Wireless signal transmission device and method in closed annulus of underwater production well

Abstract

The invention provides a wireless signal transmission device and method in a closed annulus of an underwater production well. The wireless signal transmission device comprises an oil pipe nipple, a casing pipe nipple and a protective sleeve. The oil pipe nipple is made of Inconel 625 alloy, is connected with an underground oil pipe in a meshed mode through threaded connectors arranged at the two ends and is connected with a cable laid on the oil pipe through a cable interface, the interior of the nipple is hollow, the nipple is used for an oil and gas channel, an elastic positioning block is arranged outside the nipple, and the coil and the energy transmission module are jointly arranged in an inner containing cavity of the nipple. The material of the casing pipe nipple is the same as that of a common casing pipe, the casing pipe nipple is connected with an underground casing pipe in a meshed mode through threaded connectors arranged at the two ends, a positioning sleeve is arranged on the inner wall of the pipe nipple, a protective sleeve is arranged on the outer wall of the pipe nipple, the protective sleeve is made of Inconel 625 alloy and is fixed to the casing pipe nipple in a hoop connection mode, and a containing cavity is formed in the sleeve. The coil, the energy signal transmission module and the battery energy storage module are arranged in the power supply module together, and power is supplied to an underground instrument through the interface. All the modules are matched with one another, and underground wireless electric energy signal transmission is achieved. The device can be arranged in a main well hole and all branch well holes in series along a cable in a multi-branch well according to requirements, the underground integrity monitoring range is expanded, and the device has the advantages of being easy to install, stable, reliable and free of interference on underground production.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field development and production, and in particular to a downhole wireless power signal transmission device and method based on magnetic coupling resonance. Background Art

[0002] Traditional wells on land and offshore have valves at their wellheads, so operators can easily read the data of the casing annulus in the well. However, there is an annulus blockage between the casing and the oil pipe in deepwater wellheads, making it difficult to monitor and read data. Using wired cables to penetrate the casing as a permanent transmission carrier in the well will destroy the sealing of the wellbore and increase the risk of leakage. In addition, the cable is prone to aging and damage in high temperature, high pressure and corrosive environments, making it difficult to achieve. Therefore, realizing wireless signal transmission in the closed annulus during the production process is crucial to maintaining the integrity of the wellbore and ensuring the safe production of oil and gas fields.

[0003] CN114439468A discloses a real-time monitoring system for casing annulus pressure at an underwater wellhead, which mainly includes an electromagnetic induction wireless telemetry system and a hydroacoustic telemetry system. The pressure data of the casing annulus is monitored by the electromagnetic induction wireless telemetry system, and the pressure data is sent to a data receiving device on the surface through hydroacoustic communication. The device has the advantage of being able to monitor the casing annulus pressure in real time. However, the method is difficult to implement, and there are many design instruments, which will be greatly restricted in application.

[0004] CN103670366A discloses a downhole wireless charging mechanical device, which includes an independent downhole charging short-section device and a cable-carrying charging device, and can realize the downhole wireless charging function to provide power for instruments that stay downhole for a long time. However, the device has not considered the wireless transmission of power under casing shielding, nor has it involved the design of downhole signal wireless transmission, and has a single function and is lacking.

[0005] The purpose of the present invention is to construct a wireless signal transmission device and method in a closed annulus of an underwater production well, so as to realize the transmission of electric energy signals in a closed annulus of a deepwater well, expand the monitoring range of wellbore integrity, and ensure the safety of the oil and gas production process. At present, there are no reports related to the method and device. Summary of the invention

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A wireless signal transmission device and method in a closed annulus of an underwater production well, comprising:

[0008] Tubing nipples, casing nipples and protective sleeves;

[0009] The oil pipe short section is connected to the downhole oil pipe by interlocking with the threaded joints arranged at both ends, and is lowered together with the oil pipe during the well completion operation;

[0010] The oil pipe nipple is connected to the cable laid on the oil pipe through the cable interface;

[0011] Furthermore, the tubing nipple comprises an elastic positioning block, an energy signal processing module, an electric energy transmitting coil and a signal receiving coil;

[0012] The elastic positioning block cooperates with the casing positioning sleeve to position the relative position of the oil casing. During the lowering process of the oil pipe, its elastic mechanism remains retracted. When it meets and couples with the target casing, the positioning block pops out and achieves positioning.

[0013] The energy signal processing module integrates an electric energy transmission processing module and a signal receiving processing module, one end of which is connected to the cable through a connector, and the other end of which is connected to the electric energy transmission coil and the signal receiving coil respectively through an interface;

[0014] The power transmission processing module includes a driving module and a rectifying and voltage stabilizing module, which are used to receive a 220V AC power supply from a cable and provide a stable output;

[0015] The signal receiving and processing module includes a conditioning module, a demodulation module, a decoding module and a signal acquisition module, each of which is sequentially arranged and integrated on the same circuit board. One end is connected to the signal receiving coil to receive and process the wireless signal transmitted by the signal transmitting coil; the other end is connected to the connector and cable to transmit the signal back to the remote central control.

[0016] The electric energy transmitting coil is connected to the electric energy transmitting processing module through an interface, and the coil is arranged in a groove provided in the internal accommodation cavity of the short section and is padded with a padded material;

[0017] The padding material is stacked with silicon steel sheets. After padding, there is still a gap between the outer wall of the oil pipe and the inner wall of the casing to avoid upper and lower blocking.

[0018] The signal receiving coil is connected to the signal receiving processing module through an interface, and is spatially arranged in parallel with the power transmitting coil in a groove provided in the internal accommodation cavity of the short section, and is also raised.

[0019] Furthermore, the casing pup joint is connected to the downhole casing by interlocking with threaded joints arranged at both ends, and a positioning sleeve is provided on the inner wall of the casing pup joint to cooperate with the elastic positioning block of the oil pipe for positioning.

[0020] Furthermore, the protective sleeve is hollow inside and is provided with a receiving cavity and a groove, and is fixed to the outer wall of the casing short section by a clamp connection method, and includes an energy signal processing module, an electric energy receiving coil, a signal transmitting coil and a battery energy storage module;

[0021] The energy signal processing module integrates an electric energy receiving processing module and a signal transmitting processing module, one end of which is connected to the electric energy receiving coil and the signal transmitting coil respectively through an interface, and the other end is connected to the battery energy storage module;

[0022] The power receiving and processing module includes a rectifying and voltage stabilizing module and a compensation module, which are used to stabilize the voltage fluctuation at the receiving end and reduce power loss;

[0023] The compensation module takes into account the small volume and high temperature of the underground annulus, and adopts the SS type compensation circuit topology to reduce passive components and further reduce the volume;

[0024] The signal transmission processing module includes a conditioning module, an encoding module and a modulation module, which are used to process the downhole instrument acquisition signal and transmit it to the signal transmission coil;

[0025] The power receiving coil is wound and arranged in the inner groove of the sleeve, and is connected to the power receiving processing module through an interface;

[0026] The signal transmitting coil is connected to the signal transmitting processing module through the interface, and is spatially arranged in parallel with the power receiving coil in a groove provided in the accommodating cavity inside the sleeve;

[0027] The battery energy storage module has multiple batteries arranged in a surrounding manner in the accommodating cavity groove. One end of the battery is connected to the battery management system, and the other end is connected to the downhole instrument.

[0028] The battery management system has a built-in discrimination circuit. When it is determined that charging is completed, the discrimination circuit transmits a discrimination signal back to the remote central control through the power transmission route. After receiving the signal, the remote central control issues a control instruction to shut down the power transmission part and sends a driving signal for signal transmission.

[0029] The wireless signal transmission device of the present invention can be arranged in series along the cable in a single wellbore according to the integrity monitoring requirements, and in a multi-branch well, it can be arranged in the main wellbore and each branch wellbore respectively, and each device operates independently without interfering with each other.

[0030] The aforementioned power signal transmission and distribution is performed through a downhole network controller located in the underwater production system, and electrical and communication interfaces are provided for each device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of a wireless signal transmission device in a closed annulus of an underwater production well proposed by the present invention;

[0032] Figure 2 This is a general flow chart of a wireless signal transmission device in a closed annulus of an underwater production well proposed by the present invention;

[0033] Figure 3 This is a working diagram of wireless transmission of electric energy signals of a wireless signal transmission device in a closed annulus of an underwater production well proposed by the present invention.

[0034] In the above figures, 1. remote central control; 2. sea level; 3. umbilical cable; 4. blowout preventer; 5. downhole network controller; 6. underwater wellhead; 7. seabed mud surface; 8. oil pipe; 9. casing; 10. wellbore a; 11. main wellbore; 12. wellbore b; 13. cable; 14. oil pipe short section; 15. casing coupling; 16. oil pipe coupling; 17. oil pipe side power signal processing module; 18. elastic positioning block; 19. positioning sleeve; 20. protective sleeve; 21. casing side power signal processing module; 22. power transmitting coil; 23. power receiving coil; 24. signal transmitting coil, 25. signal receiving coil; 26. battery energy storage module; 27. downhole instrument; 28. casing short section. DETAILED DESCRIPTION

[0035] The present invention is described in detail below by means of exemplary embodiments. However, it should be understood that the elements, structures and features in one embodiment may also be beneficially combined in other embodiments without further description.

[0036] In the description of the present invention, it should be noted that the terms "inside", "outside", "upper", "lower", "front", "back" and the like indicate positions or positional relationships based on the positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0037] See also Figure 1-3 The present invention proposes a wireless signal transmission device and method in a closed annulus of an underwater production well. The device and method are integrated in the modules 1-27. The main implementation process is as follows:

[0038] 1) Initialize and self-check the wireless signal transmission device in the closed annulus of the underwater production well on the ground. If all components can work normally, proceed to the next step, otherwise, repeat this step;

[0039] 2) The tubing nipple 14 and the casing nipple 28 are respectively fixed to the tubing string and the casing string by means of a coupling connection, and the protection sleeve 20 is fixed to the outer wall of the casing nipple 28 by means of a clamp connection, and is lowered together with the completion operation;

[0040] 3) Establish electrical connection between the cable 13 laid on the oil pipe and the oil pipe nipple 14 through the cable connector;

[0041] 4) The remote central control 1 sends a charging instruction to the underwater production system, and the downhole network controller 5 carried by the underwater production system performs power signal transmission and distribution to ensure that the operation of each module does not interfere with each other;

[0042] 5) After the electric energy is distributed by the downhole network controller 5, it is transmitted to the electric energy signal processing module 17 on the oil pipe side inside the oil pipe nipple 14 through the laying cable 13;

[0043] 6) The power signal processing module receives the 220V AC power from the cable and transmits it to the power transmitting coil 22 after rectification and voltage stabilization;

[0045] 7) The power transmitting coil 22 is coupled to the power receiving coil 23, and the power is transmitted to the power receiving coil 23 through the principle of magnetic induction coupling;

[0047] 8) The electric energy of the electric energy receiving coil 23 is processed by the bushing side electric energy signal processing module 21 and transmitted to the battery energy storage module 26;

[0048] 9) The battery energy storage module 26 is provided with an interface to connect to the downhole instrument 27 and supply power;

[0049] 10) The identification circuit of the battery energy storage module 26 makes a judgment. When it is judged that charging is completed, the identification signal is transmitted back to the remote central control 1 through the power transmission route. After receiving the signal, the remote central control 1 issues a control command to shut down the power transmission part and sends a driving signal for signal transmission.

[0050] 11) The battery energy storage module 26 supplies power, and the downhole instrument 27 transmits the stored data signal to the casing side power signal processing module

[0051] 21, the signal is transmitted to the signal transmitting coil 24 after being encoded, modulated, amplified and filtered.

[0052] 12) The battery energy storage module 26 supplies power, the signal transmitting coil 24 is coupled with the signal receiving coil 25, and based on the principle of electromagnetic induction, the signal is transmitted to the signal receiving coil 25;

[0053] 13) The signal receiving coil 25 transmits the signal to the electric energy signal processing module 17 on the oil pipe side. After filtering, demodulation and decoding, the signal is transmitted back to the remote central control 1 via a cable, and finally the signal transmission part is completed.

[0054] 14) When the judgment circuit of the battery energy storage module 26 determines that the battery power is lower than the set warning value, the judgment signal is transmitted back to the remote central control 1 through the power transmission route. After receiving the signal, the remote central control 1 sends a charging instruction to transmit power again.

Claims

1. A wireless signal transmission device and method in a closed annulus of an underwater production well, characterized in that: It includes tubing nipple, casing nipple and protective sleeve. The tubing pup joint is connected to the downhole tubing by interlocking with threaded joints arranged at both ends, and is connected to the cable laid on the tubing through a cable interface. It is positioned by an elastic positioning block in cooperation with a casing positioning sleeve. The pup joint includes an energy processing module, an electric energy transmitting coil and a signal receiving coil. The energy processing module is integrated with an electric energy transmitting processing module and a signal receiving processing module. One end is connected to the cable through a joint, and the other end is connected to the coil through an interface. The electric energy emission processing module includes a driving module and a rectifying and voltage stabilizing module. The driving module is used to provide power supply voltage to the circuit chip inside the module. The rectifying and voltage stabilizing module is used to stabilize the output voltage and prevent voltage fluctuations from affecting the load. At the same time, it provides current protection to prevent current overload from damaging the circuit, ultimately ensuring the power quality and providing stable output. The signal receiving and processing module includes a conditioning module, a demodulation module, a decoding module and a signal acquisition module. The conditioning module amplifies and filters the received signal to reduce noise and improve signal quality; the demodulation module is used to demodulate to restore the signal; the decoding module is used to decode the signal; and the acquisition module is used to transmit the processed signal to the remote central control through the downhole cable. The modules are sequentially arranged and integrated on the same circuit board, one end is connected to the signal receiving coil to receive and process the wireless signal transmitted by the signal transmitting coil; the other end is connected to the cable through the connector to transmit the signal back to the remote central control, and finally realize wireless signal transmission. The power transmitting coil is connected to the power transmitting processing module through an interface, and is used to wirelessly transmit power to the outside of the casing based on the principle of magnetic induction coupling. The coil is arranged in a groove set in the internal accommodation cavity of the short section, and is padded with a padded material to shorten the air gap between the power receiving coil and the power transmitting coil, thereby increasing the coupling coefficient k to generate a larger induced electromotive force, improve coupling efficiency, and reduce magnetic field leakage. The padded material is made of silicon steel sheet to further enhance magnetic conductivity and reduce losses. The signal receiving coil is connected to the signal receiving processing module through an interface, and is used to receive wireless signals from the outside of the casing based on the principle of electromagnetic induction. The signal receiving coil and the power transmitting coil do not interfere with each other and are arranged in parallel in the groove set in the internal accommodating cavity of the short section.

2. The casing pup joint as described in claim 1 is connected to the downhole casing by interlocking with threaded joints arranged at both ends. A positioning sleeve is provided on the inner wall of the pup joint to cooperate with the elastic positioning block of the oil pipe for positioning. The material of the pup joint is the same as that of the general casing.

3. The protective sleeve as described in claim 1 is fixed to the outer wall of the casing short section by a clamp connection method to ensure that the two coils are aligned and stably transmitted during the transmission of wireless power signals underground. The protective sleeve is made of Inconel 625 alloy, is hollow inside and is provided with a receiving cavity and a groove, and includes an energy processing module, an electric power receiving coil, a signal transmitting coil and a battery energy storage module. The energy processing module is integrated with an electric power receiving processing module and a signal transmitting processing module, and is connected to the coil through an interface. The power receiving and processing module is used to process the received wireless power and transmit it to the battery energy storage module. It includes a rectifier and voltage regulator module and a compensation module. The rectifier and voltage regulator module is used to stabilize the voltage fluctuation at the receiving end, and the compensation module reduces power loss to a certain extent and improves the system receiving efficiency. The signal transmission processing module includes a conditioning module, a coding module and a modulation module. The conditioning module is used to receive downhole instrument signals and convert them into standard process signals; the coding module is used for channel coding to enhance anti-interference and anti-fading capabilities; and the modulation module is used to modulate coded signals. The power receiving coil is wound and arranged in the inner groove of the sleeve, inductively coupled with the power transmitting coil to receive power, and is connected to the power receiving processing module through an interface. The signal transmitting coil is connected to the signal transmitting processing module through an interface, and transmits wireless signals to the oil pipe side based on the principle of electromagnetic induction. The signal transmitting coil and the power receiving coil do not interfere with each other and are arranged in parallel in the grooves set in the internal accommodating cavity of the short section. The battery energy storage module mainly includes multiple batteries, which are contained in the accommodating cavity in the module. To ensure the safety of the battery charging process, this module is also designed with a battery management system, whose main function is to monitor the battery's voltage, current, temperature and other parameters, realize the battery's charge and discharge control and balance management, ensure the battery's safe, stable and efficient operation, and extend the battery's service life. The built-in discrimination circuit of the battery management system is used to determine whether the battery is full, so as to adjust the charging strategy and finally realize wireless power transmission in the annulus.

4. A wireless signal transmission device and method in a closed annulus of an underwater production well as claimed in claim 1 can arrange multiple devices in series along the cable in a single wellbore according to the requirements of downhole integrity monitoring, and in a multi-branch well, they can be arranged in the main wellbore and each branch wellbore, respectively, to expand the downhole integrity monitoring range. When multiple devices are in operation, the downhole network controller located in the underwater production system performs the role of a power and communication hub, performs power signal transmission and distribution, provides electrical and communication interfaces for the device, and connects the downhole part and the uphole part together.

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