A linkage-type intelligent opening system for intelligent fracturing sleeves and its control method

Abstract

This invention relates to the field of oil and gas field development technology, and discloses a linkage-type intelligent opening system and control method for intelligent fracturing sleeves. The system includes: multiple intelligent fracturing sleeves, each internally equipped with a multi-dimensional coded response unit; each multi-dimensional coded response unit includes: a micro piezoelectric resonator array composed of multiple piezoelectric crystals with inherent acoustic resonant frequencies, the set combination of the inherent acoustic resonant frequencies of the piezoelectric crystals constituting the acoustic fingerprint encoding of the intelligent fracturing sleeve; and a micro magnetostrictive exciter having an optimal response frequency sensitive to an alternating magnetic field of a set frequency, the optimal response frequency constituting the magnetic field response encoding of the intelligent fracturing sleeve. By combining the acoustic fingerprint encoding and the magnetic field response encoding, the opening of the intelligent fracturing sleeve is not responsive to interference from a single downhole field source, such as acoustic or magnetic field fluctuations without specific encoding, thereby reducing the probability of unintended opening and improving the specificity of target selection.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field development technology, specifically to an intelligent linkage-type intelligent opening system for intelligent fracturing sleeves and its control method. Background Technology

[0002] In multi-stage fracturing operations in horizontal wells and wells with complex structures, multiple fracturing sleeves are typically pre-installed in the downhole tubing to achieve precise and efficient stimulation of different reservoir sections. How to selectively open the target fracturing sleeves in a complex downhole environment according to a predetermined sequence or actual needs is one of the key technical aspects determining the success or failure of the fracturing operation.

[0003] To achieve selective opening of fracturing sleeves, various solutions have been developed. Early technologies primarily relied on mechanical methods, such as ball-drop sleeves, which open the sleeves step by step by dropping steel balls of different sizes into the wellbore. While this method is structurally simple, its opening sequence is fixed, making it impossible to skip a particular sleeve or repeatedly open it. Furthermore, there is a risk of the ball encountering obstruction or getting stuck, limiting the flexibility and reliability of the operation.

[0004] With technological advancements, intelligent fracturing sleeves based on electrical, hydraulic, or acoustic signal control have emerged. These technologies offer significant improvements in flexibility compared to traditional mechanical methods. However, in practical applications, the activation mechanism of these intelligent systems typically relies on a response to a single physical field signal. For example, some systems utilize specific radio frequency identification (RFID) signals, while others respond to specific acoustic frequencies or pressure pulses.

[0005] This mechanism, relying on a single physical dimension for identification and triggering, presents inherent technical challenges in the harsh and complex downhole environment. The wellbore is filled with high-temperature, high-pressure fluids, and fracturing operations are accompanied by severe mechanical vibrations and intense fluid noise, or potential electromagnetic interference from other downhole tools. In some cases, the physical characteristics of these complex environmental background noises may coincidentally resemble a pre-set single activation signal, leading to the erroneous triggering of non-target sleeves. This unintended activation not only disrupts the planned fracturing operation but may also result in wasted fracturing fluid and ineffective stimulation of non-target reservoirs, directly impacting the effectiveness and economics of the entire production enhancement operation and reducing the specificity of target selection and the overall reliability of the system.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] To address the aforementioned problems, this invention proposes a linkage-based intelligent opening system and control method for intelligent fracturing sleeves, which solves the problem that existing fracturing sleeves are prone to accidental opening due to interference.

[0008] Specifically, the following technical solution was adopted:

[0009] A linkage-type intelligent opening system for an intelligent fracturing sleeve includes:

[0010] Ground control unit;

[0011] At least one intelligent fracturing sleeve installed downhole;

[0012] And, a signal transmission link connecting the ground control unit and the intelligent fracturing sleeve;

[0013] The intelligent fracturing sleeve is internally equipped with a passive multi-dimensional coding response unit, which includes:

[0014] An acoustic coding response module, which has a set acoustic fingerprint code and is configured to respond to a matching acoustic wave signal;

[0015] A magnetic field encoding response module, which has a set magnetic field response code and is configured to respond to a matching alternating magnetic field signal;

[0016] An opening mechanism, which is mechanically coupled to the acoustic coding response module and the magnetic field coding response module, is configured to be driven to open the intelligent fracturing sleeve only when the matched acoustic signal acts synchronously with the matched alternating magnetic field signal.

[0017] The ground control unit is configured to:

[0018] Based on the coding of the target intelligent fracturing sleeve, the matched acoustic signal and the matched alternating magnetic field signal are generated synchronously, and the composite field is excited through the signal transmission link;

[0019] Monitor and receive various feedback signals corresponding to the opening action of the intelligent fracturing sleeve;

[0020] The opening status of the intelligent fracturing sleeve is confirmed by real-time cross-verification of the various feedback signals.

[0021] As an optional embodiment of the present invention, the acoustic coding response module includes a miniature piezoelectric resonator array, which is composed of multiple piezoelectric crystals with inherent acoustic resonant frequencies. The set combination of the inherent acoustic resonant frequencies of the piezoelectric crystals constitutes the acoustic fingerprint coding of the intelligent fracturing sleeve.

[0022] The magnetic field encoding response module is a miniature magnetostrictive exciter, which has an optimal response frequency that is sensitive to an alternating magnetic field of a specific frequency. The optimal response frequency constitutes the magnetic field response encoding of the intelligent fracturing sleeve.

[0023] As an optional embodiment of the present invention, the piezoelectric crystal of the micro piezoelectric resonator array is made of lithium niobate or quartz material;

[0024] The magnetostrictive material of the micro magnetostrictive exciter is made of nickel-iron alloy or terbium-gallium-iron alloy.

[0025] As an optional embodiment of the present invention, the opening mechanism is connected to the micro piezoelectric resonator array and the micro magnetostrictive exciter, and is configured such that when the ultrasonic signal and the alternating magnetic field signal act synchronously on the multidimensional coded response unit and the superposition of the two reaches a preset threshold, the target intelligent fracturing sleeve is driven to open.

[0026] As an optional embodiment of the present invention, the multidimensional coding response unit further includes a miniature fiber Bragg grating, which is mechanically connected to the opening mechanism and configured to generate strain in response to the driving of the opening mechanism, thereby generating an optical feedback signal, which is fed back to the ground control unit as a feedback signal.

[0027] As an optional embodiment of the present invention, the monitoring and receiving of various feedback signals corresponding to the opening action of the intelligent fracturing sleeve includes acoustic feedback signals inside the wellbore and electromagnetic feedback signals generated by the reverse sensing of the micro piezoelectric resonator array.

[0028] The method of confirming the opening state of the intelligent fracturing sleeve based on real-time cross-verification of the multiple feedback signals includes: the intelligent fracturing sleeve is finally confirmed to be successfully opened only when the optical feedback signal indicates that the opening mechanism has undergone mechanical displacement, the acoustic feedback signal exhibits a characteristic transient acoustic spectrum mode related to the opening action, and the electromagnetic feedback signal exhibits instantaneous weak electromagnetic pulse characteristics.

[0029] As an optional embodiment of the present invention, one end of the fiber Bragg grating is fixedly connected to the outer shell fixing point of the intelligent fracturing sleeve, and the other end is fixedly connected to the inner sleeve moving point of the intelligent fracturing sleeve.

[0030] When the inner sleeve of the intelligent fracturing sleeve undergoes axial displacement, it applies axial strain to the fiber Bragg grating, causing its grating period to change. A change occurs, which causes the central reflection wavelength to change. A measurable drift occurs, thus forming the optical feedback signal, the central reflection wavelength. It can be expressed by the following formula:

[0031] ;

[0032] in, The effective refractive index of the fiber core in a fiber Bragg grating. The grating period is the fiber Bragg grating.

[0033] As an optional embodiment of the present invention, the signal transmission link includes: an acoustic wave transmission channel formed by a pressure-resistant acoustic waveguide filled with an acoustic coupling liquid or fluid inside the wellbore.

[0034] And magnetic field transmission channels formed by downhole metal casings or laid high-temperature and high-pressure resistant metal core wires.

[0035] This invention also provides a control method for the linkage-type intelligent opening system of the intelligent fracturing sleeve, comprising:

[0036] Select the target intelligent fracturing sleeve, and have the ground control unit load its corresponding acoustic fingerprint code and magnetic field response code;

[0037] The ground control unit generates and synchronously transmits an ultrasonic signal matching the acoustic fingerprint code and an alternating magnetic field signal matching the magnetic field response code. The signal transmission link is used to excite the target intelligent fracturing sleeve in a composite field to drive the opening mechanism of the target intelligent fracturing sleeve.

[0038] The ground control unit monitors in real time various feedback signals corresponding to the opening action of the target intelligent fracturing sleeve return;

[0039] The ground control unit performs real-time cross-verification of the various feedback signals to confirm the opening status of the intelligent fracturing sleeve.

[0040] As an optional embodiment of the present invention, in the control method of the present invention, the opening mechanism of the intelligent fracturing sleeve is configured to be activated only when the following conditions are met:

[0041] ;

[0042] in, Indicates the driving conditions for opening the mechanism; This indicates that the frequency combination of the applied ultrasonic signal matches the acoustic fingerprint code of the target slide. This indicates that the frequency of the applied alternating magnetic field matches the magnetic field response code of the target sliding sleeve; This represents the superimposed input energy of the ultrasonic signal and the alternating magnetic field signal acting synchronously on the multidimensional coded response unit; This indicates the preset power threshold. It is set to be higher than the maximum value that can be transmitted and converted into mechanical vibration energy by a single excitation source, i.e., a single ultrasonic signal or a single alternating magnetic field, under normal operating power, but lower than the value of the energy superposition when the two excitation sources act synchronously.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0044] 1. This invention discloses a linkage-type intelligent opening system for a smart fracturing sleeve, which combines acoustic fingerprint encoding and magnetic field response encoding. The driving conditions for the opening mechanism are set as follows: an ultrasonic signal and an alternating magnetic field signal matching the encoding must act synchronously on the multi-dimensional encoded response unit, and the superimposed energy must reach a preset threshold. This dual-condition locking mechanism ensures that the opening of the smart fracturing sleeve is not responsive to interference from a single downhole field source, such as the absence of a specific encoded acoustic or magnetic field fluctuation, thereby reducing the probability of unintended opening and improving the specificity of target selection.

[0045] 2. This invention discloses a linkage-type intelligent opening system for an intelligent fracturing sleeve. It monitors and cross-verifies three feedback signals based on different physical principles in parallel: an optical feedback signal directly related to the mechanical displacement of the opening mechanism, an acoustic feedback signal related to the transient process of the opening action, and an electromagnetic feedback signal related to the response of the piezoelectric resonator array. The opening state is confirmed only when all three signals are simultaneously identified and mutually verified within a preset time window. This measure avoids misjudgments of the opening state due to a single signal channel failure or interference, thus improving the verifiability of the state confirmation results.

[0046] 3. The intelligent fracturing sleeve linkage intelligent opening system of the present invention has a passive structure in which the downhole multi-dimensional coding response unit does not contain batteries or other active electronic components that require continuous power supply. The energy required for the unit to drive the opening mechanism comes entirely from the ultrasonic signal and alternating magnetic field signal emitted by the ground control unit. This passive design eliminates the risk of failure caused by the shortened battery life or performance degradation due to the high temperature and high pressure environment downhole, enabling the intelligent fracturing sleeve to be deployed and operated downhole for a long time. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the architecture of a linkage-type intelligent opening system for an intelligent fracturing sleeve according to the present invention.

[0048] Figure 2 This is a schematic diagram of the architecture of the intelligent fracturing sleeve of the present invention;

[0049] Figure 3 This is a block diagram of the internal structure of the multidimensional coding response unit of the present invention;

[0050] Figure 4 This is a schematic diagram of the heterogeneous feedback signal of the present invention;

[0051] Figure 5 This is a flowchart of a control method for a linkage-type intelligent opening system for an intelligent fracturing sleeve according to the present invention. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0053] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely illustrates some embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0054] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0055] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0056] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. These terms are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0057] like Figures 1-4 As shown in the figure, this embodiment of an intelligent fracturing sleeve linkage intelligent opening system includes:

[0058] Ground control unit;

[0059] At least one intelligent fracturing sleeve installed downhole;

[0060] And, a signal transmission link connecting the ground control unit and the intelligent fracturing sleeve;

[0061] The intelligent fracturing sleeve is internally equipped with a passive multi-dimensional coding response unit, which includes:

[0062] An acoustic coding response module, which has a set acoustic fingerprint code and is configured to respond to a matching acoustic wave signal;

[0063] A magnetic field encoding response module, which has a set magnetic field response code and is configured to respond to a matching alternating magnetic field signal;

[0064] An opening mechanism, which is mechanically coupled to the acoustic coding response module and the magnetic field coding response module, is configured to be driven to open the intelligent fracturing sleeve only when the matched acoustic signal acts synchronously with the matched alternating magnetic field signal.

[0065] The ground control unit is configured to:

[0066] Based on the coding of the target intelligent fracturing sleeve, the matched acoustic signal and the matched alternating magnetic field signal are generated synchronously, and the composite field is excited through the signal transmission link;

[0067] Monitor and receive various feedback signals corresponding to the opening action of the intelligent fracturing sleeve;

[0068] The opening status of the intelligent fracturing sleeve is confirmed by real-time cross-verification of the various feedback signals.

[0069] According to the above technical solution: In terms of implementation principle, this system assigns a composite identity code to the intelligent fracturing sleeve, consisting of acoustic fingerprint encoding and magnetic field response encoding. The acoustic fingerprint encoding is composed of multiple natural frequencies of its internal micro piezoelectric resonator array, while the magnetic field response encoding is defined by the unique optimal response frequency of the micro magnetostrictive exciter to a set alternating magnetic field.

[0070] During the activation operation, the ground control unit no longer excites a single physical field, but rather performs composite field excitation based on the loaded target code. This involves simultaneously emitting an ultrasonic signal that perfectly matches the target's acoustic fingerprint code and an alternating magnetic field signal that perfectly matches the magnetic field response code. The triggering condition for the downhole activation mechanism is set as follows: the acoustic and magnetic field codes must match simultaneously, and the energy superimposed by their synchronous action must reach a preset threshold. This design ensures that environmental interference from any single source cannot meet the activation conditions, effectively preventing unintended false activation and directly addressing and resolving the poor selectivity caused by single-dimensional signal recognition as described in the background technology.

[0071] In terms of status confirmation, this system also abandons the reliance on a single feedback. The successful opening of the sliding sleeve will simultaneously trigger multiple feedback signals. The ground control unit performs real-time cross-verification of multiple feedback signals, and only when the three characteristic events are completely consistent in logic and timing will the opening be determined to be successful.

[0072] Specifically, this invention provides a linkage-based intelligent opening system for an intelligent fracturing sleeve. Physically, it may include: a surface control unit, a downhole composite transmission link, and at least one intelligent fracturing sleeve deployed downhole. In the system's workflow, the surface control unit generates a composite excitation signal based on the selected target intelligent fracturing sleeve; the signal transmission link is responsible for transmitting this composite excitation signal from the surface to the downhole and transmitting the feedback signal generated by the intelligent fracturing sleeve back to the surface; the passive multidimensional coding response unit within the intelligent fracturing sleeve is responsible for identifying and responding to the composite excitation signal, executing the opening operation, and simultaneously generating feedback signals in multiple physical dimensions.

[0073] The intelligent fracturing sleeve is a tubular structure comprising a fixed outer shell and an inner sleeve that can slide axially within it. A sealed chamber is provided on the outer shell to house a passive, multi-dimensional coded response unit, isolating it from the high-temperature, high-pressure fluid environment within the wellbore.

[0074] The opening mechanism is structurally an escapement mechanism connected to an energy storage element. Both the miniature piezoelectric resonator array and the miniature magnetostrictive exciter are connected to the trigger end of the opening mechanism via a mechanical transmission structure.

[0075] Optionally, the acoustic coding response module described in this embodiment includes a miniature piezoelectric resonator array, which is composed of multiple piezoelectric crystals with inherent acoustic resonant frequencies. The set combination of the inherent acoustic resonant frequencies of the piezoelectric crystals constitutes the acoustic fingerprint coding of the intelligent fracturing sleeve.

[0076] The magnetic field encoding response module described in this embodiment is a miniature magnetostrictive exciter, which has an optimal response frequency that is sensitive to an alternating magnetic field of a set frequency. The optimal response frequency constitutes the magnetic field response encoding of the intelligent fracturing sleeve.

[0077] The multidimensional encoded response unit is an integrated functional module that specifically includes a miniature piezoelectric resonator array. This array consists of multiple independent piezoelectric crystals, each precisely fabricated to possess a unique, high-quality-factor intrinsic acoustic resonant frequency. The configuration and combination of these independent resonant frequencies... This constitutes the acoustic fingerprint encoding of the intelligent fracturing sleeve. The piezoelectric crystal material is selected from materials with high Curie temperature and stable piezoelectric coefficient, such as lithium niobate or quartz. These materials are chosen not only because of their high Curie temperature and stable piezoelectric coefficient, but also because they have a high mechanical quality factor. This results in a sharp peak at the resonant frequency, exhibiting high selectivity and effectively distinguishing the encoded frequency from ambient noise frequencies, thereby reducing the response to non-target frequencies.

[0078] When the spectrum of an ultrasonic signal applied from the ground contains a frequency combination that perfectly matches the acoustic fingerprint code, the corresponding transistors in the array resonate, converting acoustic energy into mechanical vibration energy. Simultaneously, based on the piezoelectric effect, the forced vibration of the crystals generates alternating charges, forming a weak but perceptible electromagnetic feedback signal.

[0079] The multidimensional encoded response unit also includes a miniature magnetostrictive exciter. This exciter is made of nickel-iron alloy or terbium-gallium-iron alloy and is designed to respond to a set frequency. The alternating magnetic field provides the best response. When the frequency of the alternating magnetic field applied from the ground is... When matched, the exciter exhibits significant stretching vibrations, converting magnetic field energy into mechanical vibration energy.

[0080] This response is frequency selective; magnetic field signals that deviate from the optimal response frequency cannot cause it to vibrate effectively.

[0081] Optionally, the piezoelectric crystals of the micro piezoelectric resonator array described in this embodiment are made of lithium niobate or quartz. According to the above technical solution, the primary reason for choosing lithium niobate or quartz crystals is that both materials have extremely high quality factors. A high quality factor means that its acoustic resonance has a very narrow bandwidth and extremely high frequency selectivity. This makes the response of each piezoelectric crystal resonator to the excitation signal highly concentrated at its set intrinsic resonant frequency, while producing almost no response to signals at adjacent frequencies. This characteristic is the basis for constructing a clear, crosstalk-free "acoustic fingerprint code," ensuring that the set frequency combination emitted by the ground unit intelligently and accurately activates the target resonator array that perfectly matches it, thereby greatly improving the uniqueness of the code and the accuracy of identification.

[0082] Furthermore, both materials possess excellent thermal stability and a high Curie temperature. Downhole environments are typically characterized by high temperatures, and the piezoelectric effect of many piezoelectric materials diminishes or even disappears at high temperatures. Lithium niobate and specifically cut quartz crystals maintain stable piezoelectric properties and resonant frequencies over a wide temperature range, ensuring that the acoustic fingerprint encoding of the coded response unit does not drift or fail under complex wellbore temperature variations. Simultaneously, the electromechanical coupling coefficient guarantees efficient conversion between acoustic and mechanical vibration energy, while its inherent chemical stability and mechanical hardness ensure that the resonator array can operate reliably for extended periods in downhole environments with high pressure and potentially corrosive fluids without performance degradation.

[0083] Optionally, the magnetostrictive material of the micro magnetostrictive exciter described in this embodiment is made of nickel-iron alloy or terbium-gallium-iron alloy.

[0084] Optionally, the opening mechanism is connected to the micro piezoelectric resonator array and the micro magnetostrictive exciter, and is configured to drive the target intelligent fracturing sleeve to open when the ultrasonic signal and the alternating magnetic field signal act synchronously on the multidimensional coded response unit and the superposition of the two reaches a preset threshold.

[0085] According to the above technical solution: In the initial state, the movable inner sleeve of the intelligent fracturing sleeve is locked in the closed position. After receiving the matched acoustic and magnetic signals, the micro piezoelectric resonator array and the micro magnetostrictive exciter efficiently convert the acoustic energy and magnetic energy into mechanical vibration energy, respectively. These two types of mechanical vibration energy are transmitted to the same trigger end of the opening mechanism through an integrated mechanical transmission structure.

[0086] Specifically, the opening mechanism of the intelligent fracturing sleeve is configured to be activated only when the following conditions are met: ;

[0087] in, Indicates the driving conditions for opening the mechanism; This indicates that the frequency combination of the applied ultrasonic signal matches the acoustic fingerprint code of the target slide. This indicates that the frequency of the applied alternating magnetic field matches the magnetic field response code of the target sliding sleeve; This represents the superimposed input energy of the ultrasonic signal and the alternating magnetic field signal acting synchronously on the multidimensional coded response unit; This indicates the preset power threshold. It is set to be higher than the maximum value that can be transmitted and converted into mechanical vibration energy by a single excitation source, i.e., a single ultrasonic signal or a single alternating magnetic field, under normal operating power, but lower than the value of the energy superposition when the two excitation sources act synchronously.

[0088] The determination of the opening energy threshold is based on the minimum mechanical work required for the escapement mechanism within the driving opening mechanism to unlock, and takes into account the energy loss during the energy transfer process from the excitation source to the opening mechanism. When both the acoustic fingerprint code and the magnetic field response code are matched and act synchronously, the mechanical vibration energy generated simultaneously by the piezoelectric resonator array and the magnetostrictive exciter is superimposed through the transmission structure, satisfying the condition that the input energy is greater than or equal to the energy threshold, driving the opening mechanism to act, releasing the energy storage element, and pushing the inner sleeve to undergo axial displacement.

[0089] Optionally, the ground control unit described in this embodiment is further configured to transmit ultrasonic signals and alternating magnetic field signals synchronously to ensure that the matching of acoustic fingerprint codes and the matching of magnetic field response codes occur simultaneously.

[0090] According to the above technical solution, the downhole opening mechanism is designed to be triggered only when acoustic and magnetic energy work together and their combined energy exceeds a preset threshold. If there is a significant time difference between the ultrasonic signal and the alternating magnetic field signal when they arrive at the target sliding sleeve, the energy generated by the first arriving signal will dissipate before the second signal arrives, failing to form an effective energy superposition, thus leading to opening failure.

[0091] To achieve this precise synchronization at depths of several thousand meters, the ground control unit does not simply trigger two signal sources simultaneously, but rather employs intelligent synchronization control based on propagation delay compensation. Its basic principle is as follows:

[0092] The surface control unit first identified a fundamental difference in the physical characteristics of the two signals: sound waves propagate relatively slowly in the wellbore medium, while electromagnetic signals propagate much faster along the metal tubing. If both were emitted simultaneously from the surface, their arrival times at the downhole target would inevitably differ significantly.

[0093] Therefore, the timing control module within the ground control unit actively staggers the transmission times based on the depth of the target sliding sleeve and the propagation speed characteristics of the two signals. The principle followed is to transmit the slower-propagating ultrasonic signal first, followed by the faster-propagating alternating magnetic field signal after a precisely calculated delay.

[0094] Through this precise synchronous launch control based on propagation delay compensation, the ground control unit can ensure that the energy packets of two excitation signals with different physical properties can act precisely on the multidimensional coded response unit of the target sliding sleeve at the same time after long-distance downhole transmission.

[0095] Optionally, the multidimensional coding response unit in this embodiment further includes a miniature fiber Bragg grating, which is mechanically connected to the opening mechanism and configured to generate strain in response to the driving of the opening mechanism, thereby generating an optical feedback signal, which is fed back to the ground control unit as a feedback signal.

[0096] Specifically, one end of the fiber Bragg grating is fixed to the outer shell fixing point of the intelligent fracturing sleeve, and the other end is fixed to the inner sleeve moving point of the intelligent fracturing sleeve.

[0097] When the inner sleeve of the intelligent fracturing sleeve undergoes axial displacement, it applies axial strain to the fiber Bragg grating, causing its grating period to change. A change occurs, which causes the central reflection wavelength to change. A measurable drift occurs, thus forming the optical feedback signal, the central reflection wavelength. It can be expressed by the following formula:

[0098] ;

[0099] in, The effective refractive index of the fiber core in a fiber Bragg grating. The grating period is the fiber Bragg grating.

[0100] Optionally, the monitoring and receiving of various feedback signals corresponding to the opening action of the intelligent fracturing sleeve includes acoustic feedback signals inside the wellbore and electromagnetic feedback signals generated by the reverse sensing of the micro piezoelectric resonator array.

[0101] The method described in this embodiment for confirming the opening state of the intelligent fracturing sleeve based on real-time cross-verification of the various feedback signals includes: the intelligent fracturing sleeve is finally confirmed to be successfully opened only when the optical feedback signal indicates that the opening mechanism has undergone mechanical displacement, the acoustic feedback signal exhibits a characteristic transient acoustic spectrum mode related to the opening action, and the electromagnetic feedback signal exhibits instantaneous weak electromagnetic pulse characteristics.

[0102] According to the above technical solution, the highest level of reliability is achieved by performing parallel analysis and logical correlation judgment on signals from three different physical dimensions within a preset, extremely short time window. Specifically, the algorithm of the ground control unit must simultaneously meet the following three conditions: First, a step-like center wavelength shift must be detected in the optical signal returned by the micro fiber Bragg grating, which is a direct indication that the internal components of the sliding sleeve have undergone physical displacement; second, a brief, energy-concentrated broadband impact spectrum must be identified from the acoustic signal of the wellbore, which is a characteristic signal proving that the opening mechanism releases mechanical energy during operation; finally, a transient electromagnetic pulse generated by the mechanical impact acting on the micro piezoelectric resonator array and the reverse piezoelectric effect must be detected, which is evidence that the impact event occurred precisely within the multidimensional coded response unit itself. Only when these three physically related characteristic signals appear highly synchronously in time will the control unit determine that the opening is successful, thus eliminating the possibility of misjudgment caused by interference, crosstalk, or malfunction of a single signal source.

[0103] To enable signal transmission between the surface and the well, the signal transmission link specifically includes an acoustic transmission channel, a magnetic field transmission channel, and an optical fiber feedback channel.

[0104] The acoustic wave transmission channel is used to transmit ultrasonic signals downlink and acoustic feedback signals uplink. One way to implement this channel is to use the fluid present inside the wellbore string as the acoustic wave transmission medium. Another way is to lay out a separate, high-pressure resistant acoustic waveguide filled with a low-attenuation acoustic coupling fluid such as silicone oil to form a dedicated, low-loss, low-noise acoustic wave transmission path.

[0105] The magnetic field transmission channel is used to transmit the energy of alternating magnetic field signals and sense weak electromagnetic feedback signals. One implementation method is to use existing downhole metal casing or tubing as a conductor, applying low-frequency alternating current at the wellhead to generate an alternating magnetic field along the tubing string. Another implementation method is to lay one or more high-temperature, high-pressure resistant insulated metal core wires and wind them near the target sliding sleeve to form a solenoid structure, thereby improving magnetic field transmission efficiency and local field strength.

[0106] The fiber optic feedback channel is used to transmit the center-reflected wavelength signal generated by the miniature fiber Bragg grating. This channel consists of a single-mode optical fiber encapsulated in a metal or polymer capillary tube with compressive, tensile, and corrosion-resistant properties. This fiber optic control line can be bundled to the outer wall of the production tubing and lowered into the well. Its downhole end connects to the miniature fiber Bragg grating, while its surface end connects to the optical signal demodulation equipment within the surface control unit.

[0107] See Figure 5 As shown, this embodiment also provides a control method for the linkage-type intelligent opening system of the intelligent fracturing sleeve, including:

[0108] Select the target intelligent fracturing sleeve, and have the ground control unit load its corresponding acoustic fingerprint code and magnetic field response code;

[0109] The ground control unit generates and synchronously transmits an ultrasonic signal matching the acoustic fingerprint code and an alternating magnetic field signal matching the magnetic field response code. The signal transmission link is used to excite the target intelligent fracturing sleeve in a composite field to drive the opening mechanism of the target intelligent fracturing sleeve.

[0110] The ground control unit monitors in real time various feedback signals corresponding to the opening action of the target intelligent fracturing sleeve return;

[0111] The ground control unit performs real-time cross-verification of the various feedback signals to confirm the opening status of the intelligent fracturing sleeve.

[0112] Optionally, in the control method described in this embodiment, the opening mechanism of the intelligent fracturing sleeve is configured to be activated only when the following conditions are met: ;

[0113] in, Indicates the driving conditions for opening the mechanism; This indicates that the frequency combination of the applied ultrasonic signal matches the acoustic fingerprint code of the target slide. This indicates that the frequency of the applied alternating magnetic field matches the magnetic field response code of the target sliding sleeve; This represents the superimposed input energy of the ultrasonic signal and the alternating magnetic field signal acting synchronously on the multidimensional coded response unit; This indicates the preset power threshold. It is set to be higher than the maximum value that can be transmitted and converted into mechanical vibration energy by a single excitation source, i.e., a single ultrasonic signal or a single alternating magnetic field, under normal operating power, but lower than the value of the energy superposition when the two excitation sources act synchronously.

[0114] To facilitate understanding of the above technical solutions, practical application examples will be used to illustrate them below:

[0115] Application Scenario: In a multi-stage fracturing operation of a horizontal well, 10 intelligent fracturing sleeves of this invention are arranged along the horizontal section of the wellbore, numbered sequentially from 1 to 10. The current operation objective is to selectively open the No. 5 intelligent fracturing sleeve, located at a depth of 3500 meters in the wellbore, and confirm its open status, while keeping the adjacent No. 4 and No. 6 sleeves in the closed state.

[0116] According to the pre-defined scheme, each smart fracturing sleeve is assigned a unique composite code. Among them:

[0117] The code for the No. 4 smart fracturing sleeve is: acoustic fingerprint code. Magnetic field response coding .

[0118] The code for the No. 5 intelligent fracturing sleeve (target sleeve) is: acoustic fingerprint code. Magnetic field response coding Its internal opening mechanism is set with an opening energy threshold. It is 0.5 joules.

[0119] The code for the No. 6 smart fracturing sleeve is: acoustic fingerprint code. Magnetic field response coding .

[0120] The initial center reflection wavelength of its internal miniature fiber Bragg grating in the off state. The standard calibration is 1550.10nm. The displacement after the inner sleeve is fully opened will cause a wavelength drift greater than 0.80nm.

[0121] The specific application steps of this method are as follows:

[0122] The operator selects the No. 5 intelligent fracturing sleeve as the operational target using the human-machine interface and target selection module on the ground control unit. The system automatically loads its corresponding acoustic fingerprint code. and magnetic field response coding The composite field signal generation and synchronization control module is then triggered, generating a composite ultrasonic signal containing the three acoustic frequency components mentioned above, and transmitting it through an acoustic transmission channel coupled to the fracturing fluid inside the wellbore. Simultaneously, this pulse generates a frequency of... Alternating current is applied through a magnetic field transmission channel connected to a metal oil pipe. A timing controller ensures that the two signals are generated synchronously, and calculations determine that the input energy is superimposed upon reaching the target at a depth of 3500 meters. It is approximately 0.6 joules, which is greater than the 0.5 joules threshold energy for activation.

[0123] The composite excitation signal propagates downwards along the wellbore. The multidimensional coded response units of sleeves 4 and 6, due to the mismatch between their acoustic or magnetic codes and the applied signal, cannot generate effective resonance; the energy they receive is far below their respective activation thresholds, thus they remain in the off state.

[0124] The multidimensional coded response unit of the No. 5 sliding sleeve, with its micro piezoelectric resonator array and micro magnetostrictive exciter, is frequency-matched to the received signal, generating strong resonance and efficiently converting acoustic and magnetic energy into mechanical vibration energy. The superimposed energy (0.6 joules) exceeds the threshold of 0.5 joules, driving its opening mechanism to operate, causing axial displacement of the inner sleeve and opening the sliding sleeve.

[0125] At the instant the No. 5 sliding sleeve opens, the heterogeneous feedback signal acquisition and processing module of the ground control unit simultaneously detects the following three signal changes with distinct physical characteristics within a preset 100-millisecond time window:

[0126] Optical feedback signal: The optical signal demodulation unit detected a step shift in the center reflection wavelength of the fiber Bragg grating from the No. 5 sliding sleeve, from 1550.10 nm to 1550.95 nm. The shift amount is +0.85 nm, which is greater than the preset opening confirmation threshold of 0.80 nm, indicating that the inner sleeve has moved into place.

[0127] Acoustic feedback signal: Under the background of continuous excitation sound waves, the acoustic signal acquisition unit identified a broadband impact acoustic event with a time width of approximately 15 milliseconds and a frequency range covering 5 kHz to 50 kHz through time-frequency analysis. The spectral characteristics of this event are consistent with the acoustic signal characteristics generated by the release and impact of mechanical components of the opening mechanism (such as a latch).

[0128] Electromagnetic feedback signal: In a 150 Hz excitation magnetic field background signal, the electromagnetic signal detection unit detected a non-resonant single voltage spike with an amplitude of 5 mV and a duration of less than 5 ms through a lock-in amplifier. This signal originates from the piezoelectric effect caused by the rapid movement of the inner sleeve on the piezoelectric resonator array when the sliding sleeve opens, and its characteristics are completely different from the excitation signal.

[0129] Since the three characteristic signals mentioned above, which are derived from different physical principles and represent different aspects of the sliding sleeve opening process, were all clearly detected and mutually verified within a 100-millisecond time window, the cross-validation and status confirmation algorithm module finally output the judgment: the No. 5 intelligent fracturing sliding sleeve has been confirmed to be open.

[0130] Based on this clear confirmation, the work team immediately began high-pressure fracturing operations on the section where the No. 5 sliding sleeve was located.

[0131] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described herein. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the specific embodiments described above. Therefore, any modifications or equivalent substitutions to the present invention, as well as all technical solutions and improvements that do not depart from the spirit and scope of the invention, are covered within the scope of the claims of the present invention.

Claims

1. A linkage type intelligent opening system of an intelligent fracturing sliding sleeve, characterized in that, The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore.

2. The linkage-type intelligent opening system of a smart fracturing sliding sleeve according to claim 1, characterized in that, The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore.

3. The linkage type intelligent opening system of the intelligent fracturing sliding sleeve according to claim 2, characterized in that, The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore.

4. The linkage type intelligent opening system of the intelligent fracturing sliding sleeve according to claim 2, characterized in that, The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore.

5. The linked intelligent opening system of a smart fracturing sliding sleeve according to claim 1, characterized in that, The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore.

6. The linked intelligent opening system of a smart fracturing sliding sleeve according to claim 5, characterized in that, The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. The application relates to a signal transmission link for intelligent fracturing sliding sleeve in wellbore. 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The application relates to a signal transmission link for intelligent fracturing sliding sleeve in The opening state of the intelligent fracturing sliding sleeve is confirmed based on real-time cross-checking of the plurality of feedback signals, and the opening state of the intelligent fracturing sliding sleeve is finally confirmed only when the optical feedback signal indicates that the mechanical displacement of the opening mechanism occurs, the acoustic feedback signal presents a characteristic transient acoustic frequency spectrum mode related to the opening action, and the electromagnetic feedback signal presents a transient weak electromagnetic pulse feature.

7. The linkage-type intelligent opening system of a smart fracturing sliding sleeve according to claim 5, characterized in that, One end of the fiber Bragg grating is fixed to a fixed point of an outer shell of the intelligent fracturing sliding sleeve, and the other end is fixed to a moving point of an inner sleeve of the intelligent fracturing sliding sleeve. When the inner sleeve of the intelligent fracturing sliding sleeve is axially displaced, an axial strain is applied to the fiber Bragg grating, causing the grating period of the fiber Bragg grating to change, which causes the center reflection wavelength to occur a measurable shift, thereby constituting the optical feedback signal, the center reflection wavelength is represented by the following formula: ； wherein, neffis the effective refractive index of the fiber core of the fiber Bragg grating, Λis the grating period of the fiber Bragg grating.

8. The linked intelligent opening system of a smart fracturing sliding sleeve according to claim 1, characterized in that, The signal transmission link includes an acoustic wave transmission channel composed of a fluid in a wellbore or a pressure-resistant acoustic coupling liquid filled acoustic waveguide, and a magnetic field transmission channel composed of a downhole metal casing or a laid high-temperature and high-pressure metal core wire. The signal transmission link includes an acoustic wave transmission channel composed of a fluid in a wellbore or a pressure-resistant acoustic coupling liquid filled acoustic waveguide, and a magnetic field transmission channel composed of a downhole metal casing or a laid high-temperature and high-pressure metal core wire.

9. The control method of the linkage type intelligent opening system of the intelligent fracturing sliding sleeve according to any one of claims 1-8, characterized in that, The signal transmission link includes an acoustic wave transmission channel composed of a fluid in a wellbore or a pressure-resistant acoustic coupling liquid filled acoustic waveguide, and a magnetic field transmission channel composed of a downhole metal casing or a laid high-temperature and high-pressure metal core wire. The target intelligent fracturing sliding sleeve is selected, and the corresponding acoustic fingerprint code and magnetic field response code are loaded by the ground control unit; The ground control unit generates and synchronously transmits ultrasonic signals matched with the acoustic fingerprint code and alternating magnetic field signals matched with the magnetic field response code, and performs composite field excitation on the target intelligent fracturing sliding sleeve via the signal transmission link to drive the opening mechanism of the target intelligent fracturing sliding sleeve; The ground control unit monitors the plurality of feedback signals corresponding to the opening action returned by the target intelligent fracturing sliding sleeve in real time; The ground control unit cross-checks the plurality of feedback signals in real time to confirm the opening state of the intelligent fracturing sliding sleeve.

10. The control method according to claim 9, characterized by The opening mechanism of the intelligent fracturing sliding sleeve is configured to be driven only when the following conditions are met: ； wherein, represents the driving condition of the opening mechanism; represents that the frequency combination of the applied ultrasonic signal matches the acoustic fingerprint encoding of the target sliding sleeve; represents that the frequency of the applied alternating magnetic field matches the magnetic field response encoding of the target sliding sleeve; represents the superimposed input energy of the ultrasonic signal and the alternating magnetic field signal acting synchronously on the multi-dimensional encoding response unit; represents the preset opening energy threshold, is set to be higher than the maximum value that a single excitation source, i.e., a single ultrasonic signal or a single alternating magnetic field, can deliver and convert into mechanical vibration energy under normal working power, but lower than the value after energy superposition when the two excitation sources act synchronously. When the acoustic fingerprint code and the magnetic field response code are matched and simultaneously act, the mechanical vibration energy generated by the acoustic code response module and the magnetic field code response module at the same time is superimposed through the transmission structure, and the superimposed input energy greater than or equal to an opening energy threshold value the opening mechanism is driven to act.

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