Ball seat

Abstract

The utility model provides a ball seat which comprises an upper cylinder body and a lower cylinder body which jointly define a central fluid channel, and a ball seat body arranged in the channel, and the ball seat body is constructed to be capable of abutting against a ball sealer in a sealing mode. Wherein a limiting mechanism capable of selectively limiting the ball seat body is arranged in the lower cylinder body, a containing groove capable of being selectively connected with the ball seat body in a clamped mode is formed in the upper cylinder body, and the ball seat body is constructed to be capable of being separated from the limiting mechanism under the action of pressure. And the elastic element moves downwards in the axial direction and outwards in the radial direction so as to be clamped with the containing groove, so that sealed abutting between the elastic element and the ball sealer is released. By means of the mode, the technical problems that in the prior art, when the setting technology is achieved, the ball seat falls down, later well repair operation is affected, and a channel in a well is prone to being blocked are solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of drilling and well completion, and particularly relates to a ball seat. Background Art

[0002] In oil and gas production, the ball seat is a downhole tool for setting the packer. Currently, the commonly used setting processes mainly include "ball throwing method" and "lowering self-balancing plug".

[0003] Although both methods can achieve the sealing work, when the "ball throwing method" is used, after the sealing is completed, the sealing ball and the ball seat will fall downward, resulting in more parts remaining in the well, affecting the subsequent well repair operation and easily causing obstruction of the well passage.

[0004] However, when the "self-balancing plug" is used, the plug needs to be connected to the steel wire and then lowered into the well. In this process, the steel wire is easily entangled with the well components, which also increases the risk of blocking the well passage. Utility Model Content

[0005] In order to overcome at least one or more of the above-mentioned defects in the prior art, the utility model provides a ball seat, comprising an upper cylinder and a lower cylinder that jointly define a central fluid channel, and a ball seat body disposed in the channel, wherein the ball seat body is configured to be able to sealably abut against a blocking ball.

[0006] Among them, the lower cylinder is provided with a limiting mechanism that can selectively limit the ball seat body, and the upper cylinder is provided with a receiving groove that can selectively form a snap connection with the ball seat body. The ball seat body is constructed to be able to disengage from the limiting mechanism under the action of pressure, and move axially downward and radially outward to snap into the receiving groove, thereby releasing the sealed abutment between the sealing ball and the sealing ball.

[0007] In one embodiment, the ball seat body includes an elastic deformation portion, and an abutment portion arranged at the upper end of the elastic deformation portion and extending radially outward to abut against the inner wall of the upper cylinder. The elastic deformation portion is configured to expand radially outward when the ball seat body moves downward, so that the abutment portion enters the accommodating groove to form a snap connection.

[0008] In one embodiment, the upper end surface of the abutment portion is arranged as a plane perpendicular to the axis of the deformation portion, the accommodating groove is configured to be radially recessed outward along the inner wall of the upper cylinder, and the upper end surface of the accommodating groove is arranged as a plane that fits the abutment portion, so as to limit the upward movement of the ball seat body.

[0009] In one embodiment, the limiting mechanism includes a first limiting block arranged on the inner wall of the lower cylinder, and a second limiting block located radially inside the first limiting block, the first limiting block and the second limiting block are connected to each other by a shear pin, and the shear pin is configured to be sheared under the action of the pressure to allow the second limiting block to move downward.

[0010] In one embodiment, the ball seat body further includes a fixing portion, which is disposed at the lower end of the deformation portion and abuts against the second limiting block in the axial direction.

[0011] In one embodiment, a second boss is provided on the inner wall of the lower cylinder body for receiving the ball seat body moving downward, and when the ball seat body contacts the second boss, the abutment portion is located in the receiving groove.

[0012] In one embodiment, the upper cylinder includes an outer cylinder and a connecting portion recessed radially inward along the outer cylinder, a first abutment platform is formed between the connecting portion and the outer cylinder, and the connecting portion is sleeved in the lower cylinder so that the first abutment platform and the end of the lower cylinder face each other.

[0013] In one embodiment, a stopper is provided between the first abutment platform and the end surface of the lower cylinder, for connecting the upper cylinder and the lower cylinder together.

[0014] In one embodiment, a second abutment platform which is recessed radially inward is further provided on the connection portion, and a step which is recessed radially outward is formed on the inner wall of the lower cylinder for abutting against the second abutment platform.

[0015] In one embodiment, the free end of the connecting portion abuts against the first limiting block, and a first boss extending radially inward is formed on the inner wall of the lower cylinder for receiving the first limiting block.

[0016] In general, the above technical solutions conceived by the utility model can achieve the following beneficial effects compared with the prior art:

[0017] In the utility model, an upper cylinder and a lower cylinder are provided, and the upper cylinder and the lower cylinder jointly define a central fluid channel. At the same time, a ball seat body is provided in the channel, and the ball seat body is configured to be able to seal and abut with a blocking ball. In addition, a limiting mechanism that can selectively limit the ball seat body is provided in the lower cylinder, and a receiving groove that can selectively form a snap connection with the ball seat body is provided in the upper cylinder, and the ball seat body is configured to be able to disengage from the limiting mechanism under the action of pressure, and move axially downward and radially outward to snap with the receiving groove, thereby releasing the sealed abutment with the blocking ball. In this way, the technical problem in the prior art that the ball seat falls downward when the sealing process is implemented, affecting the subsequent well repairing operations and easily causing obstruction of the channel in the well is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0019] Figure 1 The overall structure of the ball seat according to the utility model is schematically shown.

[0020] It should be noted that the drawings are not necessarily drawn according to actual scale.

[0021] In all the drawings, the same reference numerals represent the same technical features, specifically: 100-ball seat; 1-upper cylinder; 11-accommodating groove; 12-outer cylinder; 121-first abutment platform; 13-connecting portion; 131-engaging member; 132-limiting member; 133-second abutment platform; 14-stop portion; 2-lower cylinder; 21-first boss; 22-second boss; 3-passageway; 4-ball seat body; 41-fixing portion; 42-deformation portion; 43-abutment portion; 44-channel; 5-limiting mechanism; 51-first limit block; 52-second limit block; 53-shear pin; 6-sealing ring. DETAILED DESCRIPTION

[0022] In order to better understand the purpose, structure and function of the utility model, a ball seat of the utility model is further described in detail below in conjunction with the accompanying drawings.

[0023] For convenience, the direction extending along the upper cylinder is referred to as the "axial direction", "vertical direction" or similar terms, the direction perpendicular to the "axial direction" is referred to as the "radial direction", "lateral direction" or similar terms, the direction close to the outside in the "radial direction" is referred to as the "radial outward direction" or similar terms, and the direction close to the inside of the upper cylinder in the "radial direction" is referred to as the "radial inward direction" or similar terms.

[0024] like Figure 1 As shown, an embodiment of the utility model provides a ball seat 100, including an upper cylinder 1, and a lower cylinder 2 interconnected with the upper cylinder 1. In this way, the upper cylinder 1 and the lower cylinder 2 together define a central fluid channel 3. The upper cylinder 1 and the lower cylinder 2 are formed into any shape that facilitates fluid movement. In this embodiment, the upper cylinder 1 and the lower cylinder 2 are both configured as circular tubular structures.

[0025] Meanwhile, a ball seat body 4 is arranged in the channel 3. The ball seat body 4 includes a ball seat body 4 arranged in the channel 3 in a detachable manner, and a passage 44 is formed on the ball seat body 4 and passes through along the axial direction. The passage 44 is configured to be equivalent to a sealing ball, and is used to allow the sealing ball to pass through and move along the path formed by the passage 44. It should be noted that the sealing ball is configured to be dropped along the channel 3 when a sealing operation is required.

[0026] In one embodiment, Figure 1 As shown, the ball seat body 4 includes a fixing portion 41, a deformation portion 42 arranged along the end surface of the fixing portion 41 and extending toward a side away from the fixing portion 41, and an abutment portion 43 arranged at the free end of the deformation portion 42. It should be noted that the deformation portion 42 is made of any material that can undergo elastic deformation.

[0027] Among them, Figure 1 As shown, the abutment portion 43 is configured as a boss extending radially outward along the deformation portion 42. Specifically, the outer diameter formed by the abutment portion 43 is larger than the outer diameter formed by the deformation portion 42. In this way, when the abutment portion 43 and the inner wall of the upper cylinder 1 abut against each other, the free end of the deformation portion 42 can be forced to elastically deform radially inward. Specifically, the free end of the deformation portion 42 is caused to contract radially inward.

[0028] As a result, the diameter formed by the free end of the ball seat body 4 is smaller than the blocking ball, so that the blocking ball cannot enter the passage 44. In this arrangement, the free end of the ball seat body 4 can abut against the blocking ball. Moreover, when the blocking ball is subjected to pressure, the ball seat body 4 seals the blocking ball, thereby blocking the passage 44 through the blocking ball. It should be noted that the pressure is the force used by the blocking ball to achieve pressure holding in the pipe.

[0029] In one embodiment, Figure 1 As shown, a radially outwardly recessed receiving groove 11 is provided on the inner wall of the upper cylinder 1 below the abutment portion 43. The receiving groove 11 is used to receive the abutment portion 43 when the ball seat body 4 moves downward, and is mutually engaged with the abutment portion 43, thereby forming a relatively fixed connection. In this process, the deformation portion 42 will restore elastic deformation, so that the diameter formed by the free end of the ball seat body 4 will be equivalent to that of the blocking ball. As a result, the blocking ball can move along the passage 44 formed by the ball seat body 4.

[0030] According to a preferred embodiment of the present invention, Figure 1 As shown, the upper end surface of the abutment portion 43 and the upper end surface of the receiving groove 11 are both configured to be perpendicular to the axis of the deformation portion 42. Specifically, the upper end surface of the abutment portion 43 and the upper end surface of the receiving groove 11 are both configured to be horizontally stepped. In this way, when the abutment portion 43 is located in the receiving groove 11, the receiving groove 11 can limit the upward movement of the abutment portion 43, thereby limiting the upward movement of the ball seat body 4. In this way, the ball seat body 4 is prevented from moving upward.

[0031] In one embodiment, Figure 1As shown, a limiting mechanism 5 is also provided on the inner wall of the lower cylinder 2, and the limiting mechanism 5 includes a first limiting block 51 fixedly provided on the inner wall of the lower cylinder 2, and a second limiting block 52 located radially inward of the first limiting block 51 and in contact with the first limiting block 51, and the first limiting block 51 and the second limiting block 52 are connected to each other through a shear pin 53. It should be noted that, in this embodiment, the shear pin 53 is configured to allow the shear pin 53 to be sheared when the ball seat body 4 seals the blocking ball 42 and applies pressure to the blocking ball 42, so that the second limiting block 52 moves downward.

[0032] Among them, Figure 1 As shown, the fixing portion 41 and the second stopper 52 are in contact with each other. In this way, when the shear pin 53 is cut off, the first stopper 51 and the second stopper 52 can be separated from each other, so that the second stopper 52 cancels the stopper on the fixing portion 41. As a result, the ball seat body 4 can move downward under the force of gravity.

[0033] As the ball seat body 4 continues to move downward, when the abutting portion 43 and the receiving groove 11 correspond to each other, the deformable portion 42 will restore the elastic deformation, so that the abutting portion 43 is located in the receiving groove 11, and the abutting portion 43 and the receiving groove 11 are mutually engaged to form a relatively fixed connection. In this process, the diameter formed by the free end of the ball seat body 4 will be equivalent to that of the blocking ball. As a result, the blocking ball can move along the passage 44 formed by the ball seat body 4.

[0034] According to a preferred embodiment of the present invention, Figure 1 As shown, a first boss 21 extending radially inward is provided on the inner wall of the lower cylinder 2, and the first boss 21 is located below the first limit block 51 and abuts against the first limit block 51. In this way, the first boss 21 can receive the first limit block 51. Thus, the first limit block 51 can be further stably arranged in the lower cylinder 2.

[0035] In one embodiment, Figure 1 As shown, a second boss 22 extending radially inward is also provided on the inner wall of the lower cylinder 2, and the second boss 22 is located below the first boss 21. In addition, the second boss 22 is configured to be able to abut against the fixing portion 41, so as to limit the downward movement of the fixing portion 41. Thus, the downward movement of the ball seat body 4 is limited. In this embodiment, the diameter formed by the second boss 22 is equivalent to the diameter formed by the fixing portion 41. In this way, the second boss 22 can limit the downward movement of the ball seat body 4.

[0036] Meanwhile, the second boss 22 and the fixing portion 41 are configured such that when the second boss 22 and the fixing portion 41 abut against each other, the abutting portion 43 is located in the receiving groove 11 , thereby enabling the blocking ball to move along the passage 44 formed by the ball seat body 4 .

[0037] In this arrangement, when in use, first, a first stopper 51 is arranged in the lower cylinder 2, and the first stopper 51 is abutted against the first boss 21. At the same time, a second stopper 52 is arranged radially inwardly of the first boss 21, and the first stopper 51 and the second stopper 52 are connected to each other by a shear pin 53.

[0038] Secondly, the lower cylinder 2 and the upper cylinder 1 are connected to each other so that the lower cylinder 2 and the upper cylinder 1 are connected to each other, thereby forming a fluid movement channel 3. At the same time, the ball seat body 4 is arranged in the channel 3, and the fixing portion 41 and the first limit block 51 are abutted against each other, thereby limiting the downward movement of the ball seat body 4. In addition, the abutting portion 43 and the inner wall of the upper cylinder 1 are abutted against each other.

[0039] In this process, the deformable portion 42 can be forced to elastically deform radially inward. Specifically, the deformable portion 42 is caused to contract radially inward. Thus, the assembly of the ball seat 100 is completed, and the fluid can move along the passage 44 on the ball seat body 4 and the channel 3.

[0040] When sealing is required, a sealing ball is put in and moves along the channel 3. As the sealing ball continues to move downward, the sealing ball will abut against the free end of the ball seat body 4. At the same time, pressure is continuously applied to the sealing ball until the shear pin 53 is sheared off.

[0041] At this time, the second limit block 52 will be separated from the first limit block 51, and the second limit block 52 will move downward under the action of gravity. In this process, the second limit block 52 will cancel the limit on the ball seat body 4, so that the ball seat body 4 moves downward until the fixing portion 41 and the second boss 22 abut against each other.

[0042] As the ball seat body 4 continues to move downward, when the abutment portion 43 corresponds to the receiving groove 11, the deformation portion 42 will restore the elastic deformation, so that the abutment portion 43 is located in the receiving groove 11. In this process, the diameter formed by the free end of the ball seat body 4 will be equivalent to the blocking ball. As a result, the blocking ball can move downward along the passage 44 formed by the ball seat body 4. In this way, the sealing work is completed, and the ball seat body 4 and the upper cylinder 1 are mutually engaged, which prevents the ball seat body 4 from falling downward, affecting the later well repair operation and causing obstruction of the well passage.

[0043] In one embodiment, the blocking ball is made of any material that can be dissolved in formation water. In this embodiment, the blocking ball is made of an aluminum-magnesium alloy matrix plus an acid-resistant coating. It should be noted that it is well known to those skilled in the art that the aluminum-magnesium alloy matrix plus the acid-resistant coating material can be completely dissolved in formation water, and will not be repeated here.

[0044] In one embodiment, Figure 1 As shown, the upper cylinder 1 includes an outer cylinder 12, and a connecting portion 13 formed by being recessed radially inwardly along the outer cylinder 12, and the connecting portion 13 is sleeved in the lower cylinder 2. In this way, a first abutment platform 121 is formed radially inwardly on the outer cylinder 12, and the first abutment platform 121 is used to face the end of the lower cylinder 2. In this way, the upper cylinder 1 can be inserted into the lower cylinder 2 to form an integrated structure. As a result, the radial movement of the upper cylinder 1 and the lower cylinder 2 can be mutually restricted.

[0045] According to a preferred embodiment of the present invention, Figure 1 As shown, a stopper 14 is provided between the first abutment platform 121 and the end surface of the lower cylinder 2. The stopper 14 is configured as any structure capable of connecting the upper cylinder (1) and the lower cylinder (2) into one body. In this embodiment, the stopper 14 is configured as a stopper pin. In this way, the relative movement between the upper cylinder 1 and the lower cylinder 2 in the axial direction can be limited.

[0046] In one embodiment, Figure 1 As shown, the connecting portion 13 includes an engagement member 131 and a stopper 132 formed by being recessed radially inward along the engagement member 131. In this way, a second abutment platform 133 is formed between the engagement member 131 and the stopper 132. At the same time, a step (not shown) recessed radially outward is formed on the inner wall of the lower cylinder 2, and the second abutment platform 133 is used to abut against the step, thereby further limiting the relative movement between the upper cylinder 1 and the lower cylinder 2.

[0047] In addition, the stopper 132 is configured to have a diameter equivalent to that of the first stopper 51 and abuts against the first stopper 51. In this way, the first stopper 51 can be further stably arranged in the lower cylinder 2.

[0048] According to a preferred embodiment of the utility model, an external thread (not shown in the figure) is arranged around the engagement member 131. At the same time, an internal thread (not shown in the figure) matching the external thread is arranged around the inner wall of the lower cylinder 2. In this way, the upper cylinder 1 and the lower cylinder 2 can be meshed with each other through the thread. Thus, the upper cylinder 1 and the lower cylinder 2 can be further stably connected.

[0049] According to a preferred embodiment of the present invention, Figure 1 As shown, at least one sealing groove (not shown in the figure) is provided on the limiting member 132, and a sealing ring 6 is provided in the sealing groove. The sealing ring is used to abut against the outer tube 2, so that a sealed connection is formed between the outer tube 2 and the limiting member 132, thereby increasing the airtightness of the device 100.

[0050] According to a preferred embodiment of the present invention, Figure 1 As shown, at least one sealing groove (not shown) is provided on the inner wall of the upper cylinder 1, and a sealing ring 6 is provided in the sealing groove. At least one sealing ring 6 is provided between the abutting portion 43 and the upper cylinder 1, so that a sealed connection is formed between the upper cylinder 1 and the abutting portion 43. Thus, the airtightness of the device 100 is increased.

[0051] The operation of the ball seat 100 according to the present invention is as follows.

[0052] First, a first stopper 51 is arranged in the lower cylinder 2, and the first stopper 51 is in contact with the first boss 21. At the same time, a second stopper 52 is arranged radially inwardly of the first boss 21, and the first stopper 51 and the second stopper 52 are connected to each other by a shear pin 53.

[0053] Secondly, the upper cylinder 1 is screwed into the lower cylinder 2, so that the meshing portion 131 and the lower cylinder 2 are meshed together by threads. At the same time, a stopper 14 is provided on the first abutment platform 121, and the stopper 14 and the end surface of the lower cylinder 2 are abutted against each other. In this process, the second abutment platform 133 will abut against the step on the inner wall of the lower cylinder 2, and the stopper 132 and the first stopper 51 will abut against each other. In this way, the upper cylinder 1 and the lower cylinder 2 are connected into an integral structure, and together form a channel 3.

[0054] Then, the ball seat body 4 is arranged in the passage 3, and the fixing portion 41 is in contact with the first limiting block 51, so as to limit the downward movement of the ball seat body 4. Furthermore, the contact portion 43 is in contact with the inner wall of the upper cylinder 1.

[0055] During this process, the abutment portion 43 can force the deformation portion 42 to elastically deform radially inward. Specifically, the deformation portion 42 is contracted radially inward. Thus, the assembly of the ball seat 100 is completed, and the fluid can move along the passage 44 on the ball seat body 4 and the channel 3.

[0056] When sealing is required, a sealing ball (not shown in the figure) is put in and moves along the channel 3. As the sealing ball continues to move downward, the sealing ball will abut against the free end of the ball seat body 4. At the same time, a downward force is continuously applied to the sealing ball until the shear pin 53 is sheared off.

[0057] At this time, the second limit block 52 will be separated from the first limit block 51, and the second limit block 52 will move downward under the action of gravity. In this process, the second limit block 52 will cancel the limit on the ball seat body 4, so that the ball seat body 4 moves downward until the fixing portion 41 and the second boss 22 abut against each other.

[0058] As the ball seat body 4 continues to move downward, when the abutment portion 43 corresponds to the receiving groove 11, the deformation portion 42 will restore the elastic deformation, so that the abutment portion 43 is located in the receiving groove 11. In this process, the diameter formed by the free end of the ball seat body 4 will be equivalent to the blocking ball. As a result, the blocking ball can move downward along the passage 44 formed by the ball seat body 4 into the formation water and dissolve in the formation water. In this way, the sealing work is completed, and the ball seat body 4 and the upper cylinder 1 are mutually engaged, which prevents the ball seat body 4 from falling downward, affecting the later well repair operation and causing obstruction of the well passage.

[0059] It is understood that the present invention is described by some embodiments, and those skilled in the art are aware that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A ball seat, characterized in that: The invention comprises an upper cylinder (1) and a lower cylinder (2) which jointly define a central fluid channel (3), and a ball seat body (4) arranged in the channel (3), wherein the ball seat body (4) is configured to be able to sealably abut against a blocking ball. The lower cylinder (2) is provided with a limiting mechanism (5) for selectively limiting the position of the ball seat body (4), and the upper cylinder (1) is provided with a receiving groove (11) for selectively forming a snap connection with the ball seat body (4). The ball seat body (4) is configured to be able to disengage from the limiting mechanism (5) under the action of pressure, and to move axially downward and radially outward to snap connection with the receiving groove (11), thereby releasing the sealed contact with the blocking ball.

2. The ball seat according to claim 1, characterized in that: The ball seat body (4) comprises an elastic deformation portion (42), and an abutment portion (43) arranged at the upper end of the elastic deformation portion (42) and extending radially outward to abut against the inner wall of the upper cylinder (1), wherein the elastic deformation portion (42) is configured to expand radially outward when the ball seat body (4) moves downward, so that the abutment portion (43) enters the accommodating groove (11) to form a snap connection.

3. The ball seat according to claim 2, characterized in that: The upper end surface of the abutment portion (43) is arranged as a plane perpendicular to the axis of the deformation portion (42), the accommodating groove (11) is configured to be recessed radially outward along the inner wall of the upper cylinder (1), and the upper end surface of the accommodating groove (11) is arranged as a plane that fits the abutment portion (43), so as to limit the upward movement of the ball seat body (4).

4. The ball seat according to any one of claims 1 to 3, characterized in that The limiting mechanism (5) comprises a first limiting block (51) arranged on the inner wall of the lower cylinder (2), and a second limiting block (52) located radially inward of the first limiting block (51), wherein the first limiting block (51) and the second limiting block (52) are connected to each other via a shear pin (53), and the shear pin (53) is configured to be sheared under the action of the pressure to allow the second limiting block (52) to move downward.

5. The ball seat according to claim 4, characterized in that: The ball seat body (4) further comprises a fixing portion (41), wherein the fixing portion (41) is arranged at the lower end of the deformation portion (42) and abuts against the second limiting block (52) in the axial direction.

6. The ball seat according to claim 5, characterized in that: A second boss (22) is provided on the inner wall of the lower cylinder (2) for receiving the ball seat body (4) moving downward, so that when the ball seat body (4) contacts the second boss (22), the abutment portion (43) is located in the receiving groove (11).

7. The ball seat according to claim 6, characterized in that: The upper cylinder (1) comprises an outer cylinder (12) and a connecting portion (13) which is recessed radially inwardly along the outer cylinder (12); a first abutment platform (121) is formed between the connecting portion (13) and the outer cylinder (12); the connecting portion (13) is sleeved in the lower cylinder (2) so that the first abutment platform (121) and the end of the lower cylinder (2) face each other.

8. The ball seat according to claim 7, characterized in that: A stopper (14) is provided between the first abutment platform (121) and the end surface of the lower cylinder (2) for connecting the upper cylinder (1) and the lower cylinder (2) together.

9. The ball seat according to claim 8, characterized in that: A second abutment platform (133) is also provided on the connection portion (13) and is recessed radially inwards. A step recessed radially outwards is formed on the inner wall of the lower cylinder (2) and is used to abut against the second abutment platform (133).

10. The ball seat according to claim 9, characterized in that: The free end of the connecting portion (13) is in contact with the first limiting block (51), and a first boss (21) extending radially inwards is also formed on the inner wall of the lower cylinder (2) for receiving the first limiting block (51).

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