A variable diameter stabilizer

Abstract

The application relates to a variable-diameter stabilizer. Instructions are transmitted into a control module in a wiring cavity through a wiring hole on a sealing connector. The control module controls the starting of a driving mechanism. The driving mechanism drives a variable-diameter mechanism to perform a variable-diameter action. The variable-diameter mechanism generates radial telescopic movement, realizes the change of the outer diameter of the stabilizer, and the integrated shell is filled with drilling fluid. The pressure acts on the second end of a pressure stabilizing core body, pushes the axial movement of the pressure stabilizing core body, the first end of the pressure stabilizing core body compresses the oil liquid on the back surface, the oil liquid is communicated with an oil cavity of the driving mechanism through an oil path, therefore the pressure of the drilling fluid is transmitted to the inside of the closed oil path, the oil pressure in the oil cavity and the external drilling fluid pressure are always kept dynamically equal, the driving mechanism, the control module and the balancing mechanism are arranged in parallel, are integrated on a mounting frame, the function modules are stacked in the radial direction, the axial size of the variable-diameter stabilizer is compressed, the control precision of a wellbore trajectory is improved, and high-precision directional drilling is realized.

Description

Technical Field

[0001] This application relates to the field of oil drilling equipment technology, and in particular to a variable diameter stabilizer. Background Technology

[0002] In oil drilling engineering, especially in the construction of complex wellbores such as directional and horizontal wells, the stability of downhole drill string assemblies and the precise control of wellbore trajectory are crucial. To adapt to different formations and build-up rates, traditional methods require frequent tripping in and out of the well to replace fixed stabilizers with different outer diameters. This is not only time-consuming and labor-intensive, significantly increasing drilling costs, but also increasing the risks of downhole operations. Variable diameter stabilizers, as a key downhole tool technology, effectively solve the above problems by dynamically adjusting their outer diameter downhole to achieve dynamic adjustment of drill string support, playing an increasingly important role in modern drilling. However, existing variable diameter stabilizers generally have a long axial dimension. This excessive axial dimension fundamentally contradicts the "zero-length algorithm" model commonly used in downhole drill string assembly mechanics analysis (this model idealizes the stabilizer as a geometric point (fulcrum) to simplify calculations, but when the actual length of the stabilizer is too large, its effective support point position in the wellbore becomes ambiguous, severely reducing the accuracy of wellbore trajectory prediction and control), making it difficult to meet the needs of high-precision directional drilling.

[0003] Therefore, how to shorten the axial dimension of the stabilizer to achieve high-precision directional drilling is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] This application provides a variable diameter stabilizer to shorten the axial dimension of the stabilizer in order to achieve high-precision directional drilling.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A variable diameter stabilizer includes a centralizer body, a variable diameter mechanism, and an integrated housing. The variable diameter mechanism is disposed on the centralizer body, and a mounting bracket is disposed inside the integrated housing. The mounting frame is provided with a first mounting part, a second mounting part and a third mounting part arranged in parallel along the axial direction. The first mounting part is provided with a drive mechanism, the second mounting part is provided with a control module, and the third mounting part is provided with a balancing mechanism. The first end of the mounting bracket is connected to a sealing connector, and a wiring cavity is formed between the sealing connector and the first end of the mounting bracket. The drive mechanism and the control module are connected to the wiring cavity. The sealing connector is provided with a wiring hole along the axial direction, and the control module is electrically connected to the controller through the wiring hole. The second end of the mounting bracket is connected to the diameter-changing mechanism; The drive mechanism is connected to the control module and the diameter changing mechanism. The control module is used to control the drive mechanism to drive the diameter changing mechanism to perform a diameter changing action. The balancing mechanism includes a pressure balancing channel disposed within the third mounting portion, and a pressure stabilizing core housed within the pressure balancing channel and capable of axial movement. The first end of the pressure stabilizing core acts on the oil within the balancing mechanism. The oil within the balancing mechanism is connected to the oil chamber where the drive mechanism is located via an oil passage. The second end of the pressure stabilizing core is exposed in the drilling fluid between the integrated housing and the mounting bracket. The balancing mechanism is used to balance the internal and external pressures of the integrated housing.

[0006] Optionally, in the above-mentioned variable diameter stabilizer, the balancing mechanism further includes a limiting part and a limiting member. The limiting part is fixed to the mounting frame and is coaxially arranged with the pressure balancing channel. The limiting member passes through the interior of the limiting part and the interior of the pressure balancing channel. The interior of the limiting member is hollow, so as to allow drilling fluid to flow through the interior of the pressure balancing channel.

[0007] Optionally, in the above-mentioned variable diameter stabilizer, the drive mechanism includes a motor, the first end of the motor and the inner wall of the first mounting part form the oil cavity, the third mounting part is provided with a first oil injection hole, the first oil injection hole is connected to the oil cavity and the pressure balance channel, and a sealing connector is provided between the oil cavity and the wiring cavity, the sealing connector is used to connect the control module and the motor; The second end of the motor is provided with a power output shaft, which is connected to the diameter changing mechanism and is used to drive the diameter changing mechanism to change its diameter.

[0008] Optionally, the above-mentioned variable diameter stabilizer further includes an actuator, which includes an actuator housing, a lead screw, a lead screw nut, and a stop shaft, wherein: The first end of the actuator housing is connected to the integrated housing, the second end of the actuator housing is connected to the centralizer body, and the lead screw, the lead screw nut and the stop shaft are disposed inside the actuator housing; One end of the lead screw is coaxially connected to the power output shaft, the lead screw nut is sleeved on the lead screw, and the first end of the stop shaft is connected to the lead screw nut. The second end of the stop shaft extends into the interior of the centralizer body and is connected to the diameter changing mechanism. The power output shaft is used to drive the lead screw to rotate, thereby causing the lead screw nut and the stop shaft to move axially.

[0009] Optionally, in the above-described variable diameter stabilizer, the variable diameter mechanism includes at least one straightening block, at least one piston, at least one elastic element, and an actuating shaft, wherein: The body of the straightener is provided with at least one mounting groove along the circumferential direction, and the straightening block is movably disposed in the mounting groove by the piston. The first end of the actuator shaft is connected to the second end of the stop shaft, and the actuator shaft is axially movable inside the body of the stabilizer. The outer surface of the actuator shaft is provided with at least one inclined braking surface. One end of the piston is in contact with the braking surface, which is used to drive the piston to move radially, and the other end of the piston is connected to the straightening block; One end of the elastic element is connected to the straightening block, and the other end of the elastic element is connected to the straightening device body. The elastic element is used to provide radial restoring force to the straightening block.

[0010] Optionally, the above-mentioned variable diameter stabilizer further includes an adapter end, a first conversion head and a second conversion head, the first conversion head and the second conversion head being fixedly connected to the adapter end, and the first conversion head being connected to the second end of the stop shaft, and the second conversion head being connected to the first end of the actuation shaft; It also includes a sealing plug and a connecting tube, wherein the sealing plug is disposed between the end of the connecting tube and the second conversion head, and the connecting tube is disposed inside the actuating shaft; The connecting pipe, the first adapter, the second adapter, the stop shaft, the lead screw, and the motor are all coaxially provided with through holes, which are continuous channels for cables or wires to pass through.

[0011] Optionally, in the above-mentioned variable diameter stabilizer, the inner wall of the centralizer body is provided with an inner fixing sleeve, and the inner fixing sleeve and the actuating shaft enclose a balance cavity; It also includes a balancing assembly, which includes a compensation ring and a filter plate. The filter plate is disposed on the side wall of the inner fixed sleeve for filtering drilling fluid, and the first side of the compensation ring is exposed to the drilling fluid. The centralizer body has a second oil injection hole, which is connected to the mounting groove, which is connected to the balance chamber, and the second side of the compensation ring is exposed to the oil.

[0012] Optionally, in the above-mentioned variable diameter stabilizer, the straightening block includes a mounting part, a first reinforcing part and a second reinforcing part, the first reinforcing part and the second reinforcing part are arranged in a relatively staggered manner, and the straightening block is a centrally symmetrical figure. The mounting part, the first reinforcing part and the second reinforcing part are provided with a plurality of inner holes, and a diamond composite sheet is welded inside the inner holes. The surface of the straightening block is laser-coated with a tungsten carbide coating. The elastic element is located at the center of the mounting portion, and there are two pistons, which are arranged opposite each other on both sides of the elastic element.

[0013] Optionally, in the above-mentioned variable diameter stabilizer, the variable diameter mechanism further includes a limiting seat, which is arranged at the end of the straightening block and fixed to the straightening body; When the straightening block moves radially, the limiting seat abuts against the straightening block, and the limiting seat is used to limit the radial displacement of the straightening block.

[0014] Optionally, the above-mentioned variable diameter stabilizer further includes a sealing ring, a first guide sleeve, and a second guide sleeve. The actuator also includes a lead screw housing, with the lead screw and the lead screw nut disposed inside the lead screw housing, wherein: The sealing ring is disposed between the centralizer body and the actuator shaft; The first guide sleeve is fixed to the second end of the actuating shaft. A first guide hole for drilling fluid to flow is provided on the side wall of the first guide sleeve. The connecting pipe and the inner wall of the actuating shaft form a first annular cavity. The first guide hole is connected to the first annular cavity. The second guide sleeve is fixed to the first end of the actuator shaft. A second guide hole for drilling fluid to flow is provided on the side wall of the second guide sleeve. The inner wall of the actuator housing and the actuator shaft, the lead screw housing and the stop shaft form a second annular cavity. The second guide hole is connected to the second annular cavity, and the second annular cavity is connected to the interior of the limiting member.

[0015] The variable diameter stabilizer provided by this invention, in use, transmits commands through the wiring hole on the sealed connector to the control module inside the wiring cavity. The control module controls the drive mechanism to start, and the drive mechanism drives the variable diameter mechanism to perform a variable diameter action, ultimately driving the variable diameter mechanism to produce radial extension and retraction, thereby changing the outer diameter of the stabilizer. The integrated shell is filled with high-pressure drilling fluid, which acts on the second end of the pressure stabilizing core, pushing it to move axially. The first end of the pressure stabilizing core compresses the oil on its back. Since the oil is connected to the oil cavity where the drive mechanism is located through the oil passage, the pressure of the drilling fluid is transmitted to the sealed oil passage, so that the oil pressure in the oil cavity and the external drilling fluid pressure always remain dynamically equal. This ensures that the pressure on the inner and outer walls of the integrated shell is basically the same, avoiding deformation of the shell structure or sealing failure due to huge pressure difference, thereby improving the reliability and service life of the variable diameter stabilizer under high pressure conditions such as deep wells and ultra-deep wells.

[0016] The variable diameter stabilizer provided by this invention integrates the drive mechanism, control module and balancing mechanism in parallel on the mounting frame, realizing the radial stacking of functional modules, thereby compressing the axial dimension of the variable diameter stabilizer, making it more in line with the model assumption of the "zero length algorithm", improving the control accuracy of the wellbore trajectory, and realizing high-precision directional drilling. Attached Figure Description

[0017] The accompanying drawings, incorporated in and forming part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort. One or more embodiments are illustrated by way of example through the corresponding images in the accompanying drawings. These exemplary descriptions do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings represent similar elements. Unless otherwise stated, the figures in the drawings do not constitute a limitation on scale.

[0018] Figure 1 This is a front view of the variable diameter stabilizer provided in an embodiment of this application; Figure 2 This is a cross-sectional view of the variable diameter stabilizer provided in an embodiment of this application; Figure 3 Provided for the embodiments of this application Figure 2 Enlarged structural diagram of region A in the middle; Figure 4 Provided for the embodiments of this application Figure 2 A magnified structural diagram of region B in the middle; Figure 5Provided for the embodiments of this application Figure 2 A magnified structural diagram of region C in the middle; Figure 6 A perspective view of the variable diameter mechanism provided in an embodiment of this application; Figure 7 A perspective view of the mounting bracket provided in an embodiment of this application; Figure 8 This is a perspective view of the straightening block provided in an embodiment of this application.

[0019] Explanation of reference numerals in the attached figures: The centralizer body 100, inner fixing sleeve 101, balance chamber 102, compensation ring 103, filter plate 104, second oil injection hole 105, limit screw 106. 200 diameter changing mechanism, 201 straightening block, 2011 first reinforcing part, 2012 second reinforcing part, 2013 inner hole, 202 piston, 203 elastic element, 204 actuating shaft, 205 braking surface, 206 steel ball, 207 limit seat; Integrated housing 300; Mounting bracket 400, first mounting part 401, second mounting part 402, third mounting part 403, sealing connector 404, wiring cavity 405, voltage stabilizing core 406, limiting part 407, limiting component 408; Motor 500, oil chamber 501, first oil injection hole 502, sealing connector 503, power output shaft 504, thrust ball bearing 505, support ring 506; Actuating housing 600, lead screw 601, lead screw nut 602, stop shaft 603, seal 604, U-shaped fastener 605, lead screw housing 606; Adapter 700, first adapter 701, second adapter 702, sealing plug 703, connecting pipe 704, limiting bushing 705; Sealing ring 800, first guide sleeve 801, second guide sleeve 802, first annular cavity 803, second annular cavity 804. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0022] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0023] See Figures 1-5This application provides a variable diameter stabilizer, including a centralizer body 100, a variable diameter mechanism 200, and an integrated housing 300. The variable diameter mechanism 200 is disposed on the centralizer body 100. A mounting bracket 400 is disposed inside the integrated housing 300. The mounting bracket 400 has a first mounting portion 401, a second mounting portion 402, and a third mounting portion 403 arranged parallel to each other along the axial direction. A drive mechanism is disposed inside the first mounting portion 401, a control module is disposed inside the second mounting portion 402, and a balancing mechanism is disposed inside the third mounting portion 403. A sealing connector 404 is connected to the first end of the mounting bracket 400, forming a wiring cavity 405 between the sealing connector 404 and the first end of the mounting bracket 400. The drive mechanism and the control module communicate with each other in the wiring cavity 405. A wiring hole is provided along the axial direction. The control module is electrically connected to the controller through the wiring hole. The second end of the mounting bracket 400 is connected to the diameter changing mechanism 200. The drive mechanism is connected to the control module and the diameter changing mechanism 200. The control module is used to control the drive mechanism to drive the diameter changing mechanism 200 to perform the diameter changing action. The balancing mechanism includes a pressure balancing channel provided in the third mounting part 403 and a pressure stabilizing core 406 housed in the pressure balancing channel and axially movable. The first end of the pressure stabilizing core 406 acts on the oil in the balancing mechanism. The oil in the balancing mechanism is connected to the oil chamber 501 where the drive mechanism is located through the oil passage. The second end of the pressure stabilizing core 406 is exposed in the drilling fluid between the integrated housing 300 and the mounting bracket 400. The balancing mechanism is used to balance the internal and external pressures of the integrated housing 300.

[0024] Specifically, the controller is connected to the “cable from the ground” described below and is used to issue control commands.

[0025] Specifically, see Figure 7 Inside the second mounting section 402, the control module includes a circuit board and a drive frame for mounting the circuit board. The circuit board is connected to cables from the ground in the wiring cavity 405.

[0026] Specifically, the integrated housing 300 serves as the primary load-bearing and integrated structure, providing protection for the internal modules. The mounting bracket 400 provides precise positioning and support for the drive mechanism, control module, and balancing mechanism, ensuring their relative positions and connections, thereby achieving a highly integrated structural foundation.

[0027] Specifically, a passage for drilling fluid to flow is formed between the outer surface of the mounting bracket 400 and the inner wall of the integrated housing 300, thereby enabling the drilling fluid to act on the second end of the pressure stabilizing core 406.

[0028] The variable diameter stabilizer provided by this invention, when in use, transmits commands through the wiring hole on the sealing connector 404 to the control module in the wiring cavity 405. The control module controls the drive mechanism to start, and the drive mechanism drives the variable diameter mechanism 200 to perform a variable diameter action. Finally, the variable diameter mechanism 200 generates radial extension and retraction, thereby changing the outer diameter of the stabilizer. The integrated housing 300 is filled with high-pressure drilling fluid. This pressure acts on the second end of the pressure stabilizing core 406, pushing it to move axially. The first end of the pressure stabilizing core 406 compresses the oil on its back. Since the oil is connected to the oil cavity 501 where the drive mechanism is located through the oil passage, the pressure of the drilling fluid is transmitted to the sealed oil passage, so that the oil pressure in the oil cavity 501 and the external drilling fluid pressure always remain dynamically equal. This ensures that the pressure on the inner and outer walls of the integrated housing 300 is basically the same, avoiding deformation of the housing structure or sealing failure due to huge pressure difference, thereby improving the reliability and service life of the variable diameter stabilizer under high pressure conditions such as deep wells and ultra-deep wells.

[0029] The variable diameter stabilizer provided by the present invention integrates the drive mechanism, control module and balancing mechanism in parallel on the mounting frame 400, realizing the radial stacking of functional modules, thereby compressing the axial dimension of the variable diameter stabilizer, making it more in line with the model assumption of the "zero length algorithm", improving the control accuracy of the wellbore trajectory, and realizing high-precision directional drilling.

[0030] To optimize the above technical solution, the balancing mechanism also includes a limiting part 407 and a limiting member 408. The limiting part 407 is fixed to the mounting bracket 400 and is coaxially arranged with the pressure balancing channel. The limiting member 408 passes through the inside of the limiting part 407 and the inside of the pressure balancing channel. The inside of the limiting member 408 is hollow, which is used to allow drilling fluid to flow through the inside of the pressure balancing channel.

[0031] Specifically, the limiting member 408 is used to limit the pressure stabilizing core 406, preventing it from coming out of the pressure balance channel. Its hollow design creates a channel for drilling fluid to reach the pressure stabilizing core 406, thereby ensuring that the drilling fluid pressure can be applied evenly and without dead angles to the entire exposed surface of the pressure stabilizing core 406, avoiding pressure transmission delay or distortion that may be caused by poor fluid flow.

[0032] The limiting part 407 acts as a fixed bearing seat, while the limiting member 408 functions like a guide rod. The two work precisely together to strictly limit the axial movement of the voltage stabilizing core 406. This prevents radial runout or torsion of the voltage stabilizing core 406 due to uneven force, ensuring the accuracy and repeatability of its movement.

[0033] In use, when the pressure stabilizing core 406 moves axially under pressure, the limiting part 407 and the limiting element 408 work together to provide precise guidance and stroke constraint for the movement of the pressure stabilizing core 406, ensuring that it always slides smoothly along the predetermined axis, thereby guaranteeing the linearity and accuracy of pressure transmission. The guide and limiting structure combining the limiting part 407 and the limiting element 408 effectively prevents the pressure stabilizing core 406 from jamming and wearing, extending its service life. Even under complex downhole vibration and impact loads, it can ensure long-term and stable operation.

[0034] To optimize the above technical solution, the drive mechanism includes a motor 500. The first end of the motor 500 and the inner wall of the first mounting part 401 form an oil cavity 501. The third mounting part 403 has a first oil injection hole 502, which is connected to the oil cavity 501 and the pressure balance channel. A sealing connector 503 is provided between the oil cavity 501 and the wiring cavity 405. The sealing connector 503 is used to connect the control module and the motor 500. The second end of the motor 500 is provided with a power output shaft 504, which is connected to the diameter changing mechanism 200 and is used to drive the diameter changing mechanism 200 to change its diameter.

[0035] Specifically, the sealing connector 503 is a multi-core through-sealing connector 503, which is used to transmit multiple electrical signals and power while maintaining pressure sealing. The sealing connector 503 is connected to the circuit board of the control module and the leads of the motor 500, and is used to enable the control module to supply and control the power to the motor 500 while maintaining the pressure seal of the oil chamber 501 of the motor 500.

[0036] Specifically, the oil cavity 501 formed by the motor 500 and the inner wall of the first mounting part 401 is connected to the pressure balance channel of the balancing mechanism through the first oil injection hole 502, together forming a complete closed pressure compensation system. When the external drilling fluid pressure pushes the pressure stabilizing core 406, the oil pressure in the oil cavity 501 is synchronously regulated. The sealing connector 503, while enabling power transmission, isolates the pressure between the wiring cavity 405 (normal pressure or low pressure) and the oil cavity 501 (high pressure), ensuring electrical connection between two different pressure environments.

[0037] Specifically, the power output shaft 504 is provided with a thrust ball bearing 505 and a support ring 506.

[0038] In operation, the control module sends a power signal to the motor 500 through the sealed connector 503 within the wiring cavity 405. Upon receiving power, the motor 500's rotor begins to rotate, driving the power output shaft 504 to rotate, thereby transmitting power to the diameter-changing mechanism 200, which then performs the diameter-changing action. Immersing the motor 500 in oil pressure balanced with external pressure provides pressure protection for the motor 500. The use of the sealed connector 503 (preferably a twelve-pin sealed connector 503) provides a more effective pressure seal guarantee, thereby improving the high-pressure sealing reliability of the electrical connection. Furthermore, by integrating the oil passage and drilling fluid passage into the mounting bracket 400 and the integrated housing 300, a compact integrated design is formed between the drive mechanism and the balancing mechanism, further reducing the axial dimension of the diameter-changing stabilizer and achieving high-precision directional drilling.

[0039] To optimize the above technical solution, the variable diameter stabilizer also includes an actuator, which includes an actuator housing 600, a lead screw 601, a lead screw nut 602, and a stop shaft 603. The first end of the actuator housing 600 is connected to the integrated housing 300, and the second end of the actuator housing 600 is connected to the centralizer body 100. The lead screw 601, lead screw nut 602, and stop shaft 603 are disposed inside the actuator housing 600. One end of the lead screw 601 is coaxially connected to the power output shaft 504. The lead screw nut 602 is sleeved on the lead screw 601, and the first end of the stop shaft 603 is connected to the lead screw nut 602. The second end of the stop shaft 603 extends into the interior of the centralizer body 100 and is connected to the variable diameter mechanism 200. The power output shaft 504 is used to drive the lead screw 601 to rotate, thereby causing the lead screw nut 602 and the stop shaft 603 to move axially.

[0040] Specifically, a seal 604 is provided between the housing 600 and the centralizer body 100 to prevent drilling fluid from entering the balance chamber 102.

[0041] Specifically, a U-shaped fastener 605 is provided between the actuator housing 600 and the mounting bracket 400. One end of the U-shaped fastener 605 is bolted to the actuator housing 600, and the other end of the U-shaped fastener 605 is bolted to the mounting bracket 400 to provide support and improve structural stability.

[0042] In operation, the power output shaft 504 of the motor 500 drives the lead screw 601 to rotate. The lead screw nut 602, sleeved on the lead screw 601, converts the rotational motion into precise linear motion along the axis of the lead screw 601. The stop shaft 603, fixedly connected to the lead screw nut 602, synchronously generates axial displacement. This axial displacement is directly transmitted to the diameter-changing mechanism 200 inside the stabilizer body 100, thus providing an initial, controllable linear input for the diameter-changing action. The two ends of the actuator housing 600 are respectively connected to the integrated housing 300 and the stabilizer body 100, forming the core load-bearing frame of the diameter-changing stabilizer, ensuring precise coaxiality between the components along the power transmission path.

[0043] By using a lead screw pair, the extension displacement of the centralizing block 201 is strictly linearly related to the number of rotations of the motor 500. By controlling the rotation angle of the motor 500, the diameter change can be precisely controlled, realizing the digital and programmable control of the stabilizer's outer diameter, thereby improving the control accuracy of the wellbore trajectory and achieving high-precision directional drilling.

[0044] See Figure 6 To optimize the above technical solution, the variable diameter mechanism 200 includes at least one straightening block 201, at least one piston 202, at least one elastic element 203, and an actuating shaft 204. The straightener body 100 has at least one mounting groove along its circumference. The straightening block 201 is movably disposed within the mounting groove via the piston 202. The first end of the actuating shaft 204 is connected to the second end of the stop shaft 603, and the actuating shaft 204 is axially movable within the straightener body 100. The outer surface of the actuating shaft 204 has at least one inclined braking surface 205. One end of the piston 202 contacts the braking surface 205, which drives the piston 202 to move radially. The other end of the piston 202 is connected to the straightening block 201. One end of the elastic element 203 is connected to the straightening block 201, and the other end is connected to the straightener body 100. The elastic element 203 provides a radial restoring force to the straightening block 201.

[0045] Specifically, when the stop shaft 603 pushes the actuator shaft 204 to move axially, the inclined braking surface 205 on the outer surface of the actuator shaft 204 moves relative to the inner end of the piston 202. Since the piston 202 is constrained within the radial hole of the centralizer body 100 and can only move radially, the axial displacement of the inclined surface of the actuator shaft 204 is forcibly converted into the radial displacement of the piston 202. The piston 202 pushes outward, directly pushing the centralizer block 201 to overcome the tension of the elastic element 203 and the well wall resistance to extend outward, thus increasing the diameter. When retraction is required, the motor 500 controls the actuator shaft 204 to move in the reverse direction, releasing its radial constraint on the piston 202. At this time, under the restoring force provided by the elastic element 203, the centralizer block 201 drives the piston 202 to retract radially inward until the centralizer block 201 is completely retracted into the mounting groove, and the diameter stabilizer returns to its minimum outer diameter.

[0046] Specifically, the elastic element 203 is preferably a tension spring.

[0047] Specifically, an O-ring and a scraper ring are installed at the sealing position of piston 202, and a piston bushing and piston 202 are sequentially installed in the piston hole of the corresponding mounting groove. The O-ring and scraper ring are respectively installed at the mating parts of seal 604, sealing ring 800, and compensating ring 103. The tension spring is installed in the centralizer block 201 and then in the mounting groove of the centralizer body 100. The tension spring is rotated to fix it on the centralizer body 100. The aforementioned seal 604 and stroke thrust sleeve are installed on the actuator shaft 204. Hydraulic oil is injected into the cavity through the second oil injection port on the centralizer body 100, and sealed with an oil port sealing plug.

[0048] Furthermore, the outer wall of the actuator 204 is provided with a groove, and the inside of the groove is provided with a plurality of steel balls 206 to ensure the guiding accuracy and structural stability of the actuator 204 in the movement within the centralizer body 100.

[0049] Furthermore, this application preferably provides three mounting slots evenly distributed along the circumference of the centralizer body 100. Each mounting slot is used to mount a centralizer block 201. Each centralizer block 201 is provided with two pistons 202 (with two inclined braking surfaces 205 corresponding to the actuation shaft 204) and a tension spring. Each mounting slot has two piston holes for assembling the pistons 202. The pistons 202 serve to guide, seal (i.e., the pistons 202 can ensure the sealing of the balance chamber 102 even when they are in the radial stroke), and drive the centralizing motion, thereby realizing the controllable extension and retraction of the diameter-changing mechanism 200.

[0050] Specifically, the inclined braking surface 205 and piston 202 have a simple structure, clear mechanical principle, strong load-bearing capacity, and extremely high reliability even under harsh downhole conditions; the restoring force provided by the elastic element 203 ensures that the diameter changing mechanism 200 can automatically return to a safe state when the active power is lost, which greatly improves the safety of operation; the linear input of the actuator 204 is directly converted into the radial output of the straightening block 201, which makes the diameter changing action respond quickly without lag and improves the efficiency of operation.

[0051] To optimize the above technical solution, the variable diameter stabilizer also includes an adapter end 700, a first conversion head 701, and a second conversion head 702. The first conversion head 701 and the second conversion head 702 are fixedly connected to the adapter end 700. The first conversion head 701 is connected to the second end of the stop shaft 603, and the second conversion head 702 is connected to the first end of the actuation shaft 204. The variable diameter stabilizer also includes a sealing plug 703 and a connecting tube 704. The sealing plug 703 is disposed between the end of the connecting tube 704 and the second conversion head 702. The connecting tube 704 is disposed inside the actuation shaft 204. The connecting tube 704, the first conversion head 701, the second conversion head 702, the stop shaft 603, the lead screw 601, and the motor 500 are coaxially provided with through holes for cables or wires to pass through.

[0052] Specifically, the aforementioned sealing plug 703 is a six-core sealing plug 703. A limiting bushing 705 is provided on the side of the second adapter 702 away from the first adapter 701. The structural principle of the six-core sealing plug 703 is the same as that of the aforementioned twelve-core sealing connector 503, both of which serve to simultaneously achieve sealing and electrical connection. The limiting bushing 705 is used to fix and limit the six-core sealing plug 703, thereby improving connection stability.

[0053] Specifically, cables or wires from the ground system pass sequentially through the wiring holes of the sealed connector 404 into the wiring cavity 405. Then, through the wiring of the control module, they enter the coaxially arranged wiring hole inside the motor 500, lead screw 601, stop shaft 603, first converter 701, adapter end 700, second converter 702, actuator shaft 204, and connecting pipe 704. During this process, the sealing plug 703 ensures a pressure seal at the connection between the connecting pipe 704 and the second converter 702, preventing drilling fluid from entering the wiring hole. The conversion mechanism, composed of the adapter end 700, first converter 701, and second converter 702, establishes a rigid, sealed electrical transition bridge between the stop shaft 603 and actuator shaft 204, two components that may move relative to each other, ensuring the continuity of the circuit without interfering with mechanical movement.

[0054] By integrating the cable channel within the core transmission component of the variable diameter stabilizer, rather than laying it separately on the side, space is maximized, avoiding the clutter of external wiring and the increase in tool outer diameter. The adapter end 700, the first adapter 701, and the second adapter 702 are rigid and fixed, mechanically connecting the stop shaft 603 and the actuator shaft 204, and electrically providing a coherent, assemblable adapter node for the cable pass-through hole, solving the problem of direct wiring between moving parts. The connecting tube 704 passes through the inside of the actuator shaft 204, providing a smooth inner lining for the cable, preventing the cable from being scratched or worn due to relative movement inside the actuator shaft 204, and extending the cable's service life. In use, the cable can directly reach tools such as measurement while drilling below, enabling real-time, high-speed data upload and precise command issuance, laying the foundation for intelligent, closed-loop geological steering drilling. The built-in cable pass-through hole avoids the structural complexity and reliability risks associated with external cables or additional bypass pipelines, ensuring the reliability of electrical connections in extremely harsh downhole environments.

[0055] To optimize the above technical solution, the inner wall of the centralizer body 100 is provided with an inner fixing sleeve 101, which together with the actuating shaft 204 forms a balance cavity 102. It also includes a balance assembly, which includes a compensation ring 103 and a filter plate 104. The filter plate 104 is disposed on the side wall of the inner fixing sleeve 101 and is used to filter drilling fluid. The first side of the compensation ring 103 is exposed to the drilling fluid. The centralizer body 100 is provided with a second oil injection hole 105, which is connected to the mounting groove. The mounting groove is connected to the balance cavity 102. The second side of the compensation ring 103 is exposed to the oil.

[0056] Specifically, drilling fluid outside the variable diameter stabilizer, under pressure, passes through the filter plate 104 and enters the balance chamber 102 formed by the inner fixed sleeve 101 and the actuator shaft 204, acting on the first side of the compensation ring 103. Simultaneously, hydraulic oil injected through the second injection port 105 fills the space behind the mounting groove piston 202 and the second side of the compensation ring 103 in the balance chamber 102. When the external drilling fluid pressure increases, the pressure is transmitted through the filter plate 104 to the first side of the compensation ring 103, pushing the compensation ring 103 to move axially and compressing the oil on its second side. Since the oil is incompressible and the entire oil circuit is closed, this pressure is transmitted to all chambers connected to the oil circuit, especially the chamber behind the piston 202, thereby balancing the external drilling fluid pressure acting on the centralizing block 201 and the inner end face of the piston 202. This process works in conjunction with the aforementioned balancing mechanism, but the protected objects are different; the balancing assembly mainly protects the chambers where the centralizing block 201 and piston 202 are located.

[0057] Specifically, the downhole drilling fluid contains a large amount of rock cuttings and impurities. The filter plate 104 allows the liquid pressure to pass through, but blocks solid particles from entering the precision balance chamber 102, preventing the compensation ring 103 from getting stuck or scratched, thus ensuring the long-term reliability of the balance assembly.

[0058] Specifically, by arranging the inner fixing sleeve 101, an independent balance cavity 102 is separated inside the body 100 of the centralizer, providing physical space for the installation and movement of the compensation ring 103.

[0059] Specifically, the stabilizer body 100 is provided with a limiting screw 106 that cooperates with the inner fixing sleeve 101 to improve structural stability.

[0060] See Figure 8 To optimize the above technical solution, the straightening block 201 includes an installation part, a first reinforcing part 2011 and a second reinforcing part 2012. The first reinforcing part 2011 and the second reinforcing part 2012 are arranged in a staggered manner, and the straightening block 201 is a centrally symmetrical figure. The installation part, the first reinforcing part 2011 and the second reinforcing part 2012 are provided with a plurality of inner holes 2013, and diamond composite sheets are welded inside the inner holes 2013. The surface of the straightening block 201 is laser-coated with a tungsten carbide coating. The elastic element 203 is located at the center of the installation part, and there are two pistons 202, which are arranged opposite to each other on both sides of the elastic element 203.

[0061] Specifically, when the centralizing block 201 extends under the drive of the piston 202 and contacts the well wall, the radial reaction force from the well wall first acts on the robust diamond composite sheet and tungsten carbide coating on the surface of the centralizing block 201. Subsequently, this force is transmitted to the body of the centralizing block 201 through the weld root of the inner hole 2013 and the entire cladding layer. Because the centralizing block 201 adopts a centrally symmetrical design, and the first reinforcing part 2011 and the second reinforcing part 2012 are arranged in a staggered manner, the load can be evenly distributed throughout the structure, avoiding stress concentration and effectively resisting complex loads from different directions. The two pistons 202 are symmetrically arranged on both sides of the elastic element 203, ensuring the uniformity of the thrust and retraction forces and preventing the centralizing block 201 from experiencing uneven wear or jamming during movement. The elastic element 203, located at the center, provides a direct and centered reset pull force.

[0062] Specifically, the diamond composite sheet and the tungsten carbide coating form a composite wear-resistant system. The diamond composite sheet (PDC) is an extremely wear-resistant material that can withstand the most intense friction and impact; the laser-clad tungsten carbide coating acts as a "covering surface" to protect the body of the straightening block 201 from erosion.

[0063] To optimize the above technical solution, the variable diameter mechanism 200 also includes a limiting seat 207. The limiting seat 207 is arranged at the end of the straightening block 201 and fixed to the straightener body 100. When the straightening block 201 moves radially, the limiting seat 207 abuts against the straightening block 201. The limiting seat 207 is used to limit the radial displacement of the straightening block 201.

[0064] Specifically, the limiting seat 207 is fastened to the centralizer body 100 by screws.

[0065] Specifically, during the radial extension of the straightening block 201, the limiting seat 207 itself does not move. When the straightening block 201 moves outward to the preset maximum design stroke under the push of the piston 202, the end of the straightening block 201 will make physical contact (abut) with the limiting seat 207 fixed on the straightener body 100, thereby generating a reaction force. This force is directly transmitted to the straightener body 100 through the limiting seat 207, thus rigidly preventing the straightening block 201 from moving further outward. At this time, even if the actuator shaft 204 continues to apply thrust, the displacement of the straightening block 201 will not increase further, its outer diameter is strictly limited within a safe range, and the limiting seat 207 has sufficient structural strength to withstand the huge impact force transmitted from the straightening block 201, thereby ensuring the effectiveness of the limiting.

[0066] To optimize the above technical solution, the variable diameter stabilizer also includes a sealing ring 800, a first guide sleeve 801, and a second guide sleeve 802. The actuator also includes a lead screw housing 606, with the lead screw 601 and lead screw nut 602 disposed inside the lead screw housing 606. The sealing ring 800 is located between the stabilizer body 100 and the actuator shaft 204. The first guide sleeve 801 is fixed to the second end of the actuator shaft 204. A first guide hole for drilling fluid flow is provided on the side wall of the first guide sleeve 801. The connecting pipe 704 and the actuator... The inner wall of shaft 204 forms a first annular cavity 803. The first guide hole is connected to the first annular cavity 803. The second guide sleeve 802 is fixed to the first end of the actuating shaft 204. The side wall of the second guide sleeve 802 is provided with a second guide hole for drilling fluid to flow. The inner wall of the actuating housing 600, the actuating shaft 204, the lead screw housing 606 and the stop shaft 603 form a second annular cavity 804. The second guide hole is connected to the second annular cavity 804, and the second annular cavity 804 is connected to the interior of the limiting member 408.

[0067] Specifically, when the variable diameter stabilizer is located at the bottom of the well, the drilling fluid flows under pump pressure. A portion of the drilling fluid enters the second annular cavity 804, formed by the inner wall of the actuator housing 600 and the internal shaft, through the second guide hole on the second guide sleeve 802. This second annular cavity 804 is connected to the pressure balance channel of the aforementioned balancing mechanism through the internal hollow structure of the limiting member 408, ensuring that the drilling fluid can act on the pressure stabilizing core 406. Another portion of the drilling fluid enters the first annular cavity 803, formed by the connecting pipe 704 and the inner wall of the actuator shaft 204, through the first guide hole on the first guide sleeve 801. The first annular cavity 803, the second annular cavity 804, and the connected passage together provide a smooth bypass channel for the drilling fluid, bypassing precision transmission components (such as lead screws), ensuring that the drilling fluid can flow smoothly to the drill bit.

[0068] Specifically, the sealing ring 800 is disposed between the centralizer body 100 and the actuator shaft 204 to achieve dynamic pressure sealing. It isolates the internal oil chamber 501 of the centralizer body 100 from the external drilling fluid, while allowing the actuator shaft 204 to move axially.

[0069] It should be noted that the variable diameter stabilizer provided by this invention can be used in the field of oil drilling equipment technology or other fields. Other fields refer to any field other than the field of oil drilling equipment technology. The above are merely examples and do not limit the application areas of the variable diameter stabilizer provided by this invention.

[0070] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0071] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0072] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A variable diameter stabilizer, characterized in that, The device includes a centralizer body (100), a diameter-changing mechanism (200), and an integrated housing (300). The diameter-changing mechanism (200) is disposed on the centralizer body (100), and the integrated housing (300) has a mounting bracket (400) inside. The mounting bracket (400) is provided with a first mounting part (401), a second mounting part (402) and a third mounting part (403) arranged in parallel along the axial direction. The first mounting part (401) is provided with a drive mechanism, the second mounting part (402) is provided with a control module, and the third mounting part (403) is provided with a balancing mechanism. The first end of the mounting bracket (400) is connected to a sealing connector (404), and a wiring cavity (405) is formed between the sealing connector (404) and the first end of the mounting bracket (400). The drive mechanism and the control module are connected in the wiring cavity (405). The sealing connector (404) is provided with a wiring hole along the axial direction, and the control module is electrically connected to the controller through the wiring hole. The second end of the mounting bracket (400) is connected to the variable diameter mechanism (200); The drive mechanism is connected to the control module and the drive mechanism is connected to the diameter changing mechanism (200). The control module is used to control the drive mechanism to drive the diameter changing mechanism (200) to change diameter. The balancing mechanism includes a pressure balancing channel disposed in the third mounting part (403) and a pressure stabilizing core (406) housed in the pressure balancing channel and axially movable. The first end of the pressure stabilizing core (406) acts on the oil in the balancing mechanism. The oil in the balancing mechanism is connected to the oil chamber (501) where the drive mechanism is located through an oil passage. The second end of the pressure stabilizing core (406) is exposed in the drilling fluid between the integrated housing (300) and the mounting bracket (400). The balancing mechanism is used to balance the internal and external pressures of the integrated housing (300).

2. The variable diameter stabilizer according to claim 1, characterized in that, The balancing mechanism further includes a limiting part (407) and a limiting member (408). The limiting part (407) is fixed to the mounting bracket (400) and is coaxially arranged with the pressure balancing channel. The limiting member (408) passes through the interior of the limiting part (407) and the interior of the pressure balancing channel. The interior of the limiting member (408) is hollow, which is used to allow drilling fluid to flow through the interior of the pressure balancing channel.

3. The variable diameter stabilizer according to claim 2, characterized in that, The drive mechanism includes a motor (500), and the first end of the motor (500) and the inner wall of the first mounting part (401) form the oil cavity (501). The third mounting part (403) is provided with a first oil injection hole (502), which is connected to the oil cavity (501) and the pressure balance channel. A sealing connector (503) is provided between the oil cavity (501) and the wiring cavity (405). The sealing connector (503) is used to connect the control module and the motor (500). The second end of the motor (500) is provided with a power output shaft (504), which is connected to the diameter changing mechanism (200) and is used to drive the diameter changing mechanism (200) to change diameter.

4. The variable diameter stabilizer according to claim 3, characterized in that, It also includes an actuator, which comprises an actuator housing (600), a lead screw (601), a lead screw nut (602), and a stop shaft (603), wherein: The first end of the actuator housing (600) is connected to the integrated housing (300), the second end of the actuator housing (600) is connected to the centralizer body (100), and the lead screw (601), the lead screw nut (602) and the stop shaft (603) are disposed inside the actuator housing (600); One end of the lead screw (601) is coaxially connected to the power output shaft (504), the lead screw nut (602) is sleeved on the lead screw (601), and the first end of the stop shaft (603) is connected to the lead screw nut (602), and the second end of the stop shaft (603) extends into the interior of the centralizer body (100) and is connected to the diameter changing mechanism (200); The power output shaft (504) is used to drive the lead screw (601) to rotate, thereby causing the lead screw nut (602) and the stop shaft (603) to move axially.

5. The variable diameter stabilizer according to claim 4, characterized in that, The diameter-changing mechanism (200) includes at least one straightening block (201), at least one piston (202), at least one elastic element (203), and an actuating shaft (204), wherein: The body of the straightener (100) has at least one mounting groove along the circumferential direction, and the straightening block (201) is movably disposed in the mounting groove by the piston (202); The first end of the actuating shaft (204) is connected to the second end of the stop shaft (603), and the actuating shaft (204) is axially movable inside the centralizer body (100). The outer surface of the actuating shaft (204) is provided with at least one inclined braking surface (205). One end of the piston (202) is in contact with the braking surface (205), the braking surface (205) is used to drive the piston (202) to move radially, and the other end of the piston (202) is connected to the straightening block (201); One end of the elastic element (203) is connected to the straightening block (201), and the other end of the elastic element (203) is connected to the straightening body (100). The elastic element (203) is used to provide radial restoring force to the straightening block (201).

6. The variable diameter stabilizer according to claim 5, characterized in that, It also includes an adapter end (700), a first adapter head (701) and a second adapter head (702), the first adapter head (701) and the second adapter head (702) being fixedly connected to the adapter end (700), and the first adapter head (701) being connected to the second end of the stop shaft (603), and the second adapter head (702) being connected to the first end of the actuation shaft (204); It also includes a sealing plug (703) and a connecting tube (704), wherein the sealing plug (703) is disposed between the end of the connecting tube (704) and the second conversion head (702), and the connecting tube (704) is disposed inside the actuating shaft (204); The connecting pipe (704), the first adapter (701), the second adapter (702), the stop shaft (603), the lead screw (601), and the motor (500) are all coaxially provided with through holes, which are continuous channels for cables or wires to pass through.

7. The variable diameter stabilizer according to claim 5, characterized in that, The inner wall of the centralizer body (100) is provided with an inner fixing sleeve (101), and the inner fixing sleeve (101) and the actuating shaft (204) enclose to form a balance cavity (102). It also includes a balancing assembly, which includes a compensation ring (103) and a filter plate (104), the filter plate (104) being disposed on the side wall of the inner fixing sleeve (101) for filtering drilling fluid, and the first side of the compensation ring (103) being exposed to the drilling fluid; The centralizer body (100) has a second oil injection hole (105), which is connected to the mounting groove, which is connected to the balance chamber (102), and the second side of the compensation ring (103) is exposed to the oil.

8. The variable diameter stabilizer according to claim 5, characterized in that, The straightening block (201) includes an installation part, a first reinforcing part (2011) and a second reinforcing part (2012). The first reinforcing part (2011) and the second reinforcing part (2012) are arranged in a staggered manner, and the straightening block (201) is a centrally symmetrical figure. The installation part, the first reinforcing part (2011) and the second reinforcing part (2012) are provided with a plurality of inner holes (2013), and a diamond composite sheet is welded inside the inner hole (2013). The surface of the straightening block (201) is laser-coated with a tungsten carbide coating. The elastic element (203) is located at the center of the mounting portion, and there are two pistons (202) arranged opposite each other on both sides of the elastic element (203).

9. The variable diameter stabilizer according to claim 8, characterized in that, The diameter-changing mechanism also includes a limiting seat (207), which is arranged at the end of the straightening block (201) and fixed to the straightener body (100). When the straightening block (201) moves radially, the limiting seat (207) abuts against the straightening block (201), and the limiting seat (207) is used to limit the radial displacement of the straightening block (201).

10. The variable diameter stabilizer according to claim 6, characterized in that, It also includes a sealing ring (800), a first guide sleeve (801), and a second guide sleeve (802). The actuator also includes a lead screw housing (606), with the lead screw (601) and the lead screw nut (602) disposed inside the lead screw housing (606), wherein: The sealing ring (800) is disposed between the centralizer body (100) and the actuating shaft (204); The first guide sleeve (801) is fixed to the second end of the actuating shaft (204). The side wall of the first guide sleeve (801) is provided with a first guide hole for drilling fluid to flow. The connecting pipe (704) and the inner wall of the actuating shaft (204) form a first annular cavity (803). The first guide hole is connected to the first annular cavity (803). The second guide sleeve (802) is fixed to the first end of the actuating shaft (204). A second guide hole for drilling fluid to flow is provided on the side wall of the second guide sleeve (802). The inner wall of the actuating housing (600) and the actuating shaft (204), the lead screw housing (606) and the stop shaft (603) form a second annular cavity (804). The second guide hole is connected to the second annular cavity (804), and the second annular cavity (804) is connected to the interior of the limiting member (408).

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