A float collar float shoe for cementing and method of use

Abstract

The application relates to the field of float collar float shoe, in particular to a float collar float shoe for well cementing and a use method. In actual well cementing operation, the cement slurry often contains solid particles and additives, which are easy to accumulate on the upper surface of the valve ball to form cement deposits. With repeated use or time elapses, these hardened residues may cause the valve ball and the sealing ring to not completely fit, resulting in a small gap, thereby causing sealing failure and cement slurry leakage risk, seriously affecting the well cementing quality and wellbore integrity. After the cement slurry impacts the valve core, residues may be left on the surface of the valve core, causing a gap between the valve core and the sealing part. The rotating movement of the valve core generates a shearing force between the surface of the valve core and the stationary sealing part, which can effectively scrape off or shear off the residues. Rotation also ensures that the entire contact surface of the valve core can be scraped with the sealing part, avoiding cement slurry leakage caused by local gaps.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of float collar float shoe, in particular to a float collar float shoe for well cementing and a use method thereof. BACKGROUND

[0002] Well cementing refers to the process of injecting cement slurry around the casing of an oil well after drilling to seal the wellbore and consolidate the formation, protect the wellbore, stabilize the formation, prevent oil and gas from permeating from the formation to the wellhead, and ensure the safety of oil production. It is an important process in oil and gas exploration and development. During well cementing, various tools and equipment such as cement pumps, casings, float collars, and float shoes are commonly used to ensure that the cement slurry can effectively fill the wellbore space and form a strong cement sheath. The quality of well cementing directly affects the safety, stability, and production efficiency of the oil well, and therefore is an indispensable part of oil and gas exploration and development. The float collar float shoe is a commonly used tool in well cementing operations, which is used to ensure that the valve ball is in the correct position and protect it from the impact of cement slurry when cement slurry is injected into the wellbore.

[0003] As a key component in well cementing operations, the float collar float shoe is mainly used to guide the flow of cement slurry during cementing and prevent backflow, and to achieve sealing function through the built-in valve ball structure. In the prior art, the commonly used float collar float shoe adopts a spherical valve structure, and its sealing mechanism relies on the contact sealing between the valve ball and the seat ring. However, in actual well cementing operations, the cement slurry often contains solid particles and additives, which are easy to accumulate on the surface of the valve ball to form cement deposits. With repeated use or over time, these hardened residues may cause the valve ball and the sealing ring to not fully match, resulting in a small gap and causing sealing failure and cement slurry leakage risk, which seriously affects the quality of well cementing and the integrity of the wellbore. SUMMARY

[0004] The present application aims to provide a float collar float shoe for well cementing and a use method thereof to solve the problems raised in the background art. To achieve the above-mentioned purpose, the present application provides the following technical solution: a float collar float shoe for well cementing, comprising a shell, a grouting port is formed in the top of the shell along its axial direction, a sealing part is arranged at the inner top of the shell at the grouting port, a sealing plate is connected to the inner bottom of the shell, and a drainage hole for the flow of cement slurry is formed in the sealing plate, an upper valve core part is arranged vertically on the top of the sealing plate towards the direction of the grouting port, which can remove the cement slurry attached to its surface when the upper valve core part contacts the sealing part, thereby improving the sealing performance, and a lower valve core part is arranged on the sealing plate for sealing the drainage hole, the upper valve core part and the lower valve core part act synchronously to achieve the sealing of the shell, and the sealing reliability of the entire device is improved.

[0005] Preferably, the upper valve core part comprises a fixed cylinder arranged perpendicularly to the sealing plate, a support rod is slidably connected to the fixed cylinder in the direction of the grouting port, the fixed cylinder is in a hollow structure, a return spring is arranged inside the fixed cylinder, the end of the support rod extending into the fixed cylinder is connected with the return spring, a support frame is fixedly connected to the outer wall of the support rod, the support frame is arranged in a conical shape, three universal connecting rods are arranged at the top of the support frame, each universal connecting rod is arranged obliquely along the circumferential direction of the support frame and is consistent with the slope of the support frame, the upper valve plate is connected to the end of the universal connecting rod away from the support frame, the universal connecting rods provide support for the upper valve plate in a triangular distribution manner, a compression spring is arranged between the bottom of the upper valve plate and the top of the support rod, and a valve core is arranged at the top of the upper valve plate and used to abut against the sealing part at the grouting port to achieve sealing and prevent the cement slurry from flowing into the housing.

[0006] Preferably, the two ends of the universal connecting rod are provided with spherical bodies, the spherical bodies are respectively embedded in the support frame and the upper valve plate, and the top of the upper valve plate is fixedly connected with an annular sleeve disc, a plurality of protrusions are arranged on the inner wall of the sleeve disc along the circumferential direction thereof, and the protrusions can remove the attachments on the outer wall of the valve core when contacting the sealing part.

[0007] Preferably, the sealing part comprises a mounting frame arranged at the grouting port at the top of the housing, and a sealing lip is mounted on the mounting frame, a plurality of elastic balls are arranged on the sealing lip along the circumferential direction below the lip opening.

[0008] Preferably, the sealing part comprises a mounting frame, a sealing ring is mounted on the mounting frame, a cutoff plate is slidably connected to the outer side of the sealing ring at the inner top of the mounting frame, the cutoff plate is provided with an arc-shaped end matched with the arc surface of the valve core, and the arc-shaped end is made of elastic silicone rubber or polyurethane material.

[0009] Preferably, a wedge-shaped block is arranged on the inner wall of the mounting frame perpendicularly to the cutoff plate, the wedge-shaped block is connected to the mounting frame in an extension and retraction mode through a connecting spring, the wedge-shaped surface of the wedge-shaped block is wedge-shaped matched with the cutoff plate, the cutoff plate can be moved along the radial direction towards the valve core, the protrusions arranged on the inner wall of the sleeve disc intermittently contact the wedge-shaped block to drive the wedge-shaped block to move in an extension and retraction mode.

[0010] Preferably, each drainage hole is provided with a lower valve core part, the lower valve core part comprises a first connecting rod hinged to the outer wall of the support rod, a sealing disc is slidably connected to the sealing plate, the sealing disc is hinged to the end of the first connecting rod away from the support rod, and a second connecting rod is further hinged to the fixed cylinder and hingedly connected with the first connecting rod to form a cross connecting rod support mechanism.

[0011] Preferably, the method for using the float collar float shoe for well cementing comprises the following steps:

[0012] S1: After the grouting is completed, the reset spring pushes the support rod to move up, drives the upper valve plate and the valve core to move towards the sealing part through the support frame and the universal connecting rod, and preliminary sealing of the grouting port is realized;

[0013] S2: The support rod continues to move up to compress the compression spring, and the inclined arrangement of the universal connecting rod causes the upper valve plate to rotate, thereby driving the valve core to rotate and contact the sealing lip to remove the surface attachments;

[0014] S3: When the upper valve plate rotates, the convex on the outer sleeve disc contacts the elastic ball on the outer wall of the sealing lip, causing the sealing lip to vibrate, forming dynamic sealing and preventing pollutants from being retained.

[0015] Compared with the prior art, the beneficial effects of the present application are:

[0016] In the present application, after the cement slurry impacts the valve core, attachments may remain on the surface of the valve core, causing a gap between the valve core and the sealing part. The rotational movement of the valve core generates a shear force between the surface of the valve core and the stationary sealing part, which can effectively scrape off or shear off the attachments. Rotation also ensures that the entire contact surface of the valve core can be scraped with the sealing part, avoiding cement slurry leakage caused by local gaps.

[0017] In the present application, when the valve core rotates, the vibration caused by the elastic ball breaks the cement slurry sticking formed by static friction, avoiding the distortion or wear of the sealing lip caused by excessive opening and closing torque. The vibration also prevents pollutants from always staying in the same position to grind the sealing lip, making the wear more uniform and avoiding the formation of local deep grooves, thereby prolonging the service life of the sealing lip.

[0018] In the present application, when the valve core contacts and seals the grouting port with the sealing lip, the lip of the sealing lip is in close contact with the outer wall of the valve core, forming a linear seal. The elastic ball is in point contact with the outer wall of the valve core, constituting a secondary seal, enhancing the sealing reliability. If small particles in the cement slurry cause a small leakage below the sealing lip, the auxiliary sealing point of the elastic ball can also block it, further improving the sealing performance of the grouting port.

[0019] In the present application, when the valve core and the sealing ring are sealed, the outer sleeve disc stops rotating, the wedge-shaped block remains stationary under the action of the connecting spring, and the arc end of the cutting plate abuts against the sealing ring, rigidly limiting the valve core. Through the rigid bearing and self-locking action of the cutting plate, the impact resistance of the sealing structure is significantly enhanced, completely preventing leakage. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a cross-sectional view of the shell of the present application Figure One ;

[0021] Figure 2 is a cross-sectional view of the shell of the present application Figure Two ;

[0022] Figure 3The upper valve core part, the sealing part and the lower valve core part in the present application are shown in the plan view;

[0023] Figure 4 The upper valve core part and the sealing part in the present application are shown in the exploded view;

[0024] Figure 5 The upper valve core part in the present application is shown in the perspective view of the universal connecting rod driving the upper valve plate to rotate;

[0025] Figure 6 The sealing part and the outer sleeve ring in the present application are shown in the perspective view;

[0026] Figure 7 The sealing part and the outer sleeve ring in the present application are shown in the plan view;

[0027] Figure 8 The sealing part and the outer sleeve ring in the second embodiment of the present application are shown in the plan view;

[0028] Figure 9 The lower valve core part in the present application is shown in the perspective view.

[0029] In the figure: 1, the shell; 11, the grouting port; 12, the drainage hole; 13, the sealing plate; 2, the upper valve core part; 21, the fixed cylinder; 22, the support rod; 23, the reset spring; 24, the support frame; 25, the universal connecting rod; 26, the upper valve plate; 27, the compression spring; 28, the valve core; 29, the ball; 210, the outer sleeve disc; 211, the protrusion; 3, the sealing part; 31, the mounting frame; 32, the sealing lip; 321, the elastic ball; 33, the sealing ring; 331, the cutting plate; 332, the arc end; 333, the wedge block; 4, the lower valve core part; 41, the first connecting rod; 42, the plugging disc; 43, the second connecting rod. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0031] Embodiment 1:

[0032] Please refer to Figures 1 to 9The application provides a floating collar floating shoe for well cementing, which comprises a shell 1, a grouting opening 11 is formed in the top of the shell 1 along the axial direction thereof, a sealing part 3 is arranged at the inner top of the shell 1 at the grouting opening 11, a sealing plate 13 is connected to the inner bottom of the shell 1, a drainage hole 12 for the flow of cement slurry is formed in the sealing plate 13, an upper valve core part 2 is arranged on the top of the sealing plate 13 and vertically faces the direction of the grouting opening 11, the upper valve core part 2 can remove the cement slurry adhered to the surface thereof when being in contact with the sealing part 3, so that the sealing performance is improved, a lower valve core part 4 for sealing the drainage hole 12 is further arranged on the sealing plate 13, the upper valve core part 2 and the lower valve core part 4 synchronously act to realize the sealing of the shell 1, and the sealing reliability of the whole device is improved.

[0033] In the embodiment, the upper valve core part 2 comprises a fixed cylinder 21 which is arranged perpendicularly to the sealing plate 13, a support rod 22 is slidably connected to the fixed cylinder 21 and faces the direction of the grouting opening 11, the fixed cylinder 21 is in a hollow structure, a reset spring 23 is arranged in the fixed cylinder 21, the reset spring 23 is connected to the end of the support rod 22 which extends into the fixed cylinder 21, a support frame 24 is fixedly connected to the outer wall of the support rod 22, the support frame 24 is arranged in a conical shape, three universal connecting rods 25 are arranged on the top of the support frame 24, the universal connecting rods 25 are arranged in an inclined manner along the circumferential direction of the support frame 24 and are consistent with the slope of the support frame 24, an upper valve plate 26 is connected to the end of the universal connecting rod 25 which is away from the support frame 24, the universal connecting rods 25 provide support for the upper valve plate 26 in a triangular distribution manner, a compression spring 27 is arranged between the bottom of the upper valve plate 26 and the top of the support rod 22, a valve core 28 is arranged on the top of the upper valve plate 26, and the valve core 28 is used for abutting against the sealing part 3 at the grouting opening 11 to realize sealing and prevent the cement slurry from flowing into the shell 1;

[0034] The universal connecting rod 25 is provided with a ball 29 at both ends, the ball 29 is embedded in the support frame 24 and the upper valve plate 26 respectively, and the top of the upper valve plate 26 is fixedly connected with an annular sleeve disc 210, a plurality of protrusions 211 are arranged on the inner wall of the sleeve disc 210 along the circumferential direction thereof, and the protrusions 211 can remove the adherents on the outer wall of the valve core 28 when being in contact with the sealing part 3;

[0035] In the non-grouting state, the reset spring 23 pushes the support rod 22 to move axially towards the direction of the grouting opening 11, the support frame 24 moves upwards synchronously with the support rod 22, the upper valve plate 26 and the valve core 28 on the top of the upper valve plate 26 are driven to move towards the sealing part 3, and finally the sealing of the grouting opening 11 is realized through the close contact between the valve core 28 and the sealing part 3;

[0036] The support rod 22 pushes the support frame 24 to move up under the action of the return spring 23, the support frame 24 drives the upper valve plate 26 to move up through the compression spring 27 and the three sets of universal connecting rods 25, the outer sleeve disc 210 arranged on the upper valve plate 26 abuts against the inner top of the shell 1 and surrounds the sealing part 3 outside, in this process, due to the limiting action of the outer sleeve disc 210, the support rod 22 continues to move up to compress the compression spring 27, at the same time, because the universal connecting rod 25 is arranged in an inclined manner, when the upper valve plate 26 and the support frame 24 are relatively displaced, the upper valve plate 26 will generate a circular motion to drive the valve core 28 to rotate, so that the rotation contact between the valve core 28 and the sealing part 3 is generated, thereby removing the pollutants attached to the outer wall of the valve core 28;

[0037] After the cement slurry impacts the valve core 28, the surface of the valve core 28 may have residual attachments, which causes a gap between the valve core 28 and the sealing part 3, the rotational motion of the valve core 28 generates a shearing force between the surface of the valve core 28 and the stationary sealing part 3, which can effectively scrape or shear the attachments, and the rotation ensures that the entire contact surface of the valve core 28 can be scraped with the sealing part 3, avoiding the leakage of the cement slurry due to the local gap.

[0038] In the embodiment, the sealing part 3 includes a mounting frame 31 arranged at the grouting port 11 of the inner top of the shell 1, the mounting frame 31 is provided with a sealing lip 32, and a plurality of elastic balls 321 are arranged below the lip of the sealing lip 32 along the circumference of the sealing lip 32, the elastic balls 321 are integrally formed with the sealing lip 32 and can be made of elastic silicone rubber or polyurethane material;

[0039] When the valve core 28 extends into the inside of the sealing lip 32, the rotational motion of the valve core 28 contacts the inner side of the sealing lip 32 to remove the surface attachments, at the same time, the rotation of the upper valve plate 26 drives the protrusions 211 on the outer sleeve disc 210 to contact the elastic balls 321 on the outer wall of the sealing lip 32 to cause the sealing lip 32 to vibrate;

[0040] When the valve core 28 rotates, the vibration caused by the elastic balls 321 breaks the cement slurry stickiness formed by static friction, avoids the distortion or wear of the sealing lip 32 due to the excessive opening and closing torque, and prevents the pollutant particles from always staying at the same position to grind the sealing lip 32, so that the wear is more uniform, avoids the generation of a local deep groove, thereby prolonging the service life of the sealing lip 32;

[0041] When the valve core 28 contacts and seals the grouting port 11 with the sealing lip 32, the lip edge of the sealing lip 32 tightly abuts against the outer wall of the valve core 28 to form a linear seal, and the elastic balls 321 point contact with the outer wall of the valve core 28 to constitute a secondary seal, thereby enhancing the sealing reliability, if the small particles in the cement slurry cause a small leakage below the sealing lip 32, the auxiliary sealing points of the elastic balls 321 can also block the small leakage, further improving the sealing performance of the grouting port 11.

[0042] In the embodiment, each drainage hole 12 is provided with a lower valve core part 4, the lower valve core part 4 comprises a first connecting rod 41 hinged to the outer wall of the support rod 22, the sealing plate 13 is slidably connected with a blocking disc 42, the blocking disc 42 is hinged to the end of the first connecting rod 41 away from the support rod 22, the fixed cylinder 21 is further hinged with a second connecting rod 43, the second connecting rod 43 is hinged to the first connecting rod 41, forming a cross connecting rod support mechanism;

[0043] When grouting, the cement slurry at the grouting port 11 impacts the valve core 28, pushes the support rod 22 to move downward, and makes the cement slurry flow into the casing 1, when the support rod 22 moves downward, the first connecting rod 41 moves, and in turn pushes the blocking disc 42 to move, opens the blocked drainage hole 12, and the cement slurry flows into the well through the drainage hole 12, after the grouting is completed, the pressure of the cement slurry on the upper valve core part 2 disappears, the reset spring 23 pushes the support rod 22 to reset, the upper valve core part 2 recontacts with the sealing part 3 to realize sealing, and at the same time, the blocking disc 42 seals the drainage hole 12, and the bidirectional sealing mechanism further prevents the cement slurry from leaking.

[0044] Embodiment 2:

[0045] In order to further improve the sealing performance of the valve core 28 and the sealing part 3 in the static state, the embodiment one is improved as follows: Figure 8

[0046] In the embodiment, the sealing part 3 comprises a mounting frame 31, the mounting frame 31 is provided with a sealing ring 33, the inner top of the mounting frame 31 is slidably connected with a cutting plate 331 outside the sealing ring 33, the cutting plate 331 is provided with an arc-shaped end 332 matched with the arc surface of the valve core 28, and the arc-shaped end 332 is made of elastic silicone rubber or polyurethane material;

[0047] The mounting frame 31 is provided with a wedge-shaped block 333 on the inner wall perpendicular to the cutting plate 331, the wedge-shaped block 333 is connected with the mounting frame 31 through a connecting spring, the wedge-shaped surface of the wedge-shaped block 333 is matched with the cutting plate 331, and the wedge-shaped block 333 can push the cutting plate 331 to move radially towards the valve core 28, the protrusion 211 provided on the inner wall of the sleeve disc 210 intermittently contacts the wedge-shaped block 333, and drives the wedge-shaped block 333 to move in and out;

[0048] When the sleeve disc 210 rotates, the protrusion 211 intermittently extrudes the wedge-shaped block 333, the wedge-shaped block 333 moves in and out and pushes the cutting plate 331 to move radially, and the arc-shaped end 332 of the cutting plate 331 abuts against the outer wall of the sealing ring 33, and the adhering matters on the surface of the valve core 28 are removed;

[0049] ​When the valve core 28 and the sealing ring 33 are sealed, the sleeve disc 210 stops rotating, the wedge block 333 keeps static under the action of the connecting spring, the arc end 332 of the cutting plate 331 abuts against the sealing ring 33, and the valve core 28 is rigidly limited, the impact resistance of the sealing structure is significantly enhanced through the rigid bearing and self-locking action of the cutting plate 331, and leakage is completely prevented.

[0050] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Various changes and improvements can be made to the present application without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A float shoe for cementing, comprising: a shell (1) having a top opening (11) for grouting and a bottom connected with a sealing plate (13) having a flow guide hole (12) formed therein; characterized in that: a sealing part (3) is arranged at the top of the shell (1) and located at the grouting opening (11); an upper valve core part (2) is vertically arranged at the top of the sealing plate (13) and faces the grouting opening (11) for sealing contact with the sealing part (3); the upper valve core part (2) comprises: a fixed cylinder (21) arranged perpendicularly to the sealing plate (13); a support rod (22) slidingly connected in the fixed cylinder (21) and connected with the fixed cylinder (21) by a return spring (23); a support frame (24) connected to the outer wall of the support rod (22); a plurality of universal connecting rods (25) arranged obliquely along the circumferential direction of the support frame (24), and the two ends of each universal connecting rod (25) are rotatably connected with the support frame (24) and an upper valve plate (26) through a ball (29); the upper valve plate (26) is connected with the top of the support rod (22) by a compression spring (27); a valve core (28) is arranged at the top of the upper valve plate (26) for sealing contact with the sealing part (3); an outer sleeve disc (210) is fixedly connected to the top of the upper valve plate (26), and the inner wall of the outer sleeve disc (210) is provided with a protrusion (211); the sealing part (3) comprises: a mounting frame (31) arranged at the top of the shell (1); a sealing lip (32) mounted on the mounting frame (31); a plurality of elastic balls (321) arranged along the circumference below the lip of the sealing lip (32); the valve core (28) is configured to produce a rotary motion when the support rod (22) moves axially, and contact with the inner side of the sealing lip (32) to remove the attached objects; the protrusion (211) on the outer sleeve disc (210) is in contact with the elastic ball (321), causing the sealing lip (32) to vibrate.

2. The float shoe for cementing according to claim 1, characterized in that: the sealing plate (13) is provided with a lower valve core part (4) for sealing the flow guide hole (12); the lower valve core part (4) comprises: a first connecting rod (41) hinged to the outer wall of the support rod (22); a blocking disc (42) slidingly connected to the sealing plate (13) and hinged to the first connecting rod (41); a second connecting rod (43) hinged to the fixed cylinder (21) and hinged to the first connecting rod (41) to form an intersecting connecting rod mechanism.

3. A float collar float shoe for cementing a well according to claim 1, characterized in that: the sealing part (3) further comprises: a sealing ring (33) mounted on the mounting frame (31); a cutting plate (331) connected to the mounting frame (31) and located outside the sealing ring (33); the end of the cutting plate (331) is provided with an arc-shaped end (332) matched with the arc surface of the valve core (28); a wedge-shaped block (333) is arranged perpendicularly to the cutting plate (331) and is connected to the mounting frame (31) in an extension and retraction manner by a connecting spring, and the wedge surface of the wedge-shaped block (333) is wedge-shaped matched with the cutting plate (331); the protrusion (211) on the inner wall of the outer sleeve disc (210) intermittently contacts the wedge-shaped block (333), drives the wedge-shaped block (333) to move in an extension and retraction manner, and pushes the cutting plate (331) to move radially.

4. The float collar float shoe of claim 1, wherein: The upper valve core part (2) and the lower valve core part (4) realize synchronous action through the axial movement of the support rod (22).

5. The float collar float shoe of claim 1, wherein: The number of universal connecting rods (25) is three, which provide support for the upper valve plate (26) in a triangular distribution manner.

6. A method of using a float collar float shoe for cementing, using a float collar float shoe according to any one of claims 1-5, characterized in that, The method comprises the following steps: S1: After grouting is completed, the reset spring (23) pushes the support rod (22) to move upward, drives the upper valve plate (26) and the valve core (28) to move toward the sealing part (3) through the support frame (24) and the universal connecting rod (25), and realizes the preliminary sealing of the grouting port (11); S2: The support rod (22) continuously moves upward to compress the compression spring (27), the inclined arrangement of the universal connecting rod (25) causes the upper valve plate (26) to produce rotary motion, drives the valve core (28) to rotate and contact the sealing lip (32), and removes the surface attachments; S3: When the upper valve plate (26) rotates, the convex (211) on the outer sleeve disc (210) contacts the elastic ball (321) on the outer wall of the sealing lip (32), causes the sealing lip (32) to shake, forms dynamic sealing, and prevents pollutants from being retained.

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