Mud pulse generator

Abstract

The invention relates to the technical field of downhole tools, in particular to a mud pulse generator to relieve the situation that the performance of a conventional mud pulse generator cannot meet the technical requirements of ultra-deep well construction. The device comprises a nipple main body, a spring seat assembly, a flow limiting ring seat assembly, a main valve assembly and a control valve assembly, the spring seat assembly, the flow limiting ring seat assembly, the main valve assembly and the control valve assembly are sequentially inserted into the nipple main body; the spring seat assembly comprises a spring seat body, a pre-tightening baffle ring and a compression spring; the pre-tightening baffle ring is sleeved on the outer wall of the spring seat body; one end of the compression spring is fixedly connected with the spring seat body, and the other end is fixedly connected with the pre-tightening baffle ring; the side, away from the compression spring, of the pre-tightening baffle ring abuts against the flow limiting ring base assembly. An effective axial buffering and damping function is provided for the main valve assembly through the spring seat assembly, and damage of vibration caused by high-displacement liquid flow impact to core components in the drilling process is reduced.

Description

Technical Field

[0001] This invention relates to the field of downhole tool technology, and in particular to a mud pulse generator. Background Technology

[0002] In the field of oil and gas exploration and development, mud pulse generators (hereinafter referred to as pulsers) are widely used in logging-while-drilling (MWD) instruments, logging-while-drilling (LWD) tools, rotary steerable systems (RSS), or automated vertical drilling systems (VDS). The mud pressure fluctuations generated by the mud pulse generator transmit downhole measurement data to the surface for decoding and display. Therefore, the performance of the mud pulse generator directly affects the transmission of downhole measurement data. Conventional mud pulse generators are constrained by material selection and structural design, resulting in insufficient erosion resistance. Under ultra-high flow rates, they are prone to problems such as component leakage and even breakage, leading to a short lifespan. However, with the increasing number of deep and ultra-deep wells in China, especially those reaching depths of 10,000 meters, to ensure better rock-carrying performance of the drilling fluid in the upper large-diameter well section, large flow rates of 70L / s to 100L / s, or even ultra-high flow rates of 100L / s to 130L / s, are commonly used. The performance of conventional mud pulse generators cannot meet the technical requirements of ultra-deep well construction. Summary of the Invention

[0003] To alleviate the above-mentioned technical problems, the technical solution provided by the present invention is as follows: This invention provides a mud pulse generator comprising a short section body, a spring seat assembly, a flow limiting ring seat assembly, a main valve assembly, and a control valve assembly; The spring seat assembly, the flow limiting ring seat assembly, the main valve assembly, and the control valve assembly are sequentially inserted into the short section body; After entering the main body of the short section, the liquid flows sequentially through the spring seat assembly, the flow limiting ring seat assembly, the main valve assembly, and the control valve assembly; The spring seat assembly includes a spring seat body, a preload retaining ring, and a compression spring; The preload retaining ring is fitted onto the outer wall of the spring seat body; One end of the compression spring is fixedly connected to the spring seat body, and the other end is fixedly connected to the preload retaining ring; The side of the preload retaining ring furthest from the compression spring abuts against the flow limiting ring seat assembly.

[0004] Furthermore, Multiple compression springs are arranged in a ring array around the axis of the preloaded retaining ring.

[0005] Furthermore, The main valve assembly includes the main valve guide rod, the stabilizer, and the locking plug; The main valve guide rod is threadedly connected to the locking plug; The locking plug is inserted into the stabilizer.

[0006] Furthermore, A protective sleeve is also provided between the flow-limiting ring seat assembly and the main valve assembly; One end of the protective sleeve abuts against the current-limiting ring seat assembly, and the other end abuts against the centralizer.

[0007] Furthermore, A sealing ring is provided at the connection between the main valve assembly and the control valve assembly.

[0008] Furthermore, The first nozzle inside the main valve guide rod is made of hard alloy.

[0009] Furthermore, The second nozzle inside the control valve assembly is made of hard alloy.

[0010] Furthermore, The centralizer is made of hard alloy.

[0011] The beneficial effects of the mud pulse generator in this invention are analyzed as follows: The mud pulse generator provided in this solution utilizes a spring seat assembly within the short section body. Through the synergistic effect of the compression spring and the pre-tensioning retaining ring, it provides effective axial buffering and vibration reduction for the main valve assembly. This significantly reduces damage to core components caused by vibrations from high-flow-rate drilling fluid impacts during drilling, improving the stability and reliability of the system. Especially under ultra-high flow rates of 70L / s to 130L / s, this vibration-damping structure effectively alleviates fatigue stress in critical components such as the main valve guide rod and centralizer, preventing loosening and breakage due to vibration. Furthermore, this solution uses hard alloy materials to manufacture key vulnerable components such as the first nozzle in the main valve guide rod, the second nozzle in the control valve assembly, and the centralizer. This significantly enhances the erosion resistance of the components, solving the problem of localized penetration and sealing failure that commonly occurs with conventional pulse generators under long-term high-velocity drilling fluid scouring, thus significantly extending the equipment's service life. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0013] Figure 1 A schematic diagram of the structure of a mud pulse generator provided for an embodiment of the present invention; Figure 2 This is a schematic diagram of the spring seat assembly; Figure 3 A schematic diagram of the main valve assembly; Figure 4 A schematic diagram of the locking plug; Figure 5 for Figure 1 A magnified view of part A in the diagram; Figure 6 for Figure 1 A magnified view of part B in the diagram.

[0014] icon: 100-Short section main body; 200 - Spring seat assembly; 210 - Spring seat body; 220 - Preload retaining ring; 230 - Compression spring; 300-current limiting ring assembly; 400 - Main valve assembly; 410 - Main valve guide rod; 411 - First nozzle; 420 - Centralizer; 430 - Locking plug; 440 - Protective sleeve; 500 - Control valve assembly; 510 - Second nozzle. Detailed Implementation

[0015] Due to limitations in material selection and structural design, conventional mud pulse generators suffer from insufficient erosion resistance. Under ultra-high flow rates, they are prone to problems such as component leakage and even breakage, resulting in a short lifespan for the pulse generators. Furthermore, with the increasing number of deep and ultra-deep wells in China, especially those reaching depths of 10,000 meters, large flow rates of 70L / s to 100L / s, or even ultra-large flow rates of 100L / s to 130L / s, are generally required to ensure that the drilling fluid can achieve better rock-carrying performance in the upper large-diameter well section. However, the performance of conventional mud pulse generators is insufficient to meet the requirements for long-term operation.

[0016] In view of this, as shown in the figure, this solution provides a mud pulse generator to alleviate the above problems.

[0017] It includes a short section body 100, a spring seat assembly 200, a flow limiting ring seat assembly 300, a main valve assembly 400, and a control valve assembly 500; The spring seat assembly 200, the flow limiting ring seat assembly 300, the main valve assembly 400, and the control valve assembly 500 are sequentially inserted into the short section body 100; After entering the main body 100, the liquid flows sequentially through the spring seat assembly 200, the flow limiting ring seat assembly 300, the main valve assembly 400, and the control valve assembly 500. The spring seat assembly 200 includes a spring seat body 210, a preload retaining ring 220, and a compression spring 230; The preload retaining ring 220 is fitted onto the outer wall of the spring seat body 210; One end of the compression spring 230 is fixedly connected to the spring seat body 210, and the other end is fixedly connected to the preload retaining ring 220; The side of the preload retaining ring 220 away from the compression spring 230 abuts against the flow limiting ring seat assembly 300; Multiple compression springs 230 are arranged in a ring array around the axis of the preload retaining ring 220.

[0018] Specifically, this device has a spring seat assembly 200 inside the short section body 100. Through the cooperation of the pre-tightening retaining ring 220 and the compression spring 230, the compression spring 230 regulates the vibration caused when the liquid flows into the main valve assembly 400, thus providing axial buffering and shock absorption for the main valve assembly 400.

[0019] In this design, the compression spring 230 needs to be pre-pressed with a certain pressure during installation, so that the compression spring 230 is in a partially contracted state and is limited by a retaining ring. The pre-tightening force of the compression spring 230 is transmitted to the flow-limiting ring assembly 300 through the pre-tightening retaining ring 220. A wire retaining ring is also fitted on the side of the spring seat body 210 near the flow-limiting ring assembly 300 to limit the pre-tightening retaining ring 220 and prevent it from moving excessively and causing damping failure. To prevent liquid from flowing in and eroding the mating surface between the spring seat body 210 and the short section body 100, affecting subsequent disassembly and maintenance, an O-ring rubber seal is installed between the spring seat body 210 and the short section body 100.

[0020] In this solution, the main valve assembly 400 includes a main valve guide rod 410, a stabilizer 420, and a locking plug 430; The main valve guide rod 410 is threadedly connected to the locking plug 430; The locking plug 430 is inserted into the centralizer 420; A protective sleeve 440 is also provided between the flow limiting ring assembly 300 and the main valve assembly 400; One end of the protective sleeve 440 abuts against the flow-limiting ring seat assembly 300, and the other end abuts against the centralizer 420.

[0021] Specifically, the locking plug 430 has an internal hexagonal groove on the side away from the main valve guide rod 410, and each tip of the internal hexagonal groove is rounded. The centralizer 420 has a hexagonal structure mating part that mates with the internal hexagonal groove, and the side wall of the locking plug 430 has a positioning key. The centralizer 420 has a keyway that mates with the positioning key. Through the cooperation of the above structures, the centralizer 420 and the main valve guide rod 410 are axially fixed, and the relative rotation between the centralizer 420 and the main valve guide rod 410 is avoided. A sealing ring is provided at the connection between the main valve assembly 400 and the control valve assembly 500 to prevent internal pressure leakage during pulse generation.

[0022] In this design, the first nozzle 411 in the main valve guide rod 410, the second nozzle 510 in the control valve assembly 500, and the centralizer 420 are all made of hard alloy. By improving the material properties of key weak parts, their erosion resistance is enhanced, effectively preventing the overall service life from being affected by local penetration under ultra-large displacement conditions. Furthermore, the spring seat assembly 200 reduces the vibration and impact on the main valve assembly 400 during operation, avoiding the risk of cracking due to reduced toughness after the centralizer 420 is made of hard alloy, thereby achieving a dual improvement in durability and reliability.

[0023] This solution has at least the following beneficial effects: The mud pulse generator provided in this solution utilizes a spring seat assembly within the short section body. Through the synergistic effect of the compression spring and the pre-tensioning retaining ring, it provides effective axial buffering and vibration reduction for the main valve assembly. This significantly reduces damage to core components caused by vibrations from high-flow-rate drilling fluid impacts during drilling, improving the stability and reliability of the system. Especially under ultra-high flow rates of 70L / s to 130L / s, this vibration-damping structure effectively alleviates fatigue stress in critical components such as the main valve guide rod and centralizer, preventing loosening and breakage due to vibration. Secondly, this solution uses hard alloy materials to manufacture key vulnerable components such as the first nozzle in the main valve guide rod, the second nozzle in the control valve assembly, and the centralizer. This significantly enhances the erosion resistance of the components, solving the problem of localized penetration and sealing failure that commonly occurs with conventional pulse generators under long-term high-velocity drilling fluid scouring, thus significantly extending the equipment's service life. Furthermore, the design of the O-ring rubber seal and protective sleeve further enhances the equipment's sealing performance and erosion resistance, facilitating later maintenance. In summary, this solution effectively overcomes the technical bottlenecks of short lifespan and poor reliability of traditional mud pulsers in deep and ultra-deep wells with large displacement operations. It provides high-performance, long-life signal transmission assurance for drilling deep wells at depths of tens of thousands of meters, and has outstanding practical value and broad prospects for promotion and application.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A mud pulse generator, characterized in that: It includes a short section body (100), a spring seat assembly (200), a flow limiting ring seat assembly (300), a main valve assembly (400), and a control valve assembly (500); The spring seat assembly (200), the flow limiting ring seat assembly (300), the main valve assembly (400), and the control valve assembly (500) are sequentially inserted into the short section body (100); After entering the short section body (100), the liquid flows sequentially through the spring seat assembly (200), the flow limiting ring seat assembly (300), the main valve assembly (400), and the control valve assembly (500). The spring seat assembly (200) includes a spring seat body (210), a preload retaining ring (220), and a compression spring (230). The pre-tightening retaining ring (220) is fitted onto the outer wall of the spring seat body (210); One end of the compression spring (230) is fixedly connected to the spring seat body (210), and the other end is fixedly connected to the pre-tightening retaining ring (220); The side of the preload retaining ring (220) away from the compression spring (230) abuts against the flow limiting ring assembly (300).

2. The mud pulse generator according to claim 1, characterized in that: Multiple compression springs (230) are arranged in a ring array around the axis of the preload retaining ring (220).

3. The mud pulse generator according to claim 2, characterized in that: The main valve assembly (400) includes a main valve guide rod (410), a stabilizer (420), and a locking plug (430). The main valve guide rod (410) is threadedly connected to the locking plug (430); The locking plug (430) is inserted into the straightener (420).

4. The mud pulse generator according to claim 3, characterized in that: A protective sleeve (440) is also provided between the flow limiting ring assembly (300) and the main valve assembly (400). One end of the protective sleeve (440) abuts against the flow-limiting ring assembly (300), and the other end abuts against the centralizer (420).

5. The mud pulse generator according to claim 4, characterized in that: A sealing ring is provided at the connection between the main valve assembly (400) and the control valve assembly (500).

6. The mud pulse generator according to claim 5, characterized in that: The first nozzle (411) inside the main valve guide rod (410) is made of hard alloy.

7. The mud pulse generator according to claim 6, characterized in that: The second nozzle (510) within the control valve assembly (500) is made of hard alloy.

8. The mud pulse generator according to claim 7, characterized in that: The centralizer (420) is made of hard alloy.

Images