Float collar

Abstract

The float collar comprises a valve cavity with a valve port in the top, a back-pressure valve arranged in the valve cavity and a plurality of baffles arranged along the inner wall of the valve cavity in a circumferential mode, the back-pressure valve is provided with a plug capable of plugging the valve port, and the baffles are arranged below the plug and can abut against the lower surface of the plug through movement. And therefore, a plugging surface is formed with the plug. The float collar can form a blocking face used for blocking reverse flowing water in a valve cavity, the reverse sealing performance of the float collar is enhanced, and the efficiency and safety of well cementation operation are improved.

Description

Technical Field

[0001] The invention relates to the field of oil and gas well cementing tools, and in particular to a floating collar. Background Art

[0002] Floating collar is a downhole tool used in the drilling process of oil and gas wells. It is mainly used to isolate formation fluids, ensure the circulation and control of drilling fluids or completion fluids, prevent formation fluids from invading the wellbore, and ensure operation safety. The extremely high temperature environment in the well, the strong erosion during the circulation of drilling fluids, and the incomplete grouting during the injection of plugging slurry or casing operation will cause the back pressure valve of the floating collar to fail. The fluid in the valve cavity is easy to flow back out of the valve port, and the back pressure valve cannot seal the valve port because it does not have reverse sealing performance, which seriously affects the cementing quality. Summary of the invention

[0003] One object of the present invention is to provide a floating collar to form a sealing surface for blocking backflow water in a valve cavity, enhance the reverse sealing performance of the floating collar, and improve the efficiency and safety of cementing operations.

[0004] According to the present invention, a floating collar is provided, comprising: a valve cavity having a valve port at the top, a back-pressure valve arranged in the valve cavity, and a plurality of baffles arranged in a circumferential form along the inner wall of the valve cavity, wherein the back-pressure valve has a plug capable of blocking the valve port, and the plurality of baffles are arranged below the plug and can be pressed against the lower surface of the plug by movement, thereby forming a blocking surface with the plug.

[0005] In a preferred embodiment, the baffle extends from the inner wall of the valve cavity toward the bottom of the valve cavity along an inclined direction.

[0006] In a preferred embodiment, under the action of the fluid pressure inside the valve cavity, the baffle can extend from the inner wall of the valve cavity toward the top of the valve cavity in an inclined direction and press against the lower surface of the plug.

[0007] In a preferred embodiment, the baffle is connected to the inner wall of the valve cavity via an elastic member.

[0008] In a preferred embodiment, the baffle is hinged to the inner wall of the valve cavity, and the lower surface of the baffle is connected to the first end of the elastic member, and the second end of the elastic member is connected to the inner wall of the valve cavity below the baffle.

[0009] In a preferred embodiment, the elastic member is a spring.

[0010] In a preferred embodiment, the side portions of adjacent baffles abut against each other.

[0011] In a preferred embodiment, eight baffles are arranged in a circumferential form along the inner wall of the valve cavity, and each baffle is disposed below the plug.

[0012] In a preferred embodiment, the floating collar further comprises a shell, the valve cavity is arranged inside the shell, and a fixing sleeve is sleeved on the outer wall of the valve cavity.

[0013] In a preferred embodiment, the return pressure valve is connected to a column on the lower surface of the plug, and a return spring is sleeved on the outer surface of the column.

[0014] The present invention has at least the following technical effects:

[0015] According to the present invention, a valve cavity having a valve port at the top, a back pressure valve disposed in the valve cavity, and a plurality of baffles arranged in a circumferential form along the inner wall of the valve cavity are provided. The back pressure valve has a plug capable of blocking the valve port, and a plurality of baffles are disposed below the plug and can be pressed against the lower surface of the plug by movement, thereby forming a blocking surface for blocking backflow water in the valve cavity with the plug, thereby enhancing the reverse sealing performance of the floating collar and improving the efficiency and safety of cementing operations.

[0016] According to the present invention, the baffle is connected to the inner wall of the valve cavity by an elastic member, and when not affected by the fluid pressure inside the valve cavity, the baffle extends from the inner wall of the valve cavity along the inclined direction toward the bottom of the valve cavity under the action of its own weight, thereby not affecting the flow direction of the fluid flowing from the valve port toward the inside of the valve cavity; under the action of the fluid pressure inside the valve cavity, the baffle can extend from the inner wall of the valve cavity along the inclined direction toward the top of the valve cavity, and press against the lower surface of the plug to prevent the fluid inside the valve cavity from ascending and flowing back from the valve port; in addition, after ensuring that the fluid pressure inside the valve cavity is reduced or the fault is eliminated, the baffle can be reset to a state where it extends from the inner wall of the valve cavity along the inclined direction toward the bottom of the valve cavity under the action of the elastic force of the elastic member.

[0017] According to the present invention, the baffle is hinged to the inner wall of the valve cavity, and the lower surface of the baffle is connected to the first end of the elastic member, and the second end of the elastic member is connected to the inner wall of the valve cavity below the baffle. When not affected by the fluid pressure inside the valve cavity 6, the baffle extends from the inner wall of the valve cavity toward the bottom of the valve cavity in an inclined direction under the action of its own weight and the elastic force of the elastic member, so as not to affect the flow direction of the fluid flowing from the valve port toward the inside of the valve cavity; under the action of the fluid pressure inside the valve cavity, the baffle can extend from the inner wall of the valve cavity toward the top of the valve cavity in an inclined direction, and press against the lower surface of the plug to prevent the fluid inside the valve cavity from ascending and flowing back from the valve port; in addition, after ensuring that the fluid pressure inside the valve cavity is reduced or the fault is eliminated, the baffle can be reset to a state of extending from the inner wall of the valve cavity toward the bottom of the valve cavity in an inclined direction under the elastic force of the elastic member. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The overall structural diagram of the floating collar according to the present invention is schematically shown;

[0019] Figure 2 A schematic diagram of the structure of a floating collar according to the present invention is shown schematically from a top view;

[0020] Figure 3 Another structural schematic diagram of a floating collar according to the present invention is schematically shown.

[0021] In the present application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn according to the actual scale. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In the description of the present invention, it should be understood that the terms "upper", "lower", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the present invention, "multiple" refers to two or more.

[0024] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] like Figure 1 to Figure 2As shown, the floating collar 100 of the present invention comprises: a valve cavity 6 having a valve port 61 at the top, a back-pressure valve 4 arranged in the valve cavity 6, and a plurality of baffles 5 arranged in a circumferential form along the inner wall of the valve cavity 6, the back-pressure valve 4 having a plug capable of blocking the valve port 61, and the plurality of baffles 5 being arranged below the plug. When the back-pressure valve 4 cannot rebound due to a malfunction and blocks the valve port 6 through the plug, under the action of the fluid pressure inside the valve cavity 6, the plurality of baffles 5 can move and press against the lower surface of the plug, thereby forming a blocking surface with the plug 5, and preventing the fluid inside the valve cavity 6 from ascending and flowing back from the valve port 61.

[0026] According to the present invention, a valve cavity 6 having a valve port 61 at the top, a back pressure valve 4 disposed in the valve cavity 6, and a plurality of baffles 5 arranged in a circumferential form along the inner wall of the valve cavity 6 are provided. The back pressure valve 4 has a plug capable of blocking the valve port 61, and the plurality of baffles 5 are disposed below the plug and can be pressed against the lower surface of the plug by movement, thereby forming a blocking surface for blocking backflow water in the valve cavity with the plug, thereby enhancing the reverse sealing performance of the floating collar and improving the efficiency and safety of cementing operations.

[0027] In one or more embodiments, when not affected by the fluid pressure inside the valve cavity 6, the baffle 5 extends from the inner wall of the valve cavity 6 along an inclined direction toward the bottom of the valve cavity 6, thereby not affecting the flow direction of the fluid flowing from the valve port 61 toward the inside of the valve cavity 6.

[0028] In one or more embodiments, under the action of the fluid pressure inside the valve cavity 6, the baffle 5 can extend from the inner wall of the valve cavity 6 along the inclined direction toward the top of the valve cavity 6, and press against the lower surface of the plug, thereby forming a sealing surface with the plug 5, preventing the fluid inside the valve cavity 6 from ascending and flowing back from the valve port 61.

[0029] In one or more embodiments, the baffle 5 is connected to the inner wall of the valve cavity 6 via an elastic member 7. A first end of the elastic member 7 is fixed to an end of the baffle 5 close to the inner wall of the valve cavity 6, and a second end of the elastic member 7 is fixed to the inner wall of the valve cavity 6. Optionally, the elastic member 7 may be a spring.

[0030] According to the present invention, the baffle 5 is connected to the inner wall of the valve cavity 6 by an elastic member 7. When not affected by the fluid pressure inside the valve cavity 6, the baffle 5 extends from the inner wall of the valve cavity 6 along the inclined direction toward the bottom of the valve cavity 6 under the action of its own weight, thereby not affecting the flow direction of the fluid flowing from the valve port 61 toward the inside of the valve cavity 6; under the action of the fluid pressure inside the valve cavity 6, the baffle 5 can extend from the inner wall of the valve cavity 6 along the inclined direction toward the top of the valve cavity 6, and press against the lower surface of the plug to prevent the fluid inside the valve cavity 6 from ascending and flowing back from the valve port 61; in addition, after ensuring that the fluid pressure inside the valve cavity 6 is reduced or the fault is eliminated, the baffle 5 can be reset to a state where it extends from the inner wall of the valve cavity 6 along the inclined direction toward the bottom of the valve cavity 6 under the elastic force of the elastic member 7.

[0031] like Figure 3 As shown, in one or more embodiments, the baffle plate 5 is hinged to the inner wall of the valve cavity 6, and the lower surface of the baffle plate 5 is connected to the first end of the elastic member 7, and the second end of the elastic member 7 is connected to the inner wall of the valve cavity 6 below the baffle plate 5. Optionally, the baffle plate 5 is hinged to the inner wall of the valve cavity 6 by a hinge.

[0032] According to the present invention, the baffle 5 is hinged to the inner wall of the valve cavity 6, and the lower surface of the baffle 5 is connected to the first end of the elastic member 7, and the second end of the elastic member 7 is connected to the inner wall of the valve cavity 6 located below the baffle 5. When not affected by the fluid pressure inside the valve cavity 6, the baffle 5 extends from the inner wall of the valve cavity 6 toward the bottom of the valve cavity 6 along the inclined direction under the action of its own weight and the elastic force of the elastic member 7, so as not to affect the flow direction of the fluid flowing from the valve port 61 toward the inside of the valve cavity 6; under the action of the fluid pressure inside the valve cavity 6, the baffle 5 can extend from the inner wall of the valve cavity 6 toward the top of the valve cavity 6 along the inclined direction, and press against the lower surface of the plug to prevent the fluid inside the valve cavity 6 from ascending and flowing back from the valve port 61; in addition, after ensuring that the fluid pressure inside the valve cavity 6 is reduced or the fault is eliminated, the baffle 5 can be reset to the state of extending from the inner wall of the valve cavity 6 toward the bottom of the valve cavity 6 along the inclined direction under the elastic force of the elastic member 7.

[0033] In one or more embodiments, the sides of adjacent baffles 5 abut against each other, so that a sealing surface is formed between the adjacent baffles 5 .

[0034] In one or more embodiments, eight baffles 5 are arranged in a circumferential form along the inner wall of the valve cavity 6, and each baffle 5 is disposed below the plug.

[0035] In one or more embodiments, the floating collar 100 of the present invention further includes a shell 1 , a valve cavity 6 is disposed inside the shell 1 , and a fixing sleeve 7 is sleeved on the outer wall of the valve cavity 6 .

[0036] In one or more embodiments, the return pressure valve 4 is connected to a column on the lower surface of the plug, and a return spring 3 is sleeved on the outer surface of the column.

[0037] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A floating collar, comprising: A valve cavity with a valve port at the top, a back-pressure valve arranged in the valve cavity, and a plurality of baffles arranged in a circular form along the inner wall of the valve cavity, the back-pressure valve having a plug capable of blocking the valve port, the plurality of baffles being arranged below the plug and capable of being moved to press against the lower surface of the plug, thereby forming a blocking surface with the plug.

2. The floating collar according to claim 1, characterized in that: The baffle extends from the inner wall of the valve cavity toward the bottom of the valve cavity along an inclined direction.

3. The floating collar according to claim 2, characterized in that: Under the action of the fluid pressure inside the valve cavity, the baffle can extend from the inner wall of the valve cavity toward the top of the valve cavity along an inclined direction and press against the lower surface of the plug.

4. The floating collar according to claim 3, characterized in that: The baffle is connected to the inner wall of the valve cavity via an elastic member.

5. The floating collar according to claim 3, characterized in that: The baffle is hinged to the inner wall of the valve cavity, and the lower surface of the baffle is connected to the first end of the elastic member, and the second end of the elastic member is connected to the inner wall of the valve cavity below the baffle.

6. The floating collar according to claim 4 or 5, characterized in that: The elastic member is a spring.

7. The floating collar according to claim 1 or 2, characterized in that: The side portions of the adjacent baffles abut against each other.

8. The floating collar according to claim 7, characterized in that: Eight baffles are arranged in a circumferential form along the inner wall of the valve cavity, and each baffle is arranged below the plug.

9. The floating collar according to claim 1 or 2, characterized in that: It also includes a shell, the valve cavity is arranged inside the shell, and the outer wall of the valve cavity is sleeved with a fixing sleeve.

10. The floating collar according to claim 1 or 2, characterized in that: The return pressure valve is connected to a column on the lower surface of the plug, and a return spring is sleeved on the outer surface of the column.

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