Novel sealing structure of one-way valve in float collar float shoe

Abstract

The utility model relates to the technical field of petroleum downhole tools, in particular to a novel sealing structure of a one-way valve in a float collar float shoe. A core body, a rubber part, a connecting rod and a spring; one end of the connecting rod is connected with the core body, and the other end is connected with the lower valve seat; the spring sleeves the connecting rod; one end of the spring abuts against the core body, and the other end abuts against the lower valve seat. The core body can extend into the upper valve seat; the rubber part is attached to the surface of the core body. In the prior art, although a sealing ball can effectively prevent cement paste from flowing back, a small amount of cement paste can be attached to the surface of the sealing ball under repeated washing of the cement paste, so that the smoothness of the sealing ball is affected, and the sealing effect of a float collar and a float shoe is further affected. Compared with the prior art, a combined structure of the core body and the rubber part is used for sealing. After cement paste is attached to the surface of the rubber part, due to the fact that the rubber part has a certain deformation quantity, the rubber part can still be effectively matched with the core body to be pressed on the upper valve seat, and therefore the sealing effect is maintained.

Description

Technical Field

[0001] The utility model relates to the technical field of petroleum downhole tools, in particular to a sealing structure of a one-way valve in a novel floating collar and a floating shoe. Background Art

[0002] In the cementing operation of an oil well, after cementing, the cement slurry at the bottom of the well will flow back into the casing from bottom to top. This requires the installation of floating collars and floating shoes on the casing to seal the cement slurry and prevent the backflow of cement slurry.

[0003] The core component of the floating collar and floating shoe is the sealing ball, which is an egg-shaped structure with a very smooth surface. Although the sealing ball can effectively seal the cement slurry, in actual conditions, the cement slurry may flow back repeatedly. In this case, the cement slurry will wash the surface of the sealing ball. Even if the sealing ball has a high surface finish, a small amount of cement slurry may adhere to the surface of the sealing ball under repeated washing. This will affect the surface finish of the sealing ball, and then affect the sealing effect of the sealing ball, resulting in the floating collar and floating shoe being unable to effectively prevent the cement slurry from flowing back. Utility Model Content

[0004] In view of the technical problems of the prior art, the utility model provides a novel sealing structure of a one-way valve in a floating hoop and a floating shoe.

[0005] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0006] A new sealing structure of a one-way valve in a floating hoop and a floating shoe comprises: a core body, a rubber part, a connecting rod and a spring; one end of the connecting rod is connected to the core body, and the other end is connected to a lower valve seat; the spring is sleeved on the connecting rod; one end of the spring abuts against the core body, and the other end abuts against the lower valve seat; the core body can extend into the upper valve seat; and the rubber part is attached to the surface of the core body.

[0007] In actual application, the connecting rod and the spring push the core into the upper valve seat to complete the sealing. As the cement slurry is repeatedly flushed, a small amount of cement slurry will adhere to the rubber part. At this time, the attached cement slurry will become the surface protrusion of the rubber part. Because the rubber part has a certain deformation amount, the rubber part can be deformed equally, so that the combined structure of the core and the rubber part can still be tightly extended into the upper valve seat, thereby maintaining the sealing effect.

[0008] Furthermore, the core body includes an end cap and a guide portion; the end cap is arranged at one end of the guide portion; the end cap is connected to the guide portion; the guide portion is connected to the connecting rod; and an inclined surface corresponding to the upper valve seat is arranged on the guide portion.

[0009] Furthermore, a reinforcing portion is provided at one end of the guide portion away from the end head; the reinforcing portion is connected to the guide portion; the connecting rod passes through the reinforcing portion and is screwed into the guide portion; and one end of the spring away from the lower valve seat abuts against the reinforcing portion.

[0010] Furthermore, an extension wing is provided on the rubber part; the extension wing is in contact with the inner wall of the upper valve seat; and the extension wing protrudes from the surface of the core body. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 : Overall structure diagram.

[0012] Figure 2 : Partial enlarged view of the core.

[0013] In the figure: 1, core; 11, end; 12, guide part; 121, reinforcement part; 2, rubber part; 21, extension wing; 3, connecting rod; 4, spring. DETAILED DESCRIPTION

[0014] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0015] A sealing structure of a one-way valve in a new type of floating collar and floating shoe comprises: a core body 1, a rubber part 2, a connecting rod 3, and a spring 4. The core body 1 comprises an end 11 and a guide part 12. The end 11 is an approximately spherical structure. The diameter of the end 11 corresponds to the inner diameter of the upper valve seat. Thus, the end 11 can extend into the upper valve seat. At the same time, the end 11 is connected to the guide part 12. The guide part 12 is a conical structure, and an inclined slope corresponding to the inner wall of the upper valve seat is provided on the guide part 12, so that when the end 11 extends into the upper valve seat, the guide part 12 can correspond to the inner wall of the upper valve seat. A reinforcing part 121 is also provided at one end of the guide part 12 away from the end 11. The reinforcing part 121 is a cylindrical structure protruding from the surface of the guide part 12. The connecting rod 3 passes through the reinforcing part 121 and is screwed into the guide part 12. In this way, the connecting rod 3 is threadedly connected to the guide part 12. At the same time, the connection between the connecting rod 3 and the guide part 12 is strengthened by the reinforcing part 121, so that the connection between the two is more stable. The spring 4 is sleeved on the connecting rod 3. One end of the spring 4 abuts against the lower valve seat, and the other end abuts against the reinforcing part 121. Thus, the elastic force of the spring 4 cooperates with the connecting rod 3 to push the core 1 into the upper valve seat.

[0016] The rubber part 2 is attached to the surface of the core 1. The rubber part 2 is provided with an extension wing 21. The extension wing 21 is in an inclined state corresponding to the inner wall of the upper valve seat, so that it can fit with the inner wall of the upper valve seat. The extension wing 21 extends from the guide part 12 in a direction away from the end head 11, so as to protrude from the surface of the core 1.

[0017] It is worth noting that the upper valve seat and the lower valve seat are the inherent structures of the floating collar and the floating shoe. The upper valve seat and the lower valve seat will not be described here.

[0018] In actual application, it is necessary to perform a water test according to actual index requirements. The extension wing 21 can effectively facilitate the water test. At the same time, the extension wing 21 increases the surface area of ​​the rubber part 2, thereby further assisting the rubber part 2 in sealing.

[0019] After the structure of the utility model is actually assembled. Under the elastic force of the spring 4, the core 1 and the rubber part 2 are pressed into the upper valve seat. Under the extrusion of the elastic force of the spring 4, the rubber part 2 will deform to a certain extent, so that the core 1 and the inner wall of the upper valve seat are fully fitted together to complete the sealing. When the cement slurry flows back, the cement slurry will wash the rubber part 2, thereby applying a certain thrust to the rubber part 2, which may cause the combined structure of the rubber part 2 and the core 1 to be slightly displaced compared to the upper valve seat, thereby compressing the spring 4. When the backflow stops and the thrust applied to the rubber part 2 disappears, the accumulated elastic force of the spring 4 will be released, thereby pushing the core 1 toward the upper valve seat again. Because the shape of the guide part 12 matches the inner wall of the upper valve seat, the guide part 12 will guide the core 1 during this process to avoid a large offset in the relative position between the core 1 and the upper valve seat, thereby maintaining the sealing effect.

[0020] After the cement slurry washes the rubber part 2 many times, a small amount of cement slurry will adhere to the rubber part 2, thus forming a protrusion adhered to the rubber part 2. Because the rubber part 2 has a certain deformation ability, when the spring 4 presses the core 1 into the upper valve seat again, the rubber part 2 will be deformed accordingly under the pressure of the inner wall of the upper valve seat. Therefore, the combined structure of the rubber part 2 and the core 1 can still fit tightly with the upper valve seat, thereby maintaining the sealing effect. The specific deformation is shown in the attached figure.

[0021] It is worth noting that the material of the core 1 can be the same as that of the sealing ball, so as to provide sufficient support for the rubber part 2, thereby enabling the entire structure to bear a greater pressure.

[0022] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A new sealing structure of a one-way valve in a floating collar and a floating shoe, characterized in that: include: Core (1), rubber part (2), connecting rod (3), spring (4); One end of the connecting rod (3) is connected to the core (1), and the other end is connected to the lower valve seat; The spring (4) is sleeved on the connecting rod (3); One end of the spring (4) abuts against the core (1), and the other end abuts against the lower valve seat; The core (1) can extend into the upper valve seat; The rubber part (2) is attached to the surface of the core (1).

2. According to the new sealing structure of the one-way valve in the floating collar and floating shoe of claim 1, it is characterized by: The core (1) comprises an end (11) and a guide portion (12); The end head (11) is arranged at one end of the guide portion (12); The end head (11) is connected to the guide portion (12); The guide portion (12) is connected to the connecting rod (3); The guide portion (12) is provided with an inclined surface corresponding to the upper valve seat.

3. According to the new sealing structure of the check valve in the floating collar and floating shoe of claim 2, it is characterized by: A reinforcing portion (121) is provided at one end of the guide portion (12) away from the end head (11); The reinforcing portion (121) is connected to the guiding portion (12); The connecting rod (3) passes through the reinforcing portion (121) and is screwed into the guiding portion (12); One end of the spring (4) away from the lower valve seat abuts against the reinforcing portion (121).

4. According to the new sealing structure of the check valve in the floating collar and floating shoe of claim 1, it is characterized by: The rubber portion (2) is provided with an extension wing (21); The extension wing (21) is in contact with the inner wall of the upper valve seat; The extension wings (21) protrude from the surface of the core (1).

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