CN111197467A - Tubular string for changing fluid flow direction - Google Patents

Abstract

The present invention relates to a tubing string for changing the direction of fluid flow, said tubing string comprising: a reversing cylinder including a first flow passage leading from an upper end of the reversing cylinder to a lower end of the reversing cylinder, and a second flow passage leading from an upper end of the reversing cylinder to an annulus outside the tubular string, the first and second flow passages being spaced apart; and a first switching mechanism configured to selectively close the first flow passage or the second flow passage. The pipe column can lead the fluid to the annular space according to the requirement, thereby effectively and conveniently solving the problems of well leakage and the like.

Description

Tubular string for changing fluid flow direction

Technical Field

The invention relates to the technical field of drilling of petroleum, natural gas, shale gas and coal bed gas, in particular to a tubular column for changing the flow direction of fluid.

Background

In the process of drilling petroleum, natural gas, shale gas and coal bed gas, complex conditions such as well leakage, well overflow, water hole blockage and the like are frequently encountered. For example, when a well is lost, the drill needs to be tripped out to replace the drilling tool assembly for plugging operation. This causes problems such as a long processing period and a large amount of leakage. In addition, in the case of a deep well, an ultra-deep well, or the like, a drilling trip is likely to be complicated, and thus other adverse effects are likely to be brought about.

Therefore, there is a need for a device that can conveniently address lost circulation and the like.

Disclosure of Invention

In view of the above problems, the present invention provides a string for changing the flow direction of a fluid, by which the fluid can be introduced into the annulus as required, thereby effectively and conveniently solving the problems of lost circulation and the like.

According to the present invention there is provided a tubing string for changing the direction of fluid flow, the tubing string comprising: a reversing cylinder including a first flow passage leading from an upper end of the reversing cylinder to a lower end of the reversing cylinder, and a second flow passage leading from an upper end of the reversing cylinder to an annulus outside the tubular string, the first and second flow passages being spaced apart; and a first switching mechanism configured to selectively close the first flow passage or the second flow passage.

The second flow passage is closed by the first switch mechanism, and the first flow passage is opened, so that fluid in the pipe column can smoothly flow to the downstream pipe column, and normal drilling operation can be carried out. The first flow passage is closed and the second flow passage is opened through the first switch mechanism, so that fluid in the tubular column can flow to the annular space outside the tubular column, plugging slurry and the like can be injected into the annular space in such a way, and the problems of well leakage and the like can be solved.

In one embodiment, the reversing cylinder comprises an upper end main body and an extension section connected below the upper end main body, the first flow channel is formed in the upper end main body and the extension section, the pipe column further comprises an outer barrel sleeved outside the reversing cylinder, an outflow hole penetrating through the side wall is formed in the side wall of the outer barrel, the outflow hole is communicated with an annulus outside the pipe column, and the second flow channel is formed between the outer barrel and the upper end main body and is communicated with the outflow hole.

In one embodiment, the upper end body of the reversing cylinder is configured with a first opening communicating with the first flow passage, a second opening communicating with the second flow passage, and a partition provided between the first opening and the second opening, the partition extending to be connected to the extension section, the extension section being configured to be concentric with the upper end body, and the extension section having a diameter smaller than that of the upper end body, the partition being configured to be inclined to extend smoothly.

In one embodiment, the column further includes a second switching mechanism configured to close the outflow hole when the first switching mechanism closes the second flow passage and open the outflow hole when the first switching mechanism opens the second flow passage.

In one embodiment, the second switching mechanism includes a stopper disposed in the second flow passage, and an elastic member disposed below the stopper, and is configured to: when the first switching mechanism closes the second flow passage, the stop block is pushed upwards to a position for blocking the outflow hole by the elastic piece; when the first switching mechanism opens the second flow passage, the stop block is pushed downwards below the outflow hole by the fluid entering the second flow passage, and the outflow hole is allowed to be communicated with the second passage.

In one embodiment, a through hole penetrating through the side wall is formed in the side wall of the extension section, the through hole communicates with a space below the stopper, and when the first switching mechanism closes the second flow passage, the fluid in the extension section enters the space below the stopper through the through hole to push the stopper up to a position where the stopper blocks the outflow hole.

In one embodiment, a protrusion is formed on a side wall of the extension, the protrusion being located above the stopper and configured to prevent the stopper from moving toward the upper end body.

In one embodiment, a downwardly facing step surface is formed at the junction between the upper end body and the extension, the step surface being located above the boss, an empty space being formed between the boss and the step surface, fluid being able to enter the empty space and push the stopper downwardly.

In one embodiment, the first switch mechanism comprises a rotary disc covering the upper end of the reversing cylinder, an opening penetrating through the rotary disc is formed in one part of the rotary disc, and when the rotary disc rotates to a first orientation, the opening at least partially covers the first channel and completely does not cover the second channel so as to close the second channel and open the first channel; the opening at least partially covers the second channel and completely uncovers the first channel when the dial is rotated to a second orientation to close the first channel and open the second channel.

In one embodiment, the first switch mechanism further comprises a driver, and a transmission connected between the driver and the turntable, the transmission switching the turntable between the first orientation and the second orientation in response to the driver.

Compared with the prior art, the invention has the advantages that: the second flow passage is closed by the first switch mechanism, and the first flow passage is opened, so that fluid in the pipe column can smoothly flow to the downstream pipe column, and normal drilling operation can be carried out. The first flow passage is closed and the second flow passage is opened through the first switch mechanism, so that fluid in the tubular column can flow to the annular space outside the tubular column, plugging slurry and the like can be injected into the annular space in such a way, and the problems of well leakage and the like can be solved.

Drawings

The invention is described in more detail below with reference to the accompanying drawings. Wherein:

FIG. 1 shows a schematic cross-sectional view of a tubing string according to an embodiment of the present invention;

FIG. 2 shows a schematic perspective view of one embodiment of an inner barrel of the tubing string of FIG. 1;

FIG. 3 shows a schematic cross-sectional perspective view of an embodiment of an inner barrel of the tubing string of FIG. 1;

FIG. 4 shows a schematic perspective view of one embodiment of a first switching mechanism of the tubing string of FIG. 1;

FIG. 5 shows a schematic perspective cross-sectional view of one embodiment of a reversing cylinder of the pipe string of FIG. 1;

FIG. 6 shows a schematic cross-sectional view of an embodiment of a reversing cylinder of the pipe string of FIG. 1;

FIG. 7 shows a schematic cross-sectional view of one embodiment of the outer barrel of the tubing string of FIG. 1; and is

Fig. 8 shows a schematic cross-sectional view of the pipe string of fig. 1 in another state.

In the drawings, like parts are provided with like reference numerals. The figures are not drawn to scale.

Detailed Description

The invention will be further explained with reference to the drawings.

Fig. 1 schematically shows a cross-sectional view of a tubing string 100 according to an embodiment of the invention. As shown in fig. 1, the tubular string 100 includes a generally cylindrical outer barrel 110, the outer barrel 110 being capable of communicating with an upstream tubular string and a downstream tubular string such that the tubular string 100 forms a portion of an overall well tool.

A reversing cylinder 160 is installed inside the pipe string 100, and the reversing cylinder 160 forms two passages, i.e., a first flow passage and a second flow passage, which are separated from each other. The first flow passage communicates from the upper end of the reversing cylinder 160 to the lower end of the reversing cylinder 160, leading to the downstream column. The second flow passage leads from the upper end of the reversing cylinder 160 into the annulus outside the pipe string 100 (i.e., outside the outer barrel 110). The tubing string 100 further includes a first switch mechanism 140, the first switch mechanism 140 being capable of opening a first flow passage to close a second flow passage or opening a second flow passage to close the first flow passage to enable fluid within the tubing string to selectively flow into the downstream tubing string or annulus.

The specific structure of the tubular string 100 will be described in greater detail below in conjunction with fig. 2-7.

The tubular string 100 further includes an inner barrel 120 that is disposed within the outer barrel 110 and is at least partially spaced apart from the outer barrel 110 to define a space therebetween for fluid communication. The inner cylinder 120 is disposed above the reversing cylinder 160. Fig. 2 and 3 schematically show the structure of the inner tube 120. The inner cylinder 120 includes a substantially cylindrical cylinder 121, and the cylinder 121 is substantially closed and has a cavity formed therein, in which a driver or the like can be disposed. The function of these devices will be further explained below. The inner cylinder 120 further includes a support rod 122 disposed at an upper end of the cylinder 121 and extending outward in a radial direction of the cylinder 121. Accordingly, a corresponding mounting groove 113 may be provided on the inner surface of the outer tub 110 as shown in fig. 7. Thus, when the support rod 122 is engaged into the mounting groove 113, the inner cylinder 120 can be mounted into the outer cylinder 110. The shape of the mounting groove 113 is adapted to the shape of the supporting rod 122, on one hand, the bottom wall thereof can prevent the supporting rod 122 and the inner cylinder 120 including the supporting rod from moving downwards, and on the other hand, the side wall thereof can prevent the supporting rod 122 and the inner cylinder 120 including the supporting rod from rotating in the outer cylinder 110. When the string 100 of the present invention is connected to an upstream string, a nipple of the upstream string is inserted into the outer cylinder 110 and abuts against the upper end of the inner cylinder 120. Thereby preventing the inner cylinder 120 from moving upward.

For example, as shown in fig. 2 and 3, 3 support rods 122 may be uniformly arranged around the cylinder 121. With this arrangement, the inner tube 120 can be stably fixed. However, it should be understood that other numbers (e.g., 2, 4, 5, 6, etc.) of support rods 122 are possible. The support rods 122 are spaced apart to form a space for fluid communication. Thus, the fluid in the upstream string can smoothly flow through the gap between the cylinder 121 of the inner cylinder and the outer cylinder 110 and flow to the reversing cylinder 160 in the downstream.

Fig. 4 shows an embodiment of the first switching mechanism 140 described above. The first switching mechanism 140 includes a dial 142. The turntable 142 is generally flat and cylindrical in shape and has generally flat upper and lower surfaces. An opening 144 penetrating the dial 142 in the longitudinal direction is configured at a portion of the dial 142. Preferably, the opening 144 is not located at the edge of the disk 142. For example, as shown in fig. 4, the opening 144 may be generally semi-circular in shape with a straight side facing a middle portion of the disk 142 and a curved side facing an edge of the disk 142. On the outside of this opening 144 (i.e., outside of the curved edge) there remains a support edge 143. The rim 143 forms a portion of the entire circumference of the turntable 142.

The above-mentioned turntable 142 may be provided to and cover the upper end of the reversing cylinder 160. When the dial 142 is in the first orientation, the opening 144 does not cover the second channel at all and at least partially (preferably completely) covers the opening of the first channel. At this time, the first switching mechanism 140 opens the first passage and closes the second passage. When the dial 142 is in the second orientation, the opening 144 does not cover the first channel at all and at least partially (preferably completely) covers the opening of the second channel. At this time, the first switching mechanism 140 causes the second passage to be opened, and causes the first passage to be closed. In a preferred embodiment, the openings of the first channel, the second channel and the opening 144 are all identical in shape. In the first orientation, the opening 144 completely covers the first channel. In the second orientation, the opening 144 completely covers the second channel. In this case, the flow of the fluid can be made most smooth.

As shown in fig. 4, the first switching mechanism 140 further includes a driver (not shown) and a transmission member 141. The driver may be disposed in the cavity formed by the barrel 121. The drive is preferably an electric motor. Meanwhile, the cavity can be also internally provided with devices such as a sensor, a signal receiver, a motor controller, a power supply and the like for controlling the action of the driver. For example, the signal receiver may cause the driver to operate upon receiving a control signal transmitted from the surface. The motor controller can also control parameters such as the rotating speed and the number of turns of the driver, and damage to the driver under the condition of overlarge current, voltage and the like is prevented. The transmission member 141 may be configured as a rod having one end extending into the cavity and connected to the driver and the other end extending downward to be connected to the turntable 142, preferably at the center of the turntable 142. With this arrangement, the driver is allowed to rotate the dial 142 to switch the dial 142 between the first orientation and the second orientation, i.e., to open and close the first channel and the second channel.

In a preferred embodiment, as shown in FIG. 1, a retaining ring 150 is provided over the edge of the turntable 142. The fixing ring 150 can prevent the rotating disc 142 from generating a relatively severe vibration amplitude in the longitudinal direction, thereby ensuring that the fluid can only (or substantially only) flow into the first flow channel or the second flow channel through the opening 144 of the rotating disc 142, and being beneficial to preventing the rotating disc 142 from rotating unsmoothly due to excessive vibration. Meanwhile, the fixing ring 150 is used for supporting the rotating disc 142 against the reversing cylinder 160, so that the transmission member 141 is prevented from moving and vibrating in the longitudinal direction. This prevents the drive connected to the transmission member 141 from vibrating and thus extends the service life of the drive.

In addition, the tubular string 100 may further include a support 130 extending between the fixing ring 150 and the support rod 122 of the inner cylinder 120. The upper end body 161 of the reversing cylinder 160 may extend upward to surround the turntable 142. The fixing ring 150 is supported between the upper end body 161 and the support 130 with a certain gap between the lower surface thereof and the upper surface of the turntable 142. This ensures smooth rotation of the dial 142 while ensuring stability of the column 100.

It should be understood that the retainer ring 150 may be omitted if downhole longitudinal vibration is not significant. At this time, the supporter 130 may be directly supported between the support rod of the inner cylinder 120 and the upper end body 161 of the reversing cylinder 160.

Fig. 5 and 6 show an embodiment of the reversing cylinder 160 in more detail.

As shown in fig. 5 and 6, the reversing cylinder includes an upper end body 161, the upper end body 161 being substantially cylindrical, and a first opening 163 communicating with the first passage and a second opening 162 communicating with the second passage are formed on an upper end surface thereof, the two openings 163, 162 being spaced apart by a partition 165. In the pipe string 100 shown in fig. 1, the rotary table 142 covers the upper end surface of the upper end body 161, and thereby covers the first opening 163 and the second opening 162. In the first orientation, the opening 144 of the dial 142 is aligned with the first opening 163 to cover the first channel. In the second orientation, the opening 144 of the dial 142 is aligned with the second opening 162 to cover the second channel. The fluid does not flow into the two openings 163, 162 at the same time, i.e., into the two flow passages at the same time, by the partition 165 and the dial 142.

As also shown in fig. 5 and 6, the reversing cylinder 160 further includes an extension 166 connected below the upper end body 161, and the upper end body 161 and the extension 166 surround to form the first flow passage, i.e., the inner flow passage. The extension 166 extends down the outer barrel 110 and opens into a downstream tubing string. In addition, an opening is formed in a side surface of the upper end body 161. Thus, when the reversing cylinder 160 is fitted into the outer cylinder 110, a second flow passage, i.e., a side flow passage, is formed between the opening of the upper end body 161 and the outer cylinder 110. An outlet hole 111 (see fig. 1 and 7) is formed through a sidewall thereof in a radial direction at a corresponding position of the outer cylinder 110. Thereby, the fluid in the second flow passage can be directed to the annulus outside the outer cylinder 110.

In the embodiment shown in fig. 5 and 6, the upper end body 161 and the extension section 166 are substantially concentric, and the outer diameter of the upper end body 161 is greater than the outer diameter of the extension section 166. Thereby, it is ensured that the diameter of the first channel is substantially constant. In a preferred embodiment, the upper end 164 of the partition 165 is located at the center of the upper end body 161, from which the partition 165 extends smoothly and obliquely downward to be connected to the upper end of the extension 166. The upwardly inclined surface of the partition 165 forms a part of the wall of the second flow passage.

In a preferred embodiment, the tubular string 100 further includes a second switch mechanism. As shown in fig. 1, the second switching mechanism includes a stopper 170 disposed in the second flow passage. When the first opening/closing mechanism closes the second passage, the stopper 170 blocks the outflow hole 111. When the first switching mechanism opens the second passage, the stopper 170 gives way to the outlet hole 111 to allow the fluid in the second passage to exit the column 100 from the outlet hole 111. Preferably, the stopper 170 is configured to be annular to be fitted between the outer cylinder 110 and the reversing cylinder 160.

In addition, the second switching mechanism may further include an elastic member 180, and the elastic member 180 is disposed below the stopper 170. When the first opening and closing mechanism closes the second channel, the stopper 170 is pushed by the elastic member 180 to a position to block the outflow hole 111. When the first opening and closing mechanism opens the second passage, the fluid entering the second passage from the second opening can push the stopper 170 downward against the urging force of the elastic member 180 to move away from the outflow hole 111. The elastic member 180 is preferably a coil spring.

As shown in fig. 1, a stepped surface facing upward may be provided at a corresponding position of the outer tub 110, and a lower end member 190 may be provided on the stepped surface to carry the elastic member 180, thereby allowing the elastic member 180 to push the stopper 170. The lower end piece 190 is configured in a ring shape, and supports the lower end of the reversing cylinder 160 (i.e., the extension 166 thereof) at its inner edge.

Preferably, as shown in fig. 5 and 6, a through hole 167 is formed on a sidewall of the extension 166 to penetrate the sidewall. The through hole 167 corresponds to the position of the elastic member 180. Thus, when the first flow passage is opened, a part of the fluid may enter the space in which the elastic member 180 is located (i.e., the space surrounded by the stopper 170, the outer cylinder 110, the extension 166, and the lower end member 190) through the through hole 167, thereby further pushing the stopper 170 to be maintained at the position of blocking the outflow hole 111. When the second flow passage is opened, the fluid entering the second flow passage pushes the stopper 170 to move downward, so that the elastic member 180 is compressed, and the portion of the fluid in the space where the elastic member 180 is located is pressed back into the extension 166 through the through hole 167.

It will be appreciated that the opening 144 of the dial 142 is allowed to slightly cover the second channel in the first orientation when the second switch mechanism described above is provided. At this point, although a small portion of the fluid flows into the second flow path, it does not generate enough force to push the stopper 170 downward. This allows for some tolerance in the manufacture and control of the turntable 142 and allows the opening 144 to be as large as possible.

Preferably, as shown in fig. 5 and 6, a corresponding projection 168 is configured on the extension 166. At the position where the stopper 170 can block the outlet hole 111, the upper end of the stopper 170 abuts against the protrusion 168 to prevent the stopper 170 from moving upward and being misaligned with the outlet hole 111. In the preferred embodiment as shown, the boss 168 is formed by configuring the outer surface of the extension 166 to be stepped.

In addition, a downwardly facing step surface 169 may be formed at the connection between the re-extension 166 and the upper main body 161. A free space is formed between the step surface 169 and the boss 168. As a result, fluid can flow into the empty space when flowing into the second channel. This allows the fluid to be more evenly distributed over the stop 170 and thereby creates a more even and stable pushing force against the stop 170. This is very advantageous for smooth movement of the stopper.

Fig. 1 and 8 show two operating states of the pipe string 100, respectively.

In the state shown in fig. 1, the rotary plate 142 is in the first orientation with its opening 144 covering the first passage of the reversing cylinder 160. At this time, the first passage is opened and the second passage is closed, and fluid can flow from the upstream string to the downstream passage via the gap between the inner tube 120 and the outer tube 110, the opening 144, and the first passage. In this case, the fluid may be a drilling fluid to allow drilling operations to be smoothly performed.

In the state shown in fig. 2, the rotary plate 142 is rotated by a certain angle (e.g., 180 °) to be in the second orientation, and the opening 144 thereof covers the second passage of the reversing cylinder 160. At this time, the second passage is opened and the first passage is closed. Thus, fluid no longer flows to the downstream string, but instead flows through the second passage and flowbore 111 to the annulus outside of the string 100. At this time, the fluid can be plugging slurry for plugging the annular space and the bottom layer, so that the problems of well leakage and the like are solved. It will be appreciated that in this way, well spillage and plugging problems can also be addressed.

By the aid of the pipe column 100, circulation can be directly established without tripping the drilling rig, so that the drilling period can be effectively shortened, and drilling risks and cost are reduced. Fluid such as plugging slurry, well control fluid and the like is discharged from the outflow hole 111 instead of the drill bit and the like, so that tools such as a screw rod, the drill bit and the like can be effectively prevented from being blocked by large-particle plugging slurry and well control fluid particles. It is particularly important that such a string 100 can change the communication between the first and second passages an unlimited number of times without affecting subsequent operations, which is significant for complex downhole environments.

In this document, the terms "upper", "lower", and the like are all described with respect to the vertical orientation shown in the figures. It should be understood, however, that the pipe string 100 may also be used in inclined, horizontal, etc. orientations.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (10)

1. A tubing string for changing a direction of fluid flow, the tubing string comprising:

a reversing cylinder including a first flow passage leading from an upper end of the reversing cylinder to a lower end of the reversing cylinder, and a second flow passage leading from an upper end of the reversing cylinder to an annulus outside the tubular string, the first and second flow passages being spaced apart; and

a first switching mechanism configured to selectively block the first flow passage or the second flow passage.

2. The pipe string of claim 1, wherein the reversing cylinder block includes an upper end body, and an extension section connected below the upper end body, the first flow passage being formed in the upper end body and the extension section,

the tubular column is still established including the cover the urceolus outside the switching-over jar the lateral wall of urceolus is constructed to run through the discharge orifice of lateral wall, discharge orifice with the outer annular space of tubular column is linked together, the second flow channel form in the urceolus with between the upper end main part, and with discharge orifice is linked together.

3. The pipe string of claim 2, wherein the upper end body of the reversing cylinder is configured with a first opening in communication with the first flow passage, a second opening in communication with the second flow passage, and a partition disposed between the first opening and the second opening, the partition extending to connect with the extension section,

the extension is configured to be concentric with the upper end body, and the extension has a diameter smaller than that of the upper end body, and the partition is configured to be inclined to smoothly extend.

4. The string of claim 3 further comprising a second switching mechanism configured to close the outlet orifice when the first switching mechanism closes the second flow passage and open the outlet orifice when the first switching mechanism opens the second flow passage.

5. The tubing string of claim 4, wherein the second switching mechanism comprises a stopper disposed in the second flow passage, and an elastic member disposed below the stopper, the second switching mechanism being configured to:

when the first switching mechanism closes the second flow passage, the stop block is pushed upwards to a position for blocking the outflow hole by the elastic piece;

when the first switching mechanism opens the second flow passage, the stop block is pushed downwards below the outflow hole by the fluid entering the second flow passage, and the outflow hole is allowed to be communicated with the second passage.

6. The string of claim 5 wherein a through hole is formed through the side wall of the extension section, the through hole communicating into a space below the block, wherein when the first switching mechanism closes the second flow passage, fluid in the extension section passes through the through hole into the space below the block to push the block up to a position blocking the outflow hole.

7. A pipe string according to claim 5 or 6, wherein a projection is formed on a side wall of the extension section, the projection being located above the stop and being configured to prevent movement of the stop towards the upper end body.

8. The pipe string of claim 7, wherein a downwardly facing step surface is formed at a junction between the upper end body and the extension section, the step surface being located above the boss, an empty space being formed between the boss and the step surface, fluid being able to enter the empty space and push the stopper downwardly.

9. The column according to any one of claims 1 to 8, wherein the first switch mechanism comprises a rotary table covering an upper end of the reversing cylinder, an opening penetrating the rotary table being opened at a portion of the rotary table,

when the turntable is rotated to a first orientation, the opening at least partially covers the first channel and completely uncovers the second channel to close the second channel and open the first channel;

the opening at least partially covers the second channel and completely uncovers the first channel when the dial is rotated to a second orientation to close the first channel and open the second channel.

10. The tubular string of claim 9, wherein the first switch mechanism further comprises a drive, and a transmission connected between the drive and the rotary table, the transmission responsive to the drive to switch the rotary table between the first orientation and the second orientation.

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