Casing float shoe for well cementation

Abstract

The utility model discloses a casing float shoe for well cementation, which comprises a casing and a slurry guide pipe arranged in the casing, the slurry guide pipe comprises a grouting inlet and a grouting outlet, and a filling section is arranged between the casing and the slurry guide pipe. A mesh enclosure used for surrounding the grouting outlet is arranged at the end, deviating from the grouting inlet, of the filling section, a movable floating ball used for blocking the grouting outlet is arranged in the mesh enclosure, so that the sleeve float shoe is simple in structure, easy to machine, low in manufacturing cost and beneficial to cost reduction and efficiency improvement, and the sleeve float shoe can be used in construction in remote or outdated areas. And on-site materials can be flexibly adopted for self-machining, so that the construction period is prevented from being delayed.

Description

Technical Field

[0001] The utility model relates to the technical field of cementing engineering, in particular to a casing float shoe used for cementing, and is suitable for construction fields such as oil wells, natural gas wells or deep water wells. Background Art

[0002] Casing float shoe is a kind of casing guide shoe or coupling that can generate buoyancy and is a special accessory for drilling.

[0003] The casing float shoe on the market, as described in the invention patent CN103061706B, includes a float shoe shell, a valve seat, a valve core and a coupling. Its overall structure is complex and difficult to process, resulting in high procurement costs, which is not conducive to cost reduction and efficiency improvement. Moreover, when constructing in remote or backward areas, procurement and transportation are often inconvenient, resulting in shortage of casing float shoes and delays in construction. Utility Model Content

[0004] Therefore, in order to solve the above problems, the utility model provides a casing float shoe for cementing, which has a simple overall structure, is easy to process and has a low cost, and is also suitable for remote or backward areas.

[0005] To achieve the above purpose, the technical solution provided by the utility model is as follows:

[0006] The utility model provides a casing float shoe for cementing, comprising a casing and a grouting pipe arranged in the casing; the grouting pipe comprises a grouting inlet and a grouting outlet, a filling section is arranged between the casing and the grouting pipe, a mesh cover for surrounding the grouting outlet is arranged at one end of the filling section away from the grouting inlet, and a movable float for blocking the grouting outlet is arranged in the mesh cover.

[0007] Furthermore, the circumferential wall of the sleeve has an anchor body protruding radially outward.

[0008] Furthermore, the inner wall of the casing and the outer wall of the slurry guide pipe enclose a main cavity; an anti-detachment cavity connected to the main cavity is arranged in the anchor body; the main cavity and the anti-detachment cavity are connected to form a filling cavity for accommodating the filling section.

[0009] Furthermore, the number of the anchor bodies is at least two, and the plurality of anchor bodies surround the outer peripheral wall of the sleeve and are arranged at equal intervals.

[0010] Furthermore, the filler of the filling section is cement mortar; and / or the slurry guide pipe is a plastic pipe.

[0011] Furthermore, the center lines of the slurry guide pipe and the casing coincide with each other; and the length of the casing is greater than the length of the slurry guide pipe.

[0012] Furthermore, the inner diameter of the slurry guide pipe is larger than the outer diameter of the drill pipe.

[0013] Furthermore, the end of the filling section facing away from the grouting outlet is a flat end; the end of the filling section facing away from the grouting inlet is an inclined end, and the inclined end is in an inverted conical shape.

[0014] Furthermore, the included angle between the inclined surface of the inclined end and the horizontal plane is 25 degrees to 40 degrees.

[0015] Furthermore, the casing is a steel casing, and a thread is provided at one end of the casing facing away from the grouting outlet.

[0016] Through the technical solution provided by the present utility model, the following beneficial effects are achieved:

[0017] By filling the filling section between the casing and the slurry guide pipe and arranging the movable floating ball in the wire mesh cover, a casing float shoe with a simple structure is formed, which is easy to process and has a low construction cost, so as to facilitate cost reduction and efficiency improvement.

[0018] In addition, when constructing in remote or backward areas, the casing float shoe of the present utility model can also be flexibly processed with on-site materials to avoid delaying the construction period. Description of the Drawings

[0019] Figure 1 Shown is a cross-sectional view of the casing float shoe for well cementing in the embodiment;

[0020] Figure 2 Shown as Figure 1 the sectional view taken along A-A in Detailed Embodiments

[0021] To further illustrate the embodiments, the present utility model provides drawings. These drawings are a part of the disclosure of the present utility model, and are mainly used to illustrate the embodiments and can be used to explain the operating principle of the embodiments in combination with the relevant descriptions in the specification. With reference to these contents, those of ordinary skill in the art should be able to understand other possible implementation manners and the advantages of the present utility model. The components in the drawings are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0022] Now, the present utility model will be further described in combination with the drawings and specific embodiments.

[0023] Refer to Figure 1 and Figure 2As shown, this embodiment provides a casing float shoe for cementing (hereinafter referred to as the casing float shoe), the casing float shoe includes a casing 3 and a grouting pipe 2 arranged in the casing 3, the grouting pipe 2 includes a grouting inlet 21 and a grouting outlet 22 arranged in the upper and lower parts, a filling section 1 is arranged between the casing 3 and the grouting pipe 2, and a mesh cover 5 for surrounding the grouting outlet 22 is arranged at the lower end of the filling section 1 away from the grouting inlet 21, and a movable float 4 for blocking the grouting outlet 22 is arranged in the mesh cover 5.

[0024] In this embodiment, the casing 3 is a steel casing, and the upper end of the casing 3 facing away from the grouting outlet 22 is provided with a thread to form a threaded end of the casing 3. In addition, the filler of the specific filling section 1 is cement mortar, the slurry guide pipe 2 is an ordinary plastic pipe such as a PVC pipe, and the movable float 4 is a buoyancy ball with a lower density such as a wooden ball. The outer diameter of the movable float 4 is slightly larger than the inner diameter of the grouting outlet 22, and the mesh cover 5 is an ordinary wire mesh cover. The wire mesh cover is naturally concave, and the mesh gap of the mesh cover 5 is smaller than the outer diameter of the movable float 4, so as to play a role in limiting the float.

[0025] Therefore, the materials for processing the float shoe of the casing 3 of the present embodiment are relatively common, and are convenient to obtain locally, especially in remote or backward areas, and are also easy to obtain.

[0026] The center lines of the slurry guide pipe 2 and the casing 3 coincide with each other to ensure that the overall structure of the filling section 1 is relatively symmetrical.

[0027] The inner diameter of the slurry pipe 2 is larger than the outer diameter of the drill pipe, and the length of the casing 3 is larger than the length of the slurry pipe 2. For example, the size of the PVC pipe is The size of the drill pipe is After the drill rod is extended into the slurry guide pipe 2, the drill rod is guided through the slurry guide pipe 2 so that the drill rod smoothly enters the location of the movable float 4.

[0028] When cementing is required, cement slurry is poured into the grouting pipe 2 under high pressure, and the movable float 4 is displaced downward by the high-pressure cement slurry. At this time, the grouting channel in the grouting pipe 2 is opened, and the grouting pipe 2 is used as a conveying channel for high-pressure cement slurry.

[0029] After the cement slurry injection is completed, the casing float shoe of this embodiment uses the buoyancy of the movable float 4 to automatically float up after the cementing is completed until the grouting outlet 22 of the grouting pipe 2 is blocked, thereby preventing the cement slurry from overflowing from the grouting pipe 2 in the reverse direction. In this way, the cement slurry input and sealing during cementing can be completed quickly and effectively.

[0030] By filling the filling section 1 between the casing 3 and the slurry guide pipe 2 and arranging the movable float 4 in the mesh cover 5, a casing float shoe with a simple structure is formed, which is easy to process and has a low cost, so as to reduce costs and increase efficiency.

[0031] Furthermore, when construction is carried out in remote or underdeveloped areas, the casing float shoe of this embodiment can be flexibly manufactured by using on-site materials to avoid delays in construction.

[0032] In another preferred embodiment, Figure 2 As shown, the circumferential wall of the sleeve 3 has an anchor body 321 protruding radially outward.

[0033] More specifically, the inner wall of the casing 3 and the outer wall of the slurry guide pipe 2 enclose a main cavity, and an anti-detachment cavity connected to the main cavity is provided in the anchor body 321 . The main cavity and the anti-detachment cavity are connected to form a filling cavity for accommodating the filling section 1 .

[0034] In this specific embodiment, the number of anchor bodies 321 is 3, and the 3 anchor bodies 321 surround the outer peripheral wall of the casing 3 and are arranged at equal intervals, that is, the circumferential interval between two adjacent anchor bodies 321 is 120 degrees. Of course, the number of anchor bodies 321 can also be 2 or 4 or more.

[0035] Further preferably, the end of the filling section 1 away from the grouting outlet 22 is a plane end, and the end of the filling section 1 away from the grouting inlet 21 is a sloped end, the sloped end is in an inverted cone, and the angle α between the inclined surface of the sloped end and the horizontal plane is 25 degrees to 40 degrees, so as to facilitate the high-pressure injected cement slurry to quickly diffuse from the grouting outlet 22 to the surroundings, and also facilitate the movable float 4 to quickly and accurately roll toward the center of the grouting outlet 22, thereby realizing the rapid closure of the cement slurry conveying channel in the grouting pipe 2.

[0036] When it is necessary to process the casing float shoe of the present embodiment on site, a steel casing made of the same material as the drilling steel casing is first used. The total length of the steel casing is 150 cm, and it includes a first section 31, a second section 32 and a third section 33 from top to bottom. The length of the first section 31 and the third section 33 is 55 cm, and the length of the second section 32 is 40 cm.

[0037] Three holes are respectively opened on the outer wall of the second section 32 located in the middle of the steel casing. The hole dimensions are 20 cm in width and 40 cm in height. The three holes are arranged in a ring with equal intervals, that is, the central angle β of the three holes is 120 degrees. The pipe wall cut out of each hole is moved outward by 2 cm in its radial direction, and then sealed and fully welded to form an anchor body 321, so that the anchor body 321 can be tightly buckled on the steel casing.

[0038] When cement mortar is filled in the filling cavity formed by the main cavity and the anti-slip cavity and solidifies, the anti-slip ability of the filling section 1 can be increased, that is, the filling section 1 can be prevented from being separated from the steel casing due to the reaction force when high-pressure cement slurry is poured, thereby avoiding cement mortar waste and cementing failure.

[0039] Then a PVC tube is fixedly placed at the center of the pipe axis of the steel casing, and the inner diameter of the PVC tube is slightly larger than the outer diameter of the drill pipe.

[0040] After that, cement mortar is poured into the filling cavity between the steel casing and the PVC pipe to a height of 1 m. The distance between the cement mortar body in the first section 31 and the upper pipe orifice of the steel casing is 25 cm, and the distance between the cement mortar body in the third section 33 and the lower pipe orifice of the steel casing is 25 cm. That is, the height of the cement mortar body in the first section 31 and the third section 33 is 30 cm, and the height of the cement mortar body in the second section 32 is 40 cm. The filling space in the second section 32 is filled throughout the section. The cement mortar bodies in the first section 31, the second section 32, and the third section 33 together form a complete filling section 1.

[0041] In addition, the lower end of the cement mortar body in the third section 33 is arranged in an inclined plane, and the inclined plane is inclined in an inverted conical shape from the outside to the center point. The value range of the included angle α between the inclined plane and the horizontal plane is: 25° ≤ α ≤ 40°.

[0042] Before pouring the cement mortar, a wire mesh cover is pre-set 25 cm away from the lower pipe orifice of the steel casing, and the movable floating ball 4 is stuffed between the wire mesh cover and the cement mortar body in the third section 33. Then, after the cement mortar is completely poured into the filling cavity, the wire mesh cover is embedded along the inner wall of the steel casing into the filling section 1 formed by the cement mortar body, and the whole wire mesh cover is convex downward to ensure that the movable floating ball 4 has sufficient movable space.

[0043] The casing float shoe of this embodiment has low cost, is simple to manufacture, can use local materials, and can be flexibly processed. Therefore, it is beneficial to quickly complete the production target in remote or backward areas to avoid delaying the construction period.

[0044] Of course, in other embodiments, the movable floating ball 4 and the wire mesh cover can also be installed after the cement mortar body is completed.

[0045] Although the present invention is specifically shown and described in combination with the preferred implementation scheme, those skilled in the art should understand that various changes can be made to the present invention in terms of form and details without departing from the spirit and scope of the present invention defined by the appended claims, and all of them are within the protection scope of the present invention.

Claims

1. A casing float shoe for cementing, characterized in that: It comprises a casing and a slurry guide pipe arranged in the casing; The grouting pipe comprises a grouting inlet and a grouting outlet, a filling section is arranged between the casing and the grouting pipe, a mesh cover for surrounding the grouting outlet is arranged at one end of the filling section away from the grouting inlet, and a movable float for blocking the grouting outlet is arranged in the mesh cover.

2. The casing float shoe for well cementing according to claim 1, characterized in that: The circumferential wall of the sleeve has an anchor body protruding radially outward.

3. The casing float shoe for cementing according to claim 2, characterized in that: The inner wall of the casing and the outer wall of the slurry guide pipe are combined to form a main cavity; an anti-detachment cavity connected to the main cavity is arranged in the anchor body; the main cavity and the anti-detachment cavity are connected to form a filling cavity for accommodating the filling section.

4. The casing float shoe for well cementing according to claim 2 or 3, characterized in that: The number of the anchor bodies is at least two, and the plurality of anchor bodies surround the outer peripheral wall of the sleeve and are arranged at equal intervals.

5. The casing float shoe for well cementing according to any one of claims 1-3, characterized in that: The filler of the filling section is cement mortar; and / or the slurry guide pipe is a plastic pipe.

6. The casing float shoe for well cementing according to any one of claims 1-3, characterized in that: The center lines of the slurry guide pipe and the casing coincide with each other; the length of the casing is greater than the length of the slurry guide pipe.

7. The casing float shoe for cementing according to any one of claims 1-3, characterized in that: The inner diameter of the slurry guide pipe is greater than the outer diameter of the drill pipe.

8. The casing float shoe for cementing according to any one of claims 1-3, characterized in that: The end of the filling section away from the grouting outlet is a plane end; the end of the filling section away from the grouting inlet is a sloped end, and the sloped end is in an inverted cone shape.

9. The casing float shoe for cementing according to claim 8, wherein: The angle between the inclined surface of the bevel end and the horizontal plane is 25 degrees to 40 degrees.

10. The casing float shoe for well cementing according to any one of claims 1-3, characterized in that: The casing is a steel casing, and a thread is arranged at one end of the casing away from the grouting outlet.

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