Mud pulse generator driven by motor

Abstract

The utility model discloses a mud pulse generator driven by a motor. The mud pulse generator is used for extracting signals of an inclinometer while drilling. Comprising a main valve head assembly and a servo assembly, the servo assembly comprises a screen drum and a valve seat arranged in the screen drum, a valve sleeve is arranged at a mud channel of the valve seat, the valve sleeve and a servo valve rod are oppositely arranged, and the servo valve rod can move to be seamlessly attached to the valve sleeve; a servo valve rod is connected with a ball screw nut, a hexagonal shaft sleeve on a ball screw shaft is connected with a speed reducer, the speed reducer is connected with a fixing seat assembly, and the periphery of the fixing seat assembly is sleeved with an outer rotor assembly. The outer rotor assembly is connected with the motor short section and is driven by the motor. The motor is used for driving, so that rigid collision between the servo valve rod and the valve sleeve can be effectively avoided, abrasion between the servo valve rod and the valve sleeve is reduced, and the service life of the servo valve rod and the valve sleeve is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of petroleum exploration and drilling, in particular to a mud pulse generator driven by a motor. Background Art

[0002] During the oil drilling process, especially the drilling of complex wells such as horizontal wells, extended reach wells and branch wells, the various downhole parameters that the well site personnel need to know in real time are completed by the measurement while drilling (MWD) system.

[0003] At present, there are four main information transmission methods for measurement while drilling: wired cable method, mud pulse method, acoustic wave method and electromagnetic wave method. Each method has its limitations and scope of application. Among them, the mud pulse method is the most widely used and reliable. The mud pulse method is divided into three transmission modes: negative pulse, positive pulse and continuous wave. The most widely used one is the positive pulse transmission mode. The main device for the mud pulse method is the mud pulse generator. The transmission mode of the mud pulse determines the structural form of the pulse generator. Among them, the hydraulically driven reciprocating pulse generator with pilot control is the most common form of mud positive pulse transmission mode. The traditional structural form of this type of pulse generator is to drive the main throttle valve to reciprocate to generate a pressure pulse signal by the hydraulic control circuit. The medium of the hydraulic control circuit can be drilling fluid or hydraulic oil. The action of the pilot valve is mostly completed by an electromagnet, which consumes a lot of power, and the displacement of the servo valve stem cannot be accurately controlled, resulting in a rigid collision between the servo valve stem and the valve sleeve, large friction loss, and a high failure rate after long-term use.

[0004] The mud pulse generator is the top priority of most MWDs. Improving the performance of the mud pulse generator and making it simple in structure, easy to maintain, energy-saving and durable is an inevitable trend in the development of the instrument. Utility Model Content

[0005] In order to solve the above problems, the utility model provides a mud pulse generator driven by a motor with good stability and high transmission efficiency.

[0006] The technical solution adopted by the utility model is as follows:

[0007] A mud pulse generator driven by a motor comprises a main valve head assembly, one end of which is connected to a servo assembly, the servo assembly comprises a screen cylinder and a valve seat arranged in the screen cylinder, a valve sleeve is arranged at the mud channel of the valve seat, the valve sleeve is arranged opposite to a servo valve stem, and the servo valve stem can move and seamlessly engage with the valve sleeve;

[0008] The other end of the servo valve stem is fixedly connected to the ball screw nut, and the ball screw nut and the ball screw shaft are connected to form a ball screw pair; the other end of the ball screw shaft is sleeved with a hexagonal sleeve;

[0009] The hexagonal sleeve is connected to the output shaft of the reducer, the input shaft of the reducer is fixedly connected to the fixed seat assembly, the outer rotor assembly is sleeved on the periphery of the fixed seat assembly and is magnetically coupled with the outer rotor assembly; one end of the outer rotor assembly is connected to the motor short section.

[0010] Furthermore: the sieve cylinder is threadedly connected to the outer cylinder of the main valve head assembly.

[0011] Furthermore: the valve seat is connected to the inner thread of the screen cylinder.

[0012] Furthermore: the servo valve stem is connected to the ball screw nut via a lock nut.

[0013] Furthermore: the ball screw nut is slidably installed in the slide groove of the oil-filled plug, and one end of the oil-filled plug is threadedly connected to the screen cylinder; a compensating piston is slidably installed in the hole of the oil-filled plug, and the compensating piston is sleeved on the servo valve stem and slidably connected thereto.

[0014] Furthermore: a guide ring is installed on the outer side of the compensation piston, the guide ring is in friction contact with the inner wall of the oil-filled plug, and the material of the guide ring is polytetrafluoroethylene.

[0015] Furthermore: a second type of deep groove ball bearing is sleeved on the ball screw shaft, and the second type of deep groove ball bearing is installed in an oil-filled plug to support the ball screw shaft.

[0016] Furthermore: an upper plug is provided at one end of the motor short section away from the coupling, a motor short section outer cylinder is sleeved on the outer side of the motor short section, one end of the motor short section outer cylinder is threadedly connected to the upper plug, and the other end is threadedly connected to the outer cylinder.

[0017] Furthermore: the middle part of the ball screw nut crosses the pin shaft, and a first-class deep groove ball bearing is installed at both ends of the pin shaft respectively. An elastic retaining ring for the shaft is arranged on the outer side of the first-class deep groove ball bearing, and the first-class deep groove ball bearing is slidably installed in the slide groove of the oil-filled plug.

[0018] Furthermore: a plurality of groups of bar magnets are respectively arranged on the fixed seat assembly and the outer rotor assembly, and the bar magnets are evenly distributed along the circumference with NSNS poles.

[0019] Compared with the prior art, the beneficial effects of the utility model are embodied in:

[0020] 1. Good stability and high reliability. The ball screw transmission has higher mechanical efficiency than the traditional electromagnet transmission.

[0021] 2. The displacement of the servo valve stem can be controlled by controlling the rotation speed and direction of the motor, which can effectively avoid the rigid collision between the servo valve stem and the valve sleeve, reduce the wear of the servo valve stem and the valve sleeve, and increase the service life of both.

[0022] 3. Low power consumption, long maintenance cycle, long service life and good economic benefits.

[0023] Other features and advantages of the present invention will be set forth in the following description, and in part will become apparent from the description, or will be understood by implementing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the main valve head assembly;

[0025] Figure 2 It is a schematic diagram of the servo assembly;

[0026] Figure 3 The ball screw nut is Figure 2 Sectional view of the middle BB position;

[0027] Figure 4 It is a layout diagram of the bar magnets between the fixed seat assembly and the outer rotor assembly;

[0028] Figure 5 This is the connection diagram of the upper plug end.

[0029] 1-main valve head assembly; 2-screen cylinder; 3-valve sleeve; 4-servo valve stem; 5-oil-filled plug; 6-reducer; 7-elastic coupling; 8-valve seat; 9-ball screw nut; 10-lock nut; 11-pin shaft; 12-class I deep groove ball bearing; 13-compensating piston; 14-guide ring; 15-gasket; 16-ball screw shaft; 17-class II deep groove ball bearing; 18-hexagonal bushing; 19-outer cylinder; 20-fixed seat assembly; 21-outer rotor assembly; 22-upper plug; 23-motor short section outer cylinder; 24-threaded sleeve; 25-motor short section; 26-protective cap.

[0030] 101-signal valve stem; 102-piston; 103-spring. DETAILED DESCRIPTION

[0031] The utility model is described in detail below in conjunction with the accompanying drawings and embodiments, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the utility model to illustrate the utility model. However, those skilled in the art should know that the following embodiments are not the only limitations on the technical scheme of the utility model, and any equivalent changes or modifications made under the spirit of the technical scheme of the utility model shall be deemed to belong to the protection scope of the utility model.

[0032] like Figure 1As shown, the mud pulse generator includes a main valve head assembly 1, which is a mature component. The assembly includes a signal valve stem 101, a piston 102 and a spring 103. The pulse signal of the mud pulse generator is mainly generated by the signal valve stem. When the pressures at both ends of the signal valve stem are inconsistent, the signal valve stem will telescope under the action of the piston and the spring, thereby generating a pulse signal. The frequency and pulse width of the pulse signal depend on the pressure difference environment, and this is the main purpose of the design of the pulse generator.

[0033] The utility model provides a mud pulse generator driven by a motor, in which a servo component is controlled by the motor to generate a variable pressure wave. Figure 1 , Figure 2 As shown, the servo assembly is connected to the right end of the main valve head assembly 1, and the servo assembly includes a screen cylinder 2, which is threadedly connected to the outer cylinder of the main valve head assembly 1; a step hole is provided in the middle of the screen cylinder 2, and a valve seat 8 is installed on the step hole, and the valve seat 8 is connected to the inner thread of the screen cylinder 2 to fix the valve seat.

[0034] There is a mud passage between the valve seat 8 and the main valve head assembly 1. The valve seat 8 is provided with a valve sleeve 3 at one end of the passage away from the main valve head assembly 1. The valve sleeve 3 is fixedly installed in the valve seat 8 by a set screw. A servo valve stem 4 is provided on one side of the valve sleeve 3. The servo valve stem 4 can be seamlessly engaged with the valve sleeve 3 or can be separated. When the servo valve stem 4 is engaged with the valve sleeve 3, the mud passage is blocked.

[0035] The end of the servo valve stem 4 away from the valve sleeve 3 is fixedly connected to the ball screw nut 9 through a lock nut 10, and the lock nut 10 is threadedly connected to the ball screw nut 9. The ball screw nut 9 is slidably installed in the slide groove of the oil-filled plug 5, and one end of the oil-filled plug 5 penetrates into the screen cylinder 2 and is threadedly connected thereto; the end of the oil-filled plug 5 close to the screen cylinder 2 is provided with a stepped hole, and a compensating piston 13 is slidably installed in the hole. The compensating piston 13 is sleeved on the servo valve stem 4 and slidably connected thereto. The compensating piston 13 has the function of compensating pressure and can support the valve stem. A gasket 15 is provided at the end of the oil-filled plug 5, and the two sides of the gasket 15 are respectively in contact with the screen cylinder 2 and the oil-filled plug 5 to play a sealing role.

[0036] One end of the ball screw nut 9 away from the servo valve stem 4 is connected to the ball screw shaft 16. The ball screw shaft 16 and the ball screw nut 9 are connected as a ball screw pair. The servo valve stem 4 is connected to the ball screw shaft 16 through the ball screw nut 9. The ball screw shaft 16 is sleeved with two second-class deep groove ball bearings 17, which are deep groove ball bearings 6000. The two second-class deep groove ball bearings 17 are installed in parallel in the oil-filled plug 5 to support the ball screw shaft 16.

[0037] A hexagonal sleeve 18 is provided at one end of the ball screw shaft 16 away from the ball screw nut 9, and the end of the hexagonal sleeve 18 away from the ball screw shaft 16 is connected to the output shaft of the reducer 6. The input shaft of the reducer 6 is fixedly connected to the fixed seat assembly 20, and the fixed seat assembly 20 is rotatably installed in the outer cylinder 19, and the outer cylinder 19 is threadedly connected to the oil-filled plug 5.

[0038] An outer rotor assembly 21 is provided at one end of the fixed seat assembly 20 away from the reducer 6, and the outer rotor assembly 21 is sleeved on one end of the fixed seat assembly 20 and connected thereto through magnetic coupling; an elastic coupling 7 is provided at one end of the outer rotor assembly 21 away from the fixed seat assembly 20 and fixedly connected thereto, and the elastic coupling 7 is fixedly mounted on the motor short section 25, and an upper plug 22 is provided at one end of the motor short section 25 away from the elastic coupling 7.

[0039] The upper plug 22 is fixedly connected to the motor short section 25, and the motor short section outer cylinder 23 is sleeved on the outside of the motor short section 25. One end of the motor short section outer cylinder 23 is threadedly connected to the upper plug 22, and the other end is provided with a threaded sleeve 24 threadedly connected to the outer cylinder 19. The screen cylinder 2, the oil-filled plug 5, the outer cylinder 19, and the motor short section outer cylinder 23 are sequentially connected to form the outer body of the device, with the same outer diameter.

[0040] The working principle of the utility model is as follows: when the motor in the motor short section 25 is energized, the motor drives the elastic coupling 7 to rotate, the elastic coupling drives the outer rotor assembly 21 to rotate, and the polarity of the bar magnet on the outer rotor assembly changes accordingly. Under the action of magnetic coupling, the fixed seat assembly 20 sleeved on the input shaft of the reducer starts to rotate, and the high-speed, low-torque power transmitted by the motor is converted into low-speed, high-torque power through the reducer output shaft through the deceleration effect of the reducer 6. The rotation of the reducer output shaft drives the hexagonal shaft sleeve 18 to rotate, thereby rotating the ball screw shaft 16. The rotation of the ball screw shaft converts the circular motion into the linear motion of the ball screw nut 9, and the ball screw nut drives the servo valve stem 4 to move linearly.

[0041] The movement direction and distance of the servo valve stem 4 are controlled by controlling the power-on time and rotation direction of the motor. When the servo valve stem 4 is in contact with the valve sleeve 3, the mud cannot flow through the valve sleeve 3, and the piston on the main valve head assembly 1 drives the signal valve stem to start retreating under the action of the mud pressure; when the servo valve stem 4 retreats and separates from the valve sleeve 3, the mud flows through the valve sleeve 3, there is no pressure difference inside the main valve head assembly 1, the main spring is reset, and the signal valve stem is extended, and pulse pressure waves are repeatedly generated.

[0042] Furthermore, if Figure 3As shown, a pin 11 is passed through the middle of the ball screw nut 9, and a first-class deep groove ball bearing 12 is installed at both ends of the pin 11 and fixedly connected thereto. The first-class deep groove ball bearing 12 is a deep groove ball bearing 619-5. A shaft elastic retaining ring is provided on the outer side of the first-class deep groove ball bearing 12, and the first-class deep groove ball bearing 12 is slidably installed in the slide groove of the oil-filled plug 5. In this way, it can be ensured that the ball screw nut 9 will not rotate with the rotation of the ball screw shaft 16, and the ball screw nut 9 can make a linear reciprocating motion in the oil-filled plug 5. At the same time, the first-class deep groove ball bearing 12 plays a role in guiding and reducing friction resistance.

[0043] Furthermore, a guide ring 14 is installed on the outer side of the compensation piston 13, and the guide ring 14 is in frictional contact with the inner wall of the oil-filled plug 5. The material of the guide ring 14 is polytetrafluoroethylene. Polytetrafluoroethylene is a plastic material with excellent self-lubricating properties. It has an extremely low friction coefficient and extremely high chemical stability, and can still maintain good performance under high temperature and strong acid and alkali conditions.

[0044] Furthermore, the fixing seat assembly 20 and the outer rotor assembly 21 are respectively provided with a plurality of groups of bar magnets, and the bar magnets are evenly distributed along the circumference with NSNS poles. Figure 4 When the outer rotor assembly 21 rotates, the bar magnets thereon will also make circular motion. At this time, the N pole of the outer rotor assembly 21 attracts the S pole on the fixed seat assembly 20, and the S pole of the outer rotor assembly 21 attracts the N pole on the fixed seat assembly 20, so that the fixed seat assembly 20 also makes circular motion.

[0045] Furthermore, if Figure 5 As shown, a protective cap 26 is provided at one end of the upper plug 22 away from the motor short section outer cylinder 23, and the protective cap 26 is threadedly connected to the upper plug 22 for protecting the upper plug.

[0046] Although the embodiments of the present invention have been shown and described above, it is understandable to those skilled in the art that various equivalent changes, modifications and substitutions may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A mud pulse generator driven by a motor, comprising a main valve head assembly (1), one end of the main valve head assembly being connected to a servo assembly, characterized in that: The servo assembly comprises a screen drum (2) and a valve seat (8) arranged in the screen drum (2); a valve sleeve (3) is arranged at the mud channel of the valve seat (8); the valve sleeve (3) is arranged opposite to the servo valve stem (4); the servo valve stem (4) can move and seamlessly engage with the valve sleeve (3); The other end of the servo valve stem (4) is fixedly connected to the ball screw nut (9), and the ball screw nut (9) and the ball screw shaft (16) are connected to form a ball screw pair; the other end of the ball screw shaft (16) is sleeved with a hexagonal shaft sleeve (18); The hexagonal shaft sleeve (18) is connected to the output shaft of the reducer (6), the input shaft of the reducer (6) is fixedly connected to the fixed seat assembly (20), the outer rotor assembly (21) is sleeved on the periphery of the fixed seat assembly (20) and is magnetically coupled thereto; one end of the outer rotor assembly (21) is connected to the motor short section (25).

2. The motor-driven mud pulse generator according to claim 1, characterized in that: The sieve cylinder (2) is threadably connected to the outer cylinder of the main valve head assembly (1).

3. The motor-driven mud pulse generator according to claim 1, characterized in that: The valve seat (8) is connected to the screen cylinder (2) through an internal thread.

4. The motor-driven mud pulse generator according to claim 1, characterized in that: The servo valve stem (4) is connected to the ball screw nut (9) via a lock nut (10).

5. The motor-driven mud pulse generator according to claim 1, characterized in that: The ball screw nut (9) is slidably mounted in the slide groove of the oil-filled plug (5), and one end of the oil-filled plug (5) is threadedly connected to the screen cylinder (2); a compensating piston (13) is slidably mounted in the hole of the oil-filled plug (5), and the compensating piston (13) is sleeved on the servo valve stem (4) and slidably connected thereto.

6. The motor-driven mud pulse generator according to claim 5, characterized in that: A guide ring (14) is installed on the outside of the compensating piston (13), and the guide ring (14) is in frictional contact with the inner wall of the oil-filled plug (5). The material of the guide ring (14) is polytetrafluoroethylene.

7. The motor-driven mud pulse generator according to claim 1, characterized in that: The ball screw shaft (16) is sleeved with a second-class deep groove ball bearing (17), and the second-class deep groove ball bearing (17) is installed in an oil-filled plug (5) to support the ball screw shaft (16).

8. The motor-driven mud pulse generator according to claim 1, characterized in that: An upper plug (22) is provided at one end of the motor short section (25) away from the coupling, and a motor short section outer cylinder (23) is sleeved on the outer side of the motor short section (25); one end of the motor short section outer cylinder (23) is threadedly connected to the upper plug (22), and the other end is threadedly connected to the outer cylinder (19).

9. The motor-driven mud pulse generator according to claim 1, characterized in that: The middle of the ball screw nut (9) crosses the pin shaft (11), and a first-class deep groove ball bearing (12) is installed at both ends of the pin shaft (11). An elastic retaining ring for the shaft is arranged on the outer side of the first-class deep groove ball bearing (12), and the first-class deep groove ball bearing (12) is slidably installed in the slide groove of the oil-filled plug (5).

10. The motor-driven mud pulse generator according to claim 1, characterized in that: The fixing seat assembly (20) and the outer rotor assembly (21) are respectively provided with a plurality of groups of bar magnets, and the bar magnets are evenly distributed along the circumference with NSNS poles.

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