Cementing plug release devices, methods, and systems

Abstract

The application provides a cementing plug releasing device, method and system, which comprises a main body, a releasing cavity in the main body, a releasing opening on one side of the releasing cavity, a plug body arranged in the releasing cavity and having magnetism, and a pointer assembly arranged on the main body and having a freely rotating pointer, which can be limited from freely rotating by the magnetic field of the plug body in the releasing cavity. According to the technical scheme of the application, the plug releasing can be quickly, accurately and intuitively judged by the change of the posture of the pointer based on the magnetic field effect, and correct decisions can be made on the basis of accurate judgment, so as to ensure the safety of cementing construction and the quality of cementing.

Description

Technical Field

[0001] This invention relates to the field of oil and gas drilling technology, and particularly to a cement plug release device, method and system. Background Technology

[0002] In current cementing operations, there are no specialized tools or techniques to determine whether the cement plug has been successfully released. Therefore, cementing operations rely solely on experience, which carries the risk of misjudgment. In some cases, it is necessary to interrupt cementing operations and open the wellhead to check whether the cement plug has been successfully released, which is detrimental to safe production and also negatively impacts cementing quality.

[0003] Since accurate detection of cementing plug release devices is a crucial part of cementing operations, a cementing plug release device, method, and system are proposed. Summary of the Invention

[0004] To address the inaccuracies and misjudgments in existing technologies that rely on experience to determine the release status of cement plugs, this application proposes a cement plug release device, method, and system to achieve accurate determination of the release status of cement plugs.

[0005] In a first aspect, the present invention provides a cementing plug release device, comprising:

[0006] The main body has a release cavity inside, and one side of the release cavity has a release opening;

[0007] A rubber stopper body, which is disposed in the release cavity and is magnetic;

[0008] A pointer assembly is disposed on the main body and has a freely rotatable pointer that is constrained by the magnetic field of the rubber stopper body in the release chamber, thereby limiting its free rotation.

[0009] In one embodiment, the rubber stopper body includes a rubber stopper rod and a rubber sleeve fitted on the rubber stopper rod, wherein the rubber stopper rod is a magnet.

[0010] In one embodiment, a rubber stopper pin is provided on the main body near the release opening, and the stopper pin is movably disposed relative to the main body to prevent the rubber stopper body from dislodging from the release cavity. This embodiment prevents the rubber stopper body from dislodging from the release cavity, thus avoiding accidental release.

[0011] In one embodiment, the main body also has a plug-in interface at one end away from the location of the release opening, which communicates with the release chamber. The plug-in interface is used to connect to a plug-in fluid injection line. In this embodiment, the plug-in interface is used to inject plug-in fluid, press the rubber stopper body into the sleeve, and continuously push it to the pressure seat position at the bottom of the sleeve column.

[0012] In one embodiment, the end of the body away from the release opening is a removable cap that closes the rubber plug inlet of the release chamber relative to the release opening.

[0013] In one embodiment, the pointer is disposed on the end face of the body away from the location of the release opening, and the pointer is rotatable in the plane containing the axis of the release cavity, the axis of the release cavity being a straight line along the release movement direction of the rubber stopper body.

[0014] In one embodiment, the pointer assembly further includes a pointer support, the pointer being disposed on the pointer support, and a spindle being disposed on the pointer support passing through the rotation center of the pointer.

[0015] In one embodiment, the pointer assembly further includes a pointer base, the pointer support is disposed on the pointer base, and the pointer base is detachably connected to the main body.

[0016] In one embodiment, the main body is provided with threaded structures at both ends corresponding to the release opening and the rubber plug inlet, and the threaded structures at both ends are used to connect the casing of the wellbore and the pressure cap, so that the release chamber is connected to the casing.

[0017] Secondly, the present invention proposes a method for releasing cement plugs, comprising:

[0018] The release device is connected to the casing of the wellbore, and the release chamber inside the main body of the release device is connected to the casing;

[0019] Remove the rubber stopper pin on the main body and inject the stopper fluid into the release chamber through the stopper interface on the main body to release the magnetic rubber stopper body in the release chamber;

[0020] The success of the release of the rubber stopper is determined by the indication status of the pointer on the main body.

[0021] Thirdly, the present invention proposes a cementing plug release system, which includes the aforementioned cementing plug release device, and thus possesses all the technical effects it has.

[0022] The above-mentioned technical features can be combined in various suitable ways or replaced by equivalent technical features, as long as the purpose of the present invention can be achieved.

[0023] The cementing plug release device, method, and system provided by this invention have at least the following advantages compared with the prior art:

[0024] This invention discloses a cementing plug release device, method, and system. A strongly magnetic plug body is installed within the main body. Before release, a pointer is magnetized by the plug body, changing its initial free state to a specific posture. Once the plug body is successfully released, the plug body moves away from the main body, causing the pointer to quickly demagnetize and return to a non-magnetic state, i.e., a free state, rather than stabilizing in the previous specific posture. If the pointer remains stable or tends towards the previous specific posture, it indicates that the plug release has failed because the strong magnetism of the plug body still affects the pointer. This phenomenon allows for rapid detection and timely handling of problems, effectively avoiding negative impacts on cementing safety and quality. The release device of this invention promotes accurate, rapid, and intuitive judgment of the cementing process, enabling correct decision-making and improving cementing safety and quality, thus showing promising prospects for widespread application. Attached Figure Description

[0025] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0026] Figure 1 A schematic diagram of the release device of the present invention is shown (before the rubber stopper is released);

[0027] Figure 2 A schematic diagram of the release device of the present invention is shown (after the rubber stopper is released).

[0028] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not to scale.

[0029] Figure label:

[0030] 1-Main body, 11-Release chamber, 12-Release opening, 13-Plug interface, 14-Plug cap, 2-Plug body, 21-Plug rod, 22-Rubber sleeve, 3-Pointer assembly, 31-Pointer, 32-Pointer bracket, 33-Spindle, 34-Pointer base, 4-Plug stop pin. Detailed Implementation

[0031] The invention will now be further described with reference to the accompanying drawings.

[0032] Example 1

[0033] An embodiment of the present invention provides a cement plug release device, comprising:

[0034] The main body 1 has a release cavity 11 inside, and a release opening 12 on one side of the release cavity 11;

[0035] The rubber stopper body 2 is disposed in the release chamber 11 and is magnetic.

[0036] The pointer assembly 3 is disposed on the main body 1 and has a pointer 31 that can rotate freely. The pointer 31 can be constrained by the magnetic field of the rubber stopper body 2 in the release chamber 11 and thus restricted from rotating freely.

[0037] Specifically, as shown in the attached diagram. Figure 1 and Figure 2 As shown, the release device of the present invention mainly comprises three parts:

[0038] The first part is the main body 1, which serves as the outer shell. The interior of the main body 1 has a release chamber 11. One side of the release chamber 11 has a release opening 12 for connecting to the well casing. The release opening 12 also serves as the outlet of the release chamber 11.

[0039] The second part is the rubber stopper body 2, which is disposed in the release chamber 11 and can be released outward through the release opening 12. It is also magnetic.

[0040] The third part is the pointer assembly 3, which is set on the main body 1. The pointer 31 of the pointer assembly 3 is made of a material that can be affected by a magnetic field (soft magnetic metal material), that is, the pointer 31 can be a magnet, and the pointer 31 is within the influence range of the magnetic field of the rubber stopper body 2 in the release cavity 11.

[0041] The principle of the release device of the present invention is as follows:

[0042] Before release, see attached image. Figure 1 As shown, the rubber stopper body 2 is located in the release chamber 11. Its magnetic field affects and constrains the pointer 31 of the pointer assembly 3, preventing the pointer 31 from rotating flexibly. Under the action of the magnetic field, the pointer 31 is kept in a specific posture.

[0043] After release, see attached image. Figure 2 As shown, the rubber plug body 2 exits the release chamber 11 through the release opening 12 and enters the casing of the corresponding wellbore, causing the rubber plug body 2 to move away from the pointer 31 until the pointer 31 is out of the influence range of the magnetic field of the rubber plug body 2. At this time, since the constraint of the magnetic field of the rubber plug body 2 is lost, the pointer 31 can rotate freely and no longer maintains the specific posture when constrained by the magnetic field.

[0044] Therefore, during the release process, the state of pointer 31 can be used to determine whether the rubber stopper body 2 has been successfully released, and appropriate adjustment measures can be taken in time if it is not successfully released.

[0045] It should be noted that, since the rubber stopper body 2 is magnetic, in order not to affect the release of the rubber stopper body 2, the main body 1 is made of a non-magnetic material that is not affected by the magnetic field of the rubber stopper body 2.

[0046] Furthermore, the rubber stopper body 2 includes a rubber stopper rod 21 and a rubber sleeve 22 sleeved on the rubber stopper rod 21, wherein the rubber stopper rod 21 is a magnet.

[0047] Specifically, as shown in the attached diagram. Figure 1 As shown, the rubber plug body 2 includes a rubber plug rod 21 as a skeleton and a rubber sleeve 22 as a sealing structure. The rubber plug rod 21 is made of magnetic material and is a magnet. The magnetism of the rubber plug body 2 is generated by the magnetic field of the rubber plug rod 21. The rubber plug rod 21 and the rubber sleeve 22 are vulcanized together to form a complete cementing rubber plug body 2.

[0048] Furthermore, a rubber stopper pin 4 is provided on the main body 1 near the release opening 12 and inserted into the release cavity 11. The rubber stopper pin 4 is movably disposed relative to the main body 1 and is used to restrict the rubber stopper body 2 from coming out of the release cavity 11.

[0049] Specifically, as shown in the attached diagram. Figure 1 As shown in the attached figure, the rubber stopper pin 4 is inserted into the main body 1, with one end inserted into the release cavity 11 and facing the rubber stopper body 2. At this time, the rubber stopper pin 4 can prevent the rubber stopper body 2 from falling out of the release cavity 11. Figure 2 As shown, the rubber stopper pin 4 is inserted into the main body 1, but it is completely removed from the release chamber 11, thus releasing the restriction on the rubber stopper body 2. The rubber stopper body 2 can be released from the release chamber 11.

[0050] Furthermore, the main body 1 also has a plug interface 13 at one end away from the location of the release opening 12, which is connected to the release chamber 11. The plug interface 13 is used to connect the plug fluid injection pipeline.

[0051] Specifically, as shown in the attached diagram. Figure 1 and Figure 2 As shown, the plugging port 13 is located on the main body 1 at the end away from the release opening 12. It can be connected to an external plugging fluid injection pipeline to inject plugging fluid into the release chamber 11, press the rubber plug body 2 into the sleeve, and continuously push it to the bottom of the sleeve column at the pressing seat position.

[0052] Furthermore, the end of the main body 1 away from the release opening 12 is a removable pressure cap 14, which closes the rubber plug inlet of the release chamber 11 relative to the release opening 12.

[0053] Specifically, the pressure cap 14 is detachably mounted on the main body 1 and is used to close the rubber plug inlet of the release chamber 11. Before the release operation, the rubber plug body 2 needs to be inserted into the release chamber 11. At this time, the pressure cap 14 is removed, and the rubber plug body 2 is inserted into the release chamber 11 through the open rubber plug inlet. Then the pressure cap 14 is reconnected to the main body 1 to keep the rubber plug inlet closed.

[0054] Furthermore, the pointer 31 is located on the end face of the main body 1 away from the location of the release opening 12. The pointer 31 can rotate in the plane where the axis of the release chamber 11 is located. The axis of the release chamber 11 is a straight line along the release movement direction of the rubber stopper body 2.

[0055] Specifically, as shown in the attached diagram. Figure 1 and Figure 2 As shown, pointer 31 is located on the end face of the main body 1 away from the release opening 12, and points to the release chamber 11. When the release device is installed on the sleeve opening, the rubber stopper body 2 is released in the vertical direction, that is, the axis of the release chamber 11 is in the vertical direction, and pointer 31 rotates in the vertical plane.

[0056] Furthermore, the pointer assembly 3 also includes a pointer support 32, with the pointer 31 mounted on the pointer support 32, and a spindle 33 passing through the rotation center of the pointer 31 mounted on the pointer support 32.

[0057] Specifically, as shown in the attached diagram. Figure 1 and Figure 2 As shown, the pointer 31 is mounted on the pointer support 32 and rotates around its own rotation center. The support is provided with a spindle 33, which passes through the rotation center of the pointer 31 and serves as the rotation center of the pointer 31.

[0058] Furthermore, the pointer assembly 3 also includes a pointer base 34, a pointer support 32 is disposed on the pointer base 34, and the pointer base 34 is detachably connected to the main body 1 (placed on the end face of the main body 1).

[0059] Specifically, in this embodiment, the pointer assembly 3 is placed on the end face of the main body 1 via the pointer base 34, that is, the pointer assembly 3 is placed on the pressure cap 14 at one end of the main body 1. After the device is installed in the sleeve, the pointer assembly 3 is in a horizontal state on the end face of the body. In order to further maintain the stability of the pointer assembly, it can be further bonded or tied on the basis of placement.

[0060] Furthermore, the main body 1 is provided with threaded structures at the two ends of the corresponding release opening 12 and the rubber plug inlet, respectively. The threaded structures at both ends are used to connect the casing and the cap 14 of the wellbore so that the release chamber 11 is connected to the casing.

[0061] Specifically, the threaded structure (not shown in the attached drawings) at the release opening 12 at one end of the main body 1 is used to install the release device onto the sleeve. After installation, the release opening 12 of the device aligns with the opening of the sleeve. The threaded structure (not shown in the attached drawings) at the rubber plug inlet at the other end of the main body 1 is used to connect the gland 14 to the main body 1 after the rubber plug body 2 is inserted into the release chamber 11, forming a seal at the upper end of the main body 1.

[0062] The working principle of the device of the present invention is as follows:

[0063] In its initial state, the rubber stopper rod 21, along with the rubber sleeve 22, is supported by the rubber stopper pin 4 within the cement head cavity and is located below the pressure stopper interface 13. The rubber stopper rod 21 retains the skeletal function of a regular rubber stopper rod 21, and more importantly, its material must possess strong permanent magnetism to achieve efficient magnetization of the pointer 31 on the outside of the main body 1 and ensure attitude control of the pointer 31, so that the pointer 31 stably maintains or tends to a specific attitude under the action of magnetic force.

[0064] After the cement slurry is injected into the wellbore, the rubber plug retainer pin 4 is removed, and plugging fluid is injected through the plugging port 13 to press the rubber plug body 2 into the casing, and it is continuously pushed to the bottom of the casing string at the pressure seat position. Once the rubber plug body 1 is far away from the body 1, the rubber plug rod 21 will no longer have a magnetizing effect on the pointer 31 due to the large distance, and the pointer 31 will quickly demagnetize and will no longer be constrained by the magnetic field to a specific state (as shown in the attached figure in this embodiment). Figure 1 (As shown in the vertical state), it immediately returns to a free state and can rotate freely.

[0065] Before releasing the cement plug, the release device of this embodiment is installed on the casing. The pointer 31 is checked to see if it forms a significant magnetic reaction with the plug body 1. If the pointer 31 is sensitive, it is in a specific (vertical) state. Then, the plug body 2 is released. After successful release, the plug body 2 moves away from the body 1, and the pointer 31 returns to a free and flexible state. The pointer 31's state may change irregularly due to normal vibrations of the body 1. If the pointer 31 remains in or tends towards the previous specific state (vertical state), it indicates that the plug body 2 is still inside the body 1 and has not been successfully released. The measures and operating procedures should be adjusted immediately.

[0066] Example 2

[0067] An embodiment of the present invention provides a cement plug release device, comprising:

[0068] The main body 1 has a release chamber 11 inside. One side of the release chamber 11 has a release opening 12 and the other side has a rubber plug inlet. The rubber plug inlet is kept sealed by a cap 14 that is detachably connected to the main body 1 by a threaded structure.

[0069] The rubber stopper body 2 is disposed in the release chamber 11 and is magnetic.

[0070] The pointer assembly 3 is disposed on the main body 1 and has a pointer 31 that can rotate freely. The pointer 31 can be constrained by the magnetic field of the rubber stopper body 2 in the release chamber 11 and thus restricted from rotating freely.

[0071] Specifically, as shown in the attached diagram. Figure 1 and Figure 2 As shown, the release device of the present invention mainly comprises three parts:

[0072] The first part is the main body 1, which serves as the outer shell. The interior of the main body 1 has a release chamber 11. One side of the release chamber 11 has a release opening 12 for connecting to the well casing. The release opening 12 also serves as the outlet of the release chamber 11. The other side of the release chamber 11 is a rubber plug inlet. The rubber plug inlet has a pressure cap 14 connected by a threaded structure. The rubber plug inlet is used to insert the rubber plug body 2 into the release chamber 11 before the release operation. Then, the pressure cap 14 is connected to the main body 1 by the threaded structure to form a seal.

[0073] The second part is the rubber stopper body 2, which is disposed in the release chamber 11 and can be released outward through the release opening 12. It is also magnetic.

[0074] The third part is the pointer assembly 3, which is set on the main body 1. The pointer 31 of the pointer assembly 3 is made of a material that can be affected by a magnetic field (soft magnetic metal material), that is, the pointer 31 can be a magnet, and the pointer 31 is within the influence range of the magnetic field of the rubber stopper body 2 in the release cavity 11.

[0075] The principle of the release device of the present invention is as follows:

[0076] Before release, see attached image. Figure 1 As shown, the rubber stopper body 2 is located in the release chamber 11. Its magnetic field affects and constrains the pointer 31 of the pointer assembly 3, preventing the pointer 31 from rotating flexibly. Under the action of the magnetic field, the pointer 31 is kept in a specific posture.

[0077] After release, see attached image. Figure 2 As shown, the rubber plug body 2 exits the release chamber 11 through the release opening 12 and enters the casing of the corresponding wellbore, causing the rubber plug body 2 to move away from the pointer 31 until the pointer 31 is out of the influence range of the magnetic field of the rubber plug body 2. At this time, since the constraint of the magnetic field of the rubber plug body 2 is lost, the pointer 31 can rotate freely and no longer maintains the specific posture when constrained by the magnetic field.

[0078] Therefore, during the release process, the state of pointer 31 can be used to determine whether the rubber stopper body 2 has been successfully released, and appropriate adjustment measures can be taken in time if it is not successfully released.

[0079] It should be noted that, since the rubber stopper body 2 is magnetic, in order not to affect the release of the rubber stopper body 2, the main body 1 is made of a non-magnetic material that is not affected by the magnetic field of the rubber stopper body 2.

[0080] Furthermore, the rubber stopper body 2 includes a rubber stopper rod 21 and a rubber sleeve 22 sleeved on the rubber stopper rod 21, wherein the rubber stopper rod 21 is a magnet.

[0081] Specifically, as shown in the attached diagram. Figure 1 As shown, the rubber plug body 2 includes a rubber plug rod 21 as a skeleton and a rubber sleeve 22 as a sealing structure. The rubber plug rod 21 is made of magnetic material and is a magnet. The magnetism of the rubber plug body 2 is generated by the magnetic field of the rubber plug rod 21. The rubber plug rod 21 and the rubber sleeve 22 are vulcanized together to form a complete cementing rubber plug body 2.

[0082] Furthermore, a rubber stopper pin 4 is provided on the main body 1 near the release opening 12 and inserted into the release cavity 11. The rubber stopper pin 4 is movably disposed relative to the main body 1 and is used to restrict the rubber stopper body 2 from coming out of the release cavity 11.

[0083] Specifically, as shown in the attached diagram. Figure 1 As shown in the attached figure, the rubber stopper pin 4 is inserted into the main body 1, with one end inserted into the release cavity 11 and facing the rubber stopper body 2. At this time, the rubber stopper pin 4 can prevent the rubber stopper body 2 from falling out of the release cavity 11. Figure 2 As shown, the rubber stopper pin 4 is inserted into the main body 1, but it is completely removed from the release chamber 11, thus releasing the restriction on the rubber stopper body 2. The rubber stopper body 2 can be released from the release chamber 11.

[0084] Furthermore, the main body 1 also has a plug interface 13 at one end away from the location of the release opening 12, which is connected to the release chamber 11. The plug interface 13 is used to connect the plug fluid injection pipeline.

[0085] Specifically, as shown in the attached diagram. Figure 1 and Figure 2 As shown, the plugging port 13 is located on the main body 1 at the end away from the release opening 12. It can be connected to an external plugging fluid injection pipeline to inject plugging fluid into the release chamber 11, press the rubber plug body 2 into the sleeve, and continuously push it to the bottom of the sleeve column at the pressing seat position.

[0086] Furthermore, the pointer 31 is located on the end face of the main body 1 away from the location of the release opening 12. The pointer 31 can rotate in the plane where the axis of the release chamber 11 is located. The axis of the release chamber 11 is a straight line along the release movement direction of the rubber stopper body 2.

[0087] Specifically, as shown in the attached diagram. Figure 1 and Figure 2 As shown, pointer 31 is located on the end face of the main body 1 away from the release opening 12, and points to the release chamber 11. When the release device is installed on the sleeve opening, the rubber stopper body 2 is released in the vertical direction, that is, the axis of the release chamber 11 is in the vertical direction, and pointer 31 rotates in the vertical plane.

[0088] Furthermore, the pointer assembly 3 also includes a pointer support 32, with the pointer 31 mounted on the pointer support 32, and a spindle 33 passing through the rotation center of the pointer 31 mounted on the pointer support 32.

[0089] Specifically, as shown in the attached diagram. Figure 1 and Figure 2 As shown, the pointer 31 is mounted on the pointer support 32 and rotates around its own rotation center. The support is provided with a spindle 33, which passes through the rotation center of the pointer 31 and serves as the rotation center of the pointer 31.

[0090] Furthermore, the pointer assembly 3 also includes a pointer base 34, a pointer support 32 is disposed on the pointer base 34, and the pointer base 34 is detachably connected to the main body 1.

[0091] Specifically, the pointer assembly 3 is mounted on the device body 1 via the pointer base 34, and is connected in a detachable manner. The detachable manner includes, but is not limited to, bonding, binding, or connecting with connectors.

[0092] Furthermore, the main body 1 is provided with a threaded structure at the location of the release opening 12. The threaded structure is used to connect the casing of the wellbore so that the release chamber 11 is connected to the casing.

[0093] Specifically, the threaded structure (not shown in the attached drawings) is used to install the release device onto the sleeve. After installation, the release opening 12 of the device connects to the port of the sleeve.

[0094] Furthermore, the pointer 31 has a center of rotation, and the pointer 31 has pointer portions located on opposite sides of the center of rotation, as shown in the attached figure. Figure 1 and Figure 2 As shown, the two pointers 31 located on opposite sides of the rotation center have different masses and serve as the two magnetic poles of the pointers 31 respectively.

[0095] Specifically, as shown in the attached diagram. Figure 1 As shown, when the rubber stopper body 2 is placed in the release chamber 11, the magnetic pole of the rubber stopper body 2 near the pointer 31 attracts the pointer 31 part with smaller mass. After the rubber stopper body 2 is released, the pointer 31 loses the magnetic field constraint and under the action of gravity, the pointer 31 automatically rotates to the pointer 31 part with larger mass facing downwards. This makes it easier to determine whether the rubber stopper body 2 has been successfully released.

[0096] In addition, the two pointers are painted in different colors.

[0097] The working principle of the device of the present invention is as follows:

[0098] In its initial state, the rubber stopper rod 21, along with the rubber sleeve 22, is supported by the rubber stopper pin 4 within the cement head cavity and is located below the pressure stopper interface 13. The rubber stopper rod 21 retains the skeletal function of a regular rubber stopper rod 21, and more importantly, its material must possess strong permanent magnetism to achieve efficient magnetization of the pointer 31 on the outside of the main body 1 and ensure attitude control of the pointer 31, so that the pointer 31 stably maintains or tends to a specific attitude under the action of magnetic force.

[0099] After the cement slurry is injected into the wellbore, the rubber plug retainer pin 4 is removed, and plugging fluid is injected through the plugging port 13 to press the rubber plug body 2 into the casing, and it is continuously pushed to the bottom of the casing string at the pressure seat position. Once the rubber plug body 1 is far away from the body 1, the rubber plug rod 21 will no longer have a magnetizing effect on the pointer 31 due to the large distance, and the pointer 31 will quickly demagnetize and will no longer be constrained by the magnetic field to a specific state (as shown in the attached figure in this embodiment). Figure 1 (As shown in the vertical state), it immediately returns to a free state and can rotate freely.

[0100] Before releasing the cement plug, the release device of this embodiment is installed on the casing. The pointer 31 is checked to see if it forms a significant magnetic reaction with the plug body 1. If the pointer 31 is sensitive, it is in a specific (vertical) state. Then, the plug body 2 is released. After successful release, the plug body 2 moves away from the body 1, and the pointer 31 returns to a free and flexible state. The pointer 31's state may change irregularly due to normal vibrations of the body 1. If the pointer 31 remains in or tends towards the previous specific state (vertical state), it indicates that the plug body 2 is still inside the body 1 and has not been successfully released. The measures and operating procedures should be adjusted immediately.

[0101] In this embodiment, the relative position (vertical position) of the two pointers with different masses can be observed to more intuitively determine whether the rubber stopper body 2 has been successfully released.

[0102] Example 3

[0103] An embodiment of the present invention provides a method for releasing cement plugs, comprising:

[0104] The release device is connected to the casing of the wellbore, and the release chamber inside the main body of the release device is connected to the casing;

[0105] Remove the rubber stopper pin on the main body and inject the stopper fluid into the release chamber through the stopper interface on the main body to release the magnetic rubber stopper body in the release chamber.

[0106] The status of the pointer on the main body determines whether the rubber stopper has been successfully released.

[0107] Example 4

[0108] The embodiments of the present invention provide a cementing plug release system, which includes the above-mentioned cementing plug release device, and thus possesses all the technical effects thereof.

[0109] In the description of this invention, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "rear", "inner", "outer", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0110] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A cementing plug release device, characterized in that, include: The main body has a release cavity inside, and one side of the release cavity has a release opening; A rubber stopper body, which is disposed in the release cavity and is magnetic; A pointer assembly, disposed on the main body, having a freely rotatable pointer, the pointer being constrained by the magnetic field of the rubber stopper body in the release chamber, thus limiting its free rotation; The stopper body includes a stopper rod and a rubber sleeve fitted on the stopper rod, wherein the stopper rod is a magnet; The pointer is located on the end face of the main body away from the location of the release opening. The pointer can rotate in the plane where the axis of the release cavity is located. The axis of the release cavity is a straight line along the release movement direction of the rubber stopper body. The pointer assembly further includes a pointer support, the pointer is mounted on the pointer support, and the pointer support is provided with a spindle passing through the rotation center of the pointer; One of the magnetic poles of the rubber stopper rod points to the pointer; The pointer has two pointer parts located on opposite sides of the rotation center. The two pointer parts on opposite sides of the rotation center have different masses and serve as the two magnetic poles of the pointer. When the rubber stopper body is placed in the release chamber, the rubber stopper body and the pointer part with smaller mass attract each other. After the rubber stopper body is released, the pointer automatically rotates and points the pointer part with larger mass downwards. The two pointer parts are coated with different colors. The main body is made of non-magnetic material, the pointer is made of material that can be affected by a magnetic field, and after the rubber stopper body is released, the pointer is demagnetized and is no longer constrained to a specific state by the magnetic field.

2. The cement plug release device according to claim 1, characterized in that, The main body has a rubber stopper pin that is inserted into the release cavity near the release opening. The rubber stopper pin is movably disposed relative to the main body and is used to prevent the rubber stopper body from coming out of the release cavity.

3. The cement plug release device according to claim 1, characterized in that, The main body also has a plug interface at one end away from the location of the release opening, which is connected to the release chamber. The plug interface is used to connect to the plug fluid injection pipeline.

4. The cement plug release device according to claim 1, characterized in that, The end of the main body away from the release opening is a removable pressure cap, which closes the rubber plug inlet of the release chamber relative to the release opening.

5. The cement plug release device according to any one of claims 1-4, characterized in that, The pointer assembly also includes a pointer base, the pointer bracket is disposed on the pointer base, and the pointer base is detachably connected to the main body.

6. The cement plug release device according to claim 4, characterized in that, The main body is provided with threaded structures at both ends corresponding to the release opening and the rubber plug inlet. The threaded structures at both ends are used to connect the casing of the wellbore and the pressure cap, so that the release chamber is connected to the casing.

7. A method for releasing cementing plugs, characterized in that, Includes the use of the cement plug release device according to any one of claims 1-6: The release device is connected to the casing of the wellbore, and the release chamber inside the main body of the release device is connected to the casing; Remove the rubber stopper pin on the main body and inject the stopper fluid into the release chamber through the stopper interface on the main body to release the magnetic rubber stopper body in the release chamber; The success of the release of the rubber stopper is determined by the pointer's indication status on the main body.

8. A cementing plug release system, characterized in that, It includes the cementing plug release device as described in any one of claims 1 to 6.

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