is ensured that the wire bin 31 can be fixed at the upper opening end of the wellhead drill pipe joint 12, ensuring that the second wet connector 34 protrudes from the wellhead drill pipe joint 12. When the upper end of the connecting drill pipe joint 23 and the lower end of the driving rod 22 are connected, the optical power composite cable 27 is released. At this time, the rigid connecting rod 26 passes through the driving rod 22 and the connecting drill pipe joint 23. During the continuous release process, the first wet connector 262 at the lower end of the rigid connecting rod 26 is connected to the second wet connector 34 at the top of the wire bin 31. At this time, the second optical fiber 33 on the wire bin 31 and the first optical fiber 261 inside the rigid connecting rod are connected, establishing a communication connection among the second optical fiber 33, the first optical fiber 261, the optical fiber slip ring 25, and the optical power composite cable 27.

[0063] After the connection of the first wet joint 262 and the second wet joint 34 is completed, the fixation of the cable bin 31 inside the wellhead drill pipe joint 12 is cancelled, the fiber optic composite cable 27 is recovered, the cable bin 31 is lifted into the connecting drill pipe joint 23, and is anchored to the inner wall of the connecting drill pipe joint 23 through the anchoring device 32. The connecting mechanism 2 moves downward to connect the lower end of the connecting drill pipe joint 23 and the wellhead drill pipe joint 12, and the fixation of the wellhead drill pipe joint 12 on the wellhead drill floor 11 is released. At this time, the drive rod 22, the connecting drill pipe joint 23, and the wellhead drill pipe joint 12 form a drill pipe structure. The entire drill pipe structure is rotated by driving the drive rod 22 to rotate. At the same time, the drilling operation is realized by using the descent of the connecting mechanism 2. The cable bin 31 is anchored to the inner wall of the connecting drill pipe joint 23 at this time and can rotate and move downward synchronously with the drill pipe. As the cable bin 31 is lowered synchronously with the drill pipe and rotates, the second optical fiber 33 is gradually released. Due to the effect of the fiber optic slip ring 25, the cable bin 31 drives the rigid connecting rod to rotate relative to the fiber optic slip ring 25 during the rotation process, ensuring that the optical signal transmission is always maintained during the release of the second optical fiber 33, and ensuring the normal progress of optical fiber communication during the rotary drilling process after the drill pipe connection is completed.

[0064] After the connecting drill pipe joint 23 enters the wellbore, stop drilling, disconnect the upper end of the connecting drill pipe joint 23 and the lower end of the drive rod 22, fix the connecting drill pipe joint 23 on the wellhead drill floor 11, release the anchoring of the cable bin 31 and the inner wall of the connecting drill pipe joint 23, lift the cable bin 31 to the outlet end of the connecting drill pipe joint 23, and fix the cable bin 31 at the outlet end of the connecting drill pipe joint 23. Disconnect the connection between the first wet joint 262 and the second wet joint 34. The whole process returns to before the initial construction. The continuing mechanism is lifted by a certain height, a new connecting drill pipe joint 23 is reconnected, and then the connection between the first wet joint 262 and the second wet joint 34 is completed. Then, it is possible to continue to establish a communication connection between the second optical fiber 33, the first optical fiber 261, and the fiber optic composite cable 27 after the connection of the new drill pipe joint, thereby ensuring the normal progress of optical fiber communication during the drilling process and after the drill pipe connection is completed.

[0065] In this application, by setting the connecting mechanism 2 including the fiber optic slip ring 25 and the rigid connecting rod 26, and cooperating with the cable releasing mechanism 3 with detachable wet joints, a three-level optical fiber transmission path of "fiber optic composite cable 27 - rigid connecting rod 26 - cable bin 31" is constructed. The rigid connecting rod 26 can pass through the drive rod 22 and the connecting drill pipe joint 23 movably to achieve physical penetration. The fiber optic slip ring 25 ensures the continuous transmission of optical signals in the rotating state, and the wet joint structure ensures the precise docking during connection, so as to synchronously complete the establishment of the optical fiber channel and the maintenance of the communication link during the drill pipe connection process, solve the problems of the interruption of the optical fiber lowering and the communication failure caused by the drill pipe connection in the traditional scheme, and realize the continuity and reliability of optical fiber communication under the rotary drilling condition.

[0066] Since the fiber optic composite cable 27 requires a lifting and pay-off mechanism 3, in order to ensure the mechanical strength of the fiber optic composite cable 27 and prevent it from being broken during pulling, the fiber optic composite cable 27 is structurally configured in this embodiment. The fiber optic composite cable 27 includes a protective jacket 271 and at least one transmission optical fiber 272 encapsulated therein. By encapsulating the transmission optical fiber 272 in the protective jacket 271, both the physical protection of the optical fiber and the quality of optical signal transmission are ensured. The protective jacket 271 integrates a mechanical strengthening structure, such as an aramid fiber layer + steel wire armor, enabling the composite cable to have dual functions of signal transmission and mechanical load-bearing.

[0067] The load-bearing capacity of the fiber optic composite cable 27 in this embodiment is configured to be greater than the maximum total load generated by the optical slip ring 25, the rigid connecting rod 26, and the pay-off mechanism 3 during downhole operations. With this setting, the fiber optic composite cable 27 can have a strong load-bearing capacity when ensuring the lifting and pay-off mechanism 3, while ensuring stable transmission of the optical fiber signal.

[0068] In this embodiment, the reason for lifting the wire bin 31 into the internal part of the connecting drill pipe joint 23 through the fiber optic composite cable 27 and anchoring it to the inner wall of the connecting drill pipe joint 23 through the anchoring device 32 is that, on the one hand, it is to ensure that the wire bin 31 rotates and descends synchronously with the drill pipe. On the other hand, when the lower end of the driving rod 22 abuts against the connecting drill pipe joint 23 and drills into the wellbore, at this time, the wire bin 31 is just located above the connecting drill pipe joint 23, which is convenient for directly lifting the wire bin 31 into the new connecting drill pipe joint 23 after the new connecting drill pipe joint 23 is connected. The lifting displacement stroke of the wire bin 31 is small and the efficiency is high.

[0069] In order to enable the wire bin 31 to be anchored in the connecting drill pipe joint 23, the way adopted in this embodiment is to set the anchoring device 32 as electrically driven, because it is very difficult to achieve by other pure mechanical means. Specifically, as shown in the attached Figure 5 As shown, the anchoring device 32 in this embodiment includes an electric drive mechanism 321, a force transmission component 322, and a radially expandable anchoring execution component 323. The electric drive mechanism 321 drives the force transmission component 322 to convert the rotational motion into a linear displacement, forcing the anchoring execution component 323 to radially expand and form a mechanical lock with the inner wall of the drill pipe joint.

[0070] As some embodiments, the electric drive mechanism 321 is a DC servo motor. The force transmission component 322 includes a lead screw nut pair and a connecting rod mechanism. The anchoring execution component 323 is a circumferentially distributed umbrella-shaped anchor claw. When the DC servo motor is powered on, it drives the lead screw to rotate and drives the nut to move linearly, converting the axial displacement into a radial expansion motion of the umbrella-shaped anchor claw through the connecting rod mechanism, thereby anchoring to the inner wall of the connecting drill pipe joint 23.

[0071] As another implementation manner, the electric drive mechanism 321 is a piezoelectric ceramic motor, the force transmission assembly 322 includes a harmonic reducer and a cam mechanism, and the anchoring execution assembly 323 is an elastically deformable shape memory alloy ring;

[0072] When the piezoelectric ceramic motor is powered on, the cam is driven to rotate through the harmonic reducer, so that the shape memory alloy ring undergoes radial plastic deformation, forming an interference fit with the inner wall of the drill pipe joint, thereby realizing the anchoring of the wire bin 31 and the inner wall of the connecting drill pipe joint 23.

[0073] In order to supply power to the electric drive mechanism 321, the following technical solution is adopted in this embodiment.

[0074] Referring to the attached Figure 2 and 3 As shown, the optoelectronic composite cable 27 of this embodiment further includes at least one power transmission cable 273 encapsulated in the protective jacket 271. A first cable 263 is arranged in the rigid connecting rod 26. The upper end of the first cable 263 is electrically connected to the power transmission cable 273 through an optoelectronic slip ring 25. The lower end of the first cable 263 is connected to the conductive contact of the first wet joint 262. A second cable 35 is arranged in the wire bin 31. One end of the second cable 35 is connected to the conductive contact of the second wet joint 34, and the other end is connected to the anchoring device 32.

[0075] With this setting, when the first wet joint 262 and the second wet joint 34 are connected, not only the optical signal connection between the first optical fiber 261 and the second optical fiber 33 is realized, but also the electrical signal connection between the first cable 263 and the second cable 35 can be realized. In this way, while the optoelectronic composite cable 27 establishes an optical fiber communication connection through the transmission optical fiber 272, the first optical fiber 261 and the second optical fiber 33, it also establishes an electrical connection through the power transmission cable 273, the first cable 263, the second cable 35 and the electric drive mechanism 321 on the anchoring device 32, enabling the anchoring device 32 to obtain the ability of electric control, and realizing the highly integrated and collaborative optimization of the power supply and communication functions of the communication system while drilling.

[0076] By integrating a power transmission channel in the optoelectronic composite cable 27 and carrying out collaborative design with the rigid connecting rod 26 - wire bin 31 cable system, the synchronous transmission of optical fiber communication and power supply is realized, enabling the anchoring device 32 to obtain the ability of electric control, thereby achieving the integrated integration and collaborative optimization of the power supply and communication functions of the communication system while drilling.

[0077] As some embodiments, the wellhead mechanism 1 further includes a locking device 13. The locking device 13 is disposed on the wellhead drill floor 11 and is used to fix the wellhead drill pipe joint 12 to the wellhead drill floor 11 during the connection of drill pipe joints, and allows the wellhead drill pipe joint 12 to slide along the wellhead drill floor 11 during drilling. Specifically, before the drill pipe connection, the wellhead drill pipe joint 12 is first fixed to the wellhead drill floor 11 through the locking device 13. After the drill pipe connection is completed, the fixation of the wellhead drill pipe joint 12 on the wellhead drill floor 11 is released through the locking device 13, so that the connection mechanism 2 drives the wellhead drill pipe joint 12 to rotate downward and drill.

[0078] As some embodiments, the locking device 13 can be a safety slip or other mechanical clamping mechanisms, as long as it can fix the wellhead drill pipe joint 12 to the wellhead drill floor 11 and prevent axial and circumferential displacement of the wellhead drill pipe joint 12.

[0079] Before the connection of the drill pipe joint 23 is completed, it is necessary to separate the second wet joint 34 from the first wet joint 262. At this time, the entire wire laying mechanism 3 needs to be first fixed on the wellhead drill pipe joint 12 or the drill pipe joint 23 that has been drilled into the wellbore. However, since the second wet joint 34 and the first wet joint 262 are separated, the anchoring device 32 has no electric energy drive at this time and cannot anchor the wire bin 31 and the inner wall of the drill pipe. Therefore, the following technical solutions are adopted in this application to achieve it.

[0080] The wire laying mechanism 3 further includes a support member 39. The support member 39 is detachably disposed on the second wet joint 34 and is used to temporarily fix the wire bin 31 to the outlet end of the wellhead drill pipe joint 12 during the connection of drill pipe joints. With such a technical solution, before the initial connection, the support member 39 is manually installed on the second wet joint 34, and the entire wire laying mechanism 3 is placed into the wellhead drill pipe joint 12. The support member 39 contacts the upper inner wall of the wellhead drill pipe joint 12 to play a supporting role and prevent the entire wire laying mechanism 3 from falling downward.

[0081] During the subsequent connection of drill pipe joints, after the previous connected drill pipe joint 23 is drilled into the wellbore, at this time, after the driving rod 22 is disengaged from the current connected drill pipe joint 23, the wire laying mechanism 3 is lifted upward through the fiber optic composite cable 27, so that the second wet joint 34 on the wire bin 31 is exposed from the current connected drill pipe joint 23. The support member 39 is manually installed on the second wet joint 34, so that the support member 39 contacts the inside of the current connected drill pipe joint 23, realizing the temporary fixation of the wire laying mechanism 3 above the current connected drill pipe. In this way, the second wet joint 34 and the first wet joint 262 can be safely separated, and then the connection and installation of the next connected drill pipe joint 23 can be carried out. After the next connected drill pipe joint 23 is connected to the driving rod 22, the second wet joint 34 and the first wet joint 262 are connected. At this time, the support member 39 can be removed.

[0082] In this embodiment, the cable coiling device 24 includes a cable coiling shaft 241 and a power source 242. The cable coiling shaft 241 is rotatably arranged on the top of the fixed frame 21. The optical and electrical composite cable 27 is coiled around the cable coiling shaft 241. One end of the cable is used to connect to the data acquisition device, and the other end is connected to the optical and electrical slip ring 25. The power source 242 is used to drive the cable coiling shaft 241 to rotate forward or backward. By rotating the cable coiling shaft 241 forward or backward, the release and recovery of the optical and electrical composite cable 27 can be realized. In this embodiment, the power source 242 can be a reduction motor.

[0083] It should be noted that, in order to implant the optical fiber into the wellbore during the drilling process, in this embodiment, the second optical fiber 33 is wound around the wire bin 31 and thus lowered along with the drilling. In order to avoid entanglement during the release of the optical fiber, referring to the attached Figure 4 As shown, a spiral groove 311 is provided on the outer peripheral wall of the wire bin 31 of this embodiment along its axial direction, and the second optical fiber 33 is wound in the spiral groove 311.

[0084] The spiral groove 311 can guide the optical fiber to wind and release along a predetermined path, avoiding the interlacing and entanglement of the optical fibers during the release process. This design ensures that the optical fiber can be smoothly lowered during the drilling process, thus effectively avoiding the entanglement problem that may occur during the release process and ensuring the continuity and stability of the optical fiber.

[0085] In order to avoid the winding and bending of the optical fiber during the lowering process, the wire releasing mechanism 3 of this embodiment further includes a damper 38, and the damper 38 is fixedly connected to the release end of the second optical fiber 33. With this setting, the damper 38 has a certain weight and can straighten the second optical fiber 33 by pulling, avoiding the entanglement of the release end of the optical fiber without restraint.

[0086] In order to avoid the winding and knotting of the optical fiber during the release process, the wire releasing mechanism 3 of this embodiment is further provided with a wire releasing frame 36. The wire releasing frame 36 is coaxially and fixedly arranged at the bottom of the wire bin 31. The anchoring device 32 is arranged on the wire releasing frame 36. A plurality of guide wheel groups 37 are arranged outside the wire releasing frame 36. The plurality of guide wheel groups 37 are arranged at intervals in a spiral shape along the axial direction of the wire releasing frame 36. The guide wheel group 37 includes two relatively rotatable guide wheels 371. The rotation axis of the guide wheel 371 is perpendicular to the axis of the wire bin 31. A guiding gap for the second optical fiber 33 to pass through is formed between the two guide wheels 371.

[0087] The design of the guide wheel group 37 can effectively reduce the friction force of the optical fiber during the wire releasing process through the spiral arrangement and the optimization of the guiding gap. At the same time, the plurality of guide wheel groups 37 arranged at intervals in a spiral shape make the guiding of the optical fiber more accurate and not prone to accumulation. When the optical fiber passes through the guide wheel group 37, due to the rotation of the guide wheel 371 and the existence of the guiding gap, the force on the optical fiber is more uniform, avoiding the situation that the optical fiber is damaged or the lowering is not smooth due to excessive friction.

[0088] The axis of the guide wheel 371 is perpendicular to the axis of the wire bin 31, which helps the optical fiber to be smoothly lowered along an ideal path. Through the continuous action of multiple guide wheel groups 37, the optical fiber can be evenly guided, avoiding the possible bending or entanglement problems of the optical fiber during the wire pay-off process, thus improving the stability of the optical fiber lowering.

[0089] This embodiment also discloses a fiber optic communication system while drilling, including the following steps:

[0090] S1. Fix the wellhead drill pipe joint 12 on the wellhead drill floor 11, place the wire pay-off mechanism 3 inside the wellhead drill pipe joint 12, and fix the wire bin 31 at the outlet end of the wellhead drill pipe joint 12.

[0091] This step

[0092] S2. Lift the connection mechanism 2 to a certain height, and connect the upper end of the connection drill pipe joint 23 and the lower end of the drive rod 22;

[0093] S3. Release the electro-optical composite cable 27, make the first wet joint 262 pass through the connection drill pipe joint 23 and connect with the second wet joint 34, and establish the optical path connection between the first optical fiber 261 and the second optical fiber 33;

[0094] S4. Cancel the fixation of the wire bin 31 inside the wellhead drill pipe joint 12, recover the electro-optical composite cable 27, lift the wire bin 31 into the connection drill pipe joint 23, and anchor it to the inner wall of the connection drill pipe joint 23 through the anchoring device 32;

[0095] S5. Lower the connection mechanism 2, connect the lower end of the connection drill pipe joint 23 and the wellhead drill pipe joint 12, and release the fixation of the wellhead drill pipe joint 12 on the wellhead drill floor 11;

[0096] S6. Drive the drill pipe to rotate and lower for drilling;

[0097] S7. When the connection drill pipe joint 23 enters the wellbore, stop drilling, disconnect the upper end of the connection drill pipe joint 23 and the lower end of the drive rod 22, fix the connection drill pipe joint 23 on the wellhead drill floor 11, release the anchoring between the wire bin 31 and the inner wall of the connection drill pipe joint 23, lift the wire bin 31 to the outlet end of the connection drill pipe joint 23, and fix the wire bin 31 at the outlet end of the connection drill pipe joint 23, and disconnect the connection between the first wet joint 262 and the second wet joint 34;

[0098] S8. Lift the connection mechanism 2 to a certain height, connect the upper end of the new connection drill pipe joint 23 and the lower end of the drive rod 22, and repeat steps S3 - S7 to complete the continuous connection of the drill pipe.

[0099] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included within the protection scope of the present application.

Claims

1. A fiber optic communication system while drilling, characterized in that: include: A wellhead mechanism, comprising a wellhead drilling platform and a wellhead drill pipe section, wherein the wellhead drill pipe section is installed on the wellhead drilling platform; The connecting mechanism is located above the wellhead mechanism and can move up and down relative to the wellhead mechanism. The connecting mechanism includes a fixed frame, a driving rod, a connecting drill pipe section, a cable coiling device, an optoelectronic slip ring and a rigid connecting rod. The driving rod is vertically arranged on the fixed frame and can rotate relative to the fixed frame. The upper end of the connecting drill pipe section is detachably connected to the driving rod, and the lower end is detachably connected to the wellhead drill pipe section. The cable coiling device is arranged on the fixed frame and is used to retract and release the optoelectronic composite cable. A first optical fiber is arranged inside the rigid connecting rod, and a first wet joint is arranged at the lower end of the rigid connecting rod. The upper end of the rigid connecting rod is mechanically connected to the optoelectronic slip ring. One end of the first optical fiber is optically coupled to the optoelectronic slip ring, and the other end is connected to the first wet joint. The rigid connecting rod can movably pass through the driving rod and the connecting drill pipe section. The wire-releasing mechanism comprises a wire bin and an anchoring device, wherein a second optical fiber is wound on the wire bin, and a second wet joint connected to the second optical fiber is provided on the top of the wire bin, and the second wet joint is detachably connected to the first wet joint so that a communication connection is established between the first optical fiber and the second optical fiber, and the anchoring device is arranged on the wire bin for anchoring with the subsequent drill pipe section.

2. The fiber-optic communication while drilling system according to claim 1, characterized in that: The optoelectronic composite cable includes a protective jacket and at least one transmission optical fiber encapsulated therein, the protective jacket has an integrated mechanical reinforcement structure, and the load-bearing capacity of the optoelectronic composite cable is configured to be greater than the maximum total load generated by the optoelectronic slip ring, rigid connecting rod and wire-releasing mechanism during underground operation.

3. The fiber-optic communication while drilling system according to claim 2, characterized in that: The optoelectronic composite cable also includes at least one power transmission cable encapsulated in a protective jacket. A first cable is arranged in the rigid connecting rod. The upper end of the first cable is electrically connected to the power transmission cable through an optoelectronic slip ring. The lower end of the first cable is connected to the conductive contact of the first wet joint. A second cable is arranged in the wire bin. One end of the second cable is connected to the conductive contact of the second wet joint, and the other end is connected to the anchoring device.

4. The fiber-optic communication system while drilling according to claim 3, characterized in that: The anchoring device includes an electric drive mechanism, a force transmission component and a radially expandable anchoring actuator component. The electric drive mechanism receives electrical energy through a second cable, drives the force transmission component to convert rotational motion into linear displacement, and forces the anchoring actuator component to expand radially and form a mechanical lock with the inner wall of the drill pipe section.

5. The fiber-optic communication while drilling system according to claim 1, characterized in that: The outer peripheral wall of the wire bin is provided with a winding groove with a spiral structure along its axial direction, and the second optical fiber is wound in the winding groove.

6. The fiber-optic communication while drilling system according to claim 1, characterized in that: The pay-off mechanism also includes a damper, which is fixedly connected to the release end of the second optical fiber.

7. The fiber-optic communication while drilling system according to claim 6, characterized in that: The pay-off mechanism also includes a pay-off frame, which is coaxially fixed to the bottom of the wire bin, and the anchoring device is arranged on the pay-off frame. A plurality of guide wheel groups are arranged on the outside of the pay-off frame, and the plurality of guide wheel groups are spirally arranged at intervals along the axial direction of the pay-off frame. The guide wheel group includes two guide wheels that rotate relative to each other, and the rotating shaft of the guide wheel is perpendicular to the axis of the wire bin, and a guide gap is formed between the two guide wheels for the second optical fiber to pass through.

8. The fiber-optic communication while drilling system according to claim 1, characterized in that: The cable winding device includes a cable winding shaft and a power source. The cable winding shaft is rotatably arranged on the top of the fixed frame. The optoelectronic composite cable is wound on the cable winding shaft. One end of the cable winding shaft is used to connect with the data acquisition equipment, and the other end is connected with the optoelectronic slip ring. The power source is used to drive the cable winding shaft to rotate forward or reverse.

9. The fiber-optic communication while drilling system according to claim 1, characterized in that: The wellhead mechanism also includes a locking device, which is arranged on the wellhead drilling platform and is used to fix the wellhead drill rod section on the wellhead drilling platform when the drill rod section is connected, and to allow the wellhead drill rod section to slide along the wellhead drilling platform during drilling; the line-releasing mechanism also includes a support member, which is detachably arranged on the second wet joint and is used to temporarily fix the line bin to the outlet end of the wellhead drill rod section when the drill rod section is connected.

10. A method for optical fiber communication while drilling, which utilizes the optical fiber communication while drilling system according to any one of claims 1 to 9, characterized in that: The steps include: S1. Fix the wellhead drill pipe section on the wellhead drilling platform, place the wire-releasing mechanism in the wellhead drill pipe section, and fix the wire bin at the outlet end of the wellhead drill pipe section; S2, lifting the connecting mechanism to a certain height, and connecting the upper end of the connecting drill pipe section and the lower end of the driving rod; S3, releasing the optoelectronic composite cable, allowing the first wet joint to pass through the connecting drill pipe section and connect to the second wet joint, thereby establishing an optical path connection between the first optical fiber and the second optical fiber; S4, cancel the fixation of the wire bin in the wellhead drill pipe section, recover the photoelectric composite cable, lift the wire bin into the connecting drill pipe section, and anchor it through the anchoring device and the inner wall of the connecting drill pipe section; S5, the connecting mechanism descends, connects the lower end of the connecting drill pipe section with the wellhead drill pipe section, and releases the fixation of the wellhead drill pipe section on the wellhead drilling platform; S6, driving the drill rod to rotate and lower it for drilling; S7, when the connecting drill pipe section enters the wellbore, stop drilling, disconnect the upper end of the connecting drill pipe section and the lower end of the driving rod, fix the connecting drill pipe section on the wellhead drilling platform, release the anchoring of the line bin and the inner wall of the connecting drill pipe section, lift the line bin to the outlet end of the connecting drill pipe section, and fix the line bin to the outlet end of the connecting drill pipe section, and disconnect the connection between the first wet joint and the second wet joint; S8, the connecting mechanism is raised to a certain height, the upper end of the new connecting drill rod section is connected to the lower end of the driving rod, and steps S3-S7 are repeated to complete the continuous connection of the drill rod.

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