A lost circulation valve while drilling

Abstract

The application provides a drilling leak stoppage valve. The drilling leak stoppage valve comprises a leak stoppage valve body, an elastic member, a sliding sleeve, a ball seat and a ball catcher. The leak stoppage valve body comprises a first cavity, an inner step and a first opening on the side wall of the body. The bottom end of the elastic member abuts against the inner step. The sliding sleeve is slidably arranged in the first cavity and the bottom end is supported by the elastic member. The sliding sleeve comprises a second cavity and a second opening on the side wall thereof, and the second opening can be moved to a position in alignment with the first opening when the elastic member is compressed. The ball seat is arranged in the second cavity and is positioned between the second opening and the bottom end of the sliding sleeve, the ball seat is connected to the inner wall of the sliding sleeve and has a ball seat opening for accommodating a ball, and the ball seat can be deformed at a predetermined pressure to increase the radial size of the ball seat opening. The ball catcher is connected to the bottom end of the leak stoppage valve body. The drilling leak stoppage valve is more stable in performance and is not affected by the high temperature and high pressure at the bottom of the well, and is convenient for plugging the well leakage under the high temperature and high pressure environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oilfield equipment, and more particularly to a leak stoppage valve while drilling. BACKGROUND

[0002] With the deepening of oil and gas exploration and development, the number of deep wells, complex wells and special process wells is increasing year by year. The well leakage problem has become a major problem restricting the drilling speed. In the past, when well leakage occurred, it was necessary to drill up in time for leak stoppage treatment, which seriously affected the drilling speed.

[0003] In recent years, leak stoppage technology while drilling has been developed, that is, leak stoppage operation can be performed without taking the drilling tool out of the well. Leak stoppage tools while drilling have become an important means to deal with well leakage and have been widely used at home and abroad. The existing leak stoppage tools mainly include a bypass valve assembly and a ball catcher assembly. During the construction process, when leak stoppage is needed, larger leak stoppage balls are needed to be put into the wellhead to open the bypass circulation hole, and leak stoppage construction is started. After leak stoppage is completed, two smaller closing balls are put in to close the bypass hole, at this time the leak stoppage ball is deformed under pressure, passes through the ball seat and falls into the ball catcher. At the same time, the bypass valve is closed, and the two smaller closing balls also fall into the ball catcher.

[0004] In the above construction process, the leak stoppage ball goes through the stages of setting, pressure bearing and deformation, and finally enters the ball catcher. The control of this process is the key to successful leak stoppage. In order to make the leak stoppage ball deform under pressure, it is usually made of non-metallic elastic material. However, when there is high temperature and high pressure downhole, the leak stoppage ball is easy to soften and its pressure bearing capacity is greatly reduced, and it cannot bear pressure and directly falls into the ball catcher during leak stoppage construction, resulting in leak stoppage failure.

[0005] Therefore, it is necessary to develop a leak stoppage technology while drilling which can still successfully perform leak stoppage operation under high temperature and high pressure. SUMMARY

[0006] The present application aims to provide a leak stoppage valve while drilling to solve the above problems existing in the prior art. The leak stoppage valve while drilling has more stable performance and is not affected by high temperature and high pressure at the bottom of the well, and is convenient for plugging well leakage under high temperature and high pressure environment.

[0007] To achieve the above technical purpose, the technical scheme adopted by the present application is as follows:

[0008] According to one aspect of the present application, a leak stoppage valve while drilling is provided, which comprises:

[0009] a leak stoppage valve body extending in the axial direction and comprising a first cavity penetrating through the body, an inner step located on the inner wall of the body close to the bottom end, and a first opening located on the side wall of the body;

[0010] an elastic member, the bottom end of the elastic member abutting against the inner step;

[0011] a sliding sleeve slidably arranged in the first cavity and supported at a bottom end by the elastic member, the sliding sleeve comprising a second cavity and a second opening on a side wall thereof, the second opening being movable to a position in alignment with the first opening when the elastic member is compressed;

[0012] a ball seat arranged in the second cavity and positioned between the second opening and the bottom end of the sliding sleeve, the ball seat being connected to an inner wall of the sliding sleeve and having a seat opening for accommodating the ball, the ball seat being deformable at a predetermined pressure to increase a radial dimension of the seat opening;

[0013] a ball catcher connected to the bottom end of the plug valve body.

[0014] According to an embodiment of the present application, the ball seat comprises a peripheral annular base and a plurality of elastic petals distributed along a circumferential direction of the base, each elastic petal extending radially inward from the base, in an undeformed state, the plurality of elastic petals abut each other to form a complete annular shape and define a seat opening of a smaller size, in a deformed state at the predetermined pressure, the elastic petals rotate relative to the base to increase the seat opening.

[0015] According to an embodiment of the present application, the base and the elastic petals are of an integral structure and made of an elastic material, an elastic modulus of the elastic material being selected such that the elastic petals are elastically deformed when a force greater than a first pressure is applied, the first pressure being a force required to compress the elastic member to a shortest length.

[0016] According to an embodiment of the present application, a return disc spring is further included, the ball seat being supported at an upper end of the return disc spring, a lower end of the return disc spring being fixedly connected to the inner wall of the sliding sleeve, wherein the annular base of the ball seat is connected to a disc of the return disc spring and the rotation of the elastic petals is not hindered by the return disc spring.

[0017] According to an embodiment of the present application, the base and the elastic petals are of a split structure and connected by an elastic connecting member, the elastic connecting member being arranged to be elastically deformed when a force greater than a first pressure is applied to rotate the elastic petals relative to the base, the first pressure being a force required to compress the elastic member to a shortest length.

[0018] According to an embodiment of the present application, a lower portion of the first cavity has a guide portion, a guide member is further arranged between the sliding sleeve and the elastic member, a moving path of the guide member being constrained by the guide portion.

[0019] According to an embodiment of the present application, the guide portion is a groove arranged on the inner wall, the guide member comprising a tab extending into the groove.

[0020] According to an embodiment of the present application, the guide portion is a hexagonal channel arranged at a lower portion of the first cavity, the guide member is a hollow guide shaft matching the shape of the hexagonal channel.

[0021] According to one embodiment of the present application, the ball catcher is in a cylindrical shape and has a third cavity penetrating through the base thereof, and a ball catcher mandrel is arranged in the third cavity, the ball catcher mandrel has a fourth cavity, and the top of the ball catcher mandrel has a plurality of top flanges extending radially outward from the outer wall thereof, and the bottom of the ball catcher mandrel has a plurality of bottom flanges axially aligned with the top flanges, each flange extending from the outer wall of the ball catcher mandrel to the inner wall of the ball catcher, and adjacent flanges at the same axial position are spaced from each other in the circumferential direction.

[0022] According to one embodiment of the present application, the upper portion of the fourth cavity is provided with a ball blocking device, the ball blocking device includes a plurality of elastic claws, each of which extends downward and towards the central axis of the ball catcher mandrel from a base abutting the inner wall of the ball catcher mandrel, and the elastic claws are capable of moving towards the direction away from the central axis under the impact of the ball.

[0023] According to one embodiment of the present application, the middle portion of the fourth cavity is provided with a baffle, the baffle divides the fourth cavity into a first portion and a second portion which are spaced from each other, and a plurality of holes are respectively arranged on the side wall of the ball catcher mandrel around the first portion and the second portion.

[0024] With the above technical solutions, the present application has at least the following beneficial effects:

[0025] The structure feature of the conventional lost circulation valve is changed from the deformation of the ball under pressure to the deformation of the ball seat, and the performance is more stable, and the rigid ball which is not easy to deform can be used for the small ball and is not affected by the high temperature and high pressure at the well bottom.

[0026] In addition, the ball catcher with novel structure is designed, and the elastic claws and the baffle structure of the mandrel effectively solve the problem that when the drilling is down or the overflow is encountered, the lower drilling fluid upwells, pushes the small ball in the ball catcher upward, and even upwells to the upper portion of the lost circulation ball seat, so that the small ball blocks the flow passage of the drilling fluid after the pump is started, and the normal circulation pump pressure rises, which can ensure that the drilling speed is not affected. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings are included to provide a further understanding of the present disclosure and constitute a part of the specification, and together with the specific embodiments described below, serve to explain the present disclosure, but do not constitute a limitation on the present disclosure. In the drawings:

[0028] Figure 1 is a schematic diagram of the overall structure of the lost circulation valve while drilling according to one embodiment of the present application.

[0029] Figure 2 is a schematic diagram of the structure of the ball seat according to one embodiment of the present application.

[0030] Figure 3 is an interface diagram of the guide mandrel according to one embodiment of the present application.

[0031] Figure 4 is a structural schematic diagram of a ball catcher mandrel according to an embodiment of the present application.

[0032] BRIEF DESCRIPTION OF DRAWINGS

[0033] 10 plug valve body, 12 first cavity, 14 inner step, 16 first opening, 18 second inner step, 20 sliding sleeve, 22 second cavity, 24 second opening, 26 third inner step, 30 elastic member, 40 ball seat, 42 base body, 44 neck, 45 connecting part, 46 elastic flap, 50 ball catcher, 52 third cavity, 53 channel, 54 ball catcher mandrel, 54a fourth cavity, 54b top / bottom flange, 54c baffle, 54d fluid outlet, 54e fluid inlet, 54f drain, 56 ball blocker, 58 bottom plate, 60 reset disc spring, 70 guide. DETAILED DESCRIPTION

[0034] The specific embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present disclosure, and are not intended to limit the present disclosure.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description herein is for describing specific embodiments only and is not intended to be limiting of the application, for example, the terms "length", "width", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like specify relative positions according to the orientations shown in the drawings and are for convenience not for limitation of the present technical solution.

[0036] The terms "include", "has" and any variations thereof in the specification and claims of the present application and the above description of the drawings are intended to cover the non-exclusive inclusion; the terms "first", "second" and the like in the specification and claims of the present application or the above description of the drawings are used to distinguish different objects, not to describe a specific order. The meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0037] In the specification and claims of the present application and the above description of the drawings, when an element is referred to as "fixed to" or "mounted to" or "disposed to" or "connected to" another element, it can be directly or indirectly on the other element. For example, when an element is referred to as "connected to" another element, it can be directly or indirectly connected to the other element.

[0038] Furthermore, references made herein to "embodiments" mean that specific features, structures, or characteristics described in connection with an embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. As will be apparent to those of ordinary skill in the art, embodiments described herein can be combined with other embodiments.

[0039] The present application provides a lost circulation valve while drilling. Figure 1 A schematic diagram of the overall structure of a lost circulation valve while drilling according to an embodiment of the present application is shown. The lost circulation valve while drilling generally includes a lost circulation valve body 10, a sliding sleeve 20, a spring 30, a ball seat 40, and a ball catcher 50.

[0040] The lost circulation valve body 10 extends along an axial direction, and includes a first cavity 12 extending through the body, an inner step 14 near the bottom end of the body and on the inner wall of the body, and a first opening 16 on the side wall of the body. A plurality of first openings 16 can be provided at diametrically opposite positions of the lost circulation valve body 10. The first cavity 12 has a top opening and a bottom opening. The portion of the lost circulation valve body 10 near the top opening can be provided with structures for connecting other components, such as a drill pipe, and the portion near the bottom opening can be provided with structures, such as threads, for connecting the ball catcher 50. The inner step 14 is formed by a portion of the lost circulation valve body 10 having a different wall thickness. Specifically, the portion near the bottom end has a greater wall thickness than the upper portion connected thereto, thereby forming the inner step 14 that protrudes radially toward the central axis, which can be used to support the spring 30.

[0041] The bottom end of the spring 30 abuts against the inner step 14. The spring 30 extends along the axial direction, and its upper end is connected to the sliding sleeve 20. The spring 30 can specifically be a coil spring.

[0042] The sliding sleeve 20 is provided in the first cavity 12, and its bottom end is supported by the spring 30. The sliding sleeve 20 can slide along the inner wall of the lost circulation valve body 10, and in the process, compress the spring 30 to move downward. In some cases, a second inner step 18 can be provided between the bottom end of the sliding sleeve 20 and the inner step 14 to limit the lower axial movement of the sliding sleeve 20. When the bottom end of the sliding sleeve 20 moves to abut against the second inner step 18, the sliding sleeve 20 can no longer move downward. The upper limit of the axial movement of the sliding sleeve 20 can be defined by a circlip provided on the inner wall of the lost circulation valve body 10.

[0043] The sliding sleeve 20 includes a second cavity 22 and a second opening 24 located on its sidewall. The number of second openings 24 is the same as the number of first openings 16. The second openings 24 are axially closer to the top of the leak-stopping valve body 10 than the first openings 16. When the elastic element 30 is compressed, the sliding sleeve 20 moves downward. When the sliding sleeve 20 moves downward until its bottom end abuts against the second inner step 18, the second openings 24 align with the first openings 16. At this time, the second cavity 22 communicates with the external area of ​​the leak-stopping valve body 10 through the second openings 24 and the first openings 16, allowing for leak-stopping operations.

[0044] A ball seat 40 is disposed within the second cavity 22 and positioned between the second opening 24 and the bottom end of the sliding sleeve 20. The ball seat 40 is connected to the inner wall of the sliding sleeve 20 and has a ball seat opening for accommodating a ball. Existing drilling plugging valves typically use deformable non-metallic balls to deform under pressure and pass through the ball seat opening. However, the drilling plugging valve of this application preferably uses a rigid ball (e.g., a metal ball) that cannot deform, and the ball passes through the ball seat opening by deforming the ball seat, which will be described in detail below.

[0045] The upper part of the ball seat 40 is limited by a third inner step 26 provided on the inner wall of the sleeve 20. The ball seat 40 can deform under a predetermined pressure to increase the radial dimension of the ball seat opening. For example, Figure 2 As shown, the left view is an axial view of the ball seat 40, and the right view is a circumferential view taken along line AA in the left view. The ball seat 40 is a cylindrical component extending axially, mainly comprising a base 42 and elastic flaps 46. The base 42 has a neck 44 that tapers towards the central axis, and the elastic flaps 46 are provided at the neck 44. As shown in the right view, four elastic flaps 46 are distributed circumferentially along the base 42, each elastic flap 46 extending radially inward from the sidewall of the base 42. In the undeformed state, the four elastic flaps 46 abut against each other to form a complete ring and define a small ball seat opening. When a predetermined pressure is applied to the elastic flaps 46 to deform them, each elastic flap 46 rotates relative to the base 42 along the connecting portion 45 connected to the base 42, thereby increasing the radial dimension of the ball seat opening.

[0046] In some embodiments, the base 42 and the elastic flap 46 are an integral structure made of an elastic material having a predetermined elastic modulus. This elastic modulus is selected such that the elastic flap 46 undergoes elastic deformation when the pressure is greater than a first pressure, which is the force required to compress the elastic element 30 to its shortest length. That is, when the ball seat opening is blocked by the plugging ball, pressurizing the second cavity 22 first causes compression deformation of the elastic element 30. Only when the elastic element 30 is compressed to its shortest length will further increasing the pressure within the second cavity 22 cause the elastic flap 46 to rotate relative to the base 42 to expand the ball seat opening. This ensures that the plugging ball enters the ball catcher 50 only after the plugging operation has been completed.

[0047] In other embodiments, the base 42 and the elastic flap 46 are separate structures, connected by an elastic connector, such as a torsion spring. A first torsion arm of the torsion spring is fixedly connected to the base 42, and a second torsion arm of the torsion spring is fixedly connected to one of the elastic flaps 46. The number of torsion springs is the same as the number of elastic flaps 46. The strength of the torsion springs is chosen such that, at a pressure greater than a first pressure, the second torsion arm torsion relative to the first torsion arm causes the elastic flap 46 to rotate relative to the base 42, which is the force required to compress the elastic element 30 to its shortest length. Other forms of deformable ball seats are also conceivable according to the teachings of the invention, and these structures are also included within the scope of the invention.

[0048] Alternatively, in some embodiments, such as Figure 1 As shown, the leak-proof valve while drilling also includes a return disc spring 60. The return disc spring 60 can limit the ball seat 40 below it and cause the ball seat 40 to move to its initial axial position when the pressure in the second cavity 22 is relieved. The ball seat 40 is supported on the upper end of the return disc spring 60. The lower end of the return disc spring 60 is fixedly connected to the inner wall of the sliding sleeve 20. The annular base 42 of the ball seat 40 is connected to the disc of the return disc spring 60, and the rotation of the elastic flap 46 is not hindered by the return disc spring 60. That is, the radial range of the elastic flap 46 corresponds to the extension range of the central hole of the return disc spring 60, so the elastic flap 46 can open within the central hole of the return disc spring 60.

[0049] Optionally, in some embodiments, the lower part of the first cavity 12 has a guide portion, and a guide 70 is also provided between the sliding sleeve 20 and the elastic member 30, with the sliding sleeve 20 fixedly connected to the guide 70. The guide 70 is used to prevent the sliding sleeve 20 from rotating during axial movement. Specifically, the guide 70 cooperates with the guide portion, and the movement path of the guide 70 is constrained and limited by the guide portion. For example, the guide portion is an elongated groove provided on the inner wall of the leak-stopping valve body 10, and two elongated grooves can be provided on the radially opposite sides of the inner wall of the leak-stopping valve body 10. The guide may include an annular base with an outer diameter adapted to the radial dimension of the first cavity 12 and a protrusion or protrusion extending from the base into the groove. Thus, when the elastic member 30 is compressed and drives the sliding sleeve 20 to move axially, the guide 70 cooperates with the guide portion to prevent the sliding sleeve 20 from rotating, thereby ensuring that the second opening 24 can be aligned with the first opening 16.

[0050] Alternatively, in some other embodiments, the guide portion is a hexagonal channel disposed in the lower part of the first cavity 12, and the guide member 70 is a hollow guide shaft that matches the shape of the hexagonal channel. Figure 3A cross-sectional view of the guide 70 is shown. The guide 70 has a hexagonal outer shape with a hole in the center, which is larger than the diameter of the ball to ensure that the ball can pass through the hole and enter the ball catcher 50. However, it is contemplated that other angular structures can be used in accordance with the teachings of the present application, for example, the guide can be a quadrangular channel disposed in the lower portion of the first cavity 12, and the guide 70 can have a quadrangular outer shape with a hole.

[0051] The ball catcher 50 is connected to the bottom end of the ball plug valve body 10. The ball catcher 50 is installed at the bottom end of the ball plug valve body 10 to ensure that the ball does not enter the bottom drilling tool and block the bottom drilling tool. The ball catcher 50 and the ball plug valve body 10 can be connected by threads, and a snap spring retainer is installed to ensure safety and ease of disassembly.

[0052] The ball catcher 50 is cylindrical and has a third cavity 52 extending through the base of the ball catcher 50. The third cavity 52 has a ball catcher mandrel 54 disposed therein. The ball catcher mandrel 54 has a fourth cavity 54a (see FIG. 6) extending through the base of the ball catcher mandrel 54. Figure 4 For example, the inner wall of the ball catcher 50 has an inner step at a position close to the bottom end. The bottom end of the ball catcher mandrel 54 can be supported on the inner step. The bottom of the ball catcher 50 is used to connect the drill bit or drilling tool.

[0053] Optionally, in some embodiments, the ball catcher 50 further has a ball stopper 56. The ball stopper 56 is disposed at the top of the fourth cavity 54a. The ball stopper 56 includes a plurality of elastic claws. Each elastic claw extends downward from a base portion that is in contact with the inner wall of the ball catcher mandrel 54 and toward the central axis of the ball catcher mandrel 54. The elastic claws are capable of moving away from the central axis under the impact of the falling ball and restricting the ball from moving from below the ball stopper 56 to above the ball stopper 56. That is, when the ball falls from above, the elastic claws move away from the central axis to open the gap between the elastic claws. When the ball moves upward from the bottom of the ball catcher mandrel 54, the elastic claws do not move away from the central axis, thereby stopping the ball below the ball stopper 56.

[0054] Figure 4 A structural diagram of the ball catcher mandrel 54 according to an embodiment of the present application is shown. The top of the ball catcher mandrel 54 has a plurality of top flanges 54b extending radially outward from the outer wall of the ball catcher mandrel 54. The bottom of the ball catcher mandrel 54 has a plurality of bottom flanges 54b axially aligned with the top flanges 54b. Each flange 54b extends from the outer wall of the ball catcher mandrel 54 to the inner wall of the ball catcher 50. Adjacent flanges at the top (or bottom) are circumferentially spaced apart from each other. Thus, a fluid conveying channel 53 is formed by the axially aligned top flanges 54b, bottom flanges 54b, outer wall of the ball catcher mandrel 54, and inner wall of the ball catcher 50.

[0055] The catcher mandrel 54 has a fourth cavity 54a. A baffle 54c is provided in the middle of the fourth cavity 54a. The baffle 54c divides the fourth cavity 54a into a first portion and a second portion which are separated from each other. A plurality of fluid outlets 54d are provided on the side wall of the catcher mandrel around the first portion of the cavity, and a plurality of fluid inlets 54e are provided on the side wall of the catcher mandrel around the second portion of the cavity. Liquid flowing from the second cavity 22 into the fourth cavity 54a can flow into the passage 53 via the fluid outlets 54d, and then from the passage 53 into the second portion of the fourth cavity 54a via the fluid inlets 54e, so that the fluid flows around the baffle 54c out of the catcher mandrel 54.

[0056] Optionally, in some embodiments, the catcher mandrel 54 further has a bottom plate 58 on which a leakage port 54f is provided.

[0057] During drilling operation, the while-drilling plugging valve is lowered into the well as part of the drilling tool. During normal drilling operation, drilling fluid flows through the central cavities 12, 22 and 54a of the while-drilling plugging valve, and flows out of the bottom leakage port 54f, achieving the circulation in the wellbore.

[0058] When well leakage occurs and the while-drilling plugging valve is needed to plug the leakage, the pump is stopped, the kelly is removed, the plugging balls are dropped from the wellhead, and the balls are sent at a small flow rate until the plugging balls are seated on the ball seat 40. Since the plugging balls close the flow passage, the pressure in the string increases when fluid continues to be added, pushing the ball seat 40 to move downward and compress the elastic member 30. Since the elastic member 30 is configured to have a small deformation force and the reset disc spring 60 is configured to have a large deformation force, the ball seat 40 drives the sliding sleeve 20 to move downward at this time. The guide member 70 also moves downward along the side wall of the while-drilling plugging valve body 10, and the cooperation between the guide member 70 and the guide portion ensures that the sliding sleeve 20 does not rotate when it moves downward. When the sliding sleeve 20 moves to the inner step 14 of the while-drilling plugging valve body 10, the first opening 16 and the second opening 24 are aligned at this time, and the internal cavities 12, 22 of the while-drilling plugging valve are in fluid communication with the environment area outside the while-drilling plugging valve. The plugging agent is added into the internal cavities 12, 22 of the while-drilling plugging valve. The plugging agent flows to the outside of the while-drilling plugging valve and enters the leakage area. When the plugging is completed, two closing balls are dropped from the wellhead again. The closing balls flow to the two second openings 24 under the action of fluid and block the two second openings 24. At this time, the fluid is increased, and the pressure continues to rise, pushing the ball seat 40 to continue to compress the reset disc spring 60 to move downward. When the pressure rises to a predetermined pressure, the reset disc spring 60 cannot continue to move downward at this time because it has moved to a predetermined position. The elastic petals 46 of the ball seat 40 are elastically deformed or rotated, rapidly expanding outward, so that the size of the ball seat opening becomes larger. At this time, the plugging balls pass through the ball seat 40 and enter the catcher 50.

[0059] When the ball enters the ball catcher 50, the internal fluid passage closed by the ball is opened. The pressure in the ball valve is reduced, the reset disc spring 60 pushes the ball seat 40 to rise rapidly, and the elastic flap 46 is closed again under the action of the restoring force. At this time, the elastic member 30 also begins to reset. The second opening 24 moves up with the slide 20, and the first opening 16 is closed by the side wall of the slide 20. The two closing balls also pass through the ball seat 40 into the ball catcher 50.

[0060] As the number of plugging increases, the number of balls in the ball catcher mandrel 54 also gradually increases. At this time, the pump drilling can continue. The drilling fluid enters the ball seat 40 from the upper tool water eye, and then flows into the fourth chamber 54a of the ball catcher mandrel 54. The drilling fluid enters the channel 53 formed by the ball catcher mandrel 54 and the ball catcher 50 from the fluid outlet 54d of the upper flange 54b and the side wall of the ball catcher mandrel 54, and then flows into the second part of the fourth cavity 54a from the fluid inlet 54e of the channel 53, so that the fluid bypasses the baffle and flows out of the ball catcher mandrel 54, realizing the circulation of the drilling fluid.

[0061] When the drilling speed is fast or there is a small amount of fluid flowing upward in the well, the lower drilling fluid returns quickly. Since the ball catcher mandrel 54 is internally provided with a baffle 54c, the upward flowing fluid is blocked and divided at the baffle 54c. It flows into the fourth cavity 54a from the channel 53 outside the ball catcher mandrel 54, so that it does not impact the ball. Even if part of the drilling fluid flows into the cylinder of the ball catcher mandrel 54 and impacts the ball, since the top of the fourth cavity 54a is provided with a ball trap 56. The elastic claw of the ball trap 56 has a reverse blocking function, which prevents the ball from flowing upward. Under the action of the two layers of resistance, the upward flow of the ball is effectively prevented, so that the ball cannot flow upward to the ball seat, hindering the effective flow of the drilling fluid, thereby ensuring that the drilling speed is not affected.

[0062] The drilling plugging valve according to the present application solves the problem that the bypass valve cannot be normally opened due to the reduced temperature and pressure resistance of the plugging ball when the conventional drilling plugging valve is drilled in a high temperature and high pressure formation, resulting in the failure of the plugging operation. At the same time, a new type of ball catcher is designed to solve the problem of upward flow of the plugging ball and blockage of the circulation channel when the drill or the wellbore is overflowed. The drilling plugging valve has novel structure and strong practicability.

[0063] The preferred embodiments of the present disclosure are described in detail above in combination with the drawings, but the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept range of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all belong to the protection range of the present disclosure.

[0064] It should be further noted that various specific technical features described in the above specific embodiments can be combined in any suitable manner, and the disclosure will not be repeated here for various possible combinations.

[0065] In addition, various different embodiments of the disclosure can also be combined with each other as long as they do not contradict the idea of the disclosure, and they should also be considered as disclosed by the disclosure.

Claims

1. A lost circulation valve while drilling, characterized by, The application relates to a leak stop valve, which comprises: a leak stop valve body extending in an axial direction and comprising a first cavity extending through the body, an inner step located on an inner wall of the body near a bottom end of the body, and a first opening located on a side wall of the body; a resilient member, a bottom end of the resilient member abutting against the inner step; a sliding sleeve slidably arranged in the first cavity and supported at a bottom end by the resilient member, the sliding sleeve comprising a second cavity and a second opening located on a side wall of the sliding sleeve, the second opening being capable of moving to a position in alignment with the first opening when the resilient member is compressed; a ball seat arranged in the second cavity and positioned between the second opening and the bottom end of the sliding sleeve, the ball seat being connected to an inner wall of the sliding sleeve and having a ball seat opening for accommodating a ball, the ball seat being capable of deforming under a predetermined pressure to increase a radial dimension of the ball seat opening, the ball seat comprising a ring-shaped base located at a periphery and a plurality of elastic petals distributed along a circumferential direction of the base, each elastic petal extending radially inward from the base, in an undeformed state, the plurality of elastic petals abutting against each other to form a complete ring and defining a ball seat opening with a small dimension, in a deformed state under the predetermined pressure, the elastic petals are rotated relative to the base to increase the ball seat opening; a reset disc spring, the ball seat being supported at an upper end of the reset disc spring, a lower end of the reset disc spring being fixedly connected to the inner wall of the sliding sleeve, the ring-shaped base of the ball seat being connected to a disc of the reset disc spring and the elastic petals being capable of being spread in a central hole of the reset disc spring; a ball catcher connected to the bottom end of the leak stop valve body; wherein a deformation force of the resilient member is smaller than a deformation force of the reset disc spring, as pressure in the second cavity increases, the ball seat moves downward to first compress the resilient member to deform and then compress the reset disc spring to deform, the elastic petals are elastically deformed after the reset disc spring is compressed to move downward to a position where the reset disc spring cannot continue to move downward, and the reset disc spring can promote the ball seat to move to an initial axial position when pressure in the second cavity is eliminated.

2. The drift valve of claim 1, wherein, The base and the elastic petals are in an integral structure and are made of an elastic material, an elastic modulus of the elastic material is selected to be such that the elastic petals are elastically deformed when a first pressure is greater than the elastic modulus, the first pressure being a force required to compress the resilient member to the shortest.

3. The drift valve of claim 1, wherein, The base and the elastic petals are in a split structure and are connected by an elastic connecting member, the elastic connecting member being arranged to be elastically deformed when a first pressure is greater than the elastic modulus to rotate the elastic petals relative to the base, the first pressure being a force required to compress the resilient member to the shortest.

4. The drift valve of claim 1, wherein, A lower part of the first cavity has a guide portion, and a guide member is further arranged between the sliding sleeve and the resilient member, a moving path of the guide member being restricted by the guide portion.

5. The drift valve of claim 4, wherein, The guide portion is a groove arranged on the inner wall, and the guide member comprises a tab extending into the groove.

6. The drift valve of claim 4, wherein, The guide portion is a hexagonal channel arranged at a lower part of the first cavity, and the guide member is a hollow guide shaft matching the shape of the hexagonal channel.

7. The drift valve of claim 1, wherein, The ball catcher is in a cylindrical shape and has a third cavity penetrating through the base thereof, and a ball catcher mandrel is arranged in the third cavity, the ball catcher mandrel has a fourth cavity, and the top of the ball catcher mandrel has a plurality of top flanges extending radially outward from the outer wall thereof, and the bottom of the ball catcher mandrel has a plurality of bottom flanges axially aligned with the top flanges, each of the flanges extends from the outer wall of the ball catcher mandrel to the inner wall of the ball catcher, and adjacent flanges at the same axial position are spaced from each other in the circumferential direction.

8. The drift valve of claim 7, wherein, The upper portion of the fourth cavity is provided with a ball blocking device, the ball blocking device comprises a plurality of elastic claws, each of the elastic claws extends downward from a base abutting the inner wall of the ball catcher mandrel and towards the central axis of the ball catcher mandrel, and the elastic claws are capable of moving away from the central axis under the impact of a ball.

9. The drift valve of claim 7, wherein, The middle portion of the fourth cavity is provided with a baffle, the baffle divides the fourth cavity into a first portion and a second portion which are spaced from each other, and a plurality of holes are respectively arranged on the side wall of the ball catcher mandrel around the first portion and the second portion.

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