RU2550618C2 - Plug for drilled well - Google Patents

Abstract

FIELD: oil and gas industry.SUBSTANCE: invention relates to plugs for the drilled wells where the fluid flows upwards. Plug (102) with walls (104) contains pipe (112), that can be inserted in the drilled well (102), at least one diaphragm (106) out of material impermeable for fluids. At that at least one diaphragm (106) if secured impermeable for fluids in the pipe (112). At that this at least one diaphragm (106) can take state folded in the direction of pipe (112) and state unfolded in the direction from pipe (112) to walls (104). At that the pipe (112) and specified at lest one diaphragm (106) are made such that in state folded in direction to pipe (112) of the specified at least one diaphragm (106) there is a gap (108) between the specified at least one diaphragm (106) and walls (104), when the pipe (112) is inserted in the drilled well (102). At that the specified at least one diaphragm (106) has at least one fixing element. At that hardness of the specified at least one fixing element exceeds hardness of walls (104), so the specified at least one fixing element (302) can penetrate in walls (104), when the specified at least one diaphragm (106) is pressed to walls (104). At that connection with geometric closure between the specified at least one diaphragm (106) and walls (104). Is ensured besides, the plug contains activated means. At that activation of the activated means results in that specified at least one diaphragm (106) can accept state unfolded in direction from pipe (112) to walls (104).EFFECT: increased efficiency of the well disconnection in case of damages.4 cl, 6 dwg

Description

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

The so-called blowout preventers are known in the art. Blowout preventers are a series of shutoff valves that are installed when drilling directly above a borehole. Blowout preventers serve to prevent fluid from flowing out of the well. This, in particular, is necessary when the drill pipe string is damaged or the drilling falls into the overpressure zone.

During drilling, the drill string passes through a blowout preventer. If this results in a fluid outlet that cannot be stopped by other means, a two-stage mechanism is launched in the blowout preventer. In the first stage, seals are activated that clog the outer space around the drill pipe string. If this is not enough to stop the fluid from flowing out, at the second stage the drill string inside the blowout preventer is split. After this, blowout preventers can be sealed by means of shut-off valves.

However, in a separate case, the question arises whether the selected blowout preventer sizes are sufficient for separating drill pipes. A study commissioned by the US federal services in 2004 showed that only 3 of the 14 oil platforms had sufficiently strong shear rates to separate drill pipes.

The incident in Golf, Mexico City, showed that the known methods used have significant weaknesses and are very unreliable in terms of application and operation.

The objective of the invention is to indicate a device for strengthening a borehole, with the potential for closing a borehole, which can be used in a universal way and at the same time prevents the above-mentioned disadvantages of known blowout preventers.

This problem is solved by the invention using the features of an independent claim. Preferably, improvements to the invention are noted in the dependent claims. The wording of all claims by the present by reference is included in the content of this description. The invention also includes all appropriate and, in particular, all of the mentioned combinations of independent and / or dependent claims.

The invention is based on the idea of supplying drill pipes at set intervals with a plug that unfolds if necessary, or, respectively, insert a plug into a leaky borehole in which a fluid, such as oil or gas, flows upward to plug this borehole below leaks. The first wall plug of the invention for a borehole has a pipe for this purpose which can be inserted into the borehole. A pipe may consist of one or more pipe segments.

In addition, the plug has at least one diaphragm, which consists of a fluid impermeable material and is fixed on the pipe impervious to fluids. Thus, no fluid can flow between the pipe and the at least one diaphragm. The specified at least one diaphragm can be introduced into the borehole through a pipe.

The specified at least one diaphragm can take a folded or, respectively, unexpanded state in the direction of the pipe, and a deployed or, respectively, expanded state in the direction from the pipe and to the walls. The pipe and said at least one diaphragm are designed so that in the state of at least one diaphragm folded in the direction of the pipe there is a gap between the at least one diaphragm and the walls when the pipe is inserted into the borehole. A fluid may then flow up through the gap between the at least one diaphragm and the walls.

To close this gap, the plug has activated means. Activation of the activated means leads to the fact that the specified at least one diaphragm can take a deployed state in the direction from the pipe and to the walls. Activation of the activated means when the pipe has been inserted into the borehole leads to the fact that the at least one diaphragm assumes a state unfolded in the direction from the pipe and to the walls, i.e. said at least one diaphragm is transferred from a state folded in the direction of the pipe to a state unfolded in the direction from the pipe and to the walls. The activatable means can, for example, be crossbars that can hold or release said at least one diaphragm.

A geometrical connection between the at least one diaphragm and the walls occurs when the pipe has been inserted into the borehole and the at least one diaphragm has taken a state developed in the direction from the pipe to the walls. This connection fixes the plug inside the borehole and prevents the plug from slipping out of the borehole.

In order to enable such a connection between the at least one diaphragm and the walls, the at least one diaphragm has at least one locking element. The hardness of the at least one fixing element must exceed the hardness of the walls. When the specified at least one diaphragm from the state rolled in the direction of the pipe is transferred to the state developed in the direction from the pipe and to the walls and is pressed against the walls, said at least one fixing element can therefore penetrate the walls. This ensures a connection with a geometric circuit between the specified at least one diaphragm and the walls. Examples of locking elements are, for example, hooks with a spear-pointed tip or an upward-directed drill pipe string that, when activated, unfolds and wedges.

The connection between the at least one diaphragm and the walls is impervious to fluids. Since said at least one diaphragm consists of a fluid impermeable material and is fixed to a fluid impermeable pipe, the gap is closed so that the fluid cannot flow out through the gap when the pipe was introduced into the borehole and said at least one the diaphragm takes a state developed in the direction from the pipe and to the walls. In this case, the borehole is blocked.

The specified at least one diaphragm is preferably made so that the connection between the specified at least one diaphragm and the walls can be disconnected by pulling on the pipe. By pulling on the pipe, the plug can thus be removed from the borehole if necessary.

It turned out to be preferable that the transition from the state folded in the direction of the pipe to the expanded state in the direction from the pipe and to the walls occurs passively, i.e. by the pressure exerted by flowing upward in the borehole fluid at the specified at least one diaphragm. To this end, said at least one diaphragm in a state folded in the direction of the pipe forms a pocket with the pipe in the form of a gap into which the rising fluid can penetrate. As a result, the pressure necessary to translate the specified at least one diaphragm into the expanded state in the direction from the pipe to the walls.

The activation of the activated means now leads to the fact that the pressure presses the specified at least one diaphragm against the walls, so that the gap is closed and a connection is made with a force or geometric closure between the specified at least one diaphragm and the walls.

The specified at least one diaphragm is preferably made in the form of a bag or umbrella. As a material for said at least one diaphragm, a flexible material is suitable which is resistant to the fluid, i.e. whose physical properties do not change upon contact with the fluid. Said at least one diaphragm may, in particular, also consist of a textile material or of a metal braid which is coated with a suitable substance for sealing, in particular plastic, a plant-based polymer or a biopolymer.

In addition, certain plastic films or, respectively, films made from a plant-based polymer and, in particular, a biopolymer, are suitable as a material for said at least one diaphragm. In this case, it was preferable to spray onto a film or, accordingly, a textile material for protection against destruction by a fluid medium, in particular, a metal layer. If necessary, the specified at least one membrane may be provided with stiffeners to ensure the proper functioning of the specified at least one membrane and prevent damage. Alternatively, said at least one diaphragm may consist of overlapping plastic or metal plates or of plates of textile material, as described above.

In one preferred embodiment, said at least one pipe is a drill pipe on which a diaphragm is mounted, or, as explained below, a capsule, so that, if necessary, it is deployed and blocks the smooth flow of fluid.

Instead of a drill pipe string, in another embodiment, the pipe may be auxiliary drill pipes. By auxiliary drill pipes should be understood any pipe that differs from drill pipes, which serves to insert a plug into the borehole and then divert the fluid.

The fluid rising in the borehole flows at a certain flow rate. Upon reaching a certain threshold value of the flow velocity, said at least one diaphragm is deployed. If the flow velocity is too high, the at least one diaphragm during the transition from the state folded in the direction of the pipe to the expanded state in the direction from the pipe to the walls can be destroyed. To prevent this, in one of the preferred improvements of the invention there are several diaphragms. These diaphragms are located along the pipe one after another. At least one diaphragm thereof is preferably provided with a fluid inlet. This hole reduces the kinetic energy of the rising fluid. The diaphragm, which is located above or, respectively, behind the diaphragm equipped with a through hole, can protect it from destruction.

Another embodiment of a borehole plug of the invention includes at least one capsule of a fluid impervious material. Preferably, the capsule material is plastically deformable to ensure stable fastening of the plug. Metal would be suitable, for example. But the capsule may also consist of a proper expandable material, for example, one of the above diaphragm materials.

The capsule may be designed so that there is a gap between the capsule and the walls when the plug is inserted into the borehole.

For fixing in a borehole, the plug has at least one fuse. When activating the specified at least one fuse, the capsule expands or, accordingly, expands. Depending on the material chosen, plastic deformation of the capsule occurs. As a result, the capsule is pressed against the walls, so that there is a connection with force and / or geometric closure between the capsule and the walls.

Suitable fuses are energy storage devices such as, for example, compressed gases, solid fuses or pyrotechnic fuses. The released energy expands or, accordingly, expands the capsule, so that it is pressed against the walls.

The connection between the capsule and the walls is a fluid tight connection with a geometric closure due to the corresponding properties of the outer walls of the capsule. Since the capsule consists of a fluid impervious material, the fluid may leak through the gap when the plug has been inserted into the borehole and the fuse has been activated. In this case, the borehole is blocked.

In addition, the plug has a sleeve. This sleeve serves to connect the pipe to the plug. The passageway passes through the plug so that fluid can flow through the plug and can be diverted through the pipe.

When, for example, drill pipes were ejected from a borehole or removed for another reason due to an accident, the plug is another preferred development of the invention instead of the at least one pipe on which it was installed and through which it was inserted into well, may have a drive. This actuator enables the translational movement of the plug in the fluid. Preferably, the drive is in the form of a jet drive, for example, in the form of a rocket engine. A screw motor can also be used as a drive.

In order for the actuator to be able to insert a plug against the upward flowing fluid into the borehole, the actuator head velocity must exceed the flow rate of the fluid in the borehole. Under the pressure head of the drive should be understood the speed at which the drive moves progressively relative to the flowing upward in the borehole fluid.

Instead of a drive, a pipe may be used to insert the plug into the borehole. For this purpose, a plug is mounted on the pipe. The connection between the plug and pipe is impervious to fluids. The pipe may be a drill pipe or auxiliary drill pipe.

The connection between the capsule and the walls in one of the preferred improvements of the invention is a fluid tight connection with a geometric closure and / or with a force closure. To this end, the outer surface of the capsule is made accordingly. In one preferred embodiment, the outer surface of the capsule has at least one locking element. The hardness of said at least one fixing element must be greater than the wall hardness so that said at least one fixing element can penetrate the walls when the capsule expands after the plug is inserted into the borehole and the outer surface of the capsule is pressed against the walls. This ensures a connection with a geometric circuit between the capsule and the walls of the borehole. Examples of locking elements are, for example, hooks with a spear-pointed tip.

In one of the improvements to the plugs, it may have a locking pin mounted to move relative to the capsule. The specified at least one fuse can act directly on the specified at least one locking pin. When activating said at least one fuse, said at least one locking pin may at least partially extend from the capsule. If the plug is located inside the borehole and said at least one fixing pin is activated at least partially from the capsule when said at least one fuse is activated, said at least one fixing pin may penetrate the walls.

To seal the plug relative to the walls, the plug has at least one additional fuse. When activating the specified at least one additional fuse, the capsule can expand or, accordingly, expand and cling to the walls.

Preferably, in addition, one of the improvements of the invention, in which the plug can be introduced into the borehole ballistically. In this case, the plug before entering the borehole is accelerated, that is, kinetic energy is communicated to it. This energy is able to insert the plug to a certain depth in the borehole, where it is deployed using appropriate activated means.

Other details and features are contained in the following description of preferred embodiments in connection with the dependent claims. In this case, the corresponding signs can be carried out one at a time independently or several in combination with each other. The possibilities for solving the problem are not limited to these implementation examples. So, for example, range data always includes all unnamed intermediate values and all possible individual intervals.

Examples of implementation are shown schematically in the figures. The same reference signs on the individual figures mean the same or performing the same function or, accordingly, corresponding to each other in their functions elements. Separately shown:

FIG. 1A: a plug for a borehole provided with a diaphragm in a state folded in the direction of the pipe;

FIG. 1B: a plug for a borehole provided with a diaphragm in the expanded state in the direction from the pipe and to the walls;

FIG. 2: a plug for a borehole, equipped with a diaphragm in the expanded state in the direction from the pipe and to the walls, with seals;

FIG. 3: a plug for a borehole equipped with stiffeners and fixing elements;

FIG. 4: a plug for a borehole, similar to a torpedo; and

FIG. 5: movable locking element.

In FIG. 1A, a plug is shown which is inserted into a borehole 102 with walls 104. The plug has a diaphragm 106. There is a gap 108 between the diaphragm 106 and the walls 104. The diaphragm 106 is fixed to the pipe 112 in the upper region and is folded in the pipe direction.

Sensors 110 measure parameters, such as, for example, the movement of the pipe 112, the position of the pipe 112 relative to the walls 104, the hydrostatic pressure of the fluid that spans the borehole, the distance that the plug has traveled inside the borehole 102, or the flow velocity of the fluid.

The diaphragm 105 is fixed by activated means in a state folded in the direction of the pipe 112. Upon activation of the activated means by the sensors 110, the diaphragm 106 is released. A fluid that flows below the diaphragm 106 then opens the diaphragm 106.

The diaphragm 106 in the expanded state in the direction from the pipe 112 and to the walls is shown in FIG. 1B. The pressure exerted by the upward flowing fluid on the diaphragm 106 presses the diaphragm 106 against the walls 104. As a result, between the diaphragm 106 and the walls 104 there is a fluid tight connection with a force closure and / or a geometric closure. Thus, the diaphragm 106 closes the gap 108.

In order to improve the density of the joint relative to the fluid, seals 200, for example in the form of circular rings, can be mounted on the diaphragm 106. This is depicted in FIG. 2 as a whole and in the form of a part on fragment Z. Due to the pressure exerted by the upward flowing fluid on the diaphragm 106, a fluid tight connection is made with a geometric and / or force closure between the seals 200 and the walls 104.

The use of a flexible fabric or film as the diaphragm 103 is convenient, in particular, when the pressure exerted by the upward flowing fluid on the diaphragm 106 is small. At higher pressures, in contrast, the one shown in FIG. 3 example implementation. In this case, the stiffening ribs 300 support the diaphragm 106. The diaphragm 106, which in FIG. 3 for better clarity, the stiffeners 300 are not shown, located upstream of the stiffeners, so that the diaphragm 106 in the expanded state is pressed against the stiffeners 300. The design of the stiffening ribs 300 is similar to the design of the traction system of the umbrella. The stiffening ribs 300 stabilize the diaphragm 106, center the pipe 112 in the borehole 102, and also prevent damage to the diaphragm 106 by the pressure exerted by the fluid on the diaphragm 106 in the extended state from the pipe 112 and to the walls 104.

Seals 200, as shown in FIG. 2 are preferred, in particular, when the walls 104 of the borehole 102 are composed of solid material. Soft walls 104, in contrast, allow the use shown in fragment Z of FIG. 3 locking elements 302. The locking elements 302 are mounted on stiffening ribs 300 and are composed of solid material. In particular, the material of the locking elements 302 should be harder than the material of the walls 104. Preferably, the locking elements 302 have molded elements, for example, in the form of hooks with a spear-pointed tip.

When the diaphragm 106 in the expanded state in the direction from the pipe 112 and to the walls 104, the pressure that the fluid exerts on the diaphragm 106 is pressed against the walls 104, this leads to the fact that the molded elements of the locking elements 302 penetrate the walls 104. This connects with geometrical closure with walls 104.

To save material and increase reliability, the diaphragm 106 can be opened step by step. In the first step, the locking elements 302 are pressed against the walls 104, so that the molded elements of the locking elements 302 penetrate the walls and are connected with a geometric closure with the walls 104. In the second step, the gap 108 is closed by transferring the diaphragm 106 from the state folded in the direction of the pipe 112 to the expanded the state is in the direction from the pipe 112 and to the walls 104. The fluid now flows through the pipe 112. In the third step, the valves that are in the pipe 112 are closed. In this case, the borehole 102 is completely plugged.

As shown in FIG. 1A, 1B, 2 and 3 of the embodiments, the diaphragm 106 by means of the pipe 112, in the preferred embodiment, is introduced as a drill pipe fitting into the borehole 102. The plug shown in FIG. 4, in contrast, is made like a torpedo. The jet actuator 400 creates sufficient pressure to introduce a plug against the upward flowing fluid into the borehole 102.

Instead of the diaphragm 106 shown in FIG. 4, the cap has a capsule 401. The capsule 401 forms the outer shell of the bulge of the cap. The lower part 401a of the capsule 401 is hemispherical and provided with sensors 110.

Cylindrical portion 401b of capsule 401 is adjacent to the hemispherical portion of capsule 401. The cylindrical portion 401b of capsule 401 connects the hemispherical portion 401a of capsule 401 to its upper portion 401c. On the upper part 401c of the capsule 401, in turn, guide elements 402 are located, as well as a sleeve 404.

The capsule 404 covers fuses 408 and a massive carrier 406 provided with funnel-shaped recesses. Inside these recesses are pyrotechnic fuses 408.

Through the hemispherical portion 401a of the capsule 401, through the carrier 406, through the jet drive 400 and through the upper portion 401c of the capsule 401, a passage opening 414 passes. The passage opening 414 extends longitudinally through the plug and thus connects the opening in the spherical portion 401a of the capsule 401 to on top of capsule 401 401c so that fluid can flow through the plug.

Guide elements 402 serve to stabilize the plug when it is inserted into the borehole 102. Sensors 102 record the proper parameters at this time. So, the sensors 110 can, for example, measure the depth of penetration of the plug into the borehole 102 or by means of optical signals to determine damage to the walls 104.

Depending on the registered parameters, the sensors 110 initiate the activation of fuses 408. Due to the energy released as a result, the capsule 401 expands or, accordingly, expands and is pressed against the walls 104.

The capsule 401 is provided with locking elements 302. The hardness of the locking elements 302 must exceed the hardness of the walls 104 of the borehole 102. This allows the locking elements 302 to penetrate the walls 104 due to activation of the pyrotechnic fuses 408 so that the plug is secured to the walls 104 by means of a geometrical connection. depicted in fragment Y of FIG. 4, the locking elements 302 can be made in the form of hooks with a pointed tip in the form of a spear.

The energy of the explosion of fuses 408 contributes to an increase in the diameter of at least one part of the capsule 401. In order to ensure the desired deformation of the capsule 401, the capsule 401, as shown in fragment X of FIG. 4 may have a predetermined fracture location 410. When the capsule 401 expands, 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, is disconnected at a predetermined fracture location 410 from the upper part 401c of the capsule 401. This prevents damage to the remaining components of the plug, such as, for example, the passage hole 414 or sleeve 404, when expanding capsule 401.

The greater the gap between the walls 104 and the capsule 401, the greater the demands on the possibility of deformation of the capsule 401. To prevent exceeding the fracture limit of the material used for capsule 401, when expanding the capsule 401, the capsule 401 below the predetermined fracture site 410 may have vertically expanding folds.

In the expanded state, the cylindrical part of the capsule 401 is flat against the walls 104. The hemispherical part of the capsule 401 connects the cylindrical part of the capsule 401 with the inner region of the plug. Therefore, fluid cannot flow between the capsule 401 and the walls 104. The borehole is now clogged.

In order to be able to use the borehole 102 later, a plug, along with a sleeve 404, as shown in fragment Z of FIG. 4, has a valve 412. Valve 412 opens and closes the bore 414. When the valve 412 is closed, fluid cannot flow out of the borehole 102. When the valve 412, in contrast, is open, the fluid is directed through the bore 414 and, at the same time, through stub.

In addition to the poppet valve 412 shown in the drawing, other types of valves can also be used, for example, conical valves or slide valves. The latter would have the advantage of the lesser effort required to open.

The sleeve 404 serves to connect the pipe to the plug. This occurs after the plug has been secured to walls 104 by activating fuses 408. With valve 412 open, fluid may be diverted through the pipeline and further processed as provided.

The valve may also be opened during insertion of the plug into the borehole to reduce pressure on the plug. One possibility then is also to close the valve only when the pipe has been connected in the sleeve 404. Such pipe 404 is capable of absorbing a fraction of the increased forces after closing the valve.

Several plugs are possible in the embodiment shown in FIG. 4 embodiment, into borehole 102.

An embodiment is also possible in the form of a capsule as an element of equipment for drill pipes 112 mounted and inserted into borehole 102.

Different embodiments may be combined in accordance with various safety considerations.

In FIG. 5 shows a fragment of a plug provided with at least one fixing pin 500. To guide said at least one fixing pin 50, the carrier 406 has cylindrical drilling 502. In drilling 502, the fixing pin 500 is movably mounted.

Drilling 502 connects the hole 504 in the capsule 401 to the spherical firing chamber 506. Like drilling 502, the firing chamber 506 is located in the carrier 406, i.e. covered by the carrier 406 or, respectively, is formed by the carrier 406.

Drilling 502 is not vertical, but tilted at a certain angle relative to the vertical down. Thus, the locking pin 500 under the action of its gravity first slides along the drilling 502 in the direction of the inner region of the plug.

The firing chamber 506 contains a fuse 408. When this fuse is activated, the released energy drives the locking pin 500 away from the firing chamber in the direction of the walls 104 of the borehole 102. The locking pin 500 therefore passes through the gap 108 between the capsule 401 and the walls 104 and penetrates the walls 104. The cap is now fixed on the walls 104.

The gap 108 can be closed, while the capsule 401, as described above, expands or, accordingly, expands and is pressed against the walls 104. At least one fuse 408 serves, thus, to expand or, accordingly, expand the capsule, while at least one additional fuse 408 drives the locking pin 500 into the walls 104.

In order to prevent damage to the drilling 502 and said at least one fixing pin 500 when expanding or expanding the capsule 401, the drilling 502 is preferably located so that the hole 504 in the capsule 401 is located above a predetermined fracture location 410 in the upper part 401c of the capsule 401.

Reference List

102 borehole

104 Walls

106 aperture

108 clearance

110 Sensor

112 Pipe

200 Seal

300 stiffener

302 locking element

400 jet drive

401 capsule

401a Spherical capsule

401b Cylindrical part of the capsule

401c capsule top

402 Guide element

404 Coupling

406 Carrier

408 Fuse

410 Set point of destruction

414 flow hole

502 drilling

504 Ignition chamber

Claims (4)

1. A plug for a borehole (102) with walls (104), wherein the fluid in the borehole (102) flows upward, comprising:
a) a pipe (112) that can be inserted into the borehole (102);
b) at least one diaphragm (106) of a fluid impervious material,
b1) wherein this at least one diaphragm (106) is impervious to fluids fixed to the pipe (112);
b2) wherein this at least one diaphragm (106) can assume a state folded in the direction of the pipe (112) and unfolded in the direction from the pipe (112) and to the walls (104);
b3) moreover, the pipe (112) and the specified at least one diaphragm (106) are made in such a way that in the folded direction of the pipe (112) the state of the specified at least one diaphragm (106) there is a gap (108) between the specified at least one diaphragm (106) and walls (104) when the pipe (112) is inserted into the borehole (102);
b4) wherein said at least one diaphragm (106) has at least one locking element (302);
b5) wherein the hardness of said at least one fixing element (302) is greater than the hardness of the walls (104);
b6) so that said at least one fixing element (302) can penetrate the walls (104) when said at least one diaphragm (106) is pressed against the walls (104);
b7) so that a geometrical connection can be made between the at least one diaphragm (106) and the walls (104); and containing
c) activated funds
c1) moreover, the activation of the activated means leads to the fact that the specified at least one diaphragm (106) can take a deployed state in the direction from the pipe (112) to the walls (104). 2. A plug according to claim 1, characterized in that said at least one pipe (112) is a drill pipe string. 3. A plug according to claim 1, characterized in that said at least one pipe (112) is an auxiliary drill pipe string. 4. The stub according to one of paragraphs. 1-3, characterized in that it contains several diaphragms (106), which are located along the pipe (112) one after another.

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