Blowout preventer and drilling tools

Abstract

The present invention provides a blowout preventer and a drilling tool, which relate to the technical field of oil extraction. The blowout preventer includes a valve body and a valve core. The valve body has a mounting hole and a first opening and a second opening respectively connected to the mounting hole. Along the extension direction of the mounting hole, the inner surface of the mounting hole includes a bearing surface and a first sealing surface arranged at intervals. The valve core is slidably arranged in the mounting hole and is located between the bearing surface and the first sealing surface, and the valve core has a second sealing surface that can be sealed with the first sealing surface. When the pressure in the blowout preventer is less than the pressure at the bottom of the well, the valve core moves toward the first sealing surface until the second sealing surface fits with the first sealing surface, thereby achieving the purpose of closing the mounting hole. Compared with the technical solution of sleeve-arranging a spring on the outside of the valve body, the blowout preventer can avoid the phenomenon of spring failure after long-term use, improve the sealing performance of the blowout preventer, and prevent the liquid in the well from entering the drilling tool to cause a blowout.

Description

Technical Field

[0001] The invention relates to the technical field of oil production, and in particular to a blowout prevention device and a drilling tool. Background Art

[0002] During the oil extraction process, the liquid in the well can easily enter the drill bit, causing a blowout in the drill bit. Therefore, a blowout preventer needs to be installed in the drill bit to prevent the liquid in the well from entering the drill bit.

[0003] In the related art, the blowout prevention device usually includes an arrow-shaped check valve installed in the drilling tool, and the arrow-shaped check valve includes a body, a valve seat and a conical valve core installed in the body, wherein the body has a mounting hole, the valve seat is installed in the mounting hole, and the valve seat has a mounting hole, and the end of the conical valve core close to the valve seat can be inserted into the mounting hole or detached from the mounting hole to achieve the closing or opening of the arrow-shaped check valve, and in addition, a spring is also sleeved on the conical valve core. When overflow occurs in the drilling, under the action of the tension of the spring and the pressure in the drilling, the end of the conical valve core close to the valve seat is inserted into the mounting hole, and the outer surface of the conical valve core is tightly fitted with the inner surface of the mounting hole to achieve the closing of the arrow-shaped check valve, thereby achieving the purpose of closing the channel in the drilling tool.

[0004] However, after the arrow-shaped check valve has been used for a period of time, the spring is prone to failure, thereby causing the blowout preventer to fail. Summary of the invention

[0005] In view of the above problems, an embodiment of the present invention provides a blowout preventer and a drilling tool to solve the technical problem in the related art that spring failure easily causes failure of the blowout preventer, thereby improving the sealing performance of the blowout preventer.

[0006] In order to achieve the above purpose, the embodiment of the present invention provides the following technical solutions:

[0007] A first aspect of an embodiment of the present invention provides a blowout prevention device, comprising: a valve body and a valve core, the valve body having a mounting hole and a first opening and a second opening respectively connected to the mounting hole; along the extension direction of the mounting hole, the inner surface of the mounting hole comprises a bearing surface and a first sealing surface arranged at intervals; the valve core is slidably disposed in the mounting hole and is located between the bearing surface and the first sealing surface, and the valve core has a second sealing surface that can be sealed with the first sealing surface.

[0008] The blowout prevention device as described above, wherein the valve body includes an upper valve body and a lower valve body detachably connected to the upper valve body; a first mounting hole is provided in the upper valve body, and the bottom surface of the upper valve body close to the lower valve body is recessed towards the first mounting hole to form a receiving groove; the side wall of the receiving groove constitutes the first sealing surface; a second mounting hole is provided in the lower valve body, the second mounting hole includes a cylindrical first through hole connected to the first mounting hole, a conical second through hole and a cylindrical third through hole, the first through hole, the second through hole and the third through hole are connected in sequence, and the diameter of the second through hole gradually decreases from an end close to the first through hole to an end away from the first through hole; the inner surface of the second through hole constitutes the bearing surface, and the first mounting hole and the second mounting hole constitute the mounting hole.

[0009] The blowout prevention device as described above, wherein the valve core includes a cylindrical valve stem and a hemispherical valve cap; along the axial direction of the valve stem, the valve stem has a first end face and a second end face, the first end face is connected to the bearing surface, the second end face is connected to the valve cap, and the outer surface of the valve cap constitutes the second sealing surface.

[0010] The blowout prevention device as described above, wherein the valve stem is provided with at least one guide protrusion, the inner surface of the lower valve body is provided with guide grooves corresponding to the guide protrusions one by one, and the guide protrusions are slidably arranged in the guide grooves.

[0011] In the blowout prevention device as described above, the valve core is provided with a circulation channel, one end of the circulation channel is communicated with the first mounting hole, and the other end of the circulation channel is communicated with the second mounting hole.

[0012] In the blowout prevention device as described above, the outer circumference of the valve core is recessed toward the axial direction of the valve stem to form a flow channel.

[0013] The blowout prevention device as described above, wherein the first end surface of the valve stem is recessed toward the second end surface to form a buffer groove.

[0014] The blowout prevention device as described above, wherein the valve core is provided with a pressure measuring channel, the pressure measuring channel penetrates the valve body along the axial direction of the valve body, and a first one-way valve is provided at one end of the pressure measuring channel close to the second opening; the pressure measuring channel is used to transmit part of the liquid in the well to the pressure measuring device outside the well, and the pressure in the well is tested by the pressure measuring device.

[0015] The blowout prevention device as described above, wherein the pressure measuring channel includes a plurality of branch channels, the plurality of branch channels are spaced apart along the circumferential direction of the pressure measuring channel, and the axis of each branch channel has a preset angle with the axis of the pressure measuring channel; and a second one-way valve is provided at one end of each branch channel close to the second opening.

[0016] A second aspect of an embodiment of the present invention provides a drilling tool, which includes a drilling tool body and the blowout prevention device as described above.

[0017] In the blowout preventer and drilling tool provided by the embodiment of the present invention, the bearing surface and the first sealing surface are arranged at intervals on the inner surface of the installation hole, the valve core is slidably arranged in the installation hole, and the valve core has a second sealing surface. When the pressure in the blowout preventer is lower than the pressure at the bottom of the well, the valve core moves toward the first sealing surface until the second sealing surface fits with the first sealing surface, thereby achieving the purpose of closing the installation hole. Compared with the technical solution of sleeve springs on the outside of the valve body, the phenomenon of spring failure after long-term use of the blowout preventer can be avoided, and the sealing performance of the blowout preventer can be improved while preventing the liquid in the well from entering the drilling tool and causing a blowout.

[0018] In addition to the technical problems solved by the embodiments of the present invention described above, the technical features that constitute the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions, other technical problems that can be solved by the blowout prevention device and drilling tools provided by the embodiments of the present invention, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further described in detail in the specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of the structure of a blowout prevention device provided in an embodiment of the present invention;

[0021] Figure 2 for Figure 1 Sectional view in the AA direction;

[0022] Figure 3 for Figure 2 A magnified schematic diagram of the middle B area;

[0023] Figure 4 A top view of a blowout prevention device provided by an embodiment of the present invention;

[0024] Figure 5 A three-dimensional diagram of a valve core provided in an embodiment of the present invention;

[0025] Figure 6 A front view of a valve core provided in an embodiment of the present invention;

[0026] Figure 7 A top view of a valve core provided in an embodiment of the present invention.

[0027] Reference numerals:

[0028] 100: valve body;

[0029] 110: upper valve body;

[0030] 120: lower valve body;

[0031] 200: valve core;

[0032] 210: second sealing surface;

[0033] 220: valve stem;

[0034] 221: guide protrusion;

[0035] 222: buffer groove;

[0036] 223: pressure measurement channel;

[0037] 224: branch channel;

[0038] 225: first one-way valve;

[0039] 226: second one-way valve;

[0040] 230: Valve bonnet;

[0041] 310: first mounting hole;

[0042] 320: second mounting hole;

[0043] 321: first through hole;

[0044] 322: second through hole;

[0045] 323: third through hole;

[0046] 340: First sealing surface. DETAILED DESCRIPTION

[0047] In the related art, since a spring is sleeved on the conical valve core, when the conical valve core moves in the mounting hole, the spring continuously transforms between a compressed state and an extended state, causing the spring to fail easily after the arrow-shaped check valve has been used for a period of time, resulting in the conical valve core being unable to seal the mounting hole in time, and the liquid in the drilling will enter the drill bit, causing a blowout in the drill bit.

[0048] To this end, the embodiment of the present invention provides a blowout preventer and a drilling tool, which only relies on the pressure difference between the blowout preventer and the bottom of the well to drive the valve core to move in the installation hole to achieve the purpose of closing the installation hole. This can avoid the phenomenon of spring failure after long-term use of the blowout preventer, improve the sealing performance of the blowout preventer, and prevent the liquid in the well from entering the drilling tool to cause a blowout.

[0049] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. 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 belong to the scope of protection of the present invention.

[0050] The drill tool provided in an embodiment of the present invention can be used in downhole oil extraction. The drill tool may include a drill tool body and a blowout preventer. The drill tool body is a general term for a series of drilling tool combinations located between the bottom of the well and the faucet. For example, the drill tool body includes a drill bit, a drill collar, a drill pipe and a stabilizer. The stabilizer can prevent well deviation and is conducive to the smooth operation of the drill bit. The stabilizer can be arranged between the drill bit and the drill collar, or between the drill collar and the drill pipe.

[0051] During the oil production process, the liquid in the well can easily enter the drill tool body, causing a blowout in the drill tool. Therefore, a blowout preventer needs to be installed in the drill tool to prevent the liquid in the well from entering the drill tool.

[0052] There are many options for the setting position of the blowout preventer. For example, the blowout preventer can be set between any two of the drill bit, drill collar, drill rod and stabilizer. As for the setting position of the blowout preventer, this embodiment does not limit it here, as long as the function of the blowout preventer can be achieved.

[0053] In order to facilitate the description of the blowout preventer, the blowout preventer is described in detail below by taking the example that the blowout preventer is arranged between the drill bit and the drill collar.

[0054] like Figure 1 As shown, the blowout prevention device provided by the embodiment of the present invention includes a valve body 100 and a valve core 200; the valve body 100 is used to provide a space for installing the valve core 200, and the valve body 100 has an installation hole, and the valve core 200 can be installed in the installation hole. Among them, the valve body 100 can be a hollow cylinder.

[0055] The valve body 100 can be connected between the drill bit and the drill collar by threaded connection. Figure 1For example, the lower part of the valve body 100 can be connected to the drill bit, and the upper part of the valve body 100 can be connected to the drill collar, wherein the lower part of the valve body 100 has an external thread, and correspondingly, the drill head is provided with an internal thread used in conjunction with the external thread. In addition, the inner surface of the mounting hole corresponding to the upper part of the valve body 100 can form an internal thread, and correspondingly, the drill collar is provided with an external thread used in conjunction with the internal thread. The embodiment of the present invention realizes the connection between the valve body 100 and the drill bit and the drill collar by means of threaded connection, which facilitates the installation of the valve body 100 and improves the work efficiency. However, the connection method between the valve body 100 and the drill bit and the drill collar is not limited to the above method, for example, the upper part of the valve body 100 can be formed with an external thread, and the mounting hole corresponding to the lower part of the valve body 100 can be formed with an internal thread. For another example, the upper and lower parts of the valve body 100 are provided with internal threads or external threads at the same time, as long as the connection between the valve body 100 and the drill bit and the drill collar can be realized.

[0056] The valve body 100 includes a first opening and a second opening. It can be understood that the first opening can be one end of the mounting hole, that is, Figure 1 The second opening at the lower middle end may be the other end of the mounting hole, i.e. Figure 1 The first opening is connected to the drill bit, and the second opening is connected to the drill collar, so that the drilling fluid can be sprayed out from the nozzle of the drill bit through the drill pipe, the drill collar, the second opening, the mounting hole and the first opening, and then discharged to the processing equipment on the ground through the oil casing annulus.

[0057] like Figure 2 As shown, along the extension direction of the mounting hole, the inner surface of the mounting hole includes a bearing surface and a first sealing surface 340 arranged at intervals; the valve core 200 is slidably arranged in the mounting hole and is located between the bearing surface and the first sealing surface 340, and the valve core 200 has a second sealing surface 210 that can be sealed with the first sealing surface 340. It can be understood that the extension direction of the mounting hole can be the axial direction of the valve body, that is, Figure 2 In the direction of the arrow.

[0058] The bearing surface is used to support the valve core 200 to prevent the valve core 200 from falling off along the mounting hole to the outside of the valve body 100. For example, when the mounting hole is a cylindrical hole, the inner surface of the mounting hole can form a first protrusion extending in the axial direction of the mounting hole, and there is a certain distance between the end of the first protrusion facing away from the inner surface of the mounting hole and the axis of the mounting hole, which facilitates the circulation of drilling fluid, wherein the end surface of the first protrusion facing away from the first opening forms a bearing surface.

[0059] The first sealing surface 340 is used to be sealed with the second sealing surface 210 of the valve core 200 to achieve a sealed connection between the valve body 100 and the valve core 200. Exemplarily, the inner surface of the mounting hole may form a second protrusion extending in the direction of the axis of the mounting hole, and the end of the second protrusion away from the inner surface of the mounting hole is at a certain distance from the axis of the mounting hole, so as to facilitate the circulation of the drilling fluid, wherein the end surface of the second protrusion away from the second opening forms the first sealing surface 340, and accordingly, the upper end surface of the valve core 200 constitutes the second sealing surface 210 in contact with the first sealing surface 340.

[0060] In the related art, a rubber protective layer is usually provided on the valve body, so that the valve body and the valve core are not in full metal contact, resulting in low sealing performance between the valve body and the valve core. Therefore, the valve body 100 and the valve core 200 provided in the embodiment of the present invention are both made of metal, and accordingly, the contact between the first sealing surface 340 and the second sealing surface 210 is metal contact, which can increase the friction between the first sealing surface 340 and the second sealing surface 210, and improve the sealing performance between the valve body 100 and the valve core 200.

[0061] When the well is producing oil normally, the pressure at the bottom of the well is lower than the pressure in the blowout preventer. Under the action of gravity, the valve core 200 moves toward the first opening along the extension direction of the mounting hole, and the end face of the valve core 200 close to the first opening abuts against the bearing surface. At this time, the drilling fluid passes through the drill pipe, drill collar, the first opening, the mounting hole and the second opening, and is ejected from the nozzle of the drill bit, generating a strong impact force on the bottom of the well, thereby increasing the drilling speed.

[0062] When overflow occurs in the drilling, the pressure at the bottom of the well is greater than the pressure on the ground. Under the action of the pressure at the bottom of the well, the valve core 200 moves toward the second opening along the extension direction of the mounting hole, and makes the first sealing surface 340 and the second sealing surface 210 fit together, thereby realizing a sealed connection between the valve core 200 and the valve body 100, thereby preventing the liquid or drilling fluid in the well from spraying upward quickly and preventing a blowout.

[0063] In the blowout prevention device provided by the embodiment of the present invention, the valve core 200 and the valve body 100 are sealed only by the pressure difference between the blowout prevention device and the bottom of the well, which can avoid the spring being sleeved outside the valve body, thereby preventing the spring from failing, improving the sealing performance of the blowout prevention device, and preventing the liquid or drilling fluid in the well from entering the drilling tool to cause a blowout. In addition, the first sealing surface and the second sealing surface are face-sealed, which can improve the sealing strength between the valve body 100 and the valve core 200.

[0064] Continue to refer Figure 2As an optional implementation of the valve body 100, the valve body 100 includes an upper valve body 110 and a lower valve body 120 detachably connected to the upper valve body 110; wherein the upper valve body 110 can be connected to the lower valve body 120 by a threaded connection, that is, an external thread can be formed on the outer surface of the upper valve body 110, and an internal thread is formed on the inner surface of the lower valve body 120, and the connection between the upper valve body 110 and the lower valve body 120 is achieved by the coordinated use of the external thread and the internal thread.

[0065] The upper valve body 110 is provided with a first mounting hole 310, and the bottom surface of the upper valve body 110 close to the lower valve body 120 is recessed toward the first mounting hole 310 to form a receiving groove; the side wall of the receiving groove constitutes a first sealing surface 340. In order to increase the contact area between the first sealing surface and the second sealing surface, the receiving groove can be hemispherical.

[0066] The lower valve body 120 is provided with a second mounting hole 320, which includes a cylindrical first through hole 321, a conical second through hole 322 and a cylindrical third through hole 323 connected to the first mounting hole 310. The first through hole 321, the second through hole 322 and the third through hole 323 are connected in sequence, and the diameter of the second through hole 322 gradually decreases from the end close to the first through hole 321 to the end away from the first through hole 321; that is, the second mounting hole 320 is a stepped hole. The inner surface of the second through hole 322 constitutes a bearing surface, and the first mounting hole 310 and the second mounting hole 320 constitute a mounting hole.

[0067] like Figure 5 As shown, as an optional implementation of the valve core 200 , the valve core 200 includes a cylindrical valve stem 220 and a hemispherical valve cap 230 .

[0068] Along the axial direction of the valve stem 220, the valve stem 220 has a first end face and a second end face, the first end face is connected to the bearing surface, the second end face is connected to the valve cap 230, and the outer surface of the valve cap 230 constitutes the second sealing surface 210. The valve stem 220 and the valve cap 230 can be an integral part, which can ensure the structural strength of the valve core 200. In addition, the valve stem 220 and the valve cap 230 can also be detachably connected, such as screwing or clamping, so that when the valve stem 220 or the valve cap 230 is damaged, the valve stem 220 or the valve cap 230 can be replaced at any time, which increases the convenience of repairing and replacing the valve core 200.

[0069] like Figure 6As shown, at least one guide protrusion 221 is provided on the valve stem 220, and a guide groove (not shown in the figure) corresponding to the guide protrusion 221 is provided on the inner surface of the lower valve body 120, and the guide protrusion 221 is slidably arranged in the guide groove. In the embodiment of the present invention, by setting the guide protrusion 221 and the guide groove, the guide protrusion 221 can be moved along the guide groove, which is convenient for the installation of the valve core 200. In addition, the guide protrusion 221 and the guide groove form a snap connection, which can improve the connection strength between the valve body 100 and the valve core 200.

[0070] When there are multiple guide protrusions 221 , the multiple guide protrusions 221 may be distributed at intervals along the circumferential direction of the valve stem 220 .

[0071] In order to realize the normal operation of the drilling tool, the valve core 200 is provided with a circulation channel (not shown in the figure), one end of the circulation channel is connected to the first mounting hole, and the other end of the circulation channel is connected to the second mounting hole. There are many options for the form of the circulation channel, for example: the circulation channel is a through hole that penetrates the valve core 200 along the axial direction of the valve stem 220. For another example: the outer circumference of the valve core is recessed toward the axial direction of the valve stem to form a circulation channel.

[0072] Continue to refer Figure 5 The first end surface of the valve stem 220 is recessed toward the second end surface to form a buffer groove 222. The buffer groove 222 can buffer the impact force of the drilling fluid on the valve stem 220 and reduce damage to the valve stem 220. The buffer groove 222 is hemispherical in shape.

[0073] The valve core 200 is provided with a pressure measuring channel 223, which penetrates the valve body 100 along the axial direction of the valve body 100, and a first one-way valve 225 is provided at one end of the pressure measuring channel 223 close to the second opening. The pressure measuring channel 223 is used to transmit part of the liquid in the well to the pressure measuring device outside the well, and the pressure in the well is tested by the pressure measuring device. It can be understood that the pressure measuring device can be a vertical pressure gauge.

[0074] When the first sealing surface 340 is in contact with the second sealing surface 210, the wellbore is in a closed state, and the operator cannot obtain the pressure change in the wellbore, and thus cannot operate normally. In the embodiment of the present invention, a pressure measuring channel 223 is provided on the valve core 200, and a small amount of liquid can enter the pressure measuring device on the ground through the pressure measuring channel 233 and the first one-way valve 225. The pressure measuring device can read the pressure of the liquid and thus obtain the pressure in the wellbore. In addition, the pressure measuring channel 223 can be a through hole, and the aperture of the pressure measuring channel is small, which ensures that the pressure in the wellbore is obtained in time, and will not cause blowout, thereby increasing the safety of the mining process.

[0075] In the related art, there is no pressure measuring channel on the valve core 200. If the pressure in the well needs to be tested, the well pump needs to be turned on and the pressure in the well needs to be tested by the liquid produced by the well pump. However, when testing the pressure in the well in the above manner, reverse high pressure is caused to the oil production equipment on the ground, increasing the safety risk.

[0076] The embodiment of the present invention can detect the pressure in the well without starting the drilling pump by setting the pressure measuring channel, thereby improving safety.

[0077] refer to Figure 3 , Figure 4 and Figure 7 The pressure measuring channel 223 may also include a plurality of branch channels 224, which are spaced apart along the circumferential direction of the pressure measuring channel 223, and the axis of each branch channel 224 has a preset angle with the axis of the pressure measuring channel 223, that is, one end of each branch channel 224 close to the pressure measuring pipeline 223 is connected to the pressure measuring pipeline 223, and the other end of each branch channel 224 away from the pressure measuring pipeline 223 extends in a direction away from the pressure measuring pipeline 223, and the plurality of branch channels 224 are distributed in the form of radial lines with the axis of the pressure measuring channel 223 as the center. A second one-way valve 226 is provided at one end of each branch channel 224 close to the second opening.

[0078] In the embodiment of the present invention, by setting up multiple branch pipes 224, the pressure measuring device on the ground can detect multiple data at the same time, and obtain the pressure value in the borehole by taking the average value of the multiple data, thereby improving the accuracy of the pressure value.

[0079] The various embodiments or implementation methods in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0080] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0081] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0082] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "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 one; it can be a mechanical connection, an electrical connection, or communication with each other; 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, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0083] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A blowout prevention device, characterized in that: Including valve body and valve core; The valve body has a mounting hole and a first opening and a second opening respectively connected to the mounting hole; along the extending direction of the mounting hole, the inner surface of the mounting hole includes a bearing surface and a first sealing surface arranged at intervals; The valve body comprises an upper valve body and a lower valve body detachably connected to the upper valve body; A first mounting hole is provided in the upper valve body, and the bottom surface of the upper valve body close to the lower valve body is recessed toward the first mounting hole to form a receiving groove; the side wall of the receiving groove constitutes the first sealing surface; A second mounting hole is provided in the lower valve body, the second mounting hole comprises a cylindrical first through hole, a conical second through hole and a cylindrical third through hole connected to the first mounting hole, the first through hole, the second through hole and the third through hole are connected in sequence, and the diameter of the second through hole gradually decreases from one end close to the first through hole to one end away from the first through hole; The inner surface of the second through hole constitutes the bearing surface, and the first mounting hole and the second mounting hole constitute the mounting hole; The valve core is slidably disposed in the mounting hole and is located between the bearing surface and the first sealing surface, and the valve core has a second sealing surface that can be sealed with the first sealing surface; The valve core comprises a cylindrical valve stem and a hemispherical valve cap. Along the axial direction of the valve stem, the valve stem has a first end face and a second end face. The first end face is connected to the bearing surface, the second end face is connected to the valve cap, and the outer surface of the valve cap constitutes the second sealing surface. The valve core is provided with a circulation channel, one end of the circulation channel is communicated with the first mounting hole, and the other end of the circulation channel is communicated with the second mounting hole; The first end surface of the valve stem is recessed toward the second end surface to form a buffer groove.

2. The blowout prevention device according to claim 1, characterized in that: At least one guide protrusion is arranged on the valve stem, and a guide groove corresponding to the guide protrusion is arranged on the inner surface of the lower valve body, and the guide protrusion is slidably arranged in the guide groove.

3. The blowout prevention device according to claim 1, characterized in that: The outer circumference of the valve core is recessed in the axial direction of the valve stem to form a flow channel.

4. The blowout prevention device according to any one of claims 1 or 2, characterized in that: The valve core is provided with a pressure measuring channel, the pressure measuring channel penetrates the valve body along the axial direction of the valve body, and a first one-way valve is provided at one end of the pressure measuring channel close to the second opening; The pressure measuring channel is used to transmit part of the liquid in the well to the pressure measuring device outside the well, and the pressure in the well is tested by the pressure measuring device.

5. The blowout prevention device according to claim 4, characterized in that: The pressure measuring channel comprises a plurality of branch channels, the plurality of branch channels are spaced apart along the circumferential direction of the pressure measuring channel, and an axis of each branch channel has a preset angle with the axis of the pressure measuring channel; A second one-way valve is disposed at one end of each branch channel close to the second opening.

6. A drilling tool, characterized in that: It comprises a drilling tool body and a blowout prevention device as claimed in any one of claims 1 to 5; The blowout prevention device is connected to the drilling tool body.

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