EP2591203A2

EP2591203A2 - Closure for a drill hole

Info

Publication number: EP2591203A2
Application number: EP11730308.1A
Authority: EP
Inventors: Wulf Splittstoesser
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-07-08
Filing date: 2011-07-07
Publication date: 2013-05-15
Anticipated expiration: 2031-07-07
Also published as: RU2550618C2; EP2591203B1; WO2012004366A2; RU2586342C1; WO2012004366A3; DE102010050494A1; CN204200146U; CA2804679A1; DE102010050494B4; CA2804679C; RU2013105263A; JP3184356U; US20130112396A1; CN203452703U

Abstract

The object of the invention is to provide a device for closing a drill hole (102), which can be universally used and is capable of closing the drill hole (102) even in the case of damages which are located below a blowout preventer that may be present. The invention is based on the idea of introducing a closure into the drill hole (102) in order to seal the same in the event of damage and rising fluid. To this end, the closure comprises at least one skirt (106) or one capsule (401). A non-positive and/or positive connection to the wall (104) of the drill hole (102) is achieved by opening the skirt (106) or expanding the capsule, so that the drill hole (102) is closed.

Description

Closure for a borehole

description

Field of the invention

The invention relates to a closure for a borehole in which a fluid, such as oil or gas, flows on.

State of the art

So-called blowout preventers are known from the prior art. A blowout preventer is a series of shut-off valves that are mounted directly over the wellbore in a well. Blowout preventers serve to prevent the escape of a fluid from the wellbore. This is necessary to ^¬ special when the drill pipe is damaged or hits the hole to a pressure zone.

While a bore is performed, the strands will Bohrge ^¬ passes through the blowout preventer. If there is an exit of the fluid, which can not be stopped by other means, occurs in the blowout preventer, a two-stage mechanism in place. In a first stage, seals are activated that seal the outer space around the drill string. Should this not be enough to stop a leakage of Flu ^¬ ids, in a second stage, the drill string is severed within the blowout preventer. Thereafter, a sealing of the blowout preventer by means of gate valves is possible.

It is questionable in the individual case whether the Dimensio ^¬ discrimination of the blowout preventer used is sufficient for severing the drill string. In 2004, a study commissioned by US federal agencies found that only 3 out of 14 oil rigs had sufficiently strong shears to cut the drill string.

The events in the Gulf of Mexico has shown that the ver ^¬ used known methods have significant weaknesses and are very susceptible to interference regarding the use and operation.

task

The object of the invention is to provide a device for securing a borehole with the potential for closing the borehole, which can be used universally and avoids the disadvantages of known blowout preventer mentioned in the introduction.

solution

This object is achieved by the invention with the features of the independent claim. Advantageous developments of the invention are characterized in the subclaims. The wording of all claims is hereby incorporated by reference in ^¬ halt this description. The invention also includes all reasonable and in particular all mentioned combinations of independent and / or dependent claims.

The invention is based on the idea of providing a drill pipe at fixed intervals with a closure which unfolds in case of need or to introduce a closure into a leaked borehole in which a fluid, such as oil or gas, flows up the borehole below the wellbore Seal leaks. A first closure according to the invention for a borehole with a wall has for this purpose a tube which can be introduced into the borehole. The tube may consist of one or more tube segments.

Furthermore, the closure has at least one skirt, which consists of a fluid-tight material and is fixed in a fluid-tight manner to the tube. Between the tube and the at least ei ^¬ NEN apron thus no fluid can pass. The Minim ^¬ least an apron can be performed by means of the pipe into the borehole a ^¬.

The at least one skirt can be a folded or unstretched state to the pipe and away from the pipe and to

Wall towards unfolded or stretched state assume. The tube and the at least one skirt are formed such that in the folded state of the at least one skirt, there is a gap between the at least one skirt and the wall when the tube is inserted into the wellbore. The fluid can then flow through the gap between the at least one skirt and the wall.

To close the gap, the closure has activatable means. An activation of the activatable means leads to the fact that the at least one skirt can assume the state unfolded from the tube and towards the wall. Activation of the activatable means, when the tube has been inserted into the borehole, results in the at least one skirt the state unfolded away from the pipe and towards the wall, ie the at least one skirt is transferred from the folded state to the pipe in the state unfolded from the pipe and towards the wall. Activatable agents may, for. B. bars that can hold or release the minimum apron.

A positive connection between the at least one skirt and the wall is achieved when the tube has been inserted into the wellbore and the at least one skirt has assumed the state unfolded from the tube and towards the wall. This connection fixes the closure within the wellbore and prevents the closure from sliding out of the wellbore.

In order to enable such a connection between the at least one skirt and the wall, the at least one skirt has at least one fixing element. The hardness of the at least one fixing element must exceed the hardness of the wall. When the at least one skirt is transferred from the state folded towards the tube into the state unfolded from the tube and towards the wall and pressed against the wall, the at least one fixing element can consequently penetrate into the wall. This results in a positive connection between the at least one apron and the wall to conditions. Examples of fixing elements are about ken Widerha- or an upward linkage which unfolds at Akti ^¬ crossing and wedged.

The connection between the at least one skirt and the wall is fluid-tight. Further, since the at least one scrub ^¬ ze consists of a fluid-tight material and is fixed in a fluid-tight manner on the tube, the gap is closed, so that no fluid can escape through the gap when the tube was inserted into the well and the at least one apron away from the pipe and towards the wall unfolded state. The borehole is hereby sealed.

The at least one skirt is preferably ^{ausgestal ¬} Tet, that the connection between the at least one skirt and the wall can be solved by train on the pipe. By pulling on the tube, the closure can thus be removed from the wellbore as needed.

Be advantageous, it has been found that the transfer from the pipe towards the folded state in the way and to the wall towards the expanded state passively from the pipe, ie by means of a by aufströmende in the borehole fluid to the min ^¬ least an apron applied pressure, he follows. For this purpose, bil ^¬ det the at least one apron to the tube in the folded state with the tube a slot-shaped pocket into which the rising fluid can penetrate. This has the effect that the pressure required for transferring the at least one skirt into the state unfolded from the tube and towards the wall is achieved.

The activation of the activatable means now leads to the fact that the pressure presses the at least one skirt against the wall, so that the gap is closed and the non-positive or positive connection between the at least one skirt and the wall comes about.

The at least one skirt is preferably designed sack or screen ^¬ shaped. As a material for the at least one

Apron is a flexible material that is resistant to the fluid, ie its physical properties do not change when in contact with the fluid. If necessary, the at least one apron can also consist of a textile material or of a metal mesh which is coated for sealing with a suitable substance, if appropriate with a plastic, a polymer based on plants or a biopolymer. Furthermore, certain plastic films or films of a polymer based on plants and optionally biopolymers as Ma ^¬ material for the at least one apron are suitable. It has proven to be advantageous to steam the film or the textile material to protect against destruction by the fluid optionally with a metal ^¬ layer. If necessary, the at least one Memb ^¬ ran may be provided with reinforcing ribs in order to allow a proper function of the at least one membrane and to prevent damage. Alternatively, the at least one skirt may consist of overlapping plastic or metal lamellae or lamellae of textile material as described above.

In a preferred embodiment, the at least one tube is a drill string on which the skirt is mounted - as will be explained below - the capsule to deploy as needed and to block the unimpeded outflow of fluid. Instead of the drill string, the pipe in a further preferred embodiment may be a temporary linkage. Under a Behelfsgestänge is meant any, other than the drill pipe which is used to perform a ^¬ of the closure in the well bore and the subsequent discharge of the fluid.

The rising fluid in the borehole flows at a ge ^¬ know flow rate. If a certain threshold value of the flow velocity is reached, the at least one apron unfolds. If the flow velocity is too high, the at least one skirt can be destroyed during the transition from the folded state to the pipe in the unfolded from the pipe and towards the wall state. To prevent that, has an advantageous embodiment of the invention, a plurality of aprons. These are arranged one behind the other along the tube. At least one apron is ^{vorzugswei ¬} se provided with a passage for the fluid. This reduces the kinetic energy of the rising fluid. A

Apron, which is located above or behind the provided with the passage apron, can save them from destruction. Another embodiment of the closure according to the invention for the borehole has at least one capsule from egg ^¬ nem fluid-tight material upon. Preferably, the material of the capsule is plastically deformable to ensure a stable anchoring of the closure. Suitable would be about metal. The capsule may also consist of a suitable deployable material, such as one of the above-mentioned materials of the apron.

The capsule is formed such that there is a gap between the capsule and the wall when the closure is inserted into the wellbore.

For anchoring in the borehole, the closure has at least one propellant charge. By activation of the at least one propellant the capsule is deployed or expanded. Depending on the selected material, a plastic deformation of the capsule occurs. As a result, the capsule is pressed against the wall, so that a positive and / or positive Ver ^¬ bond between the capsule and the wall is formed.

As propellant are energy storage, such as compressed gases, solid propellant charges or pyrotechnic propellant charges. The released energy unfolds or expands the capsule so that it is pressed against the wall.

The connection between the capsule and the wall is shaped by the corresponding nature of the outer wall of the capsule. conclusively fluid-tight. Since the capsule is made of a fluid-tight Ma ^¬ TERIAL, no fluid can escape through the gap when the shutter is inserted into the borehole and the blowing ^¬ set has been activated. The borehole is hereby sealed.

Furthermore, the closure has a coupling. This serves to connect a pipeline with the closure. An aperture passes through the closure, allowing fluid to flow through the closure and drain through the conduit.

For example, if the drill string has been ejected from the borehole due to an accident or has been removed therefrom for another reason, the closure may be inserted into the hole in a further advantageous development of the invention instead of the at least one pipe on which it is mounted to have a drive. This allows movement of the closure in the fluid. Preferably, the drive as a recoil drive, in ^¬ example, as a rocket engine, designed. A propeller drive can also be used as the drive.

So that the drive is able to introduce the closure against the aufströmende fluid into the wellbore must ^¬ Before the flow velocity of the fluid exceed feed speed of the drive in the borehole. The speed of advance of the drive means the speed at which the drive travels relative to the fluid flowing up the wellbore.

Instead of the drive, a tube can be used to insert the closure into the wellbore. For this purpose, the closure is attached to the tube. The connection between the closure and the tube is fluid tight. The pipe may be the drill pipe or a temporary linkage. The connection between the capsule and the wall is in an advantageous development of the invention positive and / or non-positive and fluid-tight. For this purpose, the outer surface of the capsule is designed accordingly. In a preferred embodiment, the outer surface of the capsule has at least one fixing element. The hardness of the Minim ^¬ least has a fixing member, the hardness of the wall überstei ^¬ gene, so that can penetrate at least one fixing element in the wall, when the capsule is expanded after the introduction of the shutter into the wellbore and the outer surface of the capsule is pressed against the wall becomes. This results ei ^¬ ne positive connection between the capsule and the wall of the borehole to conditions. Examples of fixing are also about barbs.

In a further development of the closure, the latter can have a fixing pin displaceably mounted relative to the capsule. The at least one propellant can act directly on the at least one fixing pin. By activating the Minim ^¬ least a propellant charge of at least one fixing pin can be at least partially pushed out of the capsule. Be ^¬ there is the closure and within the wellbore, the at least one fixing pin penetrating through activation of at least one propellant at least partially out of the capsule herausge ^¬ pushed, allows the at least one fixing pin in the wall.

Around the closure relative to the wall of the borehole ERS ^¬ tight, the closure comprises at least one further blowing rate on. By activating the at least one other

Propellant, the capsule can be deployed or expanded and pressed against the wall. In addition, a development of the invention in which the closure can be introduced ballistically into the borehole is advantageous. The closure is thereby accelerated before entering the borehole, that is acted upon by a kinetic energy. This energy is suitable to introduce the Ver ^¬ circuit up to a certain depth in the borehole where it joins tet ^¬ entfal activatable by appropriate means. Further details and features will become apparent from the following description of preferred embodiments in conjunction with the subclaims. In this case, the respective features can be implemented on their own or in combination with one another. The possibilities to solve the problem are not limited to the embodiments. For example, area information always includes all - not mentioned - intermediate values and all imaginable subintervals.

The embodiments are shown schematically in the figures. The same reference numerals in the individual figures denote identical or functionally identical elements or corresponding elements with respect to their functions. In detail shows:

FIG. 1A shows a closure for a borehole with a skirt in the folded state towards the tube; FIG.

FIG. 1B shows a closure for a borehole with an apron in the state unfolded away from the tube and towards the wall; FIG.

2 shows a closure for a borehole with an apron in the state away from the tube and towards the wall with seals;

3 shows a closure for a borehole with reinforcing ribs and fixing elements; 4 shows a closure for a borehole in the manner of a torpedo; and

Fig. 5 is a displaceable fixing pin.

FIG. 1A shows a closure inserted into a wellbore 102 having a wall 104. The closure has an apron 106. There is a gap 108 between the skirt 106 and the wall 104. The skirt 106 is fastened to a tube 112 in the upper region and is in the folded state towards the tube 112.

Sensors 110 measure data such as the movement of the tube 112, the position of tube 112 relative to the wall 104, the hydrostatic pressure of the fluid which surrounds the closure, the distance that has returned placed within the wellbore 102 to ^¬ the closure, or the flow rate of the fluid.

The skirt 106 is fixed by activatable means in the folded state to the tube 112. Activation of the activatable means by the sensors 110 releases the skirt 106. Fluid flowing under the skirt 106 thereafter causes the skirt 106 to open.

The skirt 106 in the folded away from the tube 112 and towards the wall, Fig. IB shows. The pressure exerted by the fluid flowing on the skirt 106, the skirt 106 presses against the wall 104. Between the skirt 106 and the wall 104 as a result creates a frictional and / or positive and fluid-tight connection. Thus, the skirt 106 closes the gap 108.

To verbes the density of the compound to the fluid verbes, seals 200, for example in the form of 0-rings, may be attached to the skirt 106. This is shown in FIG. 2 as a whole and as a detail Z. By the pressure, which exerts the fluid flowing on the skirt 106, a positive and / or non-positive, fluid-tight connection between the seals 200 and the wall 104 comes about. The use of a flexible fabric or a foil as

Apron 103 is particularly practicable when the pressure exerted by the fluid flowing on the skirt 106 is low. At higher pressures, however, the embodiment shown in Fig. 3 is preferred. Here, 300 support the reinforcing ribs, the skirt 106. The skirt 106, which is not shown in Fig. 3 for better illustration of the reinforcing ribs 300, upstream of the reinforcing ribs positio ^¬ defined so that the skirt 106 is pressed in the unfolded state against the reinforcing ribs 300 , The structure of the reinforcing ribs 300 is similar to the frame of an umbrella. The

Reinforcing ribs 300 stabilize the skirt 106, center the tube 112 in the wellbore 102, and also prevent damage to the skirt 106 by the pressure that the fluid exerts on the skirt 106 in the inflated state away from the tube 112 and toward the wall 104.

Seals 200, as shown in FIG. 2, are particularly advantageous when the wall 104 of the borehole 102 is made of a hard material. On the other hand, a soft wall 104 allows the use of the fixing elements 302 shown in detail Z of FIG. 3. The fixing elements 302 are attached to the reinforcing ribs 300 and are made of a hard material. Specifically, the material of the fixing elements 302 has to be harder than the material of the wall 104. Preferably, the fixing elements 302 sit be ^¬ formations, for example in the form of barbs.

If the skirt 106 in the unfolded from the tube 112 and toward the wall 104 out state by the pressure exerted by the fluid on the skirt 106, pressed against the wall 104 leads this in that the formations of the fixing elements 302 penetrate into the wall 104. This results in a positive connection with the wall 104th

To protect the material and increase safety, the skirt 106 can be opened gradually. In a first step, the fixing elements 302 are pressed against the wall 104, so that the formations of the fixing elements 302 penetrate into the wall 104 and a positive connection to the wall 104 comes about. In a second

Step, the gap 108 is closed by transferring the skirt 106 from the folded toward the tube 112 in the unfolded from the tube 112 and the wall 104 towards folded state. The fluid now flows through the tube 112. In a third step, valves located in the tube 112 are closed. Hereby, the borehole 102 is completely sealed.

In the embodiments shown in FIGS. 1A, 1B, 2 and 3, the skirt 106 is inserted into the wellbore 102 by means of the tube 112, in the preferred embodiment as an equipment element of a drill string. The closure of Fig. 4, however, is designed in the manner of a torpedo. A jet drive 400 generates enough feed to the einzu Ver ^¬ circuit against the aufströmende fluid in the wellbore 102 ^¬ lead.

Instead of the skirt 106, the illustrated in Fig. 4 Ver ^¬ circuit to one capsule four hundred and first The capsule 401 forms the outer shell of the belly of the closure. The lower part 401 a of the capsule 401 is hemispherical in shape and provided with sensors 110.

The hemispherical part of the capsule 401 is adjoined by a cylindrical part 401b of the capsule 401. The cylindrical part 401b of the capsule 401 connects the hemispherical part 401a of the capsule 401 with the upper part 401c thereof. At the upper part 401c of the capsule 401 turn guide elements 402 and a coupling 404 are attached.

The capsule 401 encloses propellant packs 408 and a solid support member 406 with funnel-shaped indentations. Within these indentations are pyrotechnic propellant charges 408.

Through the semi-spherical portion 401a of the capsule 401, through the carrier member 406, through the jet drive 400 and through the upper portion 401c of the capsule 401, a passage leads 414. The passage 414 extends longitudinally through the fastener and ver ^¬ binds an opening in the spherical portion 401a the capsule 401 with an opening in the upper part 401c of the capsule 401 so that fluid can flow through the closure.

The guide elements 402 serve to stabilize the closure as it is introduced into the wellbore 102. Meanwhile, the sensors 110 acquire appropriate data. For example, the sensors 110 can measure the penetration depth of the closure into the borehole 102 or determine damage to the wall 104 by means of optical signals.

Depending on the acquired data, the sensors initiate

110, the activation of the propellant charges 408. Due to the energy released as a result, the capsule is deployed 401 or up ^¬ expands and is pressed against the wall of the 104th

The capsule 401 is provided with fixing elements 302. The hardness of the fixing elements 302 must exceed the hardness of the wall 104 of the borehole 102. This allows the fixing elements 302 to be able to penetrate into the wall 104 as a result of the activation of the pyrotechnic propellant charges 408, so that the closure is anchored in the wall 104 by means of a positive connection. As shown in detail Y of Fig. 4, the fixing elements 302 may be configured as barbs.

The energy of the explosion of the propellant charges 408 causes an increase in the diameter of at least a portion of the capsule 401. In order a defined deformation of the capsule 401 to ge ^¬ währleisten, the capsule 401 may, as shown in detail X of Fig. 4, have a predetermined breaking 410.. When the capsule 401 is expanded, the lower part of the capsule 401, consisting of the hemispherical part 401a of the capsule 401 and the cylindrical part 401b of the capsule 401, comes off along the predetermined breaking point 410 from the upper part 401c of the capsule 401 Expanding the capsule 401 the remaining components of the closure, such as the passage 414 or the coupling 404, damaged.

The larger the gap existing between the wall 104 and the capsule 401, the greater the demands placed on the deformability of the capsule 401. In order to prevent the breaking point of the material used for the capsule 401 from being exceeded when the capsule 401 is expanded, the

Capsule 401 below the predetermined breaking point 410 have vertically duri ^¬ Fende expansion folds.

In the expanded state of the cylindrical part of the capsule 401 is flat against the wall 104 at. The hemispherical part of the capsule 401 connects the cylindrical part of the capsule 401 with the interior of the closure. Consequently, no fluid can escape between the capsule 401 and the wall 104. The borehole is now sealed.

In order to continue to use the borehole 102, the closure next to the coupling 404 - as in detail Z of

Fig. 4 shown - a valve 412 on. The valve 412 opens and closes the passage 414. If the valve 412 CLOSED ^¬ sen, can not escape of fluid from the wellbore 102nd If the valve 412 is open, however, the fluid is passed through the passage 414 and thus through the closure.

In addition, the drawn poppet valve 412, other types of valves can be used, for. B. cone valves or slide valves. The latter would have the advantage, less

Force to open.

The coupling 404 serves to connect a pipeline to the closure. This happens after the closure has been anchored by activation of the propellant charges 408 in the wall 104. With the valve open, the fluid 412 can be removed through the pipeline and as provided further processed ^¬ the.

The valve may also be open during insertion of the closure into the wellbore to reduce pressure on the closure. One possibility then is in ^¬ also to close the valve only when a pipe is connected to the clutch 404th Such a conduit 404 is capable of receiving portions of the increased forces upon closure of the valve.

It is possible to introduce a plurality of fasteners in the gezeig ^¬ th in Fig. 4 embodiment in the drill hole 102.

It is also possible to mount the embodiment as a capsule as an item of equipment of a drill string 112 and insert it into the wellbore 102.

Various embodiments can be combined according to unterschiedli ^¬ cher security considerations.

FIG. 5 shows a section of the closure with at least one fixing pin 500. For guiding the at least one

Fixing pin 500, the support member 406 has a zylinderför ^¬ shaped bore 502. In the bore 502 of the fixing pin 500 is slidably mounted.

The bore 502 connects an opening 504 in the capsule 401 with a spherical ignition chamber 506. Like the bore 502, the ignition chamber 506 is located in the carrier element 406, ie is surrounded by the carrier element 406 or is formed by the carrier element 406. The bore 502 is not perpendicular, but is inclined by ei ^¬ nen certain angle relative to the vertical downwards. Thus, the fixing pin 500 slips due to its

Gravity first along the bore 502 toward the interior of the closure.

The firing chamber 506 contains a propellant charge 408. If the ^¬ ser activated, the released energy 104 of the borehole 102. drives the fixing pin 500 from the ignition chamber 506 in the direction away of the wall of the fixing pin 500 comes as a result, through the between the capsule 401 and the wall 104 existing

Gap 108 and penetrates into the wall 104 a. The closure is now fixed to the wall 104.

The gap 108 can be closed by the capsule 401 - as described above - unfolded and pressed against the wall 104. At least one propellant charge 408 thus serves to deploy or expand the capsule, while at least one further propellant charge 408 drives the fixing pin 500 into the wall 104.

To prevent the hole 502 and the at least one fixing pin 500 is damaged during deployment or dilating the capsule 401, the bore 502 is preferably as angeord ^¬ net, that the opening 504 in the capsule 401 above the predetermined breaking point 410 in the upper Part 401c of the capsule 401 befin ^¬ det.

Reference sign

well

wall

apron

gap

sensor

pipe

poetry

reinforcing rib

fixing

jet propulsion

capsule

a spherical part of the capsule c cylindrical part of the capsule upper part of the capsule

vane

clutch

support element

propellant

Breaking point

Valve

passage

drilling

ignition chamber

Claims

claims

1. closure for a borehole (102) with a wall

(104) wherein fluid flows into the wellbore (102), comprising: a) a tube (112) insertable into the wellbore (102);

b) at least one apron (106) from a fluid-tight Ma ^¬ TERIAL,

bl) wherein the at least one skirt (106) is fixed in a fluid-tight manner to the tube (112);

b2) wherein the at least one skirt (106) can assume a folded state towards the tube (112) and a state unfolded away from the tube (112) and towards the wall (104);

b3) wherein the tube (112) and the at least one apron (108) are formed such that, in (for tube 112) toward ge ^¬ unfolded state of the at least one apron (106) is a gap (108) between the at least one apron ( 106) and the Wan ^¬ dung (104) when the tube (112) is inserted into the wellbore (102);

b4) wherein the at least one skirt (106) has at least one fixing element (302);

b5) wherein the hardness of the at least one fixing element (302) exceeds the hardness of the wall (104);

b6) so that the at least one fixing element (302) can penetrate into the wall (104) when the at least one skirt (106) is pressed against the wall (104);

b7) so that a positive connection between the at least one skirt (106) and the wall (104) can come about; and with

c) activatable means,

cl), wherein activation of the activatable means results in the at least one skirt (106) protruding from the tube (112) may take away and toward the wall (104) unfolded state.

2. Closure according to the preceding claim,

characterized,

in that the at least one tube (112) is a drill string.

3. Closure according to claim 1,

characterized,

in that the at least one tube (112) is a temporary linkage.

4. Closure according to one of the preceding claims, characterized by,

a plurality of skirts (106) disposed one behind the other along the tube (112).

5. A closure for a bore hole (102) having a wall (104), wherein a fluid in the wellbore (102) aufströmt, comprising: a) at least a capsule (401) from a fluid-tight Ma ^¬ TERIAL,

al) wherein the capsule (401) is formed such that a gap (108) exists between the capsule (401) and the wall (104) when the closure is inserted into the wellbore (102);

b) at least one propellant (408),

bl) wherein the capsule (401) can be expanded by activating the at least one drive ^¬ set (408); and c) a coupling (404) for connecting a pipeline to the closure; d) wherein a passage (414) passes through the closure so that the fluid can flow through the closure and be discharged through the conduit.

6. Closure according to the preceding claim,

marked by,

a drive (400) allowing the closure to move in the fluid.

7. A closure according to claim 5,

characterized,

the closure is attached to a tube (112) insertable into the wellbore.

8. Closure according to one of claims 5 to 7,

characterized,

that the outer surface of the capsule (401) has at least one fixing element (302);

wherein the hardness of the fixing member (302) exceeds the hardness of the dung Wan ^¬ (104);

so that the at least one fixing element (302) can penetrate into the dung Wan ^¬ (104) when the outer surface of at least a capsule (401) is pressed against the wall (104).

9. Closure according to one of claims 5 to 8,

characterized,

that the closure has at least one fixing pin (500) on ^¬ which can be pushed out by activation of the at least one propellant charge (408) at least partially out of the capsule (401);

wherein the hardness of the at least one fixing pin (500) exceeds the hardness of the wall (104); so that the at least one fixing pin (500) can penetrate into the wall (104) when the at least one fixing pin (500) is at least partially pushed out of the capsule 401 by activating the at least one propellant charge (408).