Mechanical blowout prevention valve device

Abstract

The invention discloses a mechanical blowout prevention valve device which comprises an upper body and a lower body which are connected in sequence. A limiting step is arranged in the upper body; a steel ball is arranged in the lower body, and when oil gas enters the lower body from the lower portion, the steel ball can move upwards along the lower body till the steel ball abuts against the lower end of the limiting step. When overflow occurs in a well and oil gas enters the lower body, the steel ball starts to move upwards under the pushing of the oil gas and stops moving until the other limiting steps abut against each other, and at the moment, due to blocking of the steel ball, the oil gas can be prevented from further flowing upwards; other devices on the ground can judge whether overflow display exists or not according to the change of the standing pressure, corresponding measures are taken, the device can prevent the blowout phenomenon, it is guaranteed that an oil and gas well does not have overflow and blowout accidents to the maximum extent, the construction operation cost is reduced, and the construction safety of oil and gas well perforation operation or underground operation is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum exploration and development, and relates to a mechanical anti-blowout valve device. Background Art

[0002] In the process of oil and gas exploration, the number of complex wells and special process wells such as ultra-deep wells, high-sulfur oil and gas wells, high-angle wells, and horizontal wells has increased dramatically, and new situations and new problems have continuously emerged in production safety. Especially in the process of oil testing in the "three high gas fields", it is necessary to open the oil and gas layer for perforation operations. Generally, the drilling tool is transmitted and perforated before the completion of the well packer string. Since the "three high" gas wells are mostly ultra-high pressure gas reservoirs, they communicate with the production layer after perforation. If overflow occurs after perforation, the internal blowout prevention tools such as plugs and blowout prevention single roots prepared at the wellhead can only be connected and the well can be shut down. However, when the string is blown out, a large amount of oil and gas is sprayed out, which affects the construction personnel's operating line of sight. Especially when the overflow in the string forms a certain spraying momentum, it is difficult to connect the plug or arrow-shaped check valve, which is not easy to center and lead the buckle, and the psychological pressure of the wellhead operator is high. Therefore, in some extreme cases, it is very difficult to connect the blowout prevention tool to shut down the well, which causes the failure of well control or can only close the shear full-sealed gate. However, whether the shear full-sealed gate is effective in an emergency cannot be verified at ordinary times. Once a blowout accident occurs, it will cause great economic losses and casualties, and even have adverse social impacts.

[0003] At present, in the process of oil field exploration and development, once overflow or blowout occurs, the existing technology is used to shut down the well. After demonstration and analysis, there are mainly the following shortcomings:

[0004] First, when overflow is detected during drilling and repair, it is not possible to determine whether it is a real overflow. If the circulation continues, the overflow will become more serious. The more formation fluid invades the wellbore, the more likely it is to cause a blowout. The existing blowout prevention equipment can only choose to "shut down the well immediately when overflow is found, and shut down the well for inspection when overflow is suspected", but cannot actively prevent blowouts.

[0005] Secondly, once overflow or blowout occurs, the existing technology mainly relies on the internal blowout prevention tool and semi-sealed gate prepared at the wellhead to achieve emergency well shut-in. Under normal circumstances, emergency well shut-in can be achieved by emergency connection. However, if the formation pressure is very high and the overflow or blowout in the tubing is serious, the operator's line of sight will also become poor, making it more difficult to connect and affecting the success rate of the emergency connection.

[0006] At the same time, if the emergency connection fails, there is no better way than to close the fully sealed shear gate. However, the success rate of shutting down the well by the fully sealed shear gate cannot be guaranteed. In some areas, there have been many cases where the fully sealed shear gate failed to shear the drilling tools at critical moments, leading to blowout accidents. Summary of the invention

[0007] The purpose of the present invention is to solve the problem in the prior art that when overflow occurs, blowout is likely to occur and blowout cannot be actively prevented, and to provide a mechanical blowout prevention valve device.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A mechanical blowout prevention valve device comprises an upper body and a lower body connected in sequence;

[0010] A limited step is arranged inside the upper body;

[0011] A steel ball is arranged inside the lower body. When oil and gas enter the lower body from the bottom, the steel ball can move upward along the lower body until the steel ball abuts against the lower end of the limiting step.

[0012] The present invention is further improved in that:

[0013] The limiting step is distributed circumferentially along the inner side wall of the upper body, and the inner diameter of the limiting step is smaller than the diameter of the steel ball.

[0014] The limiting step includes an inclined portion and a vertical portion;

[0015] One end of the inclined portion is connected to the side wall of the upper body, and the other end is connected to the vertical portion.

[0016] There are two groups of inclined parts, which are symmetrically arranged at the upper and lower ends of the vertical part.

[0017] A ball seat is arranged inside the lower body, and the steel ball is placed on the ball seat.

[0018] The ball seat is a flap-type ball seat.

[0019] The petal-type ball seat is welded to the inner wall of the lower body.

[0020] The upper body and the lower body are connected via upper and lower connecting threads.

[0021] An upper female buckle is arranged at the upper port of the upper body.

[0022] A lower male buckle is arranged at the lower port of the lower body.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention discloses a mechanical anti-blowout valve device, wherein a steel ball is arranged inside a lower body, and a limiting step is arranged inside an upper body, wherein the limiting step can limit the steel ball, and when overflow occurs in the well and oil and gas enter the lower body, the steel ball starts to move upward under the push of the oil and gas, and stops moving when the remaining limiting steps abut against each other. At this time, due to the obstruction of the steel ball, the oil and gas can be prevented from further flowing upward, and a blowout of the oil and gas will not occur immediately. Other equipment on the ground can judge whether there is an overflow display according to the change of the vertical pressure, and take corresponding measures. The device disclosed by the present invention can prevent the blowout phenomenon, and ensure that the oil and gas wells do not have overflow and blowout accidents to the greatest extent, reduce the construction operation cost, and ensure the safety of the perforating operation or downhole operation of the oil and gas wells.

[0025] Furthermore, in the present invention, the inner diameter of the limiting step is smaller than the diameter of the steel ball, thereby improving the limiting effect on the steel ball.

[0026] Furthermore, in the present invention, the ball seat is a flap-type ball seat, which can not only ensure the support of the steel ball, but also affect the flow of the internal liquid.

[0027] Furthermore, in the present invention, the flap-type ball seat is welded to the inner wall of the lower body to ensure the installation strength of the flap-type ball seat. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 It is a structural diagram of the limiting step of the present invention.

[0031] Among them: 1-upper female buckle; 2-limiting step; 3-upper body; 4-upper and lower connecting threads; 5-lower body; 6-steel ball; 7-ball seat; 8-lower male buckle. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, 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 part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0035] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0036] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0037] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0039] See also Figure 1The embodiment of the present invention discloses a mechanical blowout prevention valve device. Under normal circumstances, the mechanical blowout prevention valve device is installed at a certain position in the middle and lower part of the drilling tool, which does not affect the normal positive circulation of mud. At this time, the steel ball in the mechanical blowout prevention valve device is on the valve disc inside the device, and there is a circulation channel around the valve disc, which does not affect the normal production operation. When overflow occurs, oil and gas flow into the wellbore from the formation. Since the oil and gas move upward in the wellbore, the steel ball is also pushed upward. If the oil and gas invasion speed is further accelerated, the steel ball will move upward and get stuck on the slope, thereby effectively blocking the oil and gas flow from continuing to invade. The present invention has the characteristics of simple structure, safe use, and convenient operation. It can effectively overcome or avoid the disadvantages of existing internal blowout prevention tools, give full play to the advantages of safe control of formation oil and gas as much as possible, guarantee the safety of construction operations to the greatest extent, and improve the safety production time of oil wells.

[0040] Specifically include:

[0041] Upper female buckle 1; limiting step 2; upper body 3; upper and lower connecting threads 4; lower body 5; steel ball 6; ball seat 7 and lower male buckle 8.

[0042] Example 1

[0043] The present embodiment discloses a mechanical blowout prevention valve device, comprising an upper body 3 and a lower body 5 connected in sequence; a limiting step 2 is arranged inside the upper body 3; a steel ball 6 is arranged inside the lower body 5, and when oil and gas enter the lower body 5 from the bottom, the steel ball 6 can move upward along the lower body 5 until the steel ball 6 abuts against the lower end of the limiting step 2.

[0044] Example 2

[0045] This embodiment discloses a mechanical blowout prevention valve device, comprising an upper body 3 and a lower body 5 connected in sequence; a limiting step 2 is arranged inside the upper body 3; a steel ball 6 is arranged inside the lower body 5, and when oil and gas enter the lower body 5 from the bottom, the steel ball 6 can move upward along the lower body 5 until the steel ball 6 abuts against the lower end of the limiting step 2. The limiting step 2 is circumferentially distributed along the inner side wall of the upper body 3, and the inner diameter of the limiting step 2 is smaller than the diameter of the steel ball 6, thereby improving the limiting effect on the steel ball.

[0046] When the steel ball 6 moves to the lower part of the limiting step 2, since the diameter of the steel ball 6 is larger than the inclined inner diameter of the limiting step 2, the steel ball 6 blocks the upward flow channel of the oil and gas flow under the action of the bottom hole oil and gas flow, thereby preventing overflow or blowout.

[0047] Example 3

[0048] This embodiment discloses a mechanical blowout prevention valve device, comprising an upper body 3 and a lower body 5 connected in sequence; a limit step 2 is arranged inside the upper body 3; a steel ball 6 is arranged inside the lower body 5, and when oil and gas enter the lower body 5 from the bottom, the steel ball 6 can move upward along the lower body 5 until the steel ball 6 abuts against the lower end of the limit step 2. Figure 2 The limiting step 2 is distributed circumferentially along the inner wall of the upper body 3, and the inner diameter of the limiting step 2 is smaller than the diameter of the steel ball 6; the limiting step 2 includes an inclined portion and a vertical portion; one end of the inclined portion is connected to the side wall of the upper body 3, and the other end is connected to the vertical portion.

[0049] Furthermore, in this embodiment, two groups of inclined portions are provided, and the two groups of inclined portions are vertically symmetrically arranged at both ends of the vertical portion.

[0050] Furthermore, in this embodiment, the end of the inclined portion close to the vertical portion extends along the inner side wall of the upper body 3 toward the center of the upper body 3 .

[0051] Furthermore, in this embodiment, the limiting steps 2 can be distributed along the circumference of the inner diameter of the upper body 3, or can be distributed along the internal intervals, as long as the limiting of the steel ball 6 can be achieved.

[0052] Example 4

[0053] The present embodiment discloses a mechanical blowout prevention valve device, comprising an upper body 3 and a lower body 5 connected in sequence; a limiting step 2 is arranged inside the upper body 3; a steel ball 6 is arranged inside the lower body 5, and when oil and gas enter the lower body 5 from the bottom, the steel ball 6 can move upward along the lower body 5 until the steel ball 6 abuts against the lower end of the limiting step 2, and a ball seat 7 is arranged inside the lower body 5, and the steel ball 6 is placed on the ball seat 7.

[0054] Furthermore, in the embodiment of the present invention, the ball seat 7 is a flap-type ball seat, and a mounting groove can be opened on the inner wall of the lower body 5, and the flap-type ball seat and the mounting groove are welded together to improve the installation strength and ensure the stability of the connection.

[0055] Furthermore, in the embodiment of the present invention, due to the structural characteristics of the flap-type ball seat itself, a circulation channel can be formed around and inside the flap-type ball seat, and the circulation channel can carry out positive circulation of mud. When overflow or blowout occurs, the bottom hole pressure is greater than the pressure of the liquid column in the water eye of the tubing column, and the bottom hole oil and gas flow enters the lower part of the mechanical blowout prevention valve device from the bottom of the tubing column. Since the bottom hole pressure is greater than the pressure of the liquid column in the water eye, the oil and gas flow inside the water eye of the tubing column moves from bottom to top, flows through the flap-type ball seat and acts on the steel ball 6. When the oil and gas flow inside the water eye of the tubing column moves from bottom to top, it can pass through the flap-type ball seat 7 and act on the steel ball 6, pushing the steel ball 6 to move upward.

[0056] Example 5

[0057] The present embodiment discloses a mechanical blowout prevention valve device, comprising an upper body 3 and a lower body 5 connected in sequence; a limiting step 2 is arranged inside the upper body 3; a steel ball 6 is arranged inside the lower body 5, and when oil and gas enter the lower body 5 from the bottom, the steel ball 6 can move upward along the lower body 5 until the steel ball 6 abuts against the lower end of the limiting step 2, and the upper body 3 and the lower body 5 are locked by upper and lower connecting threads 4.

[0058] Example 6

[0059] Furthermore, the embodiment of the present invention is based on any of the aforementioned embodiments, and an upper female buckle 1 is provided at the upper port of the upper body 3, and the upper female buckle 1 is used to connect other equipment at the lower part of the mechanical blowout prevention valve device.

[0060] Furthermore, in the embodiment of the present invention, a lower male buckle 8 is provided at the lower port of the lower body 5, and the lower male buckle 8 is used to connect other equipment at the upper end of the mechanical blowout prevention valve device.

[0061] The working principle of the embodiment of the present invention is as follows:

[0062] Place the mechanical blowout prevention valve device into the well and adjust the lowering depth to meet the well requirements;

[0063] During the normal operation of the perforating string, the mud enters the water hole from the wellhead and is transmitted to the mechanical blowout prevention valve device. The steel ball 6 sits on the flap-type ball seat. There is a flow channel around the flap-type ball seat for positive circulation of the mud.

[0064] When overflow or blowout occurs, the bottom hole pressure is greater than the pressure of the liquid column in the water eye of the tubing, and the bottom hole oil and gas flow enters the lower part of the mechanical blowout prevention valve device from the bottom of the tubing. Since the bottom hole pressure is greater than the pressure of the liquid column in the water eye, the oil and gas flow inside the water eye of the tubing moves from bottom to top, flows through the flap-type ball seat and acts on the steel ball 6, causing the steel ball 6 to also move upward. When the steel ball moves to the lower part of the limiting step 2 of the upper body 3, since the diameter of the steel ball 6 is greater than the inner diameter of the limiting step 2 of the upper body 3, under the action of the bottom hole oil and gas flow, the steel ball 6 blocks the upward flow channel of the oil and gas flow, thereby preventing overflow or blowout.

[0065] The mechanical blowout prevention valve device disclosed in the embodiment of the present invention is only applicable to downhole operations of positive circulation, but not to reverse circulation operations.

[0066] The mechanical blowout prevention valve device disclosed in the embodiment of the present invention can be used for perforating operation tubing or for downhole operation tubing during operation. The mechanical blowout prevention valve device is located at the lower end of the tubing string assembly and is sent into the formation together with the tubing string assembly, followed by perforating operations or downhole operations. Once overflow occurs, it can effectively block the continued invasion of oil and gas flows.

[0067] To prevent blowouts during perforation or well repair operations of "three high" gas wells, and to achieve safe well shut-in, the mechanical blowout prevention valve device is installed in the middle and lower part of the drilling tool. During normal operation, the steel ball in the mechanical blowout prevention valve device is on the flap-type support in the valve, which does not affect the downward flow of mud. When the formation oil and gas invade the wellbore and there is an overflow display, the upward oil and gas flow pushes the steel ball to the step to prevent the oil and gas from flowing further upward. The ground can judge whether there is an overflow display according to the change of the vertical pressure, and take measures to fill the weighted mud to balance the formation pressure. The present invention can effectively overcome or avoid the defects of the current internal blowout prevention tool well shut-in, and to the greatest extent ensure that oil and gas wells do not have overflow and blowout accidents, reduce the construction cost, and ensure the safety of oil and gas well perforation operations or downhole operations.

[0068] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A mechanical blowout prevention valve device, characterized in that: It comprises an upper body (3) and a lower body (5) which are connected in sequence; A limiting step (2) is provided inside the upper body (3); A steel ball (6) is arranged inside the lower body (5). When oil and gas enter the lower body (5) from the bottom, the steel ball (6) can move upward along the lower body (5) until the steel ball (6) abuts against the lower end of the limiting step (2).

2. A mechanical blowout prevention valve device according to claim 2, characterized in that: The limiting step (2) is distributed circumferentially along the inner side wall of the upper body (3), and the inner diameter of the limiting step (2) is smaller than the diameter of the steel ball (6).

3. A mechanical blowout prevention valve device according to claim 2, characterized in that: The limiting step (2) comprises an inclined portion and a vertical portion; One end of the inclined portion is connected to the side wall of the upper body (3), and the other end is connected to the vertical portion.

4. A mechanical blowout prevention valve device according to claim 3, characterized in that: There are two groups of inclined parts, which are symmetrically arranged at the upper and lower ends of the vertical part.

5. A mechanical blowout prevention valve device according to claim 1, characterized in that: A ball seat (7) is arranged inside the lower body (5), and the steel ball (6) is placed on the ball seat (7).

6. A mechanical blowout prevention valve device according to claim 5, characterized in that: The ball seat (7) is a flap-type ball seat.

7. A mechanical blowout prevention valve device according to claim 6, characterized in that: The flap-type ball seat is welded to the inner wall of the lower body (5).

8. A mechanical blowout prevention valve device according to claim 1, characterized in that: The upper body (3) and the lower body (5) are connected via upper and lower connecting threads (4).

9. A mechanical blowout prevention valve device according to claim 1, characterized in that: An upper female buckle (1) is provided at the upper port of the upper body (3).

10. A mechanical blowout prevention valve device according to claim 9, characterized in that: A lower male buckle (8) is provided at the lower port of the lower body (5).

Images