Automatic detection sealing device in oil well casing emptying channel

Abstract

The invention relates to the technical field of oil production engineering, in particular to an automatic detection sealing device in an oil well casing emptying channel. A locking mechanism is arranged at the position, close to one end, of the body and used for clamping the body in an oil well casing emptying channel. The interior of the main body is hollow, two ends of the main body are open, the part of the main body close to one end is a cylinder, and the part of the main body close to the other end is a semicircular cylinder; the end part of the semicircular cylinder of the main body is provided with an inclined surface with a preset angle; an automatic plugging mechanism is installed on the non-arc-shaped side, close to the end, of the semicircular cylinder of the body. The invention relates to an anti-theft oil switch, and aims to solve the problems that the use cost is high and the labor intensity is increased due to the fact that the existing anti-theft oil switch needs to use a tubular column and heavy mechanical equipment when being mounted and used and cannot be quickly mounted or dismounted.

Description

Technical Field

[0001] The invention relates to the technical field of oil production engineering, and in particular to an automatic detection and sealing device in an oil well casing venting channel. Background Art

[0002] At present, with the continuous rise of international oil prices, the production management situation of oil fields is becoming increasingly severe. Some oil wells are often damaged by illegal elements. Although the oil fields have taken many measures to prevent theft of oil, as time goes by, these anti-theft oil devices have also been cracked and damaged, and sometimes even our own workers cannot open them. Therefore, there is an urgent need for a safe, simple and easy-to-install casing anti-theft oil equipment, which adopts human and technical joint defense to solve the problem of oil theft and the environmental pollution caused by it to the greatest extent.

[0003] The existing casing anti-oil theft switch is installed between the first and second oil pipes in the well, which can prevent oil theft. However, it needs to be installed by heavy crane or working frame using pipe column. The installation process is complicated and costly, which has great limitations for on-site promotion and use. Summary of the invention

[0004] The present invention proposes an automatic detection and sealing device in an oil well casing venting channel to solve the problem that the existing anti-theft oil switch needs to use a pipe column and heavy mechanical equipment during installation and use, and cannot be installed or disassembled quickly, resulting in high use costs and increased labor intensity.

[0005] According to one aspect of the present invention, there is provided an automatic detection and sealing device in an oil well casing venting channel, characterized in that it comprises: a main body; The main body is provided with a locking mechanism near one end, and the locking mechanism is used to clamp the main body in the oil well casing venting channel; The interior of the main body is hollow, and both ends are open, wherein the part of the main body close to one end is in the shape of a cylinder, and the part of the main body close to the other end is in the shape of a semicircular cylinder; The end of the semicircular cylinder of the main body has an inclined surface with a predetermined angle; An automatic blocking mechanism is installed near the end position on the non-arc-shaped side of the semicircular cylinder of the main body, and the automatic blocking mechanism is used to automatically block the opening at the other end of the main body when the liquid level in the venting channel reaches the other end of the main body upward, and / or automatically open the opening at the other end of the main body when the liquid level in the venting channel moves away from the main body.

[0006] Preferably, the locking mechanism comprises: an expansion screw, a locking tooth block and a wrench; A mounting hole is provided inside the main body near one end, and the expansion screw is fixed in the mounting hole by threaded engagement; The portion of the expansion screw tube close to one end of the main body has a conical annular surface; A through hole is provided on the main body at a position corresponding to the conical annular surface, and the locking tooth block is installed inside the through hole; The inner shape of the tightening screw matches the outer shape of the wrench.

[0007] Preferably, the body of the locking tooth block is an elliptical cylinder, the outer side wall of the locking tooth block has a toothed structure, and the shape of the inner side wall of the locking tooth block matches the shape of the conical annular surface of the expansion screw.

[0008] Preferably, the blocking mechanism comprises: a flap valve and a float; One end of the flap valve is axially connected to an end of the main body away from the locking mechanism; The float is installed on a side of the flap valve away from the main body, and in a natural state, the flap valve is in a vertical state; The main body of the float is a semicircular cylinder with inclined slopes at both ends.

[0009] Preferably, it also includes: a return sealing rubber ring; An annular groove is provided on the outer side wall surrounding the locking tooth block and the main body, and the return sealing rubber ring is arranged inside the annular groove.

[0010] Preferably, it also includes: a guard plate; The guard plate is installed inside the cylindrical part of the main body, on the inner wall of one side of the semicircular cylinder close to the main body; The body of the guard plate is semicircular or semi-elliptical.

[0011] Preferably, the floating plate is made of EVA foam.

[0012] Preferably, it also includes: a safety sheath; An L-shaped groove is provided on the outer side wall of the main body around the main body, and the side of the L-shaped groove away from the locking mechanism is open; The safety sheath is sleeved on the outside of the L-shaped groove and is interference fit with the L-shaped groove; Wherein, the material of the safety sheath is nylon.

[0013] The present invention has at least the following beneficial effects: The present invention proposes an automatic detection and sealing device in an oil well casing venting channel. By arranging a locking mechanism and an automatic blocking mechanism on the main body, the problem of difficulty in installing a casing anti-theft oil switch is solved, and the cost expenditure of using the pipe string for operation is reduced. The automatic detection closer can be freely installed and disassembled in the channel without moving the oil well pipe string. When the liquid level rises automatically, the channel is automatically closed to block the spraying of liquid, and it is automatically opened when the liquid level drops. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present invention and, together with the specification, are used to explain the technical solutions of the present invention.

[0015] Figure 1 A schematic structural diagram of an automatic detection and sealing device in an oil well casing venting channel according to an embodiment of the present invention is shown; Figure 2 A schematic diagram showing the structure of a main body according to an embodiment of the present invention; Figure 3 A schematic structural diagram of a wrench according to an embodiment of the present invention is shown; Figure 4 A schematic structural diagram of an expansion spiral tube according to an embodiment of the present invention is shown; Figure 5 A schematic structural diagram of a locking tooth block according to an embodiment of the present invention is shown; Figure 6 A schematic structural diagram of a guard plate according to an embodiment of the present invention is shown; Figure 7 A schematic diagram showing the structure of a flap valve according to an embodiment of the present invention is shown; Figure 8 A schematic structural diagram of a float according to an embodiment of the present invention is shown; Fig. 9 A schematic structural diagram of an installation sheath according to an embodiment of the present invention is shown.

[0016] In the figure, 1-main body, 2-expansion screw, 3-locking tooth block, 4-wrench, 5-conical ring surface, 6-tooth structure, 7-flap valve, 8-float, 9-return sealing rubber ring, 10-guard plate, 11-safety sleeve, 12-through hole. Implementation

[0017] Various exemplary embodiments, features and aspects of the present invention will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0018] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0019] The term "and / or" herein is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the term "at least one" herein represents any combination of at least two of any one or more of a plurality of. For example, including at least one of A, B, and C can represent including any one or more elements selected from the set consisting of A, B, and C.

[0020] In addition, in order to better illustrate the present invention, numerous specific details are provided in the following specific embodiments. It should be understood by those skilled in the art that the present invention can be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present invention.

[0021] Figure 1 A schematic structural diagram of an automatic detection and sealing device in an oil well casing venting channel according to an embodiment of the present invention is shown; Figure 2 A schematic diagram showing the structure of a main body according to an embodiment of the present invention; Figure 3 A schematic structural diagram of a wrench according to an embodiment of the present invention is shown; Figure 4 A schematic structural diagram of an expansion spiral tube according to an embodiment of the present invention is shown; Figure 5 A schematic structural diagram of a locking tooth block according to an embodiment of the present invention is shown; Figure 6 A schematic structural diagram of a guard plate according to an embodiment of the present invention is shown; Figure 7 A schematic diagram showing the structure of a flap valve according to an embodiment of the present invention is shown; Figure 8 A schematic structural diagram of a float according to an embodiment of the present invention is shown; Fig. 9 FIG. 2 is a schematic diagram showing the structure of the installation sheath according to an embodiment of the present invention. Figure 1-9As shown, an automatic detection and sealing device in an oil well casing venting channel comprises: a main body 1; a locking mechanism is arranged near one end of the main body 1, and the locking mechanism is used to clamp the main body 1 in the oil well casing venting channel; the interior of the main body 1 is hollow, and both ends are open, wherein the part of the main body 1 near one end is in the shape of a cylinder, and the part of the main body 1 near the other end is in the shape of a semicircular cylinder; the end of the semicircular cylinder of the main body 1 has an inclined surface of a predetermined angle; an automatic blocking mechanism is installed near the end position on the non-arc side of the semicircular cylinder of the main body 1, and the automatic blocking mechanism is used to automatically block the opening at the other end of the main body 1 when the liquid level in the venting channel reaches the other end of the main body 1 upward, and / or automatically open the opening at the other end of the main body 1 when the liquid level in the venting channel is away from the main body 1.

[0022] In the embodiments of the present invention and Figure 1 , 2 The predetermined angle is 30 degrees. The upper half of the main body 1 is a cylinder, and one side thereof shrinks inward halfway from the middle left and right position downward, thereby forming a cylindrical upper half and a semicircular cylindrical lower half. The automatic blocking mechanism is installed at the lower end of the shrinking side of the main body 1. The other end of the main body 1 is an inclined surface, that is, the end of the semicircular cylinder is designed to have a beveled outlet shape with a 30-degree angle, and the shorter side of the beveled outlet is on the side where the diameter of the main body 1 shrinks inward.

[0023] When in use, firstly, the casing pressure in the oil well is released. For wells with high casing pressure, the well is also pressed by well washing. Then, the clamp screws of the casing gate are removed and the casing gate is dismantled.

[0024] The main body 1 is slowly placed from the other end into the oil well casing venting channel, that is, the large four-way outlet channel. At this time, the automatic blocking mechanism makes the other end opening of the main body 1 open. At this time, the internal channel of the semicircular column of the main body 1 is in a through state with the inside of the casing venting channel; through the locking mechanism, the main body 1 is clamped on the inner wall of the casing venting channel to complete the installation.

[0025] When the liquid level in the casing reaches the large four-way outlet, the automatic plugging mechanism detects that the liquid level reaches the other end of the main body 1, that is, below the main body 1, and automatically plugs the other end of the main body 1, that is, the end of the semicircular cylinder away from the locking mechanism, so that the entire channel is completely closed and oil and gas cannot be sprayed out, and the automatic closing action is realized, thereby preventing production losses and environmental pollution caused by oil theft and leakage. When the liquid level in the casing drops, the automatic plugging mechanism controls the automatic opening of the other end of the main body 1, so that operations such as lowering equipment can be realized.

[0026] In the present invention, the locking mechanism includes: an expansion screw 2, a locking tooth block 3 and a wrench 4; a mounting hole is provided inside the main body 1 near one end, and the expansion screw 2 is fixed in the mounting hole by threaded fitting; the portion of the expansion screw 2 near one end of the main body 1 has a conical annular surface 5; on the main body 1, a through hole 12 is provided at a position corresponding to the conical annular surface 5, and the locking tooth block 3 is installed inside the through hole 12; the internal shape of the expansion screw 2 matches the external shape of the wrench 4.

[0027] In the embodiments of the present invention and Figure 3 , 4 , 5, wherein the number of through holes 12 is 3, which are evenly distributed along the circumference of the side wall of the main body 1, and a locking tooth block 3 is installed in each through hole 12. Both ends of the mounting hole are open and communicated with the inside of the cylinder of the main body 1, and the side wall of the mounting hole has an internal thread.

[0028] exist Figure 4 In FIG. 1 , FIG. a is a front view of the expansion screw 2, and FIG. b is a left view of the expansion screw 2; Figure 4 As shown, the expansion screw 2 is hollow inside and open at both ends. The end away from the main body 1 is a cylinder, and the end close to the main body 1 is a cone; the internal shape of the expansion screw 2 is an ellipse. The expansion screw 2 has an external thread that matches the internal thread of the mounting hole. The internal shape of the mounting hole matches the external shape of the expansion screw 2. The expansion screw 2 is rotatably fixed inside the mounting hole of the main body 1 through the threaded structure. In the initial state, the expansion screw 2 is at the end of the mounting hole away from the main body 1; the side of the locking tooth block 3 close to the main body 1 is in contact with the conical annular surface 5 of the expansion screw 2 close to the main body 1, that is, the side wall of the conical part.

[0029] The main body of the wrench 4 is T-shaped or L-shaped, and the shape of one end of the wrench 4 matches the internal shape of the expansion screw 2, that is, an elliptical cylinder.

[0030] When in use, put the main body 1 into the casing venting channel, insert one end of the wrench 4 into the hollow interior of the expansion screw 2, and rotate the other end of the wrench 4 clockwise to drive the expansion screw 2 to rotate along the axis. When the expansion screw 2 rotates, it cooperates with the thread of the mounting hole to move toward the middle direction of the main body 1. Because one end of the expansion screw 2 is a conical annular surface 5, during the movement into the inside of the main body 1, the locking tooth block 3 is squeezed outward, so that the locking tooth block 3 moves toward the inner side wall of the casing venting channel, and the side of the locking tooth block 3 away from the main body 1 is tightly stuck to the inner side wall of the casing venting channel, thereby fixing the main body 1 inside the casing venting channel.

[0031] During disassembly, insert one end of the wrench 4 into the hollow interior of the expansion screw 2 and rotate the other end of the wrench 4 in the opposite direction, so that the expansion screw 2 moves away from the main body 1, thereby no longer applying thrust to the locking tooth block 3. The pressure of the locking tooth block 3 on the inner wall of the sleeve venting channel is reduced, and the main body 1 can be removed.

[0032] In the present invention, the body of the locking tooth block 3 is an elliptical cylinder, the outer wall of the locking tooth block 3 has a toothed structure 6 , and the shape of the inner wall of the locking tooth block 3 matches the shape of the conical annular surface 5 of the expansion screw 2 .

[0033] In the embodiments of the present invention and Figure 5 In the figure, Figure a is a front view of the locking tooth block 3, and Figure b is a bottom view of the locking tooth block 3; the locking tooth block 3 has a tooth structure 6 on the side away from the main body 1, and the top of the tooth structure 6 is triangular, with the tip facing upward. The side of the locking tooth block 3 close to the expansion screw 2 is an inclined angle that matches the conical annular surface 5 of the expansion screw 2, and has an arc-shaped concave surface that matches the side wall of the conical body of the expansion screw 2. When the locking tooth block 3 is inside the mounting hole, the side close to the main body 1 is tightly fitted with the side wall of the expansion screw 2.

[0034] In the present invention, the blocking mechanism includes: a flap valve 7 and a float 8; one end of the flap valve 7 is axially connected to an end of the main body 1 away from the locking mechanism; the float 8 is installed on the side of the flap valve 7 away from the main body 1, and in a natural state, the flap valve 7 is in a vertical state; the body of the float 8 is a semicircular cylinder with inclined slopes at both ends.

[0035] In the present invention, the floating plate is made of EVA foam.

[0036] In the embodiments of the present invention and Figure 7 , 8 In the embodiment, the flap valve 7 is in a semi-elliptical tongue shape, which matches the opening shape of the other end of the main body 1. The semi-elliptical straight bottom edge of the flap valve 7 is connected to the straight bottom edge of the semicircular cylindrical end of the main body 1 through a hinge axis. The density of the float 8 needs to be less than that of water, and it can be made of EVA foam rod; one side of the float 8 is connected to the side of the flap valve 7 away from the main body 1, and the length of the side of the float 8 connected to the flap valve 7 is greater than the length of the other side, so that the overall shape is roughly boat-shaped.

[0037] The main function of the float 8 is to sense the buoyancy brought by the liquid. When the liquid in the sleeve reaches the bottom of the float 8, the float 8 drives the flap valve 7 to rotate upward along the axis of the connection part with the main body 1 through the buoyancy of the liquid. When the flap valve 7 rotates to fit with the end of the semicircular cylinder of the main body 1, the flap valve 7 completely covers the opening at the other end of the main body 1, so that the liquid cannot enter the main body 1, thereby automatically blocking the internal channel of the main body 1.

[0038] A portion of the main body 1 is designed as a semicircular cylinder, so that the half space formed by its inward contraction can accommodate the float 8 and the flap valve 7, so that the flap valve 7 can maintain a vertical state in a natural state, and the opening at the other end of the main body 1 can be fully opened, and at this time, the side of the float 8 away from the flap valve 7 is in contact with the inner wall of the sleeve; when the liquid reaches the float 8 and the flap valve 7 upward, the float 8 contacts the inner wall of the sleeve to play a limiting role, even if the liquid flow rate and pressure are large, the flap valve 7 will not be pushed to the inner wall of the sleeve close to the side of the float 8, preventing the flap valve 7 from opening too large an angle, resulting in the float 8 failing to float normally, and the flap valve 7 failing to close normally.

[0039] The present invention further comprises: a return sealing rubber ring 9; an annular groove communicating with the outer side wall of the main body 1 and surrounding the locking tooth block 3, wherein the return sealing rubber ring 9 is arranged inside the annular groove.

[0040] In the embodiment of the present invention, there are two return sealing rubber rings 9, which are respectively arranged near the two ends of the locking tooth block 3. The return rubber ring is an O-shaped rubber ring, which has two main functions: one is to tighten and fix the locking tooth block to prevent it from falling out of the installation hole; the other is that when the expansion screw 2 pushes the locking tooth block 3 to move away from the main body 1, the return sealing rubber ring 9 will be stretched and deformed. When the main body 1 needs to be removed, the expansion screw 2 no longer applies thrust to the locking tooth block 3, and the return sealing rubber ring 9 can rebound and pull the locking tooth block back into the installation hole of the main body 1.

[0041] The present invention also includes: a guard plate 10; the guard plate 10 is installed on the inner wall of one side of the semicircular cylinder close to the main body 1 inside the cylindrical part of the main body 1; the main body of the guard plate 10 is semicircular or semi-elliptical.

[0042] In the embodiments of the present invention and Figure 6 In the figure, the guard plate 10 is installed in the cylindrical channel of the main body 1 and is located above the semicircular cylinder. Its function is to prevent objects floating upward with the liquid in the sleeve from entering the main body 1 and sealing the outlet at one end of the main body 1.

[0043] The present invention also includes: a safety sheath 11; an L-shaped groove is provided on the outer wall around the main body 1, and the side of the L-shaped groove away from the locking mechanism is open; the safety sheath 11 is sleeved on the outside of the L-shaped groove and has an interference fit with the L-shaped groove; wherein the material of the safety sheath 11 is nylon.

[0044] In the embodiments of the present invention and Fig. 9 In the figure, the left picture is a front view of the safety sheath 11, and the right picture is a left view of the safety sheath 11; the safety sheath 11 is cylindrical in shape and is tightly fitted with the main body 1. The diameter of the cylindrical part of the main body 1 at the L-shaped groove is 52 mm, and the outer diameter of the safety sheath 11 after being sleeved in the L-shaped groove is 61 mm.

[0045] The function of the safety sheath 11 is to limit the insertion depth of the automatic detection closer in the oil well casing venting channel, that is, the part of the main body 1 with the safety sheath 11 is inserted into the casing cross-way, tightly fits against the inner wall of the casing to prevent shaking, and the diameter of the main body 1 part outside the safety sheath 11 is larger than the inner diameter of the casing, so that it is stuck outside the casing; in addition, the safety sheath 11 can also protect the flap valve 7 and the float 8 to prevent deformation or damage caused by bumps and collisions during transportation, resulting in failure.

[0046] During installation, first remove the clamp screws of the casing gate and dismantle the casing gate. At this time, put the prepared main body 1 into the large four-way outlet channel, keep the flap valve 7 and the float 8 vertically downward, and the semicircular through hole 12 of the column is in a through state. Insert the elliptical part of the special wrench 4 into the expansion screw 2, and rotate the special wrench 4 with force to drive the expansion screw 2. The front end conical ring surface of the expansion screw 2 pushes the locking tooth block 3 to move vertically, and pushes the locking tooth block 3 out of the main body 1. After it is in close contact with the inner ring surface of the casing channel, take out the special wrench 4 and the installation work is completed.

[0047] When the liquid level in the casing reaches the large four-way outlet, the float 8 drives the flap valve 7 to rotate through the buoyancy. As the buoyancy continues to increase, the flap valve 7 flips upward to achieve automatic control until the entire main body 1 channel is completely closed and oil and gas cannot be sprayed out, achieving automatic closing action; when the liquid level in the casing drops, the buoyancy gradually disappears, and the flap valve 7 flips downward under the action of its own gravity, and the channel is automatically opened.

[0048] It can be understood that the above-mentioned various embodiments mentioned in the present invention can be combined with each other to form a combined embodiment without violating the principle logic. Due to space limitations, the present invention will not go into details.

[0049] The overall structural design of the present invention is novel and unique. The main body 1 is a cylindrical barrel structure. The locking tooth block 3 is pushed by the expansion screw 2 to realize the anchoring function, and the return sealing rubber ring 9 realizes the function of retracting the locking tooth block 3. The cylindrical design of the front half is changed to a semicircular cylindrical design in the middle and rear sections to ensure sufficient flow area, and also ensure the design space of the anchoring structure and the unique shape of the outlet. The end of the main body 1 is cut at an angle of 30 degrees into an oblique outlet shape, which is conducive to the installation of the flap valve 7 and the float 8.

[0050] The anti-theft part of the present invention adopts a special wrench 4 and a matching expansion screw 2. The docking part of the two is an elliptical structure, which has a good anti-theft function; the conical ring surface at the front end of the expansion screw 2 is used to push the locking tooth block 3 to push it out, and expand and tighten with the inner ring surface of the sleeve channel, and an interference fit is generated under the action of the locking tooth block 3, so that the anchoring is safer and more reliable; the "O"-shaped return sealing rubber ring 9 is used as a spring function, which saves a lot of design space; a guard plate 10 is designed in the cylindrical channel of the main body 1, which can cover the semicircular channel behind, effectively preventing the destructive effect of foreign objects entering from the outside.

[0051] The flap valve 7 of the present invention realizes automatic anti-theft closing. The float 8 is made of EVA foam rod and has a semicircular shape. It is installed under the flap valve 7. Its main function is to sense the buoyancy brought by the liquid, thereby driving the flap valve 7 to move and realize automatic closing of the semicircular channel of the main body 1; the flap valve 7 is a tongue-shaped body and is installed at the semicircular outlet of the main body 1. The lower part of the flap valve 7 is connected to the column in a hinge-axis connection manner. Under the action of external force on the float 8, the flap valve 7 can flip around the axis to realize the automatic opening or closing of the channel of the main body 1.

[0052] During the research and development process, 60 sets of this invention were experimentally applied in multiple operating areas of oil pumping wells, and a good anti-theft effect was achieved. Without moving the oil well pipe string, it can be freely installed and disassembled in the channel. When the liquid level rises, the valve linkage automatically closes the channel to block the liquid spraying. When the liquid level drops, the channel will automatically open, solving the problem of casing oil theft and environmental pollution. After the experimental application, the cumulative crude oil loss has been reduced by 630 tons, and the net profit of the efficiency increase is 2.411 million yuan. It has high economic and social benefits and broad prospects for promotion.

[0053] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An automatic detection and sealing device for an oil well casing venting channel, characterized in that: include: Subject (1); The main body (1) is provided with a locking mechanism near one end, the locking mechanism being used to clamp the main body (1) in the venting channel of the oil well casing; The interior of the main body (1) is hollow, and both ends are open, wherein the portion of the main body (1) close to one end thereof is in the shape of a cylinder, and the portion of the main body (1) close to the other end thereof is in the shape of a semicircular cylinder; The end of the semicircular cylinder of the main body (1) has an inclined surface with a predetermined angle; An automatic blocking mechanism is installed near the end of the non-arc-shaped side of the semicircular cylinder of the main body (1), and the automatic blocking mechanism is used to automatically block the opening at the other end of the main body (1) when the liquid level in the venting channel reaches the other end of the main body (1) upward, and / or automatically open the opening at the other end of the main body (1) when the liquid level in the venting channel moves away from the main body (1).

2. The automatic detection and sealing device for the emptying channel of the oil well casing according to claim 1 is characterized in that: The locking mechanism comprises: an expansion screw (2), a locking tooth block (3) and a wrench (4); A mounting hole is provided inside the main body (1) near one end, and the expansion screw (2) is fixed in the mounting hole by threaded engagement; The portion of the expansion spiral tube (2) close to one end of the main body (1) has a conical annular surface (5); A through hole (12) is provided on the main body (1) at a position corresponding to the conical annular surface (5), and the locking tooth block (3) is installed inside the through hole (12); The internal shape of the expansion screw tube (2) matches the external shape of the wrench (4).

3. The automatic detection and sealing device for the emptying channel of the oil well casing according to claim 2 is characterized in that: The body of the locking tooth block (3) is an elliptical cylinder, the outer wall of the locking tooth block (3) is provided with a toothed structure (6), and the shape of the inner wall of the locking tooth block (3) matches the shape of the conical annular surface (5) of the expansion screw tube (2).

4. The automatic detection and sealing device for the emptying channel of the oil well casing according to claim 1 is characterized in that: The blocking mechanism comprises: a flap valve (7) and a float (8); One end of the flap valve (7) is axially connected to an end of the main body (1) away from the locking mechanism; The float (8) is mounted on a side of the flap valve (7) away from the main body (1), and in a natural state, the flap valve (7) is in a vertical state; The body of the float (8) is a semicircular cylinder with inclined slopes at both ends.

5. The automatic detection and sealing device for the emptying channel of the oil well casing according to claim 2 is characterized in that: Also includes: Return sealing ring (9); An annular groove is provided on the outer side wall of the main body (1) and surrounding the locking tooth block (3), and the return sealing rubber ring (9) is arranged inside the annular groove.

6. The automatic detection and sealing device for the emptying channel of the oil well casing according to claim 1 is characterized in that: Also includes: Guard plate (10); The guard plate (10) is installed inside the cylindrical part of the main body (1) on the inner wall of one side of the semicircular cylinder close to the main body (1); The body of the guard plate (10) is semicircular or semi-elliptical.

7. The automatic detection and sealing device for the emptying channel of the oil well casing according to claim 4 is characterized in that: The float is made of EVA foam.

8. The automatic detection and sealing device for the emptying channel of the oil well casing according to any one of claims 1 to 7, characterized in that: Also includes: Safety sheath (11); An L-shaped groove is provided on the outer side wall of the main body (1) around the main body, and the side of the L-shaped groove away from the locking mechanism is open; The safety sheath (11) is sleeved on the outside of the L-shaped groove and is interference fit with the L-shaped groove; Wherein, the material of the safety sheath (11) is nylon.

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