Blowout preventer sealing rubber plug and sealing performance monitoring method thereof

Abstract

The invention relates to the technical field of oil field drilling, in particular to a blowout preventer sealing rubber plug and a sealing performance monitoring method thereof, and the rubber plug is characterized in that a first-stage inner fluid channel and a second-stage inner fluid channel are arranged in a rubber plug body; the positions of one ends of the first-stage and second-stage inner fluid channels are close to the contact sealing part of the inner wall of the rubber plug body and a drilling tool, the distance between one end of the first-stage inner fluid channel and the inner wall of the rubber plug body is a first preset distance, and the distance between one end of the second-stage inner fluid channel and the inner wall of the rubber plug body is a second preset distance; a sealing performance monitoring mechanism used for detecting whether the inner fluid channels are in a closed state or not is arranged in a cavity of the rubber plug body or the blowout preventer center pipe, and the cavity is communicated with the other ends of the first-stage inner fluid channel and the second-stage inner fluid channel. Monitoring and early warning of the sealing performance of the rubber plug and the rubber core are achieved, waste caused by replacing the rubber core in advance is avoided, the use cost is reduced, meanwhile, risks caused by sealing failure are avoided, and construction safety is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of oilfield drilling technology, and in particular to a blowout preventer sealing plug and a method for monitoring its sealing performance. Background Technology

[0002] The application of controlled pressure drilling technology in well operations, especially in narrow-window formations and high-pressure formations, can improve drilling safety, reduce well construction costs, mitigate well control risks, and increase production. Controlled pressure drilling equipment mainly consists of a rotary blowout preventer (BOP), a choke manifold, and a backpressure pump. The rotary BOP, installed at the wellhead, is the core equipment in controlled pressure drilling; its main function is to seal the wellhead, provide a passage for the drill string, and achieve a seal between the drill string and the wellhead.

[0003] Rotary blowout preventers (BOPs) come in active sealing, passive sealing, and hybrid types, all relying on a rubber core to grip the drill string. Currently, passive rotary BOPs are widely used, and their structure is as follows: Figure 1 As shown, the system includes a drive unit 1, an upper core cylinder 2, an upper rubber plug 3, a rotating assembly 4, a clamp 5, a housing 6, a lower rubber plug 7, and a connecting flange 8. Since it is directly mounted on the wellhead, the rotating assembly 4 operates directly in the wellbore. The lower rubber plug 7 is bolted to the rotating assembly 4. During use, the drill string needs to move axially, and the upper and lower rubber plugs 3 and 7 must firmly grip the drill string to achieve a sealing effect and provide rotational power. With increased usage time, the wear of the rubber plugs inevitably increases, leading to a decrease in sealing performance. Currently, rubber plugs are either replaced only after a leak occurs or replaced periodically after a certain usage period. The first scenario results in unplanned downtime, increasing drilling risks and costs; the second scenario results in a large number of rubber plugs with good sealing performance being discarded, increasing the application cost of controlled pressure drilling technology. Summary of the Invention

[0004] This invention proposes a blowout preventer sealing plug and a method for monitoring its sealing performance, in order to solve the problem that the sealing performance of existing sealing plugs cannot be monitored, which leads to the inability to detect sealing failures in a timely manner or to frequently replace the plugs, increasing the cost of use.

[0005] According to one aspect of the present invention, a blowout preventer sealing plug is provided, comprising: a plug body; The rubber stopper body is provided with at least one primary internal fluid channel and at least one secondary internal fluid channel inside the body. The positions of one end of the primary internal fluid channel and the secondary internal fluid channel are close to the contact and sealing part between the inner wall of the rubber plug body and the drill bit, and the distance between one end of the primary internal fluid channel and the inner wall of the rubber plug body is a first predetermined distance, and the distance between one end of the secondary internal fluid channel and the inner wall of the rubber plug body is a second predetermined distance. Wherein, the first predetermined distance is greater than the first predetermined value of the second predetermined distance; The rubber stopper body or the blowout preventer central tube connected to it has a chamber inside. The chamber is equipped with a sealing performance monitoring mechanism for detecting whether the primary internal fluid channel and the secondary internal fluid channel are in a closed state. The chamber is connected to the other end of the primary internal fluid channel and the secondary internal fluid channel.

[0006] Preferably, the sealing performance testing mechanism includes: a first pressure testing module and a second pressure testing module; The first pressure detection module is used to detect the real-time pressure in the primary internal fluid channel; The second pressure detection module is used to detect the real-time pressure in the secondary internal fluid channel.

[0007] Preferably, the sealing performance testing mechanism further includes: a first humidity detection module and a second humidity detection module; The first humidity detection module is used to detect the real-time humidity in the primary internal fluid channel; The second humidity detection module is used to detect the real-time humidity in the secondary internal fluid channel.

[0008] Preferably, the value range of the first predetermined distance is 5~15mm.

[0009] Preferably, the value range of the second predetermined distance is 15~25mm.

[0010] Preferably, the range of the first predetermined value is 5~10mm.

[0011] Preferably, it further includes: screws and embedded nuts: The embedded nut is disposed inside the rubber stopper body; The bottom end of the screw passes through the bolt hole on the center tube flange of the blowout preventer and is inserted into the rubber plug body. It is then connected to the center tube flange and the rubber plug body by threaded engagement with the embedded nut.

[0012] Preferably, the outer surface of the embedded nut is provided with rough texture to increase friction.

[0013] Preferably, an annular protrusion is provided on the side wall of the inner nut near the bottom.

[0014] Preferably, there are two embedded nuts, which are arranged one above the other. After the screw passes through the upper embedded nut, its bottom end is connected to the lower embedded nut. The screw and the two embedded nuts are both threaded.

[0015] Preferably, it also includes: an anti-detachment buckle; The side wall of the rubber stopper body is provided with a snap-fit ​​mounting hole; The anti-detachment buckle is C-shaped, with the upper arm of the C-shape positioned above the flange and the lower arm of the C-shape inserted into the buckle mounting hole; The upper and lower support arms of the anti-detachment buckle are provided with threaded holes. After the screw passes through the threaded holes of the upper and lower support arms, it is connected to the embedded nut.

[0016] Preferably, the chamber is connected to the hollow interior of the central tube.

[0017] Preferably, it further includes: a rubber stopper loosening detection mechanism; The rubber stopper loosening detection mechanism is located between the flange and the rubber stopper body; The rubber plug loosening detection mechanism is used to detect the real-time pressure between the rubber plug body and the central flange of the blowout preventer.

[0018] Preferably, the rubber stopper loosening detection mechanism includes: a third pressure detection module; The third pressure detection module is located between the contact surface of the flange and the rubber stopper body.

[0019] According to one aspect of the present invention, a method for monitoring the sealing performance of a blowout preventer sealing plug is provided, comprising the blowout preventer sealing plug as described above, specifically including: Obtain the initial pressure and initial humidity values ​​in the primary and secondary internal fluid channels within the rubber plug body of the blowout preventer sealing plug; The control sealing performance monitoring mechanism is activated to detect the real-time pressure and / or real-time humidity in the primary and secondary internal fluid channels; Determine whether the real-time pressure in the primary internal fluid channel exceeds the second predetermined value of the corresponding initial pressure and / or whether the real-time humidity exceeds the third predetermined value of the corresponding initial humidity. If yes, the sealing performance is a primary sealing failure. Determine whether the real-time pressure in the secondary internal fluid channel exceeds the fourth predetermined value of the corresponding initial pressure and / or whether the real-time humidity exceeds the fifth predetermined value of the corresponding initial humidity. If so, the sealing performance is a secondary seal failure.

[0020] Preferably, the initial pressure and initial humidity values ​​inside the hollow center tube are obtained; The chamber is connected to the hollow interior of the central tube, and the sealing performance monitoring mechanism detects the real-time pressure and / or real-time humidity inside the hollow interior of the central tube. Determine whether the real-time pressure inside the hollow central tube exceeds the sixth predetermined value of the corresponding initial pressure and / or whether the real-time humidity exceeds the seventh predetermined value of the corresponding initial humidity. If so, the sealing performance is considered to be completely unsealable.

[0021] Preferably, the initial connection pressure value between the flange and the rubber plug body is obtained; A third pressure detection module is installed between the contact surface of the flange and the rubber stopper body, and the third pressure detection module detects the real-time connection pressure between the contact surface of the flange and the rubber stopper body. Determine whether the real-time connection pressure exceeds the eighth predetermined value of the initial connection pressure. If so, a loosening occurs between the flange and the rubber plug body.

[0022] Preferably, if the judgment result is a first-level seal failure, a second-level seal failure, a complete seal failure, or loosening between the flange and the rubber plug body, the control alarm mechanism is activated to sound an alarm.

[0023] The present invention has at least the following beneficial effects:

[0024] This invention proposes a blowout preventer sealing plug and its sealing performance monitoring method. By setting primary and secondary internal fluid channels inside the plug and a sealing performance testing mechanism connected to them, the sealing performance monitoring and early warning of the plug core is realized, avoiding the waste caused by premature replacement of the core, reducing the cost of use, and avoiding the risks caused by sealing failure, thus ensuring construction safety. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present invention and, together with the specification, serve to explain the technical solutions of the present invention.

[0026] Figure 1 A schematic diagram of a passive rotating blowout preventer in the prior art is shown.

[0027] Figure 2 A schematic diagram of the structure of a blowout preventer sealing plug according to an embodiment of the present invention is shown; In the diagram, 1-driver, 2-upper core cylinder, 3-upper rubber core, 4-rotating assembly, 5-clamp, 6-housing, 7-lower rubber core, 8-connecting flange, 9-rubber plug body, 10-lower embedded nut, 11-anti-disengagement buckle, 12-screw, 13-center tube, 14-primary internal fluid channel, 15-secondary internal fluid channel, 16-sealing performance testing mechanism, 17-upper embedded nut. Detailed Implementation

[0028] Various exemplary embodiments, features, and aspects of the present invention will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0029] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0030] In this document, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0031] Furthermore, to better illustrate the present invention, numerous specific details are set forth in the following detailed embodiments. Those skilled in the art will understand that the present invention can be practiced without certain specific details. In some instances, methods, means, elements, and circuits well known to those skilled in the art have not been described in detail in order to highlight the spirit of the invention.

[0032] Figure 2 A schematic diagram of the structure of a blowout preventer sealing plug according to an embodiment of the present invention is shown. Figure 2 As shown, a blowout preventer (BOP) sealing plug includes: a plug body 9; the plug body 9 has at least one primary internal fluid channel 14 and at least one secondary internal fluid channel 15 inside; one end of the primary internal fluid channel 14 and the secondary internal fluid channel 15 is located near the inner wall of the plug body 9 and the contact sealing part with the drill bit, and the distance between one end of the primary internal fluid channel 14 and the inner wall of the plug body 9 is a first predetermined distance, and the distance between one end of the secondary internal fluid channel 15 and the inner wall of the plug body 9 is a second predetermined distance; wherein, the first predetermined distance is greater than the second predetermined distance by a first predetermined value; a chamber is provided inside the plug body 9 or the BOP central tube 13 connected thereto, and a sealing performance monitoring mechanism for detecting whether the primary internal fluid channel 14 and the secondary internal fluid channel 15 are in a closed state is provided inside the chamber, and the chamber is connected to the other end of the primary internal fluid channel 14 and the secondary internal fluid channel 15.

[0033] In this embodiment of the invention, the inner wall of the rubber plug body 9 has an annular protrusion for sealing with the drill bit. One end of the primary internal fluid channel 14 and the secondary internal fluid channel 15 extends to the inner wall of the rubber plug body 9 near the annular protrusion, and there is a certain distance between the primary internal fluid channel 14 and the secondary internal fluid channel 15 and the inner wall of the rubber plug body 9. One end of the primary internal fluid channel 14 is closer to the inner wall of the rubber plug body 9, and one end of the secondary internal fluid channel 15 is farther from the inner wall of the rubber plug body 9. The other ends of the primary internal fluid channel 14 and the secondary internal fluid channel 15 extend to the top of the rubber plug body 9, and the top of the rubber plug body 9 is connected to the bottom end of the blowout preventer center tube 13 via a flange.

[0034] Two chambers are provided inside the rubber stopper body 9 or the blowout preventer, including a first chamber and a second chamber. The first chamber is connected, and the second chamber is connected to the secondary internal fluid channel 15. A sealing performance testing mechanism 16 is provided in the inner part of each chamber.

[0035] During use, the drill string moves up and down along the axis inside the rubber plug body 9 of the blowout preventer. The inner wall of the annular protrusion inside the rubber plug body 9 contacts and seals with the outer wall of the drill string. As the usage time increases, the inner wall (sealing surface) of the annular protrusion in contact with the outer wall of the drill string wears down, and the inner wall of the rubber plug body 9 becomes thinner in this part. This gradually reduces the distance between one end of the primary internal fluid channel 14 and the secondary internal fluid channel 15 and the inner wall of the rubber plug body 9. When the rubber plug body 9 wears down to the point where the inner wall reaches one end of the primary internal fluid channel 14, it will connect the primary internal fluid channel 14 with the inside of the rubber plug, and some well fluid will enter the interior of the primary internal fluid channel 14. At this time, the sealing performance detection mechanism 16 inside the chamber corresponding to the primary internal fluid channel 14 detects that the interior of the primary internal fluid channel 14 is connected to the interior of the rubber plug body 9, that is, when the primary internal fluid channel 14 is not sealed, it issues a primary sealing failure warning signal and transmits it to the main control unit via the wireless transmission module. The operator can determine from the primary seal failure signal received by the main control unit that the downhole sealing plug (plug body 9) is in a state of slight seal failure and can choose not to deal with it or replace the sealing plug.

[0036] If the sealing plug is not replaced (no action is taken), as the drilling tool is used for longer periods, the inner side of the plug body 9 will wear further. When the wear reaches one end of the secondary internal fluid channel 15, the secondary internal fluid channel 15 will connect with the inside of the plug, and some well fluid will enter the interior of the secondary internal fluid channel 15. At this time, the sealing performance detection mechanism 16 inside the chamber corresponding to the secondary internal fluid channel 15 detects that the interior of the secondary internal fluid channel 15 is connected to the interior of the plug body 9, that is, the secondary internal fluid channel 15 is not in a sealed state, and issues a secondary seal failure warning signal, which is transmitted to the main control unit via the wireless transmission module. The operator determines that the downhole sealing plug is in a state of basic seal failure based on the secondary seal failure signal received by the main control unit, and the sealing plug needs to be replaced.

[0037] In this invention, the sealing performance testing mechanism 16 includes: a first pressure testing module and a second pressure testing module; the first pressure testing module is used to detect the real-time pressure in the primary internal fluid channel 14; the second pressure testing module is used to detect the real-time pressure in the secondary internal fluid channel 15.

[0038] In this embodiment of the invention, the rubber stopper having a primary internal fluid channel 14 and a secondary internal fluid channel 15 can be cast in one piece using a mold of a corresponding shape during manufacturing. The portion of the mold used to form the primary and secondary internal fluid channels 14 and 15 can be removed from the top of the stopper after it is formed. After removal, the primary and secondary internal fluid channels 14 and 15 are open at the top of the stopper body 9. Because the stopper body 9 is fixed below the central tube 13 during installation and use, the central tube 13 can seal one end of the opening of the primary and secondary internal fluid channels 14 and 15, thus keeping the interior sealed and preventing changes in humidity and pressure. A first pressure detection module is installed in the first chamber, and a second pressure detection module is installed in the second chamber. The first and second pressure detection modules are connected to the main control unit via a wireless transmission module.

[0039] Before use, the first and second pressure detection modules detect the initial pressure values ​​in the corresponding primary internal fluid channel 14 and secondary internal fluid channel 15, respectively. During use, the first and second pressure detection modules detect the real-time pressure in the corresponding primary internal fluid channel 14 and secondary internal fluid channel 15, respectively. When the inner wall of the annular protrusion of the rubber stopper body 9 wears down, the inner wall of the rubber stopper body 9 becomes thinner, and the primary internal fluid channel 14 and secondary internal fluid channel 15 connect with the inside of the rubber stopper, the channels change from a sealed state to an open state, and the original balanced pressure in the channels is broken. When the first pressure detection module detects that the real-time pressure in the primary internal fluid channel 14 has changed compared to the initial pressure and exceeds a first predetermined pressure, it sends a primary seal failure signal to the main control unit; when the second pressure detection module detects that the real-time pressure in the secondary internal fluid channel 15 has changed compared to the initial pressure and exceeds a first predetermined pressure, it sends a secondary seal failure signal to the main control unit.

[0040] After receiving the primary or secondary seal failure signal, the main control unit activates the alarm module to issue an alarm notification.

[0041] In this invention, the sealing performance testing mechanism 16 further includes: a first humidity detection module and a second humidity detection module; the first humidity detection module is used to detect the real-time humidity in the primary internal fluid channel 14; the second humidity detection module is used to detect the real-time humidity in the secondary internal fluid channel 15.

[0042] In this embodiment of the invention, a first humidity detection module is installed in a first chamber, a second humidity detection module is installed in a second chamber, and the first and second humidity detection modules are connected to the main control unit via a wireless transmission module.

[0043] Before use, the first and second humidity detection modules detect the initial humidity values ​​in the corresponding primary internal fluid channel 14 and secondary internal fluid channel 15, respectively. During use, the first and second humidity detection modules detect the real-time humidity in the corresponding primary internal fluid channel 14 and secondary internal fluid channel 15, respectively. When the inner wall of the annular protrusion of the rubber stopper body 9 wears down, the inner wall of the rubber stopper body 9 becomes thinner, and the primary internal fluid channel 14 and secondary internal fluid channel 15 connect with the inside of the rubber stopper, the channels change from a sealed state to an open state. Well fluid between the inner wall of the rubber stopper body 9 and the drilling tool enters the primary internal fluid channel 14 and secondary internal fluid channel 15, causing a change in their internal humidity. When the first humidity detection module detects that the real-time humidity in the primary internal fluid channel 14 has changed compared to the initial humidity and exceeds a first predetermined humidity, it sends a primary seal failure signal to the main control unit; when the second humidity detection module detects that the real-time humidity in the secondary internal fluid channel 15 has changed compared to the initial humidity and exceeds a first predetermined humidity, it sends a secondary seal failure signal to the main control unit.

[0044] After receiving the primary or secondary seal failure signal, the main control unit activates the alarm module to issue an alarm notification.

[0045] In this invention, the value range of the first predetermined distance is 5~15mm.

[0046] In this invention, the value range of the second predetermined distance is 15~25mm.

[0047] In this invention, the range of the first predetermined value is 5~10mm.

[0048] In this embodiment of the invention, if the first predetermined distance is 5mm, the second predetermined distance is 15mm, and the first predetermined value is 10mm, then when the inner wall of the rubber plug body 9 wears outward by more than 5mm, the end of the primary internal fluid channel 14 opens, and the well fluid between the rubber plug body 9 and the drilling tool enters the primary internal fluid channel 14. At this time, the first pressure detection module and / or the first humidity detection module inside the first chamber corresponding to the primary internal fluid channel 14 detects that the real-time pressure and / or humidity in the primary internal fluid channel 14 has changed, and when the initial pressure and / or humidity in the primary internal fluid channel 14 exceeds the corresponding first predetermined pressure and / or first predetermined humidity, a primary seal failure signal is sent to the main control unit.

[0049] When the inner wall of the rubber plug body 9 wears outward by more than 15mm, the end of the secondary internal fluid channel 15 opens, and the well fluid between the rubber plug body 9 and the drill string enters the secondary internal fluid channel 15. At this time, the second pressure detection module and / or the second humidity detection module inside the second chamber corresponding to the secondary internal fluid channel 15 detects that the real-time pressure and / or humidity in the secondary internal fluid channel 15 has changed. When the initial pressure and / or humidity in the secondary internal fluid channel 15 exceeds the corresponding first predetermined pressure and / or first predetermined humidity, a secondary seal failure signal is sent to the main control unit.

[0050] The first and second chambers can be located inside the rubber stopper body 9 or inside the central tube 13. The pressure and humidity detection modules inside the chambers located in the central tube 13 can be connected to probes via wiring. The probes are located in the primary internal fluid channel 14 and the secondary internal fluid channel 15.

[0051] In this invention, it also includes: a screw 12 and an embedded nut: the embedded nut is disposed inside the rubber stopper body 9; the bottom end of the screw 12 passes through the bolt hole on the flange of the blowout preventer center tube and is inserted into the rubber stopper body 9, and is connected to the flange of the center tube 13 and the rubber stopper body 9 by thread engagement with the embedded nut.

[0052] In this embodiment of the invention, the embedded nut is pre-installed inside the rubber stopper body 9 during the manufacturing process. During installation, the screw 12 passes through the bolt hole of the flange and is inserted downwards into the rubber stopper body 9. After reaching above the embedded nut, it continues to be inserted downwards into the embedded nut. Through the threaded engagement with the embedded nut, the rubber stopper body 9 is connected and fixed to the flange.

[0053] In this invention, the outer surface of the embedded nut is provided with rough texture to increase friction.

[0054] In this embodiment of the invention, by adding texture to the outer surface of the embedded nut, the friction between the embedded nut and the rubber stopper body 9 is increased, thereby preventing the embedded nut from sliding out of the hole in the rubber stopper body 9 where the screw 12 is installed.

[0055] In this invention, an annular protrusion is provided on the side wall of the inner nut near the bottom.

[0056] In this embodiment of the invention, the annular protrusion is located near the bottom of the embedded nut. Because the outer surface of the embedded nut is tightly fitted to the inside of the rubber stopper body 9, the inverted T-shape formed by the embedded nut and the annular protrusion hooks into the inside of the rubber stopper body 9, preventing the embedded nut from coming out.

[0057] In this invention, there are two embedded nuts, which are arranged one above the other. After the screw 12 passes through the upper embedded nut, its bottom end is connected to the lower embedded nut. The screw 12 and the two embedded nuts are threaded together.

[0058] In this embodiment of the invention, there are two embedded nuts, including an upper embedded nut 17 and a lower embedded nut 10. During installation, the screw 12 passes through the bolt hole of the flange and is inserted downward into the rubber plug body 9. After passing downward through the upper embedded nut, it continues to be inserted downward into the lower embedded nut to complete the connection.

[0059] In this invention, it also includes: an anti-detachment buckle 11; a buckle mounting hole is provided on the side wall of the rubber stopper body 9; the anti-detachment buckle 11 is C-shaped, the upper support arm of the C-shape is above the flange, and the lower support arm of the C-shape is inserted into the buckle mounting hole; the upper and lower support arms of the anti-detachment buckle 11 are provided with threaded holes, and the screw 12 passes through the threaded holes of the upper and lower support arms respectively and is connected to the embedded nut.

[0060] In this embodiment of the invention, the buckle mounting hole is located between two embedded nuts. During installation, the lower support arm of the C-shaped anti-detachment buckle 11 is inserted into the buckle mounting hole. At this time, the upper support arm of the anti-detachment buckle 11 is above the flange, and the lower support arm is between the two embedded nuts. The screw 12 is passed through the threaded hole of the upper support arm of the anti-detachment buckle 11, and then through the upper embedded nut 17, the threaded hole of the lower support arm of the anti-detachment buckle 11, and the lower embedded nut in sequence to complete the connection.

[0061] By setting a C-shaped buckle on the outside of the rubber plug body 9, the connection between the flange and the rubber plug body 9 is made more secure, preventing the rubber plug body 9 from separating from the flange during the continuous movement of the drill bit.

[0062] In this invention, the chamber is connected to the hollow interior of the central tube 13.

[0063] In this embodiment of the invention, a third chamber is further provided inside the rubber plug body 9 or the central tube 13, and the sealing performance monitoring mechanism further includes a fourth pressure detection module and / or a third humidity detection module. The fourth pressure detection module and / or the third humidity detection module are installed inside the third chamber, and the probes of the fourth pressure detection module and / or the third humidity detection module are located inside the central tube 13. The fourth pressure detection module and / or the third humidity detection module detects the initial pressure and / or initial humidity inside the central tube 13. During use, when the rubber plug body 9 is severely worn and experiences sealing failure, well fluid will enter the central tube 13 upwards from the gap between the rubber plug body 9 and the drill string. At this time, the fourth pressure detection module and / or the third humidity detection module detect that the real-time pressure and / or real-time humidity inside the central tube 13 have changed compared to their corresponding initial pressure and humidity, and if this changes exceed a third predetermined pressure and / or a second predetermined humidity, a sealing failure signal is sent to the main control unit.

[0064] By detecting changes in humidity and pressure within the central tube 13, the sealing status of the rubber stopper can be determined more accurately. This prevents situations where pressure and humidity changes in the primary internal fluid channel 14 and the secondary internal fluid channel 15 are not detected due to equipment damage or other reasons, thus ensuring timely detection of rubber stopper failure.

[0065] The present invention further includes: a rubber plug loosening detection mechanism; the rubber plug loosening detection mechanism is disposed between the flange and the rubber plug body 9; the rubber plug loosening detection mechanism is used to detect the real-time pressure between the rubber plug body 9 and the blowout preventer center tube flange.

[0066] In this invention, the rubber stopper loosening detection mechanism includes a third pressure detection module; the third pressure detection module is disposed between the contact surface of the flange and the rubber stopper body 9.

[0067] In this embodiment of the invention, a fourth chamber is further provided inside the rubber stopper body 9 or the central tube 13. The third pressure detection module of the rubber stopper loosening detection mechanism is located inside the fourth chamber, and the probe of the third pressure detection module is positioned between the rubber stopper body 9 and the flange. After the rubber stopper body 9 and the flange are installed, the third pressure detection module of the rubber stopper loosening detection mechanism detects the initial pressure between the rubber stopper body 9 and the flange. During use, when the connection between the rubber stopper body 9 and the flange becomes loose, the third pressure detection module detects that the real-time pressure between the rubber stopper body 9 and the flange has changed compared to the initial pressure and exceeds a second predetermined pressure, and then sends a rubber stopper loosening signal to the main control unit.

[0068] By detecting pressure changes at the connection between the rubber stopper and the flange, it is possible to detect loose rubber stoppers in a timely manner and prevent accidents caused by the rubber stopper falling off.

[0069] In this embodiment of the invention, the pressure detection module can be a pressure sensor, and the humidity detection module can be a humidity sensor.

[0070] This invention also proposes a method for monitoring the sealing performance of a blowout preventer (BOP) sealing plug, comprising the BOP sealing plug as described above, specifically including: acquiring the initial pressure and initial humidity values ​​within the primary internal fluid channel 14 and the secondary internal fluid channel 15 of the plug body 9 of the BOP sealing plug; controlling the activation of a sealing performance monitoring mechanism to detect the real-time pressure and / or real-time humidity within the primary internal fluid channel 14 and the secondary internal fluid channel 15; determining whether the real-time pressure within the primary internal fluid channel 14 exceeds a second predetermined value of the corresponding initial pressure and / or whether the real-time humidity exceeds a third predetermined value of the corresponding initial humidity; if so, the sealing performance is a primary sealing failure; determining whether the real-time pressure within the secondary internal fluid channel 15 exceeds a fourth predetermined value of the corresponding initial pressure and / or whether the real-time humidity exceeds a fifth predetermined value of the corresponding initial humidity; if so, the sealing performance is a secondary sealing failure.

[0071] In this embodiment of the invention, the central tube 13 flange and the rubber plug body 9 are connected and fixed by screws 12, embedded nuts, and anti-disengagement buckles 11. The blowout preventer with the rubber plug connected is installed at the wellhead, and the drill string is lowered into the well. The outer wall of the drill string is in close contact with the inner wall of the rubber plug body 9 for sealing.

[0072] The system controls the first pressure detection module and the first humidity detection module in the first chamber to start detecting the initial pressure and initial humidity in the primary internal fluid channel 14, and controls the second pressure detection module and the second humidity detection module in the second chamber to start detecting the initial pressure and initial humidity in the secondary internal fluid channel 15.

[0073] When in use, when the wear thickness of the inner wall of the rubber stopper body 9 reaches 5mm or more, and the first-level internal fluid channel 14 is connected to the inside of the rubber stopper, the first pressure detection module and the first humidity detection module detect that the real-time pressure and humidity in the first-level internal fluid channel 14 have changed compared with the initial pressure and humidity, and the difference between the real-time pressure and the initial pressure exceeds the second predetermined value, and / or the difference between the real-time humidity and the initial humidity exceeds the third predetermined value, then a first-level seal failure signal is sent to the main control unit.

[0074] When the wear thickness of the inner wall of the rubber stopper body 9 reaches more than 15mm, and the secondary internal fluid channel 15 is connected to the inside of the rubber stopper, the second pressure detection module and the second humidity detection module detect that the real-time pressure and humidity in the secondary internal fluid channel 15 have changed compared with the initial pressure and humidity. When the difference between the real-time pressure and the initial pressure exceeds the fourth predetermined value, and / or the difference between the real-time humidity and the initial humidity exceeds the fifth predetermined value, a secondary seal failure signal is sent to the main control unit.

[0075] In this invention, the initial pressure and initial humidity values ​​inside the hollow interior of the central tube 13 are obtained; the chamber is connected to the hollow interior of the central tube 13; the sealing performance monitoring mechanism detects the real-time pressure and / or real-time humidity inside the hollow interior of the central tube 13; it is determined whether the real-time pressure inside the hollow interior of the central tube 13 exceeds the sixth predetermined value of the corresponding initial pressure and / or whether the real-time humidity exceeds the seventh predetermined value of the corresponding initial humidity; if so, the sealing performance is completely failed.

[0076] In this embodiment of the invention, the fourth pressure detection module and / or the third humidity detection module inside the third chamber are activated to detect the initial pressure and / or initial humidity inside the central tube 13. During use, when the rubber stopper body 9 is severely worn and fails to seal, if the difference between the real-time pressure inside the central tube 13 detected by the fourth pressure detection module and its corresponding initial pressure exceeds a sixth predetermined value, a sealing failure signal is sent to the main control unit.

[0077] And / or, if the real-time humidity in the central tube 13 changes compared to its corresponding initial humidity and exceeds the seventh predetermined value, the third humidity detection module sends a blocking failure signal to the main controller.

[0078] In this invention, the initial connection pressure value between the flange and the rubber stopper body 9 is obtained; a third pressure detection module is set between the contact surfaces of the flange and the rubber stopper body 9, and the third pressure detection module detects the real-time connection pressure between the contact surfaces of the flange and the rubber stopper body 9; it is determined whether the real-time connection pressure exceeds the eighth predetermined value of the initial connection pressure, and if so, the flange and the rubber stopper body 9 become loose.

[0079] In this embodiment of the invention, the third pressure detection module inside the fourth chamber detects the initial connection pressure between the rubber stopper body 9 and the flange. During use, when the connection between the rubber stopper body 9 and the flange becomes loose, and the third pressure detection module detects that the difference between the real-time connection pressure between the rubber stopper body 9 and the flange and the initial connection pressure exceeds an eighth predetermined value, it sends a rubber stopper loosening signal to the main control unit.

[0080] In this invention, if the judgment result is a first-level seal failure, a second-level seal failure, a complete seal failure, or loosening between the flange and the rubber plug body 9, the control alarm mechanism will be activated to trigger an alarm.

[0081] In this embodiment of the invention, the second, fourth, sixth and eighth predetermined values ​​are 0.5 MPa, and the third, fifth and seventh predetermined values ​​are 50%.

[0082] This invention designs a primary internal fluid channel 14 and a secondary internal fluid channel 15 inside the rubber core (rubber stopper body 9). One end of each fluid channel is connected to a sealing performance testing mechanism 16 installed inside the central tube 13, and the other end extends to the sealing part of the rubber core. The fluid channels of the rubber core are not connected to the outside. As the sealing surface of the rubber core wears down during use, the two fluid channels will gradually connect to the outside, disrupting the original pressure balance within the channels, and some pressurized drilling fluid will enter the channels, causing changes in humidity. The changes in pressure and humidity within the channels are detected in real time by the sealing performance testing mechanism 16. When the detected value reaches the threshold condition for a decrease in sealing performance, a corresponding warning is issued. The difference between the primary internal fluid channel 14 and the secondary internal fluid channel 15 lies in their unequal distance from the sealing surface. As the sealing surface of the rubber core wears down, the primary and secondary internal fluid channels 15 connect to the outside successively, issuing warnings when the sealing performance of the rubber core decreases to approximately 80% and 40%, respectively.

[0083] By setting an anti-detachment connection structure between the rubber core and the central tube 13, namely, the rubber core is designed with an embedded nut, which is divided into a lower embedded nut 10 and an upper embedded nut 17. The embedded nut and its external protrusion form a stepped cylindrical shape, and the outer surface is machined with textures to increase the connection with the rubber core. The steps of the protrusion can ensure that the embedded nut will not detach from the rubber core. By designing the embedded nut connection, a locking screw can be applied to the screw 12 to improve the reliability of the connection between the rubber core and the central tube 13 and further reduce the possibility of disengagement. Corresponding slots (snap-fitting holes) are made on the side of the rubber core and at the connecting flange of the central tube 13 for installing the anti-detachment snap-fit ​​11. The lower end of the anti-detachment snap-fit ​​11 extends into the hole on the side of the rubber core to suspend the rubber core; the upper end fits into the slot on the connecting flange of the central tube 13, and the fastening bolt passes through to achieve tight positioning. A gasket with a pressure sensor (third pressure detection module) is set between the connecting flange of the rubber core and the central tube 13. When the fastening bolt becomes loose, the pressure sensor will detect the pressure change and issue a corresponding warning.

[0084] It is understood that the various embodiments mentioned above in this invention can be combined with each other to form combined embodiments without violating the principle and logic. Due to space limitations, this invention will not elaborate further.

[0085] Those skilled in the art will understand that, in the above-described method of the specific implementation, the order in which each step is written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0086] This invention addresses the significant safety risks posed by loose threads and subsequent dislodgement of the rubber plug in existing rotary blowout preventers (BOPs), leading to plug detachment and blockage of the wellhead. Loosening of the fixing bolts can also cause accidents as the plug falls into the well. Currently, these issues can only be detected through operator experience or after an accident has occurred, and the unpredictable sealing performance of the rubber plug results in waste. The invention designs a novel sealing plug with an internal fluid channel and a wear-based sealing performance test, along with an anti-detachment latch 11 connecting the central tube 13 to the plug. Additionally, a pressure detection module is designed to detect loose connections between the central tube 13 and the rubber plug.

[0087] The novel anti-detachment structure designed in this invention effectively prevents the rubber core from separating from the central tube 13, which could cause the rubber core to detach and block the wellhead. The rubber plug loosening detection mechanism enables immediate detection and alarm of any loosening connection between the rubber core and the rotating assembly, further reducing the risk of detachment. By setting an alarm internal fluid channel in the central tube 13 under the rubber core and rotating assembly, the sealing performance of the rubber core is monitored and warned, avoiding the waste caused by premature replacement of the rubber core and the risk of sealing failure. At the same time, it avoids safety accidents caused by the rubber core and screw 12 detaching and blocking the wellhead.

[0088] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A blowout preventer sealing plug, characterized in that, include: Rubber stopper body (9); The rubber stopper body (9) is provided with at least one primary internal fluid channel (14) and at least one secondary internal fluid channel (15). The positions of one end of the primary internal fluid channel (14) and the secondary internal fluid channel (15) are close to the inner wall of the rubber plug body (9) and the sealing part in contact with the drill bit. The distance between one end of the primary internal fluid channel (14) and the inner wall of the rubber plug body (9) is a first predetermined distance, and the distance between one end of the secondary internal fluid channel (15) and the inner wall of the rubber plug body (9) is a second predetermined distance. Wherein, the first predetermined distance is greater than the first predetermined value of the second predetermined distance; The rubber plug body (9) or the blowout preventer center tube (13) connected thereto has a chamber inside. The chamber is equipped with a sealing performance monitoring mechanism for detecting whether the primary internal fluid channel (14) and the secondary internal fluid channel (15) are closed. The chamber is connected to the other end of the primary internal fluid channel (14) and the secondary internal fluid channel (15).

2. The blowout preventer sealing plug according to claim 1, characterized in that, The sealing performance testing mechanism (16) includes: a first pressure testing module and a second pressure testing module; The first pressure detection module is used to detect the real-time pressure in the primary internal fluid channel (14); The second pressure detection module is used to detect the real-time pressure in the secondary internal fluid channel (15).

3. The blowout preventer sealing plug according to claim 2, characterized in that, The sealing performance testing mechanism (16) further includes: a first humidity detection module and a second humidity detection module; The first humidity detection module is used to detect the real-time humidity in the primary internal fluid channel (14); The second humidity detection module is used to detect the real-time humidity in the secondary internal fluid channel (15).

4. The blowout preventer sealing plug according to claim 1, characterized in that: The first predetermined distance has a range of 5~15mm.

5. The blowout preventer sealing plug according to claim 1, characterized in that: The second predetermined distance is in the range of 15~25mm.

6. The blowout preventer sealing plug according to claim 1, characterized in that: The range of the first predetermined value is 5~10mm.

7. The blowout preventer sealing plug according to any one of claims 1-6, characterized in that, Also includes: Screw (12) and embedded nut: The embedded nut is disposed inside the rubber stopper body (9); The bottom end of the screw (12) passes through the bolt hole on the flange of the blowout preventer center tube and is inserted into the rubber plug body (9). It is connected to the flange of the center tube (13) and the rubber plug body (9) by thread engagement with the embedded nut.

8. The blowout preventer sealing plug according to claim 7, characterized in that: The outer surface of the embedded nut is provided with rough texture to increase friction.

9. The blowout preventer sealing plug according to claim 7, characterized in that: An annular protrusion is provided on the side wall near the bottom of the outer part of the embedded nut.

10. The blowout preventer sealing plug according to claim 7, characterized in that: There are two embedded nuts, which are arranged one above the other. After the screw (12) passes through the upper embedded nut, its bottom end is connected to the lower embedded nut. The screw (12) and the two embedded nuts are both threaded.

11. The blowout preventer sealing plug according to claim 7, characterized in that, Also includes: Anti-detachment buckle (11); The side wall of the rubber stopper body (9) is provided with a snap-fit ​​mounting hole; The anti-detachment buckle (11) is C-shaped, with the upper arm of the C-shape positioned above the flange and the lower arm of the C-shape inserted into the buckle mounting hole; The upper and lower arms of the anti-detachment buckle (11) are provided with threaded holes. The screw (12) passes through the threaded holes of the upper and lower arms respectively and is connected to the embedded nut.

12. The blowout preventer sealing plug according to claim 1, characterized in that: The chamber is connected to the hollow interior of the central tube (13).

13. The blowout preventer sealing plug according to any one of claims 1-12, characterized in that, Also includes: Rubber stopper loosening detection agency; The rubber stopper loosening detection mechanism is located between the flange and the rubber stopper body (9); The rubber plug loosening detection mechanism is used to detect the real-time pressure between the rubber plug body (9) and the blowout preventer center tube flange.

14. The blowout preventer sealing plug according to claim 13, characterized in that, The rubber stopper loosening detection mechanism includes: a third pressure detection module; The third pressure detection module is located between the contact surface of the flange and the rubber stopper body (9).

15. A method for monitoring the sealing performance of a blowout preventer sealing plug, comprising the blowout preventer sealing plug as described in any one of claims 1-14, characterized in that, include: Obtain the initial pressure and initial humidity values ​​in the primary internal fluid channel (14) and the secondary internal fluid channel (15) inside the rubber plug body (9) of the blowout preventer sealing plug; The control sealing performance monitoring mechanism is activated to detect the real-time pressure and / or real-time humidity in the primary internal fluid channel (14) and the secondary internal fluid channel (15); Determine whether the real-time pressure in the first-level internal fluid channel (14) exceeds the second predetermined value of the corresponding initial pressure and / or whether the real-time humidity exceeds the third predetermined value of the corresponding initial humidity. If yes, the sealing performance is a first-level sealing failure. Determine whether the real-time pressure in the secondary internal fluid channel (15) exceeds the fourth predetermined value of the corresponding initial pressure and / or whether the real-time humidity exceeds the fifth predetermined value of the corresponding initial humidity. If yes, the sealing performance is a secondary seal failure.

16. The method for monitoring the sealing performance of the blowout preventer sealing plug according to claim 15, characterized in that: Obtain the initial pressure and initial humidity values ​​inside the hollow center tube (13); The chamber is connected to the hollow interior of the central tube (13), and the sealing performance monitoring mechanism detects the real-time pressure and / or real-time humidity inside the hollow interior of the central tube (13). Determine whether the real-time pressure inside the hollow center tube (13) exceeds the sixth predetermined value of the corresponding initial pressure and / or whether the real-time humidity exceeds the seventh predetermined value of the corresponding initial humidity. If yes, the sealing performance is completely failed.

17. The method for monitoring the sealing performance of the blowout preventer sealing plug according to claim 15 or 16, characterized in that: Obtain the initial connection pressure value between the flange and the rubber plug body (9); A third pressure detection module is provided between the contact surface of the flange and the rubber stopper body (9), and the third pressure detection module detects the real-time connection pressure between the contact surface of the flange and the rubber stopper body (9); Determine whether the real-time connection pressure exceeds the eighth predetermined value of the initial connection pressure. If yes, then there is loosening between the flange and the rubber plug body (9).

18. The method for monitoring the sealing performance of the blowout preventer sealing plug according to claim 17, characterized in that: If the judgment result is a first-level seal failure, a second-level seal failure, a complete seal failure, or a loosening between the flange and the rubber plug body (9), the control alarm mechanism will be activated to trigger an alarm.

Images