CN113775335B - A drilling fluid pulse signal generator - Google Patents

Abstract

The invention provides a drilling fluid pulse signal generator, which comprises: a housing; the inner core is concentrically arranged in the shell, a cavity is arranged in the inner core, and a rotor shaft and a stator coil are arranged in the cavity; the turbine is arranged at the first end of the inner core and is fixedly connected with the rotor shaft; a valve disc mechanism disposed between the inner core and an axial direction of the turbine, the valve disc mechanism including a stator disc and a rotor disc, the rotor disc being configured to be capable of being driven to rotate by the turbine so as to cause a flow area of the valve disc mechanism to vary periodically; the pressure acquisition device is arranged at the wellhead; the turbine can drive the rotor disc and the rotor shaft to rotate under the pushing action of drilling fluid, so that the drilling fluid flowing through the valve disc mechanism generates periodic pressure pulses, the stator coil can control the rotating speed of the rotor shaft through electrifying and cutting off the power, the signal frequency of the pressure pulses is controlled, and the signal frequency is collected and analyzed through the pressure collecting device, so that underground measurement information transmission is completed.

Description

A drilling fluid pulse signal generator

Technical Field

The invention belongs to the technical field of petroleum drilling engineering, and in particular relates to a drilling fluid pulse signal generator.

Background technique

During the drilling process, especially in the drilling process of complex wells such as horizontal wells, extended reach wells and branch wells, well site personnel usually use MWD and LWD systems to understand various downhole parameters in real time. At present, the commonly used MWD and LWD systems are composed of downhole controllers, various downhole parameter measuring instruments, MWD information transmission systems and ground information receiving, processing and display systems. The information transmission system is one of the key technologies, and the transmission of drilling information is particularly important during the drilling process.

At present, the drilling fluid pulse signal generator commonly used in the prior art generally uses a reciprocating or rotating component to change the drilling fluid channel in the drill bit, thereby forming a drilling fluid pressure pulse to work. However, there are still some problems with the existing drilling fluid pulse signal generator. For example, the reciprocating or rotating component needs to be actively controlled by a motor or solenoid valve, or a hydraulic valve, which makes the reciprocating or rotating component affected by the battery life and the generator life, resulting in a short application life of the entire system, affecting construction efficiency. In addition, the existing reciprocating or rotating components have a complex structure, high production cost, and high maintenance cost.

Summary of the invention

In response to the technical problems mentioned above, the present invention aims to provide a drilling fluid pulse signal generator, which can cause the drilling fluid flowing through the drilling fluid pulse signal generator to generate periodic pressure pulses, and can control the pulse signal frequency to transmit information, which can effectively extend the service life of the drilling fluid pulse signal generator.

To this end, according to the present invention, a drilling fluid pulse signal generator is proposed, comprising: an outer shell; an inner core concentrically arranged inside the outer shell, the inner core is arranged to be fixed with the outer shell, a cavity is arranged inside the inner core, and a rotor shaft and a stator coil are concentrically arranged inside the cavity; a turbine is arranged on the axial outside of the first end of the inner core, the turbine is fixedly connected to the rotor shaft; a valve disc mechanism is arranged between the inner core and the axial direction of the turbine, the valve disc mechanism includes a stator disc and a rotor disc, the rotor disc is arranged to be driven to rotate by the turbine, so that the flow area of the valve disc mechanism changes periodically; and a pressure acquisition device arranged at a wellhead; wherein the turbine can drive the rotor disc and the rotor shaft to rotate under the driving action of the drilling fluid, so that the drilling fluid flowing through the valve disc mechanism generates periodic pressure pulses, and the stator coil can control the rotation speed of the rotor shaft by powering on and off to control the signal frequency of the pressure pulse, and the signal frequency is collected and analyzed by the pressure acquisition device, so as to complete the transmission of downhole measurement information.

In one embodiment, the stator disk is provided with a plurality of flow passage holes uniformly distributed in the circumferential direction and axially penetrating the stator disk, and the rotor disk is provided with a plurality of flow grooves that can be adapted to the flow passage holes.

The rotor disk rotates with the turbine to periodically connect the flow groove with the flow channel hole, thereby periodically opening the valve disk mechanism.

In one embodiment, the turbine is fixedly connected to the rotor shaft via a connecting shaft.

In one embodiment, the first end of the connecting shaft passes through the stator disk and the rotor disk in sequence and is fixedly connected to the turbine, and the connecting shaft is fixedly connected to the rotor disk and rotatably connected to the stator disk.

The second end of the connecting shaft passes through the first end of the inner core and extends to the inner cavity, thereby being fixedly connected to the rotor shaft.

In one embodiment, a sealing member is provided between the connecting shaft and the first end of the inner core in a radial direction, so that the connecting shaft and the inner core form a rotating seal.

In one embodiment, the valve disc mechanism is fixedly connected to the outer shell via an inner sleeve, and the stator disc is fixedly connected to the inner sleeve.

In one embodiment, a sealing plug is provided at the second end of the cavity, and the interior of the cavity is filled with insulating liquid.

In one embodiment, a centralizer is provided at the second end of the inner core, and the inner core is concentrically fixed inside the outer shell through the centralizer.

In one embodiment, the stator winding package is fixed on the inner wall of the cavity, and the rotor shaft is arranged through the stator winding package.

In one embodiment, the stator winding package is a multi-turn generator winding package, and the rotor shaft is a multi-pole generator permanent magnet shaft.

Compared with the prior art, the advantages of this application are:

The drilling fluid pulse signal generator according to the present invention can make the drilling fluid flowing through the drilling fluid pulse signal generator generate periodic pressure pulses, and can control the pulse signal frequency to transmit information. In addition, the drilling fluid pulse signal generator can generate a passive continuous wave drilling fluid pulse signal, which controls the frequency of the drilling fluid pressure pulse signal through a valve disc mechanism and a rotor shaft, thereby effectively improving the validity and reliability of downhole measurement results. The use of the liquid pulse generator is conducive to improving the efficiency of downhole measurement while drilling, thereby improving the efficiency of drilling construction. In addition, the drilling fluid pulse signal generator has a simple structure, low production cost, low maintenance cost, and can effectively extend the service life of the drilling fluid pulse signal generator.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described below with reference to the accompanying drawings.

FIG. 1 schematically shows the structure of a drilling fluid pulse signal generator according to the present invention.

FIG. 2 schematically shows the structure of a stator disk in the drilling fluid pulse signal generator shown in FIG. 1 .

FIG. 3 schematically shows the structure of a rotor disk in the drilling fluid pulse signal generator shown in FIG. 1 .

In the present application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn according to the actual scale.

Detailed ways

The present invention will be described below with reference to the accompanying drawings.

It should be noted that, in the present application, the end of the drilling fluid pulse signal generator according to the present invention lowered into the wellbore close to the wellhead is defined as the "upper end" or similar terms, and the end away from the wellhead is defined as the "lower end" or similar terms.

FIG1 schematically shows the structure of a drilling fluid pulse signal generator 100 according to the present invention. As shown in FIG1 , the drilling fluid pulse signal generator 100 includes a cylindrical housing 10. The upper end (right end in FIG1 ) and the lower end (left end in FIG1 ) of the housing 10 are respectively configured with connection joints, and the housing 10 is connected to the upper and lower drilling tools through the connection joints at both ends. In one embodiment, the connection joints at both ends of the housing 10 are configured as negative tapered connection buckles.

As shown in FIG1 , the drilling fluid pulse signal generator 100 further includes an inner core 20 disposed inside the outer shell 10. A centralizer 27 is provided at the second end (left end in FIG1 ) of the inner core 20, and the inner core 20 is concentrically fixed inside the outer shell 10 through the centralizer 27, and the inner core 20 is fixed to the outer shell 10 through a stator disk 31 (see below). The centralizer 27 can effectively ensure the concentric arrangement between the inner core 20 and the outer shell 10, and is conducive to ensuring the stability of the inner core 20. The inner core 20 includes a body portion that is roughly cylindrical, and a cavity 21 is provided inside the body portion of the inner core 20. The first end (upper end) of the inner core 20 is configured as an axially outward cylindrical extension portion, the outer diameter of the extension portion is smaller than the outer diameter of the body portion, and is arranged in a streamlined structure. This structure of the inner core 20 can especially prevent direct erosion of the main body by drilling fluid. A bearing (not shown) is installed in the main body to form a rotational connection between the rotor shaft 23 and the main body of the inner core 20, thereby ensuring that the rotor shaft 23 is centrally installed and can rotate flexibly.

In this embodiment, the second end (lower end) of the inner core 20 is provided with a through hole extending axially and penetrating the second end, the through hole is communicated with the cavity 21, and a sealing plug 26 is fixedly installed in the through hole. The sealing plug 26 is preferably a high-pressure sealing plug. The sealing plug 26 is configured in a cylindrical shape, and the inside of the sealing plug 26 is provided with an axially penetrating wire, and the outer edge of the sealing plug 26 is provided with a sealing ring. The sealing plug 26 can ensure that when a wire passes through, the inner and outer cavities can each withstand high-pressure sealing, thereby ensuring that the loss is minimized in the case of a seal failure at one end.

According to the present invention, a rotor shaft 23 and a stator winding package 22 are provided inside the cavity 21 of the inner core 20. The stator winding package 22 is fixedly arranged on the inner wall of the cavity 21, and the rotor shaft 23 is concentrically arranged inside the cavity 21, and the rotor shaft 23 is arranged through the stator winding package 22. The lower end of the rotor shaft 23 (the left end in FIG. 1) passes through the stator winding package 22 and forms a rotational connection with the inner wall of the inner core 20. For example, the lower end of the rotor shaft 23 can form a rotational connection with the inner wall of the inner core 20 through a bearing. In one embodiment, the stator winding package 22 is a multi-turn generator winding package, and the rotor shaft 23 is a multi-stage permanent magnet shaft of the generator. The functions of the rotor shaft 23 and the stator winding package 22 are described below.

As shown in FIG1 , the drilling fluid pulse signal generator 100 further includes a turbine 40. The turbine 40 is connected to the axially outer side of the first end of the inner core 20, and the central rotating shaft of the turbine 40 is fixedly connected to the rotor shaft 22. In one embodiment, a connecting shaft 24 is connected between the turbine 40 and the rotor shaft 22, and the turbine 40 is fixedly connected to the rotor shaft 22 through the connecting shaft 24. Preferably, the blades of the turbine 40 are configured in a spiral shape, and the turbine 40 can generate a rotational motion under the flow of the drilling fluid.

In this embodiment, the first end of the inner core 20 is provided with a mounting portion that axially penetrates the extension portion, and the mounting portion is communicated with the cavity 21. The second end (lower end) of the connecting shaft 24 is installed in the mounting portion and passes through the first end of the inner core 20, and extends to the cavity 21, so as to be fixedly connected with the rotor shaft 23. A sealing member 25 is provided between the connecting shaft 24 and the mounting portion of the first end of the inner core, so that the connecting shaft 24 and the inner core 20 form a rotating seal to ensure the sealing of the cavity 21.

In order to balance the pressure of the inner core 20, the cavity 21 is filled with insulating liquid. The insulating liquid can lubricate the rotor shaft 23, which is beneficial to the rotation of the rotor shaft 23. In addition, the insulating liquid can dissipate heat and cool the rotor shaft 23 and the stator coil 22, thereby effectively ensuring the working performance of the drilling fluid pulse signal generator 100 and extending the service life of the drilling fluid pulse signal generator 100.

According to the present invention, the drilling fluid pulse signal generator 100 further includes a valve disc mechanism 30. As shown in FIG1 , the valve disc structure 30 is arranged between the inner core 20 and the axial direction of the turbine 40. The valve disc mechanism 30 includes a stator disc 31 and a rotor disc 32. The first end of the connecting shaft 24 passes through the stator disc 31 and the rotor disc 32 in sequence and is fixedly connected to the turbine 40, and the connecting shaft 24 is fixedly connected to the rotor disc 32, and the connecting shaft 24 is rotationally connected to the stator disc 31. The rotor disc 32 is configured to be driven to rotate by the turbine 40, and the flow area of the valve disc mechanism 30 is periodically changed, so that the drilling fluid flowing through the valve disc mechanism 30 can generate periodic pressure pulses.

In this embodiment, the valve disc mechanism 30 is fixedly connected to the housing 10 through the inner sleeve 50. In one embodiment, the outer wall surface of the inner sleeve 50 and the inner wall surface of the housing 10 are fixedly connected by threaded connection. In addition, the stator disc 31 is fixedly sealedly connected to the inner wall surface of the inner sleeve 50, and the rotor disc 32 is configured to be rotatable relative to the inner sleeve 50. In this way, the sealing performance between the valve disc structure 30 and the housing 10 can be effectively guaranteed, thereby enhancing the working performance of the valve disc mechanism 30.

FIG2 schematically shows the structure of the stator disk 31. As shown in FIG2, the stator disk 31 is configured as a disk-shaped member, and a central through hole for the connecting shaft to pass through is provided in the middle of the disk-shaped member. A plurality of flow channel holes 311 axially penetrating the stator disk 31 are provided on the disk surface of the stator disk 31, and the plurality of flow channel holes 311 are evenly spaced and distributed circumferentially on the stator disk 31. Preferably, eight flow channel holes 311 are provided on the disk surface of the stator disk 31. The cross-sectional shape and number of the flow channel holes 311 can be set according to actual flow requirements.

FIG3 schematically shows the structure of the rotor disk 32. As shown in FIG3, the rotor disk 32 is constructed as a disk-shaped member, and a central through hole for the connecting shaft to pass through is provided in the middle of the disk-shaped member. A plurality of flow grooves 321 that can be adapted to the flow channel holes 311 on the stator disk 31 are provided on the disk surface of the rotor disk 32. The flow grooves 321 extend radially inward along the outer periphery of the rotor disk 32, and the plurality of flow grooves 321 are evenly spaced and distributed circumferentially on the rotor disk 32. The rotor disk 32 rotates with the turbine 40 to enable the flow grooves 321 and the flow channel holes 311 to be alternately connected or closed, so that the flow grooves 321 and the flow channel holes 311 are periodically connected, thereby periodically opening or closing the valve disk mechanism 30. As a result, the drilling fluid flowing through the valve disk mechanism 30 can generate periodic pressure pulses.

According to the present invention, the drilling fluid pulse signal generator 100 further comprises a pressure acquisition device (not shown) arranged at the wellhead. The pressure acquisition device is used to acquire downhole measurement information transmitted by the drilling fluid pulse signal generator 100 and perform information recovery, thereby acquiring and analyzing various parameters measured downhole.

In the actual working process of the drilling fluid pulse signal generator 100 according to the present invention, the drilling fluid from the upper drilling tool flows through the turbine 40 to drive the turbine 40 to rotate, and the turbine 40 drives the rotor shaft 23 to rotate through the connecting shaft 24, and drives the rotor disk 32 to rotate together. During the rotation of the rotor disk 32, the flow slot 321 on the rotor disk 32 and the flow channel hole 311 on the stator disk 31 are alternately connected and closed to periodically open the valve disk structure 30, so that the drilling fluid flowing through the valve disk mechanism 30 generates periodic pressure pulses. At the same time, by controlling the power on and off of the coil connector of the stator coil 22 (i.e., connecting or disconnecting an electronic load), the rotor shaft 23 generates intermittent counter-torque based on the principle of electromagnetic induction, so that the rotation speed of the rotor shaft 23 is fast and slow, so as to control the frequency of the drilling fluid pressure pulse signal generated by the stator disk 31 and the rotor disk 32 to be fast and slow. Therefore, the information is encoded using the frequency signals of different speeds, and then the signal frequency is collected by the wellhead pressure acquisition device to restore and analyze the information, thereby completing the transmission of the measurement information from the bottom of the well to the wellhead.

The drilling fluid pulse signal generator 100 according to the present invention can make the drilling fluid flowing through the drilling fluid pulse signal generator 100 generate periodic pressure pulses, and can control the pulse signal frequency to transmit information. In addition, the drilling fluid pulse signal generator 100 can generate a passive continuous wave drilling fluid pulse signal, which controls the frequency of the drilling fluid pressure pulse signal through the valve disc mechanism 30 and the rotor shaft 23, thereby effectively improving the validity and reliability of the downhole measurement results. The use of the liquid pulse generator 100 is conducive to improving the efficiency of downhole measurement while drilling, thereby improving the efficiency of drilling construction. In addition, the drilling fluid pulse signal generator 100 has a simple structure, low production cost, low maintenance cost, and can effectively extend the service life of the drilling fluid pulse signal generator 100.

Finally, it should be noted that the above is only a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (8)

1. A drilling fluid pulse signal generator, comprising:

a housing (10);

An inner core (20) concentrically arranged inside the housing, the inner core being arranged to remain fixed with the housing, a cavity (21) being arranged inside the inner core, a rotor shaft (23) and a stator coil (22) being concentrically arranged inside the cavity; a sealing plug (26) is arranged at the second end of the cavity, and the interior of the cavity is filled with insulating liquid;

a turbine (40) disposed axially outboard of the first end of the inner core, the turbine being fixedly connected to the rotor shaft;

a valve disc mechanism (30) disposed between the inner core and an axial direction of the turbine, the valve disc mechanism including a stator disc (31) and a rotor disc (32) disposed so as to be rotatable by the turbine, thereby periodically varying an area of flow passing through the valve disc mechanism; the stator disc is provided with a plurality of runner holes (311) which are uniformly distributed in the circumferential direction and axially penetrate through the stator disc, the rotor disc is provided with a plurality of flow passing grooves (321) which can be matched with the runner holes, and the rotor disc rotates along with the turbine to periodically conduct the flow passing grooves and the runner holes so as to periodically open the valve disc mechanism; and

The pressure acquisition device is arranged at the wellhead;

The turbine can drive the rotor disc and the rotor shaft to rotate under the pushing action of drilling fluid, so that the drilling fluid flowing through the valve disc mechanism generates periodic pressure pulses, the stator coil can control the rotating speed of the rotor shaft through power on and power off so as to control the signal frequency of the pressure pulses, and the pressure acquisition device acquires and analyzes the signal frequency, so that the transmission of underground measurement information is completed.

2. Drilling fluid pulse signal generator according to claim 1, characterized in that the turbine is fixedly connected to the rotor shaft by a connecting shaft (24).

3. The drilling fluid pulse signal generator according to claim 2, wherein a first end of the connecting shaft is fixedly connected with the turbine through the stator disc and the rotor disc in turn, and the connecting shaft is fixedly connected with the rotor disc and is rotatably connected with the stator disc,

The second end of the connecting shaft passes through the first end of the inner core and extends to the cavity, thereby being fixedly connected with the rotor shaft.

4. A drilling fluid pulse signal generator according to claim 3, characterized in that a seal (25) is provided between the connection shaft and the radial direction of the first end of the inner core, so that the connection shaft forms a rotary seal with the inner core.

5. Drilling fluid pulse signal generator according to claim 1 or 2, characterized in that the valve disc means is fixedly connected to the housing via an inner sleeve (50) and the stator disc is fixedly connected to the inner sleeve.

6. Drilling fluid pulse signal generator according to claim 1, characterized in that a centralizer (27) is provided at the second end of the inner core, by means of which centralizer the inner core is concentrically fixed inside the outer shell.

7. The drilling fluid pulse signal generator of claim 1, wherein the stator coil is fixed to an inner wall of the cavity, and the rotor shaft is disposed through the stator coil.

8. The drilling fluid pulse signal generator of claim 7, wherein the stator coil is a multi-turn generator coil and the rotor shaft is a multi-stage pair generator permanent magnet shaft.