DE3337510A1 - BLOW-OUT PREVENTER - Google Patents

Description

"Ausblaspr-eventer"

The invention relates to blowout valves, such as blowout preventers of the ram type, which are used in drilling 5

and in the completion of oil and gas wells Find use.

In particular, however, the invention is concerned with improvements to blowout preventers that are based on a Let the wellhead mount and its ram are able to support a pipe, for example a Drill string, shear in the bore of the housing of the preventer as soon as it moves out of the open position

be moved inside to then when they have their on-15

continue upward movement, shear the pipeline, and with respect to each other and with respect to the guideways in the housing, the preventer in which the Move the plunger to form a seal, and thereby

to close the hole. In this way, 20

Withdraw the upper sheared end of the drill string from the borehole, if so desired should in order to remove the drill pipe from the ■ drill hole at short notice.

In this context, however, the invention is also concerned with improvements to valves and in particular blow-out preventers, in which the or the closure body or plunger of the preventer between the opening and

Closed positions with the help of a fluid-30

actuated system are moved, which has pistons that are connected to it with the help of rods and are from the cylinders of the system into chambers within the housing at the ends of the closure bodies or plungers

__ extend, causing the fluid within the 35

Chambers acts on the cross-sectional area of the rod,

in order to generate a force that opposes the closing movement of the closing body or plunger is. The invention also relates to improvements in valves and in particular blow-out preventers, in which a bypass groove is the bore of the valve body or Preventer-Gehäu.ses with the chamber behind connects each body or plunger in such a way that a force which cancels the force of the actuation system, thereby closing the body or plunger keep.

For example, as in the US patents

2 919 Hl and 2 969 838 described blow-out preventers shown, the pipeline is flattened and then sheared off with the help of cutting edges on the inner ends of the plungers, that pass close to each other. A sealing device, which includes a pack, is used by each Plunger face carried to come into contact with a packing on the other plunger in a plane that in the vertical direction from the cutting edges or cutting edges is separated. In the further US-PS

3 5βΐ 526 shown preventer is on each ram face Above or below the ram cutting edge a pack is arranged, which is from a surface on the inner end of the other ram, which is adjacent to its cutting edges, is touched. if the hole of the preventer is empty, the plungers only work as "blind plungers" to close the open hole.

When using any of these preventers, however, there is a need to shear after them Inward movement of the pipeline was made to retract the plunger to allow the upper sheared end of the Pipeline can be lifted out of the way between the end seals, to then as soon as

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The pipeline has been removed in this way, the plunger back inward into the fully closed Move back position. In the preventer of U.S. Patent 3,561,526, the need also exists Ability to move or drop the lower end of the sheared pipeline to allow the plungers to move can close. In the modified embodiment however, of the preventer of US Pat. No. 2,969,838, the lower sheared end of the conduit is like this , Q arrange that it can be received in a recess can, so that there is only a need to remove the upper sheared end of the pipeline.

The purpose of the preventers according to US Pat. Nos. 3,817,326 and 3,736,982 is to thereby prevent this process to simplify that plungers are created that are able to shear and then seal to thereby to close the bore with the rams moving forward continuously, i.e. without the rams first

2Q to withdraw. Thus, the sealing devices the plunger opens a package carried by a horizontal surface which extends from the cutting edge of the one ram extends rearwardly to thereby connect to an opposing surface, which extends backwards from the cutting edge of the other sheet and thus along the Shear plane to form a seal when the surfaces move across each other after the shear. The sheared ends of the pipeline are in

QQ recesses formed in each ram outside the cutting edges and thus outside the path of the shear movement.

However, difficulties that have arisen have the surfaces facing each other sufficiently hold together close enough to hold the pack

between them to get in touch with the pretty small packing areas on which the plunger closing force acts, led to the fact that one has returned to shear rams, the transverse lip end packings exhibit. Such a construction is shown in US Pat. No. 4,132,265, the inner end of the one The plunger is tapered upward and outward too, with one shoulder on the inner end of the other Work together to the effect that the upper part of the ram above a forehead packing located on it The cut end of the pipeline will be wedged up * ■ * · and in doing so will go off track between the inner end of the one plunger and the pack. An obvious one The disadvantage of a preventer of the last-mentioned construction is the frictional resistance to displacement ■ the cut end of the pipe over the beveled inner end of one plunger. Also, the end if the angle between the beveled end and the vertical is relatively large in order to reinforce the mechanical action of the wedge, so thin, that it can break under the load on the end of the pipe.

The object of the invention is therefore to create a 'blowout prevention device in which the cut off End of the pipeline out of the path between the sealing surfaces of the tappets only due to the steady inward movement the plunger to shear the pipeline and to close the bore is removed without the upper one having to wedge the cut end of the pipeline in an out-of-the-way position as described, for example, in said US Pat. No. 4,132,265.

The force required to shear a pipe in a blowout preventer is significant larger than that which is required to make the

To cause ram packing to seal between the tappets and between the latter and the preventer guide tracks. However, this force can create extremely high pressures in the pack in preventers equipped with conventional fluid operated systems for moving the plungers, so that in each case a pressure considerably higher than that required to ensure adequate sealing contact of the plunger packings with the IQ them interacting surfaces on the rams and guideways is needed.

It is therefore a further object of the invention to provide a blow-out preventer in which the shear rams

] _5 after shearing off the pipeline with a force in the closed position are moved, which is not significantly greater than the one used to seal between them themselves and between them and the preventer guide tracks is required, in particular the Preventer equipped with a relatively simple and compact fluid operated drive system should be able to move the shear ram inward to cope with the pipeline a first relatively large force and then to move the ram further inward to move them to seal with respect to each other and with respect to the guideways, with a second relative small force.

Preventers of this type are usually equipped with a device through which the bore under the closed plungers is connected to the chambers behind them, whereby with closed plungers on at least part of the area of the outer ends. the plunger — fluid pressure in— acts to thereby generate a force which increases the hydraulic operating pressure that the tappet packings in seal contact holds, adds. For this purpose, in the subpages

. - The plunger grooves are provided that the bore and keep the chamber in communication with each other. An attempt to reduce the dimensions of the actuation system, that is necessary to generate an opening force

j. - thereby overcoming this additional force with respect to the downhole fluid is described in US Pat. No. 3,036,807. In this document a preventer is proposed which is provided with tappets which have valve-controlled channels through which the bore is connected to the chambers when the tappets are closed and which then connect the chamber to the bore above the closed tappets which usually under much less pressure than the bore below them, causing over the ends of the tappets

substantially pressure equilibrium is reached when 15

the plungers perform the outward opening movement. In that in copending U.S. patent application No. 337 383 described preventer, the "hydraulic actuated valves "are located in the undersides of the tappet grooves, and the flow through one

-

Channel connecting the chamber with the bore above each closed plunger is made with the help of a Valve head controlled at the end of the rod, which is connected to a piston in the cylinder of the actuation system and an idle connection with the plunger

so that the outer end of each channel is closed when the plunger moves inwards with the piston rod and opens as soon as the plunger moves with the piston rod moved outwards.

Although the Preventer mentioned in both the US patent 3 O36 807 as well as in the above-mentioned pending Patent application is described, the desired result of reducing the force corresponds to the required to retract the plungers require the plungers of this patent, and to some extent the require The plunger of the pending patent application has a complicated construction which increases the overall cost of the preventer.

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It is therefore also an object of the invention to provide a To create preventers that basically achieve the same goal, but with less effort.

g As further stated in the pending patent application is the actuation system of the blowout preventer described in U.S. Patent No. 3,036,807 constructed so that the force due to the downhole fluid exerted on the piston rod

, Q acts, which enters the ram chamber to the To counteract movement of the plunger in the closed position, is significantly reduced or eliminated entirely. Thus, from the outer end of the piston of the actuation system, a rod extends into for each tappet an outer chamber of the housing into it, and the piston as well as the outer rod and the inner rod are with provided a through hole so that when the rods have substantially the same cross-sectional area, they are in balance.

In the preventer described in the above patent application, a fitting piece is inserted into the outer chamber "and the through-hole of the rods and the piston injected grease, and the drilling mud as well as the grease

2g are slidable in the hole with the help of a plug sits, separated when the outer rod moves in the outer chamber, so that the drilling mud in the bore of the housing remains essentially excluded from the chamber and thus the seals that the

3Q surround the outer rod leading into this chamber, to be protected. In particular, slots are provided in the bore at the inner and outer ends of the rods, which allow the fat to bypass the plug as it approaches an inner limit and which also allow the downhole fluid to flow past the plug, when moved to an outer limit position thereby closing any voids in the outer chamber

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to fill.

Although this feature of this actuation system is necessary to substantially remove downhole fluid Keeping it away from the compensation chamber is still an expensive addition because the Bypass slots must be machined into the rods. It is therefore a further task of the present invention, a preventer and ram actuation system or similar flow control device of the type described, in which the same goals are achieved with lower processing costs and thus with a lower total cost.

The solutions to the above-mentioned problems are characterized in the claims.

In the drawing, exemplary embodiments of the invention are shown schematically. In it shows:

1 is a vertical sectional view of a blow-out preventer of the type according to the invention, in which the plungers are retracted into positions within their guideways,

FIG. 2 is a vertical sectional view of the preventer, similar to that of FIG. 1, but in which the plungers are moved inward to shear the pipeline, the top cut off . End of the pipeline from the path between the devices on the ram surfaces that are used for Serve seal, is moved out, and then the seal in relation to each other and in in relation to the guideways is

Fig. 3 is a view of the two from their guideways

distant plungers, viewed from the inner end,

one side and from above,
Fig. 4 is a vertical sectional view of a portion of the preventer, including the right plunger and

° of its actuation system, xvob the piston of the actuation system outwards into the completely retracted positions are moved, thereby bringing the plunger into the open position.

¹ ^ Pig. 5 a view similar to FIG. 4, but after the inward movement of the plungers under the action of the control fluid on the outer sides of the pistons of the actuation system, thereby bringing the inner ends of the cutting edges of the blades into contact and with the flattening of the start opposite sides of a pipeline within the bore of the housing,

Figure 6 is a view similar to Figure 5, but after further inward movement of the plungers has occurred, thereby shearing the blades of the pipeline and causing the inner ends of the gripping and lifting arms to flatten the opposite sides of the pipeline over the cutting blades of the plungers ₇ with the outer annular piston of the actuation system moved to the position in which it rests against the inner end of the cylinder,

pig. 7 is a view similar to FIG. 6, but in which the The plunger has been moved further inwards after the pipeline has been sheared, thereby causing the arms to slide the upper sheared end of the pipeline over the upper To clear the cutting blade and thus out of the path between the inner end and the upper cutting blade and wherein the pack extends across the inner end of the other ram, over the lower cutting

leaf extends, and wherein the movement of the inner piston of the actuation system with respect to
the stationary outer piston is shown inwards,
5

Fig. 8 one of the Pig. 7 similar view, but after
a further inward movement of the tappets and
another inward movement of the inner
Plunger, thereby removing the cut end of the
To raise the pipeline further, over the
inner ends of the plungers out, and to bring the inner end of the upper cutting blade into sealing contact with the packing on the lower cutting blade, thereby closing the through-bore of the housing, and

FIG. 9 is a view similar to FIG. 8, but after Remove the upper sheared end of the pipeline from the engaging and lifting-20

the arms, thereby allowing their inner ends to pivot downwardly and inwardly to engage each other, the
Inside of the pistons of the actuation system

"*>. Control fluid is supplied to thereby the inner

25th

Withdraw the end of the rod on the right piston

and to open the existing passage and thus the one over the inner and outer ends of both
Compensate the pressure on the ram.

30 '

In FIGS. 1 and 2, the preventer, hereinafter referred to as the blow-out valve, is designated as a whole by 20. This
Blow-out valve has a housing 21 with a vertical
Through hole 22 and flanges on its upper and lower
lower ends with which it can be attached, like that

that it forms part of a wellhead, wherein
its bore 22 is axially aligned with the bore of the wellhead. As shown in the drawing

extends perpendicularly through the bore of the blow-off valve a pipe 24 which is part of a drill string which is suspended from a drill pipe and provided with a chisel at its lower end which extends towards the bottom of the borehole. As is known per se when drilling boreholes, drilling mud is circulated down the drill string, exiting the bit and then slides upward in annulus 25 between the drill string and "LQ" of the bore.

The blow-off valve has a pair of plungers 26A and 26B, which sit in guide tracks 27, which are opposite Cut sides of the bore 22 to between "5 outer layers in which, as can be seen from Pig. are withdrawn from the wellbore during the downhole drilling operation, and inner layers in which they extend across the bore to seal each other and with respect to the housing and so that the bore can be closed, as shown in FIG. 2, to be able to be moved. Every plunger will moved between open and closed positions with the help of an actuation system. This system includes a Cylinder 28 of the housing 21, which is located outside of each tappet guide track, a piston in each Cylinder is reciprocable and a rod 30 which is sealed by a pack or Seal 31 extends into an opening through a wall of the housing, which has a chamber behind the plunger of the cylinder to connect the plunger to the piston. As will be described below, one external source supplied to the cylinder hydraulic fluid or returned from it to this source, namely on both sides of the piston 29, thereby selectively moving the piston and thus the plunger in the direction of the Hole or move away from the hole.

Each housing 21 has a main body 21A in which

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the bore 22 and the guideways 27 are formed, as well as a pair of hoods 32, each of which is on the outer surface The end of a guide track 27 is attached and forms a chamber for receiving one of the open plungers. Thus can c each hood is pivotable with one side of the main body be connected, as described in detail in the pending patent application mentioned and is shown so that the hood between a closed position transverse to the guide track and a

, _Q can move the open position to one side of the guideway, thereby enabling the plungers to be removed from the chamber for replacement or repair. Alternatively, as is also known per se, the hoods can instead be provided with a main body of the

are ^ c housing connected by a fluid-actuated auxiliary system that allows the hoods back with respect to the opposite sides of the main body of the housing in axial directions and to be moved in order and to allow replacement or repair ^ ^he plunger ..

each ram has a metallic tappet body 33 which has a generally oval cross-sectional shape to axially can inwardly and slide outward, and • 25 ^while i ⁿ the direction of the hole R and away from and within a guide path of the Preventergehäuses. Furthermore, blades BU, BL are present on the right and left tappets 26B and 26a, which have cutting edges with which the pipeline 24 is sheared off as soon as it opens

QQ move the two leaves on top of each other. Specifically, the cutting edge of the upper sheet BU on the right ram 26b can move over the cutting edge of the lower sheet BL on the left ram 26A, and a package 3 ^ is carried by the ram 26b over the sheet BL so that it fits with the inner end 35 of sheet 26B is in sealing contact when the pipe is sheared and the upper, sheared end of that pipe,

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as will be described below, is raised as soon as the plunger moves further inwards move to the closed position.

g In addition, each pestle carries a pack that contains on opposite sides of the laterally extending pack 3 ^ (in the case of the left ram) and the blade end surface 35 (in the case of the right ram) inner front parts 36 up.

■ jQ has side parts 37 _} which extend rearwardly from each such end part along each side of the tappet body, and also head parts 38 which are connected to the outer ends of the side parts 37 and extend over the head of the tappet.

stretch jg. As can be seen from the drawing and known per se, the head parts J> 8 in the guideways when the plungers move into their outer positions, whereby the plunger packs form a continuous seal that closes the bore of the preventer housing.

The cutting edges of the lower and upper blades are shaped like a flat "V" in order to center the Pipeline, as soon as they move towards and past each other to shear the pipeline, to work together. When the upper sheared end of the pipeline is out of line between the pack 3 ^ and the surface 35 is lifted to thereby enabling the plungers to make sealing contact with one another when they are in the closed position be brought, the lower end of the sheared pipe can be in a recess move in, which is formed in the underside of the right plunger, so that the pipeline the complete closing movement of the plunger is not hindered.

As already described above, the pre

direction to grab the opposite sides of the pipeline and lift the upper sheared one Pipeline end has an arm 53 on each plunger, the outer end of which is pivotably mounted on it, so that it pivots a generally horizontal axis transverse to the axis of reciprocation of the plunger can be. When the plunger is moved inwards, thereby causing its inner end 5 ^, to come into contact with one side of the pipeline, it becomes in one in the upper side of the plunger existing recess supported so that its inner end is above its pivot axis is located so that when the plunger moves further inward to raise the pipeline, the Arm is pivoted about its pivot axis upwards ver. In this way, the predominantly horizontal force components the plunger, when the pipeline is gripped and sheared, becomes predominantly vertical Components of force as soon as the cut end of the pipeline is lifted. Preferably extends an imaginary line passing through the inner end of each arm and its pivot or hinge axis, at an angle of about 30 ° to the horizontal, in the supported positions of the tappets, and at an angle of about 60 ° to the horizontal as soon as the tappets are in the closed position.

As can be seen from the drawing, the inner end of each arm has a wide band of horizontal teeth, with those the sides of the pipeline over the sides of the flattened or flattened by the leaves Pipeline can be gripped and flattened, so that then the flattened sides can be held between the teeth to lift the pipeline at its inner ends once the arms are swung. Thus, as can be seen from FIG. 5, the inward movement of the The plunger leaves the pipeline initially along the

Shear plane compressed somewhat when the inner ends of the arms are first connected to the pipeline over the Cutting edges of the sheets engage. If the tappets then move further inwards, the leaves continue to flatten the sides of the pipeline as the arms do above the leaves begin to flatten the sides there (see Pig. 5). Once the leaves the pipeline have sheared off and the tappets continued to move

Moving IQ inward, as shown in Fig. 6, the arms will pivot upward as the teeth at their inner ends roll over the flattened sides of the tubing, thereby lifting the cut end above the top sheet (Fig. 7) and thus to clear the path of movement between the surface 35 ^and the sealing body 3 ^.

If the sheared end of the pipeline is then lifted up a certain distance, the tappets come into sealing contact with one another, as shown in FIG. 8. At this time can then the upper sheared end of the pipeline from the dashed lines in Fig.9 Lift freely the position shown in order to remove it together with the drill string from the hole of the preventer. This allows the inner ends of the arms to pivot downward and towards the rear internally to engage with each other as shown in FIG. Then when the tappets in retracted their open position, the inner ends of the arms will begin their joint downward pivoting motion in the propped position and then separate from each other in order to join together with move the plunger outward into the retracted position. It can be seen that when in the borehole there is no pipeline, the inner ends of the arms come into contact with each other as soon as the The plungers move inward to a position that

Approximately in the middle between that in FIGS. 6 and 7 position shown, whereupon the inner ends of the arms pivot upward together when the inward movement the plunger is continued so that the plungers come into seal contact.

As best seen in Fig. 6, extend the inner ends of the arms through the open front ends of the recesses to the front, so that these inner ends are spaced apart in their supported position as soon as the Pipeline has sheared off. Preferably the distance is one and a half times as large as twice Thickness of the wall of the pipe to be sheared. The energy stored in the pipeline when this being squeezed together by the arms when sheared, creates a force that tends to pull the cut off The end of the pipeline to jump away. As best seen in Fig. 3, the recess opens 55 in the right ram 26B to a lower recess in the ram above the sheet BU, while in the case of the left tappet 26A, the recess 56 over a shoulder of the tappet body above the Sealing body 34 is formed. The inner end this paragraph moves into the lower recess of the right plunger 26B when the Move the plunger into the closed position (see Fig. 8).

The outer end of each arm is curved so that it fits snugly into the curved outer end of each recess fits (Fig.3) j to thereby enable pivoting of the arm in the manner described. The tops of the arms are substantially flush with the tops of the tappet bodies so that the tops the guide ways prevent the arms from swinging upwards from the protected positions, until they emerge from the guideways and engage opposite sides of the pipeline

step. If the arms do not pivot downward once the plungers are withdrawn from the closed position are grasped by the inner ends of the guiding tracks and into the protected position pushed down. The recesses preferably have upper inclined walls which are able to the pivoting movements of the lifting arms, which go well beyond the position shown in Fig. 8, to limit.

The piston device 29 of the actuation system for each tappet has a first outer, annular one Piston 60, which has a sealing ring for sliding sealing in the cylinder 28 between the innermost and

·] _5 possesses extreme positions determined by it are that the inner and outer ends of the cylinders 28 come into contact with the piston. Further there is an inner piston 6l which carries a sealing ring which is in the outer piston sealed slides. This inner piston is attached to the piston rod 30 to move together with the The plungers move inwards and outwards while the inner and outer pistons are equipped with means are that allow only a limited axial movement of the pistons with respect to each other. So shows the outer piston has a first flange 62A at its inner end that prevents its outward movement limited with respect to the inner piston 61, as well as a flange 62B at its inner end, which is his Inward movement with respect to the piston 61 is limited.

Like from Pig. 4, when actuating fluid takes place through the inner ends of both pistons the opening P. has been supplied to the ram open, both pistons to their extreme positions, i.e. the outer piston 60 is at the outer end of the cylinder in contact, and the outside of the piston 6l contacts the face 62B of the outside

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Piston. In order to move the plunger inwards and thereby shear the pipeline and close the hole of the preventer, actuating _{fluid is supplied to the outer sides of the pistons through the openings P 2} and carried away from the inner sides of the pistons through the openings P. During the initial inward movement, the pistons move together because the flange 62B of the piston 60 is in contact with the outside of the piston 6l until the

^ q Arms grasp the opposite sides of the pipeline and flatten them as shown in Fig. 5, and then leaves the pipeline, like shown in Fig. 6, shear. During this stage, the force generated by the actuation system has the

jg moves the plunger, its maximum, since the actuating fluid acts on the effective pressure-sensitive surfaces of both pistons.

However, if the pipeline is sheared like this

2Q 'shown in Fig. 6 comes the inner end of the outer piston 60 with the inner end of its cylinder 28 in contact to further inward movement stop of the piston. As a result, the plungers move further inward to thereby to lift the sheared end of the pipeline and due to each other and their guideways the force supplied by the actuating fluid acting on the inner piston 6l, a seal to effect. As a result, neither the pressure in the sealing device is carried by the plungers is still the force with which the plunger is held in the closed position by the actuating fluid become too high. As can be seen from Fig. 8, the inner end of the piston 60, when the descended The pipeline has been lifted and the tappets have been brought into contact with the seal, spaced from flange 62A so that its contact with the flange provides full sealing

engagement between the tappets is not hindered and a certain amount of wear and tear on the sealing surfaces of the Ram is allowed during continued use of the preventer.

When the plungers are to be withdrawn to their opening positions, actuation fluid is introduced into the cylinders on the inside of the pistons _{through the openings P 1 and discharged from the outside of the cylinders through the openings P 1.} As a result, as shown in FIG. 9, the outer pistons 60 move outwardly with respect to the inner pistons 61 until the flanges 62A contact the inner pistons and then the

j_g take the inner piston and the piston rods 30 with you. the The plungers then continue to move outward until the outer ends of the pistons 20 reach the outer end contact the cylinder and the inner pistons move outwardly with respect to the flanges 62B to get in touch.

As is known in this field of technology, everyone is Plunger body provided with a groove G in its underside, which the bores 22 of the housing on the inner end connects to the chamber at the outer end of the plunger, thus when the plunger is closed borehole fluid pressure from the bore acts on the outer ends of the rams to keep them closed to hold, with a force that acts in addition to that of the actuation system. Thus, in the ram closed positions, the wellbore fluid pressure below the rams is usually higher than that above the plungers, so that on the surface of the plunger by the sealing device is enclosed, there is a relatively large pressure difference.

As with the preventer of the imfc pending patent application, so also here in the right plunger 26 'a channel 40 is formed, which at its outer end with. the Plunger chamber on the outside of the plunger and at its inner end with the upper inner part of the The plunger, which is enclosed by the continuous seal, is in communication and thus with the bore of the Preventer housing above the plunger, in the closed state of the same. The inner end

• j ^ q of the channel 40 preferably has diverging Branches 40A, which form the lower recess of the plunger 26b below the arm 53 and above the blade BU connect and thereby with an open area between the inner ends of the closed plungers

■ | _g (see Pig. 9). Furthermore, for the same reasons, mentioned in the pending patent application, the cross-sectional area of the channel is greater than that the groove G.

Also in accordance with the preventer of the earlier application, the inner end of the piston rod 30 of the right plunger 26B on an enlarged head 4l, which is provided with pin 42, the protrude from its inner end on opposite sides of an annular packing 43, which is arranged coaxially with the channel 40 to thereby alternatively the outer end of the plunger around the to touch the outer end of the channel 40 in a sealing manner and thus to close the channel or for the purpose of opening to get out of touch with him. In detail, this means that the pins 42 in enlarged T-slots 43 are removably received in the right ram on opposite sides of the channel 40, thereby creating an idle connection between the rod and the plunger so that the package 43 can move freely to the outside Seal the end of the channel 40 when the actuation system moves the plunger inward, but outwardly

To make contact with the outer end of ^{the plunger to open channel 1} JO as soon as the actuation system is driven to withdraw the right plunger. The lower ends of the T-slots extend through the lower ends of the right plunger, thereby providing a means by which the plunger can be attached or removed from the inner end of the piston rod when the right piston enters the Open position is moved.

Thus, as in the case of both plungers of the preventer of the earlier application mentioned, by switching on the Actuating system for withdrawing the right plunger automatically the channel 40 located in it opened to thereby equalize the pressure prevailing over the inner and outer ends of the right tappet and thus to enable the plunger to be opened with less force. As in the above, however,

2Q, allows the inner end of the right tappet to be withdrawn from sealing contact with the inner end of the left tappet, although the left tappet 26k is more or less conventionally constructed in that it does not have a through-channel.

2g indicates that the pressure is above the inner and outer Ends of the left plunger is also substantially balanced in this way and thus its retraction is also facilitated.

QQ The rod 30 of the left plunger 26A and the device by which they are connected may be identical to the rod 30 for the plunger 26B and their interconnection. Alternatively, however, since the inner end of the rod does not meet the puncture of opening and closing a passageway through the plunger 26A, there may be pegs on this inner end of the rod that fit snugly into T-slots in the outer end of the plunger.

333751Q

Thus, the connection enables the plunger to be replaced or repaired, but prevents it any substantial axial relative movement between the rod and the plunger during the opening and

Closing cycle.
5

As also provided in the preventer of the prior application, another rod 44 extends from the piston 6l to the outside and runs sealed by a sealing ring 46 which is in an opening in the outer end of the cylinder 28, as well as into the outer chamber 45 within the hood. So is a tubular body 48 bolted to a counterbore in the outer end of the opening in the end of the cylinder, so that the outer chamber 45 is formed, and 15

an additional packing is received in the inner end of the body 48 which is used to seal between this body and the rod 44 is used outside the ring.

In particular, the piston and both the inner rod 30 and the outer rod 44 extend through it a bore 47, and the cross-sectional area of the inner and outer rods passing through the sealing

__ directions 31 and 46 extending are essentially 25th

same. Characterized the rods consist essentially in the case of the right tappet 26b not only under pressure equilibrium when the plunger is withdrawn and the head is separated 4l from the outer end of the _place plunger 46b during the opening of the plunger at a distance, but also during the closing of the plunger 26B when the bore 47 is connected to the channel 40. A similar bore can be found in the piston and stems 40 and 44 of the left tappet

_ot 26a are formed so that the rod 30, which with ob

connected to the left pushrod by an idle connection, as in the case of rod 30 of pusher 26B also while withdrawing the plunger

Pressure equilibrium is. Of course, if so desired, the connection of the rod be snugly fitted with the plunger, and an opening in the rod 30 for the plunger 26A allows the through-

Connect the passage bore 47 to the chamber 45.

As also described in the earlier pending patent application, a fitting E is from the housing hood worn, i.e. from the outer end of the tubular

-, Q body 48 so that fat enters the outer chamber 45 and at least part of the bore connected to this can be injected to substantially to prevent drilling mud from entering the chamber 45 and thereby the seal 46, which the outer

^ g end of rod 44 surrounds to protect. A stopper 49 made of plastic or other suitable material is in the bore 47 between the inner and outer limit positions slidingly arranged, so that it normally separates the well fluid from the fat. The limits of movement of this plug are determined by snap rings fitted in the inner and outer ends of the inner rod 30 and the outer rod 44 sit.

When the plunger moves to the closed position 25

have been, the pin 49 by the fact that

the main parts of the outer rods 44 from the chambers 45 are withdrawn, moved outward in positions which are at least in the vicinity of their outer limit positions are located. In the event that fat from the 30th

Chamber 45 is lost, the plug is held in the bore by the outer snap ring, and a certain amount of drilling mud can flow through a narrowed channel 50 located therein. When the tappets are withdrawn, and 35

As the outer rods 44 enter the chambers 45, the plugs 49 are inwardly into their innermost Pressed layer, as shown in FIG. fat

can pass through a narrowed channel 50 in the plug, thereby eliminating the need to be in the through hole of the rods to form slots, as explained in the earlier application is not applicable.

Considering now the overall operation of the preventer and assuming that the rams are retracted to their extreme positions, as can be seen in FIGS. 1 and k , and that a pipe 24 in the bore 22 is to be sheared off, so will Control fluid is supplied to the outside of the piston assemblies 29 and carried away from the inside thereof, thereby causing the plungers to move inwardly and contact the opposite sides of the conduit. It will be understood that the plungers do not necessarily move to these positions simultaneously and, in fact, one of the plungers will usually contact one side of the pipeline earlier than the other. This is of course particularly the case when the control rod of only one of the tappets is under pressure equilibrium in the relevant stage of the operating cycle. In this case, the ram in question usually moves inwards before the other ram. In any case, by touching the inner end of one plunger on one side of the pipeline, its further inward movement is delayed until the other plunger has moved inwardly with its inner end on the opposite side of the pipeline to get in touch.

As already described above, both rams are moved with a relatively small force, because borehole fluid acts on the outer ends of both inner and outer pistons 60 and 61, respectively.

Like from Pig. 5, the continued inward movement of the plunger causes this relative little force that their inner ends begin to flatten the sides of the pipe and then continue this flattening until the pipeline is sheared when the cutting edges meet move the plungers past each other, as shown in FIG. 6. As also with reference to Fig. 6 recognizable, the plungers for shearing off the pipeline become the inner ones during this movement Ends of arms 53 in contact with opposite sides of the pipeline above the blades brought to flatten these sides as well. So if the tappets keep moving in, after the Ronrleitung is sheared, begin the inner ends of the plungers 53, which the flattened Grab sides of the pipeline to pivot upward from their supported positions and thereby lifting the upper sheared end of the pipeline above the inner end of the Path between the inner end 35 of the right pestle leaves and the transverse packing 3 ^, like this Fig. 7 is evident. When the pipeline is sheared, the inner end of the outer piston 60 is closed moved so that it has come into contact with the inner end of the cylinder 28 so that the shocks] with a relatively small force due to the control fluid acting only on the outer end of the piston 6l acts, can be moved further inwards.

The plungers continue their inward movement into the closed Position, causing the inner end 35 of the blade of the right plunger to go below Effect of a relatively small force to come into seal contact with the packing 34. Simultaneously the arms 53 are, of course, made to pivot further upward to thereby achieve this upper sheared end of the pipeline over the

333751Q

lift out the inner ends of the pestles above their blades, while the lower sheared end of the pipeline has been pushed into the recess 52, so that any obstruction of the full Closing movement of the plunger is avoided.

The upper cut end of the tubing can then be removed with the drill string to remove the Drill pipe from which the string is suspended,

To allow IQ to be moved out of the borehole so that the inner ends of the arms are free to swing inwardly to come into contact with one another. At the same time, control fluid can be fed into the cylinders 28 on the left-hand side of the pistons.

IQ and are diverted from the right sides of the pistons, thereby retracting the plungers to their outer position.

Like from Pig. 9, everyone is moving

2Q outer piston 60 initially outwardly of the inner piston until flange 62A contacts the inside of each inner piston, which results in the rams initially with a relatively small force caused by the action of the control fluid on the inner ends both pistons, are withdrawn. The outward movement of the rod 30 naturally leads to the opening of the outer end of the channel 40 in the right plunger 26B ₅ so that the relatively high pressure

QQ inside the chamber behind the plunger 26B to the bore 22 is relaxed above the closed plunger. As mentioned above, this doesn't just affect the significant pressure equilibrium is generated over both ends of the right tappet, but when moving back

gg pulling the right plunger from the left also im substantial pressure equilibrium across the inner and outer ends of the left plunger 26A, creating the retraction of each plunger is facilitated.

In the event that there is no pipeline in the bore 22 24 is located, and the tappets like conventional ones "Blind plungers" are supposed to work, the inner ones are Ends of the arms 53 upon the inward movement of the tappets into a position immediately beyond the in 6, in contact with one another. At this stage of the closing movement of the plunger, the Cutting edges of the Schner blades past each other to thereby open the inner ends of the arms

IQ possible to touch and with continued inward movement of the control rod or piston rod of each tappet to pivot upwards to an inclined position. This inward movement and upward pivoting of the arms continues until

IQ the inner end 35 of each leaf of the right pestle touches the package 3 ^. At this point the arms are inclined as shown in FIG.

2Q The plunger is located during the opening and closing cycles the rod for actuating the right plunger 26b regardless of whether a pipeline sheared or an open hole is closed, constantly in equilibrium and the rod to Actuation of the left plunger 26A is under pressure equilibrium during an opening movement. Of the plug 49 also acts in the manner described above Manner such that the entry of drilling mud into the equilibrium chamber 45 in the

QQ is essentially excluded.

From the above it can be seen that the invention described achieves or specifies all of the aims aimed for Tasks are solved and in an advantageous manner.

Claims (9)

PATENT CLAIMS 1. Blow-out preventer with a housing that has a through-hole and opposing guideways which intersect the through-hole, furthermore in the guideways towards and from one another away movable plungers, each of which has a cutting edge on its inner end, which extends moved transversely to the cutting edge of the ram located in the other guideway to one in the bore Shear off the existing pipeline when the plungers move towards each other, and with a device for sealing between the rams over the cutting edges and between each ram and the guideway around the hole after shearing off the pipeline and moving the tappets towards each other to decide, characterized by a device (53) carried by the plungers (26a, 26B) for detecting the opposite sides of the pipeline (24) as soon as the tappets move towards each other, to shear the pipeline and to lift out the upper sheared end of the gripped pipeline Bayerische Vereinsbank Munich, Account No. 882495 (BLZ 700202 70) - Deutsche Bank Munich, Account No. 82/08050 (BLZ 70070010) Post office in Munich, account no. 163397 - 802 (bank code 700 100 80) out of the path of the device for the purpose of sealing between the plungers as soon as the plungers begin to move to continue on each other. 2. Ausblaspreventer according to claim I _3, characterized in that the device (53) for gripping and lifting, which is carried by each plunger (26A, 26B), an arm which is mounted on the plunger so that it around one approximately horizontal IQ axis is pivotable transversely to the axis of reciprocation of the plunger, and has means for supporting each arm in such a position that its inner end with one side of the pipe (24) over its pivoting IQ kungsachse moved into the engaged state, whereby with continued inward movement of the plunger (26A, 2dB) the arms (53) pivot upwards about the pivot axis, thereby lifting the sheared end of the pipeline with increasing vertical force components. 3. Ausblaspreventer according to claim 2, characterized in that an imaginary line extends through the pivot axis and the inner end of each arm (53) with respect to the horizontal forms an angle which extends from about 30 ° in the support position of the arm to about Enlarged 60 ° when the pipeline is raised and the tappets are closed. QO 4. Ausblaspreventer according to claim 2 or 3, characterized in that when there is no pipe (24) in the bore (22), the inner end ^N n (54) of the arms touch each other and are inclined upward to thereby the inner ends gg allow the plunger (26A, 26B) to interfere with each other to come into contact with the seal. 5- blowout preventer according to claim 2, characterized indicates that each ram (26A ₃ 26B) has a recess (56) in its top which is open at its front end and that each arm (53) of each ram is supported in the recess with its inner end extending therethrough the open end of the recess extends therethrough with the top of the track limiting movement of the top of the arm 53 out of the recess (56) when the plunger is moved to the closed position and is engageable with the top of the arm, in order to ensure its return to the recess as soon as the plunger (2ÖA, 26Β) returns to the open position. 6. blow-out preventer as claimed in claim 1, characterized in that the sealing device (3 * 0 a packing strip on one of the plunger ^(26A,: 26b) above the lower cutting surface of the plunger provided with a surface on the inside end of the other ram above the upper cutting surface of this ram is engageable. 7. Blow-out preventers with a housing in which there is a through-hole and guide tracks, which cut the through hole, as well as a plunger arrangement, characterized in that the The ram assembly comprises a pair of rams (26A, 26B), each of which in a guide track (27) in Move towards the other ram, which is movable in the other guide track, and this another ram can move away, further by a cutting edge (BL) on the inner end of each Ram that moves transversely to the cutting edge of the other ram to a pipe (24) in the Shear off the hole (22) as soon as the plungers move towards each other, and through existing ones on the plungers Means (34) providing a seal between form them above the cutting edges and between them and the guide track (27) in which the The plunger moves, thereby opening the bore (22) after the pipeline has been sheared and continued to move the plunger to close in the direction of each other, and with another device that is of the Plungers (26a, 26B) and for gripping the opposite sides of the pipeline (24) is used when the plungers move towards each other to shear and through the pipeline which the upper sheared end of the pipeline can be lifted out of the path of the sealing device (34) located between them when the Movement of the plunger towards each other is continued. 8. plunger assembly according to claim 7, characterized in that the device (53) for gripping and lifting the sheared upper end of the pipeline carried by each plunger (26A ₉ 2βΒ), an arm (53) which on the The plunger is mounted pivotably about an approximately horizontal axis transverse to the axis of reciprocation of the plunger, and means which support each arm in such a position that its inner end moves so that it is in contact with the side of the pipeline ( 24) comes into engagement above its pivot axis, whereby with continued inward movement of the plunger (26A ₉ 26B) QQ the arms (53) around said pivot axis pivot upward to lift the sheared end of the pipeline with a force equal to its vertical component becomes increasingly larger. 3g 9. plunger arrangement according to claim 8, characterized in that that an imaginary line extends through the pivot axis, and that the inner end each tappet forms an angle with the horizontal which increases from about 30 ° in the supported position of the arm (53) to about 60 ° when the pipeline (24) is raised and the tappets (26A ₉ 26B) are closed. 10. plunger arrangement according to claim 8, characterized that when there is no pipe (24) in the bore (22), the inner ends "10 ■ of the arms (53) touch each other and move them upwards. - Tends * to thereby affect the inner ends of the plungers (26A, 26b) to come into sealing contact with one another. 11. tappet arrangement according to one of claims 8 to 10, characterized in that each tappet (26A, 26b) has in its upper side a recess (56) which is open at its front end, and that each arm (53) of each tappet in the recess is supported so that its inner end extends through the open end of the recess, the top of the track (27) limiting the movement of the top of the arm (53) out of the recess (27) when the plunger in ^ i ^{e closed} position, and can be brought into contact with the upper side of the arm (53) in order to ensure its return into the recess as soon as the plungers return to the open position. 12. plunger arrangement according to claim 8, characterized in that the sealing device (34) a strip of packaging on the one pestle (26A) above the lower cutting surface of the pestle gg having a surface on the inside End of the other ram above the upper cutting surface of this ram comes into contact. 13 · Blow-out preventer tappet with a body that is in a guide track of a blow-out preventer housing in the direction of a bore which traverses the housing and which is cut by the guideway is, can be moved back and forth from this bore, furthermore with a cutting edge on the inner end of the plunger body which is transverse to a cutting edge of the other plunger in an opposite Guide track is movable so that a pipe located in the bore shears off is, as soon as the plungers move against each other, further with one on the inner end of the Plunger body located above the cutting edge sealing device with a on the inner End of the body of the other ram above its cutting edge and along opposite sides in Sealing contact can be brought into sealing contact over the top of the tappet body with the guideway when the pipeline is severed and the tappets move closer to each other are, characterized in that a device carried by the ram (26A, 26B) for There is gripping of one side of the pipeline (24) which is opposite to that side of the pipeline which is gripped by the gripping device carried by the other ram, when the plungers move towards each other to shear the pipeline and the with the gripping device carried by the other ram cooperates to shear off the upper one End of the pipe (24) from the path of the sealing device (34) on the inner ends of the Lift out the tappet body as soon as the tappets continue their movement towards each other. 14. tappet arrangement according to claim 13, characterized in that that the gripping and lifting device carried by the plunger body (33) has one on the plunger body mounted arm (53), 'which about an approximately horizontal axis transversely to Axis of the reciprocating movement of the plunger is pivotable, as well as a device for supporting this arm in such a position that its inner end with one side of the pipeline (24) can be brought into engagement above the pivot axis of the arm, so that when proceeding ■ continued inward movement of the plunger the arm is inclined upwards about said axis, thereby to lift the sheared end of the pipeline with a force that is ever increasing possesses vertical component. '15 plunger arrangement according to claim 14, characterized by an imaginary line that extends through the pivot axis, where the inner end of each arm (53) forms an angle with the horizontal which is about 30 ° in the supported Position of the arm increases to about 60 ° when the pipe (24) is lifted and the Tappets are closed. l6. Tappet arrangement according to Claim 14, characterized in that the tappet body (33) has a recess (56) has in its top which opens at its front end, and that the arm (53) is carried in the recess so that its inner end extends through the open end of the recess extends through it, the top of the guide track (27) moving out the top of the arm limited from the recess when the plunger is moved into the closed position, and with ■ the top of the arm is engageable to ensure its return into the recess, when the plunger returns to the open position. 17. The plunger device according to claim 13, characterized in that the device on the inner end of the plunger body (33) is a transverse packing element (3 * 0).
5 l8. Plunger device according to claim 13, characterized in that characterized in that the device has on the inner end of the plunger body a surface which with a transverse packing element (3 * 0 on the other tappet body can be brought into contact. 19 · Ausblaspreventerj with a housing that has a Includes through hole and guideways that intersect the through hole, also an in Each guide track in the direction of the other ram movable ram, each ram one Has a cutting edge at its inner end which cooperates with a cutting edge on the other ram, to shear a pipe within the bore when the tappets are against each other to move, characterized in that each plunger (26a, 26b) has a device for sealing against the other plunger and against the guide track (27) to close the bore after the pipeline has sheared and the plungers have been moved further towards each other are, and that a fluid operated Device (30, 4l, 6l) is present, which the plunger (26A) as long as with a first force moved inside until the pipe (24) has sheared, and then the plunger with a second, smaller one Force moved further inward to close the bore (22). 20. Blow-out preventer according to claim 19, characterized by one on the tappets (26A, 26B) located device (53) for lifting the upper sheared end of the pipe (24) above the Sealing device (3 ² O on the inner ends of the plungers (26A ₉ 26b) as a function of the inward movement of the plungers with said second force. 21. Ausblaspreventer according to claim 19 or 20, characterized by a pair of cylinders (28) within of the housing, first and second pistons (60, 6l) which are sealed reciprocable in each cylinder are to selectively control fluid the opposite sides of the pistons within the cylinder 's to feed in or take away from these pages in order to thereby pushing the piston in the direction of the housing bore (22) or away from it, furthermore by a rod (30) that supports one of the pistons (6l) in each cylinder with each tappet (26A, 2βΒ) connects to this together with the piston according to to move inside or outside by a device for connecting the other piston (60) in each Cylinder with a piston (61) in it for limited inward and outward movement with respect to the cylinder, causing the other piston to move inwardly to with the to come into contact with a piston in dependence on the supply of control fluid to its outer ends, thereby moving the plunger (26A, 26b) inwards and first shearing the pipeline (24) with a force due to this fluid acting on both pistons (60, 6l), and through a device in each cylinder (28 ) to stop the inward movement of the other piston, once the plungers have been moved inward to shear the pipeline, each plunger through a second force generated by means of the control fluid is transferred to only one piston, moves further inward to the sealing position. 22. Ausblaspreventer according to claim 21, characterized characterized in that each first piston (60) slides sealed in the cylinder (28), and that every second piston (61) slides sealed in the first piston (60). 23. Ausblaspreventer according to claim 22, characterized characterized in that the first piston (60) is the other piston and the second piston is the first calf is. 24. Blow-out preventers with a housing in which a through hole and opposing guideways that intersect this hole, are also in the guideways between the positions in which the hole is open and in which it is closed, reciprocating plungers, a device for bringing about a Sealing between the inner ends of the tappets and between each tappet and its guideway, when the plungers are closed and a device for connecting the bore of the housing below the closed tappets in the chambers of the housing, behind the closed tappets, like this that fluid in the bore pushes the plunger into the closed position, characterized by a device to which a channel (40) belongs, which the chamber behind only one of the plungers (26A, 26b) connects with the bore (22) of the housing above the closed plunger and through a Device (30, 60, 6l) with which the plungers (26A, 26b) between the open and closed positions are reciprocable and which includes a device (4l) for closing the channel (40) as soon as the one plunger is moved inwards, and for Q ₅ Opening of the channel as soon as it is enclosed on the outside. 25. A flow control device, comprising a body having a flow path, further comprising a element reciprocable in the body between first and second positions, in which Positions the element constricts the flow to a greater or lesser extent, des further comprising means for reciprocating the element between the first and second Positions, characterized in that outside the body a cylinder (28) is a and reciprocating piston (60, 6l), a rod attached to the piston (6l) which seals one another extending into the body in order to connect the element so that it fits into moves to its first position as soon as the rod (30) is moved inwards and that it is in its second position moves as soon as the rod is moved outward, further characterized by another rod on the piston, which is sealed in a chamber outside the cylinder extends, a through the piston and both rods through bore for connecting the Inside the body with the outer chamber, a plug (49) which is in the bore (47) between inner and outer limitation points is slidable to and fro, and a fitting piece (E) * for injecting fat into the outer chamber (45) and the bore outside the plug (49), the one from the plug as it moves volumes displaced between its inner and outer boundaries essentially is equal to that which the other rod (44) as it moves in the outer chamber (45) is displaced, and wherein the plug (49) has a constricted passage channel (50) which allows the grease to bypass the plug once it is in its inner position, and that allows line fluid to bypass the plug as soon as it is in its outer position.