EP3828378A1 - Device and method for protecting deep boreholes against pressure - Google Patents

Abstract

The present invention relates to a device (12) and a method for pressure protection of deep boreholes (10), in particular geothermal, oil, gas and / or cavern boreholes, the device (12) having at least one receiving body (46, 146, 246) which is designed to receive a compressible medium (72) in an interior space, wherein the receiving body (46, 146, 246): has at least one opening (54, 56) which forms a transition between the interior space and the surroundings of the receiving body (46, 146, 246), wherein the at least one opening (54, 56) can be closed with at least one closure element (58, 60) which is arranged in the opening (54, 56) assigned to it and is designed to be in To assume an open and a closed state as a function of a predetermined pressure difference between the interior space and the environment, characterized in that the receiving body (46, 146, 246) is at least partially covered by a winding n tubular member (48, 148, 248) is formed.

Description

The present invention relates to a device and a method for pressure protection of deep boreholes, in particular geothermal, oil, gas and / or cavern boreholes.

When drilling deep, it can happen that closed spaces are created along the deep drilling. Such a space can arise, for example, in the form of an annular space between an inner and an outer casing of the deep bore. In this case, media with a coefficient of thermal expansion other than zero are present in these closed spaces. This includes fluids such as water. If the temperature in the closed space changes, an increased pressure difference can arise between the closed space and its surroundings, since the closed space does not allow any or only a very slight outflow and no or only a very small expansion of the enclosed medium. This phenomenon is known in the technical field as "Annular Pressure Build up" (APB) or as "Trapped Annular Pressure" (TAP). The change in the temperature of the enclosed medium occurs, for example, at a high temperature of the conveyed medium in the deep borehole. The high temperature of the medium conveyed in the deep borehole is at least partially transferred to the closed space. The resulting change in the pressure difference can be so great that damage to the deep bore occurs as a result.

Due to the structure of the deep drilling, the necessary piping and the necessary cementation processes, such closed spaces cannot be avoided or can only be avoided to a very limited extent in the case of deep drilling.

In order to prevent such critical pressure differences and associated damage, it is known from the prior art to make the casing of the deep bore more stable. This can be done by increasing the steel quality or by increasing the wall thickness of the tubing so that the tubing of the deep borehole can withstand a higher pressure difference. As a result of these measures, however, the available inside diameter of the deep borehole can turn out to be reduced, which, for example, can have negative effects on a delivery rate of the conveyed medium of the deep borehole. In addition, a more stable design with higher costs to manufacture, the Transport and installation of the piping connected. Furthermore, the theoretically necessary wall thicknesses may also not be available or be difficult to implement in practice.

Furthermore, in order to prevent impermissible pressure differences, it is known that the piping conveying a medium with an increased temperature is thermally insulated in order to reduce a temperature increase in the adjacent closed spaces and thus to minimize the pressure increase. However, these solutions also lead to increased costs, longer installation times and are impractical for some types of deep drilling. Furthermore, the space available for deep drilling is usually limited, so that insulation cannot be provided or can only be provided to a very limited extent.

Another attempt to prevent an impermissible pressure difference is made by creating a connection between the closed rooms and the environment. However, this weakens the tubing and deliberately destroys the barrier provided by the tubing. It is also known to establish a connection between the closed spaces and the surface of the earth or a sea bed. However, this is only possible with piping or piping sections that are led to the surface of the earth or to the sea bed.

It is also known to introduce pressure-compensating materials such as foams in a targeted manner for pressure equalization in the closed spaces in the areas in which closed spaces can arise. These then enable a targeted expansion of the media expanding in the closed spaces. Such methods are, however, very costly and require precise calculations and examinations for the design. In addition, the installation is very time-consuming and costly.

In addition, it is generally known in the prior art to provide mechanical components in the areas in which closed spaces can arise. These mechanical components can open and allow a targeted expansion of the enclosed medium by flowing out into other areas. However, previously known solutions are very complex, expensive and also require a precise calculation beforehand for the design of the mechanical components.

There is thus a need for solutions that address the problem of enclosed spaces along deep wells. It is therefore the object of the present invention to solve at least some of the above-described problems known from the prior art and to provide an improved solution for dealing with media located in closed spaces and the associated risks.

The object of the invention is achieved by a device for pressure protection of deep boreholes according to patent claim 1. Furthermore, the object according to the invention is achieved by a method for pressure protection of deep boreholes according to patent claim 19. Advantageous further developments of the invention are described in the dependent claims.

The above-mentioned object is achieved according to claim 1 by a device for pressure protection of deep boreholes, in particular geothermal, oil, gas and / or cavern boreholes. The device comprises at least one receiving body which is designed to receive a compressible medium in an interior. The receiving body has at least one opening which forms a transition between the interior and the surroundings of the receiving body. The at least one opening can be closed with at least one closure element and is arranged in the opening assigned to it. The closure element is also designed to assume an open and a closed state as a function of a predetermined pressure difference between the interior and the surroundings. The receiving body is formed at least in sections by a coiled tubular element.

The device according to the invention advantageously makes it possible to prevent impermissible pressure differences. Furthermore, a simple receiving body for pressure protection is provided by the device according to the invention. The design of the receiving body can take place as required. Tube elements are available on the market with different properties such as diameters, material and strength and can therefore be selected in a wide variety of designs for the intended use. Such pipe elements can be standardized according to DIN, ISO or ASME. Standardized tubes can be used as tube elements. If necessary, these can be adjusted afterwards and, for example, brought into the required winding shape or length.

The wide availability of tubular elements on the market also leads to comparatively low acquisition costs. In addition, pressure vessels in a round shape, as in the case of pipe elements, are particularly robust against pressure differences between a pipe interior and the environment. Furthermore, the length of the pipe elements used can be adapted as a function of the required size of the receiving body. The size of the receiving body is therefore very variable. The scope of the pressure protection can thus be adjusted.

The winding shape of the tubular elements allows the at least one receiving body to be adapted to existing geometries. Thus, the winding shape can take into account an existing shape of the deep hole, for example a pipe of the deep hole. For example, the wound tubular element can at least partially wrap around a tube of the deep bore around its circumference. Furthermore, it can be guided along an existing pipe of the deep bore in the longitudinal direction. In addition, the winding shape enables a narrow design of the device according to the invention, which is based on the available spatial conditions.

The absorbable compressible medium, for example air or an inert gas, makes it possible to be compressed in the event of a pressure increase which occurs, for example, when another medium flows into the receiving body according to the invention. The compressible medium thus serves as a kind of buffer that at least partially compensates for an increase in pressure with additional space. Furthermore, the compressible medium can be specifically selected in advance, depending on its properties and the existing requirements.

The closure element makes it possible to secure the pressure in the deep bore depending on a predetermined pressure difference. The predetermined pressure difference at which the closure element assumes the closed or the open state can thus be adapted as required. In this way it can be prevented that the pressure is safeguarded even if the pressure difference is too low, i.e. h the closure element opens too early. It can also be achieved that the compressible medium does not escape from the at least one receiving body in advance, for example during an installation of the device according to the invention at its place of use, and is replaced by a less compressible or even incompressible medium that would restrict or prevent pressure protection. If the closure element assumes the open state, a pressurized medium can enter the receiving body from the surroundings of the receiving body expand. The pressure in the receiving body can increase and the compressible medium can be compressed. However, the pressure in the vicinity of the receiving body can also be reduced. This prevents impermissibly high pressures from occurring when drilling deep. Furthermore, the closure element makes it possible to adapt the device according to the invention directly at the place of use, for example on a surface of the deep bore prior to assembly. It can be provided that the closure element is connected to the receiving body, for example via a thread, so that different closure elements can be optionally screwed in.

The device according to the invention also enables it to be manufactured and assembled remotely from its place of use and then to be adapted and installed at the place of use. For example, spatial restrictions at the place of use can be circumvented.

The small number of individual components of the device according to the invention enables a low susceptibility to errors. Furthermore, the assembly effort in the factory and on site can be reduced.

According to a further development of the invention, it can be provided that the at least one receiving body is made of metal, in particular steel. The receiving body can also be formed from a plastic or a composite material. Furthermore, it can be provided that the at least one closure element is made of metal, in particular steel, plastic, ceramic, glass, a composite material or a combination of materials. In addition, different areas of the closure element can be formed from a different material suitable for use. The materials of the receiving body and of the closure element can therefore advantageously be selected for the intended use.

Furthermore, it can be provided according to the invention that the wound tubular element is formed at least in sections in a spiral, helical, meandering shape, or in the form of a combination thereof.

The various geometrical characteristics of the wound pipe element make it possible to adapt the pipe element to the existing geometries of a deep bore. Furthermore, a receiving body can be formed which extends continuously extends. The length can be adjusted as required. Existing rooms can be used efficiently.

If the wound tubular element is helical, it can, for example, wrap around another element. Furthermore, the slope of the helix is freely adjustable. In other words, the number of turns of the coiled tubular element is freely adjustable in relation to a length extension of the helical shape. Helical shapes are understood to be shapes similar to a helix, a cylindrical spiral or a helix.

The meandering design of the wound tubular element enables flexible adaptation to existing conditions. So the loop sizes of the meander shape can be freely adjusted.

The spiral shape as well as the meander shape enable a mat-like design of the wound tubular element. This means that the available space can be used efficiently.

The combination of the shapes of the coiled tubular element is as flexible as possible and tailored to existing conditions. A combination of a helical shape and a spiral shape could, for example, lead to a helical course of the wound tubular element, the course being designed similar to a lateral surface of a cone. The radius with which the coiled tubular element winds around a central axis can therefore be variable, for example.

Furthermore, it can be advantageous to design the coiled tubular element in advance in the form of a mat, which is then adapted to geometric conditions during installation, for example bent to match the cavity to be filled.

A further development of the invention provides that two or more receiving bodies are arranged adjacent to one another, in particular in a radial direction of the deep bore. It can be provided that a coiled tubular element of an outer receiving body engages around a coiled tubular element of an inner receiving body. It is thus possible to increase the number of receiving bodies in a deep hole. In addition, the space available in a deep borehole can be used efficiently. Overall, the ability to pressure-proof the deep hole is improved.

According to one aspect of the invention it can be provided that the tubular element is wound in such a way that adjacent turns are arranged at a distance from one another or rest against one another. If adjacent windings are arranged in contact with one another, the available space can be used efficiently. If adjacent turns are arranged at a distance from one another, space can be specifically provided that can be used for other purposes, for example. For example, the objectionable arrangement can provide access to a wrapped element. The tubular element itself can possibly consist of flexibly expandable material, at least in sections.

A further development of the invention provides that the receiving body is designed to wrap around an inner tubing arranged in the deep bore and / or to be received in an outer tubing. If the receiving body winds around an inner piping, the device for securing the pressure can protect the pressure outside this inner piping. Accordingly, the pressure protection device can protect the pressure within an outer piping when it is received by the latter.

According to one aspect of the invention, the receiving body is designed to be arranged in an intermediate space between the inner tubing and the outer tubing. In this way, the pressure in the intermediate space can be secured with the device according to the invention. The coiled tubular element can be adapted to the existing geometry of the space.

In addition, it can be provided that the at least one closure element has a predetermined breaking point. The predetermined breaking point can be designed in such a way that it breaks in a predetermined manner. In this way, the predetermined breaking point of the closure element can advantageously break at a predetermined pressure difference. The predetermined pressure difference can be a value below a critical pressure difference. Thus, the pressure equalization can advantageously take place before a critical pressure occurs and the deep borehole, in particular one of the pipework, would be damaged. Furthermore, such breaking elements can be inexpensive to manufacture and easy to use and replace on site.

A further development of the invention provides that the at least one closure element is a valve, a pressure-adjustable pressure valve, a bursting disc or a bursting plug. The valve enables the receiving body to be filled in advance with a compressible medium and thus a certain amount of the compressible medium Provide medium in the receiving body. Furthermore, the valve makes it possible to apply a certain pressure to the compressible medium in the receiving body in advance. The pressure-adjustable pressure valve enables the pressure at which the valve opens and closes to be set variably. For this purpose, the pressure-adjustable pressure valve can have a spring, the spring force of which can be adjusted. In contrast to the valve and the pressure-adjustable pressure valve, the bursting disc and the bursting plug change their state irreversibly. If the bursting disc or bursting plug break, the closure element is permanently open.

According to one aspect of the invention it can be provided that the compressible medium comprises a fluid. According to a preferred aspect, the compressible medium is a compressible gas, a compressible liquid or a combination thereof. For example, the fluid can comprise air, nitrogen, other compressible media or a mixture thereof. Fluids have the advantage that they adapt to existing geometries and at least partially fill them. They can also be fed in via hose systems. A gas is usually associated with the advantage that it is more compressible than a solid or a liquid and its density is lower at the same time.

According to a further development of the invention, it can be provided that the thermal expansion coefficient of the compressible medium in the interior space is lower than the thermal expansion coefficient of a medium surrounding the device according to the invention. For example, if the device according to the invention with the compressible medium contained therein and the medium surrounding the device according to the invention heat up, it can be ensured that the pressure of the compressible medium in the interior increases less than the pressure of the surrounding medium.

Furthermore, it can be provided that the receiving body can be fixed in the deep bore with at least one fixing arrangement. It is thus advantageously possible to arrange the receiving body at a predetermined position in the deep bore. It is also possible to arrange several receiving bodies at different points in the deep hole. In this way, receiving bodies can be arranged in a targeted manner and as required at different distances from the deep bore. Furthermore, the fixing arrangement can have a protective effect on the receiving body, so that damage to the receiving body can be prevented.

According to a further development, it can be provided that the at least one fixing arrangement can be fixed with respect to the inner piping and / or outer piping. The device according to the invention can thus be arranged flexibly.

In addition, it can be provided that the at least one fixing arrangement prevents an axial movement of the receiving body along the inner tubing and / or outer tubing.

According to one embodiment of the invention, it can be provided that a receiving body is fixed in the deep bore with two fixing arrangements. Thus, the two fixing arrangements can be arranged on different sides of the receiving body. One fixing arrangement can be arranged on an underside of the receiving body, while the other fixing arrangement is arranged on an upper side of the receiving body. The fixing arrangement on the underside of the receiving body can prevent the receiving body from slipping further into the deep bore. The fixing arrangement on the upper side of the receiving body can also prevent the receiving body from slipping out of the deep bore, for example by buoyancy forces.

According to one aspect, it can be provided that the fixing arrangement is clamped with respect to the inner piping and / or outer piping. Jamming is associated with the advantage that damage to the inner piping and / or outer piping is prevented. At the same time, a reliable fixation is made possible. Sensitive piping can be protected and weak points in the inner and / or outer piping prevented.

Furthermore, according to a development, it can be provided that the fixing arrangement comprises at least one screw. This can be screwed against the inner piping and / or outer piping. Screws represent a flexible means to releasably fix the fixing arrangement. Furthermore, a large number of screws can be provided to fix the fixing arrangement. In this way, a force distribution and a force introduction into the inner piping and / or outer piping can be distributed over the multitude of screws. Furthermore, the effect of incorrect fastening of a single screw on the fixation of the fixation assembly is also reduced.

According to one aspect it can be provided that the at least one screw is designed as a stud screw. This can be screwed against the inner piping and / or outer piping.

Furthermore, it can be provided that the fixing arrangement has a fixing ring which has a greater thickness in the radial direction than the receiving body. This can produce a protective effect on the receiving body. If the receiving body is arranged at a certain position in the deep bore, the fixing ring first collides with surrounding elements such as the inner tubing and / or outer tubing. As a result, damage to the receiving body during installation or assembly at the place of use can at least be reduced or prevented.

According to a development, the fixing ring can be designed in such a way that it at least partially fills an annular gap between the inner tubing and the outer tubing. This is particularly advantageous when a fixation with respect to the inner or outer tubing is provided.

According to one aspect, the fixing ring can be designed in such a way that it does not completely fill the annular space between the inner tubing and the outer tubing in the radial direction, at least in sections along its circumference. This enables an increased circulation of media in the space. For example, this can be advantageous for cementation processes or a more homogeneous distribution of a medium in the space.

According to one aspect of the invention it can be provided that the fixing ring is designed with a variable wall thickness in the radial direction. This is particularly advantageous when increased circulation is desired in the space between the inner tubing and the outer tubing. For example, this can be advantageous for cementation processes or a more homogeneous distribution of a medium in the space.

Furthermore, it can be provided that the fixing ring has ribs with free passages arranged in between, the ribs being formed larger in the radial direction than the free passages. The ribs can be arranged on the outside of the fixing ring. The at least one screw of the fixing arrangement can be arranged in one of the free passages. It can extend in the radial direction for fixation.

According to one embodiment, it can be provided that the fixing ring is made of metal, in particular steel. Furthermore, the fixing ring can be formed from a plastic such as a synthetic resin or from a cement-based material or a composite material. The fixing ring can be a cast part, a turned part, a milled part, a 3D printed part or a combination.

A further development of the invention provides that the receiving body comprises several different closure elements. This enables a flexible configuration of the device according to the invention. For example, a valve can be provided to apply a predetermined pressure to the receiving body. This can be done during installation or assembly. A pressure-adjustable pressure valve, a rupture disk or a rupture plug can be provided to take the open and the closed state for pressure protection at a later point in time. Furthermore, several closure elements increase the reliability of the pressure protection.

Furthermore, it can be provided that the different closure elements assume the open and the closed state in the event of a different pressure difference between the interior and the surroundings. This can enable staggered pressure protection.

According to a further development, the receiving body comprises a plurality of sections which are separated from one another by closure elements. This can enable staggered pressure protection. The device according to the invention can be flexibly adapted to circumstances.

According to one aspect of the present invention, the plurality of closure elements can be designed to assume the open and the closed state in the event of a different pressure difference between the adjacent sections. This can enable staggered pressure protection.

According to one embodiment, the device comprises a plurality of receiving bodies. In this way, the scope of the pressure protection can be adapted to existing conditions. Furthermore, the reliability can be increased. The plurality of receiving bodies can have different closure elements. This enables a flexible configuration of the device according to the invention.

If the device comprises a plurality of receiving bodies, it can be provided that the plurality of receiving bodies assume the open and the closed state in the event of a different pressure difference between the respective interior space and the surroundings. In this way it can be achieved that the receiving bodies secure pressure at different pressure differences. Furthermore, this can enable staggered pressure protection.

Furthermore, the object on which the invention is based and identified at the outset is achieved by a method for pressure protection of deep boreholes, in particular geothermal, oil, gas and / or cavern boreholes. The method is preferably carried out with a device of the type described above. At least one receiving body is designed to receive a compressible medium in an interior. In addition, at least one closure element is designed to assume an open and a closed state as a function of a predetermined pressure difference between the interior of the receiving body and an environment. The method comprises the step of applying a predetermined pressure to the receiving body, the step of arranging the receiving body in the deep bore and the step of pressure equalizing a pressure difference between the interior and the surroundings of the receiving body, the closure element at least temporarily assuming an open state.

The method according to the invention enables a simple solution for pressure protection in deep boreholes. Furthermore, the method according to the invention can be flexibly adapted and is therefore advantageous for different types of deep boreholes.

Applying a predetermined pressure to the receiving body makes it possible to adapt the receiving body to its intended use and to modify it as required. It can be provided that a compressible medium is filled into the receiving body.

The step of arranging the receiving body in the deep bore makes it clear that the receiving body can first be produced and modified away from its place of use and finally installed and arranged at the place of use. In this way, for example, spatial restrictions at the place of use can be circumvented, which would not allow modification of the receiving body, such as applying a predetermined pressure to the receiving body, or would only make it possible to a limited extent.

The pressure equalization described above ensures the pressure protection of the deep borehole. It enables critically high pressures in the vicinity of the device according to the invention to be reduced and / or prevented. Damage to the deep bore, in particular to the pipes used, by critically high pressure, in particular in the vicinity of a pipe, such as in an intermediate space or an annular space, can thus be avoided. In addition to the immediate surroundings of the device according to the invention, the pressure equalization can also have a positive effect on regions of the deep bore that are further away, since the pressure can also decrease there, depending on the structure of the surroundings. The effective range can therefore be larger than the direct vicinity of the device according to the invention.

The method according to the invention is easy to carry out. It also offers the option of being adapted to the particular circumstances. Furthermore, the receiving body used in the method and / or the closure element can be adapted accordingly to the circumstances.

A further development of the method according to the invention provides that a medium flows into the receiving body during the pressure equalization. In this way, an additional expansion volume can be generated. This can reduce the pressure of the inflowing medium.

According to one aspect of the method according to the invention, it can be provided that during the pressure equalization a compressible medium in the interior of the receiving body changes its volume. The change in volume can bring about a reduced pressure in the vicinity of the device according to the invention. In this way, an inadmissibly high pressure in the environment can be prevented.

According to a further development of the method according to the invention, it can be provided that the at least one closure element assumes a permanently open state during pressure equalization. It can thus be an irreversibly actuatable closure element.

One embodiment of the method according to the invention provides that the closure element assumes an open state above the specified differential pressure and a closed state below the specified differential pressure. It can thus be a reversibly actuatable closure element.

It is clear to the person skilled in the art that features, properties and advantages of the invention which have been explained in connection with the device according to the invention also apply to the method according to the invention. The reverse is also clear to the person skilled in the art.

Fig. 1

eine schematische Schnittansicht einer Tiefenbohrung, die die erfindungsgemäße Vorrichtung umfasst;

Fig. 2

eine schematische Detailansicht einer Ausführungsvariante der erfindungsgemäßen Vorrichtung in der Tiefenbohrung;

Fig. 3

eine schematische Detailansicht einer Ausführungsvariante einer erfindungsgemäßen Fixieranordnung, angeordnet in der Tiefenbohrung;

Fig. 4

eine schematische Seitenansicht eines erfindungsgemäßen Aufnahmekörpers;

Fig. 5

eine schematische dreidimensionale Seitenansicht des erfindungsgemäßen Aufnahmekörpers;

Fig. 6

eine schematische Explosionszeichnung einer erfindungsgemäßen Fixieranordnung;

Fig. 7

eine schematische Detailansicht einer erfindungsgemäßen Fixieranordnung angeordnet in einer Tiefenbohrung;

Fig. 8

eine schematische Detailansicht einer erfindungsgemäßen Fixieranordnung mit Stiftschrauben;

Fig. 9

eine schematische Detailansicht einer Öffnung des Aufnahmekörpers mit Verschlusselement;

Fig. 10

eine schematische Schnittansicht durch ein Verschlusselement an dem Aufnahmekörper der erfindungsgemäßen Vorrichtung;

Fig. 11

eine schematische Ansicht einer erfindungsgemäßen Vorrichtung mit mäanderförmig gewundenem Rohrelement; und

Fig. 12

eine schematische Ansicht einer erfindungsgemäßen Vorrichtung mit spiralförmig gewundenem Rohrelement.

The invention is explained below by way of example with reference to the accompanying figures. They represent:

Fig. 1

a schematic sectional view of a deep bore comprising the device according to the invention;

Fig. 2

a schematic detailed view of an embodiment variant of the device according to the invention in the deep bore;

Fig. 3

a schematic detailed view of an embodiment variant of a fixing arrangement according to the invention, arranged in the deep bore;

Fig. 4

a schematic side view of a receiving body according to the invention;

Fig. 5

a schematic three-dimensional side view of the receiving body according to the invention;

Fig. 6

a schematic exploded view of a fixing arrangement according to the invention;

Fig. 7

a schematic detailed view of a fixing arrangement according to the invention arranged in a deep bore;

Fig. 8

a schematic detailed view of a fixing arrangement according to the invention with studs;

Fig. 9

a schematic detailed view of an opening of the receiving body with closure element;

Fig. 10

a schematic sectional view through a closure element on the receiving body of the device according to the invention;

Fig. 11

a schematic view of a device according to the invention with a meandering tubular element; and

Fig. 12

a schematic view of a device according to the invention with a spirally wound tubular element.

Figure 1 shows a schematic sectional view of a deep bore 10, which comprises a plurality of devices 12 according to the invention for pressure protection. The deep bore 10 runs to the surface of the earth 14 and extends with several sections into the soil 16, the diameter of the deep bore 10 being smaller the further the deep bore 10 extends into the earth 16. The deep borehole 10 is formed essentially axially symmetrical to a borehole axis A. A borehole wall 18 is located at the surface 14 of the earth. The borehole wall 18 may include a cementation 20. Within the borehole wall 18, that is to say with a smaller diameter, a standpipe 22 is arranged in the length of the depth extension of the borehole wall 18. Inside the standpipe 22 there is a casing, hereinafter referred to as casing 24, with a smaller diameter compared to the location 22. The casing 24 has a greater depth than the standpipe 22. The standpipe 22 and the casing 24 can be made of steel. In an intermediate space between the standpipe 22 and the casing 24, a cementation 20 is also arranged, which lines the intermediate space and extends over the entire length of the casing 24. With a smaller diameter than the casing 24, an anchorage designated as a tie-back 26 is formed within the casing 24. The tie back 26 adjoins the production hole 28 of the deep borehole 10. A first fluid 30 and a device 12 according to the invention are located between the casing 24 and the tie-back 26.

A lower area of the tie-back 26 adjoins a first production liner 32. Outside the first production liner 32, a cementation 20 is also formed in a lower area, which forms a transition to the ground 16. In the inner radial direction, the first production liner 32 forms a transition to the borehole 28. No cementation is formed in an upper area of the first production liner 32, but in a transition area 33 in which the length of the first production liner 32 and the casing 24 intersect, a second fluid 34 and one of the devices 12 according to the invention are arranged. The second fluid 34 can be a free water after a cementation process.

Above the second fluid 34, in the transition region 33 between the tie back 26 and the first production liner 32 in a radial extension to the casing 24, there is a first Separating element 36 is arranged, which separates the first fluid 30 from the second fluid 34. The first separation element 36 can be an element known in the art as a "top liner hanger packer".

Further in the interior of the borehole 28, a second production liner 38 is arranged with a smaller diameter opposite the first production liner 32 and at a distance from it. A second separating element 40 and a third separating element 42 are arranged in an intermediate space 39 between the first production liner 32 and the second production liner 38. The second separating element 40 closes the intermediate space 39 between the first production liner 32 and the second production liner 38 towards the top, that is to say oriented in the direction of the earth's surface 14, towards the borehole. The third separating element 42 is also arranged below the second separating element 40 in the space 39 between the first production liner 32 and the second production liner 38 and divides a non-cemented area into two sub-areas, in each of which a device 12 according to the invention is arranged. Each of the subregions is at least partially filled with the second fluid 34. In an area of the second production liner 38 arranged further down in the deep bore 10, a cementation 20 is also formed on the outside of the second production liner 38, which extends to a lower end of the second production liner. The upper end of the cementation 20 essentially coincides with the lower end of the first production liner 32.

In the deepest area of the deep borehole 10, a perforated tubular element 44 adjoins an inner area of the second production liner 38, which is perforated opposite the conveyor hole 28 and extends deeper into the borehole 28 than the second production liner 38.

Figure 2 shows a schematic detailed view of an embodiment variant of the device 12 according to the invention in the deep bore 10. The schematic detailed view according to FIG Figure 2 is a partial section through the deep hole 10 according to Figure 1 at the level of the marking M.

Figure 2 shows the device 12 according to the invention with a receiving body 46. The receiving body 46 is formed by a wound, helical tubular element 48. The coiled tubular member 48 includes a plurality of turns that abut one another and surround inner tubing 50. Outer tubing 52 is arranged on the outside opposite the coiled tubular element 48.

Regarding Figure 1 the inner tubing 50 corresponds to the second production liner 38 and the outer tubing 42 corresponds to the first production liner 32. Outside the outer tubing 52 a cementation 20 is formed. The wall thickness of the cementation 20 is pronounced differently in the length of the deep bore 10. The soil 16 adjoins the cementation 20.

The coiled tubular member 48 is hollow inside. A first opening 54 is formed at one end of the coiled tubular element 48 and a second opening 56 is formed at the other end of the coiled tubular element 48. A first closure element 58 is arranged in the first opening 54 and a second closure element 60 is arranged in the second opening 56.

A first fixing arrangement 62 is arranged on one end of the receiving body 46 and a second fixing arrangement 64 is arranged on the other end of the receiving body 46. The two fixing arrangements 62, 64 each have a fixing ring 63, 65. The fixing rings 63, 65 enclose the inner tubing 50 and are surrounded by the outer tubing 52. The fixing rings 63, 65 are designed essentially the same, but one fixing ring 63 is rotated by 180 degrees with respect to the other fixing ring 65, so that the same sides are arranged with respect to the receiving body 46.

The configuration of the fixing arrangements 62, 64 in relation to the second fixing arrangement 64 is briefly illustrated below. The second fixing ring 65 comprises a plurality of ribs 66. The ribs 66 are evenly distributed in the circumferential direction of the second fixing ring 65 and extend outward in the radial direction of the fixing ring 65. The ribs 66 extend in the longitudinal direction of the fixing ring 65 and thus also in the longitudinal direction of the deep bore 10 and the receiving body 46. A respective clearance 68 is formed between two ribs 66. The ribs 66 are formed larger in the radial direction than the free passages 68. A plurality of screws 70, which are configured as studs, are arranged in each case on the respective free passages 68. The free passages 68 never rest on the outer tubing 52 due to their smaller lateral extent. If the ribs 66 are in contact with the outer tubing and the fixing ring 65 surrounds the inner tubing 50, free space remains due to the free passages 68, which can enable a simple cementation process. Furthermore, media surrounding the fixing ring 65 can freely circulate.

Figure 3 FIG. 11 shows a schematic detailed view of an embodiment variant of the device 12 according to the invention, arranged in the deep bore 10, in a section along the marking M from FIG Figure 1 . The device 12 according to the invention is arranged in the intermediate space 39 between the inner tubing 50 and the outer tubing 52. In the representation according to Figure 3 only a part of the receiving body 46 with a part of the coiled tubular element 48 is shown. The first closure element 58 is arranged at the first opening 54.

The first fixing arrangement 62 is also arranged in the intermediate space 39 above the receiving body 46. The fixing ring 63 of the first fixing arrangement 62 extends in the radial direction over the entire space 39 and touches the inner piping 50. The fixing ring 63 is fixed to the inner piping 50. The representation according to Figure 3 is not to scale, because the fixing ring 63 is in fact spaced apart from the outer tubing 52. It is also possible that the fixing ring 63 touches the outer tubing 52. This is particularly the case when the fixing ring 63 is fixed to the outer tubing 52. The second fluid 32 is located in the illustrated remaining intermediate space 39.

The cementation 20, which forms a transition to the ground 16, is formed outside the outer casing 52. As in connection with Figure 2 explained, the wall thickness of the cementation 20 in the longitudinal direction of the deep bore 10 is designed to be different.

A compressible medium 72 is located in the coiled tubular element 48. The compressible medium 72 is not shown in detail, but includes, for example, air, nitrogen, other compressible media or a mixture thereof.

Figure 4 FIG. 12 is a schematic side view of the receptacle body 46 of the present invention formed by the coiled tubular element 48. It can be seen that the turns of the tubular element 48 lie against one another. The tubular element 48 is helically wound around the borehole axis A with a constant radius. The first opening 54 of the coiled tubular member 48 is shown in FIG Figure 4 not visible. In the illustration shown, the first opening 54 is formed on the rear side of the receiving body 46. The second opening 56 of the coiled tubular element 48 is formed on another, in the illustration shown lower side of the coiled tubular element 48. The second closure element 60 is arranged in the second opening 56.

Figure 5 is a schematic three-dimensional side view of the receiving body 46 according to the invention. The second opening 56 of the wound tubular element 48 is closed with the second closure element 60. The second closure element 60 is designed as a bursting plug. The first opening 54 is shown in FIG Figure 5 not visible, since it is formed on the rear side of the receiving body 46 in the illustration shown.

In this illustration, too, it can be seen that the tubular element 48 is wound helically around the borehole axis A with a constant radius. Furthermore, the turns of the coiled tubular element 48 rest against one another.

Figure 6 is a schematic exploded view of a fixing arrangement 62, 64 according to the invention. The fixing ring 63, 65 comprises the plurality of ribs 66 which are evenly distributed in the circumferential direction of the fixing ring 63, 65 and extend outward in the radial direction. The free passages 68 are formed between the ribs 66. A multiplicity of threads 74 are formed in the free passages 68 and extend in the radial direction of the fixing ring. The screws 70 shown floating in the exploded view are designed to be screwed into the threads 74 in the free passages 68 of the fixing ring 63, 65. The screws 70 are designed as studs.

A circumferential surface 76 of the fixing ring 63, 65 lying on the inside in the radial direction is essentially flat. The inner circumferential surface 76 is equally spaced at every point from the longitudinal axis of the fixing ring 63, 65. As explained, an outer circumferential surface 78 of the fixing ring 63, 65 is not designed to be flat, but rather comprises the ribs 66 and the free passages 68.

In the illustration shown, the fixing ring 63, 65 has a bevel 80 which extends in the circumferential direction and is arranged between a front side of the fixing ring 63, 65 and the outer circumferential surface 78. Such a bevel 80 can also be formed on the rear side of the fixing ring 63, 65. In the illustration shown, however, no such bevel 80 is formed on the rear side of the fixing ring 63, 65.

Figure 7 is a schematic detailed view of a fixing arrangement 62, 64 according to the invention arranged in a deep bore 10. The fixing arrangement 62, 64 is arranged between the internal piping 50 and the external piping 52. The inner casing 50 is substantially opposite the borehole axis A centered. Accordingly, the fixing arrangement 62, 64 and the outer casing 52 are also essentially centered with respect to the borehole axis A. The ribs 66 of the fixing ring 63, 65 rest on the outer tubing 52. The inner circumferential surface of the fixing ring 63, 65 rests against the inner piping 50. As can be seen from the illustration, the free passages 68 form a free passage between the fixing ring 63, 65 and the outer tubing 52. The respective transitions between the free passages 68 and the ribs 66 are not formed with sharp edges, but radii form a smooth transition .

Figure 8 is a schematic detailed view of a fixing arrangement 62, 64 according to the invention with screws 70 in section. The locating assembly 62, 64 is positioned in the deep bore 10 and disposed between the outer casing 52 and the inner casing 50. The section through the fixing arrangement 62, 64 is shown in FIG Figure 7 along the line BB. Correspondingly, one of the free passages 68 is cut through the cut.

As shown in the illustration, the fixing ring 63, 65 is fastened with respect to the inner tubing 50. This is achieved in that the screws 70 of the fixing ring 63, 65 are screwed into the fixing ring 63, 65 in the direction of the inner piping 50 and a front end face of the screws 70 is pressed against the inner piping 50. This creates a clamping force that prevents the fixing ring 63, 65 from slipping or twisting with respect to the inner piping 50.

The number of screws 70 can be selected almost arbitrarily, but a minimum clamping force is required so that no slipping or twisting takes place. A higher number of screws 70 results in a better distribution of the forces applied by the screws 70 to the inner tubing 50, since a single screw 70 then has to apply a lower clamping force and at the same time the individual clamping forces are distributed over a larger area of the inner tubing 50.

Figure 9 shows a schematic detailed view of an opening 54, 56 of the receiving body 46 with the closure element 58, 60. More precisely, FIG Figure 9 a detail Figure 4 shown in a front view, namely the second opening 56 with the second closure element 60. It can be seen that the second closure element 60 is arranged inside the coiled tubular element 48 and closes the second opening 56.

Figure 10 FIG. 12 shows a schematic sectional view through the closure element 60 on the receiving body 46 of the device 12 according to the invention. More precisely, the closure element 60 is shown in FIG Figure 9 shown in section along the line CC. The closure element 60 is arranged at the opening 56 of the receiving body 46. In the illustration shown, the closure element 60 is designed as a bursting plug which comprises an end cap 82, a pipe socket 84 and a bursting plug element 86. The end cap 82 is attached to an end face of the opening 56 of the receiving body 46. The pipe socket 84 is arranged on an inside of the end cap 82. The outside of the pipe socket 84 rests against the inner circumference of the end cap 82 and its end face partially touches the end face of the opening 56. Inside the pipe socket 84, the bursting plug element 86 is arranged. It is connected to the pipe socket 84.

Arranged in the bursting plug element 86 is a rupturable element 88 which breaks above a permissible differential pressure between the inner region of the receiving body 46 and the other side of the rupturable element 88 on an outer side of the receiving body. For this purpose, the rupturable element 88 can be designed with a predetermined breaking point. The rupturable element 88 can be formed from ceramic or a metal, for example.

The coiled pipe element 48, the end cap 82, the pipe socket 84 and the burst plug element 86 can be formed as a weldable metallic material and welded to one another. Furthermore, they can be connected to one another by other suitable types of connection such as, for example, gluing or by means of threads.

In the illustration shown, the pipe socket 84 is welded to the end cap 82. On the inside of the pipe socket 84, a thread is formed, which can be attached subsequently, into which the bursting plug element 86 is screwed. The end cap 82 is welded to the coiled tubular element 48 in the illustration shown.

The closure element 60 from Figure 10 and its arrangement opposite the coiled tubular element 48 serves only as an exemplary embodiment. The closure element 60 can also be designed differently and thus, for example, be arranged completely within the opening 56 of the receiving body 46.

Figure 11 shows a schematic view of a device 12 according to the invention with a meandering pipe element 148. The shown coiled pipe element 148 of the receiving body 146 comprises essentially straight sections and / or slightly curved sections which are connected to one another with curved sections. The compressible medium 72 is located inside the meandering tubular element 148. The device 12 shown comprises two closure elements 58, 60 which are arranged in respective openings 54, 56.

The length of the coiled tubular element 148, the number of curved sections and the spacing of the straight sections can be adapted almost as desired to the requirements of a deep bore 10. Thus, the coiled tubular element can be designed similar to a mat. If the geometry of the place of use requires it, then it can be provided to bend the coiled tubular element 148 further, for example about an axis which lies in the plane of the drawing.

Figure 12 shows a schematic view of a device 12 according to the invention with a receiving body 246 with a spirally wound tubular element 248. The spirally wound tubular element 248 is not shown in section in the illustration shown. The device 12 comprises two closure elements 58, 60, which are arranged in respective openings 54, 56, not shown in detail.

For the use of a device 12 according to the invention for securing pressure from a deep borehole, the desired shape of the one or more receiving bodies 46, 146, 246 can first be selected in a first step.

Furthermore, the at least one receiving body 46, 146, 246 is formed from corresponding coiled tubular elements 48, 148, 248. The individual components of the receiving body 46, 146, 246 can be connected to one another via suitable connecting means.

In addition, the appropriate at least one closure element 58, 60 is selected for use and arranged in the receiving body 46, 146, 246.

The receiving body 46, 146, 246 is also filled with a compressible medium 72. In addition, the receiving body 46, 146, 246 can now be subjected to a predetermined pressure.

In a further step, the receiving body 46, 146, 246 is now arranged in the deep bore 10. For this purpose, the receiving body 46, 146, 246 can be fixed in the deep bore 10 with the at least one fixing arrangement 62, 64. The fixing can be carried out simply by tightening the screws 70, for example.

If the pressure outside of the receptacle body 46, 146, 246 according to the invention increases and exceeds a predetermined pressure of the at least one closure element 58, 60, the closure element 58, 60 opens and the medium surrounding the receptacle body 46, 146, 246 according to the invention can enter the receptacle body 46, 146, 246 flow in. It displaces and compresses the compressible medium 72 in the receiving body 46, 146, 246. The pressure in the vicinity of the receiving body 46, 146, 246 can be reduced, in particular in the vicinity of the opened closure element 58, 60.

This process can be reversible, i. H. it can be repeated or it occurs once. The receiving body can also be configured in such a way that it can be used several times or only once.

Claims (15)

Device (12) for pressure protection of deep boreholes (10), in particular geothermal, oil, gas and / or cavern boreholes, wherein the device (12) comprises at least one receiving body (46, 146, 246) which is designed to hold a to receive compressible medium (72) in an interior space, the receiving body (46, 146, 246): has at least one opening (54, 56) which forms a transition between the interior and the surroundings of the receiving body (46, 146, 246), wherein the at least one opening (54, 56) can be closed with at least one closing element (58, 60) which is arranged in the opening (54, 56) associated therewith and is designed for this purpose, depending on a predetermined pressure difference between the interior and the to adopt an open and a closed state of the environment, characterized in that the receiving body (46, 146, 246) is formed at least in sections by a coiled tubular element (48, 148, 248). Device (12) according to Claim 1, characterized in that the wound tubular element (48, 148, 248) is designed in the form of a spiral, helix, meander or in the form of a combination thereof. Device (12) according to Claim 1 or 2, characterized in that the tubular element (48, 148, 248) is wound in such a way that adjacent turns are arranged at a distance from one another or lie against one another. Device (12) according to one of the preceding claims, characterized in that the receiving body (46, 146, 246) is designed to wrap around an inner tubing (50) arranged in the deep bore (10) and / or in an outer tubing ( 52), preferably to be arranged in a space (39) between the inner tubing (50) and the outer tubing (52). Device (12) according to one of the preceding claims, characterized in that the at least one closure element (58, 60) has a predetermined breaking point. Device (12) according to one of the preceding claims, characterized in that the at least one closure element (58, 60) is a valve, a pressure adjustable pressure valve, a bursting disc or a bursting plug. Device (12) according to one of the preceding claims, characterized in that the compressible medium (72) comprises a fluid, preferably a compressible gas, a compressible liquid or a combination thereof. Device (12) according to claim 4, characterized in that the receiving body (46, 146, 246) can be fixed with at least one fixing arrangement (62, 64) in the deep bore (10), preferably opposite the inner piping (50) and / or outer tubing (52) can be fixed, in particular preventing axial movement of the receiving body (46, 146, 246) along the inner tubing (50) and / or outer tubing (52),
wherein, as an optional feature, the fixing arrangement (62, 64) is clamped relative to the inner tubing (50) and / or outer tubing (52). Device (12) according to claim 8, characterized in that the fixing arrangement (62, 64) comprises at least one screw (70), preferably at least one stud screw, which preferably against the inner tubing (50) and / or outer tubing (52) is screwed. Device (12) according to one of claims 8 or 9, characterized in that the fixing arrangement (62, 64) has a fixing ring (63, 65) which has a greater thickness in the radial direction than the receiving body (46, 146, 246) , and preferably at least partially fills an annular gap between the inner tubing (50) and outer tubing (52), the fixing ring (63, 65) being designed with variable wall thickness in the radial direction as an optional feature. Device (12) according to claim 10, characterized in that the fixing ring (63, 65) preferably has ribs (66) on its outside with clearance (68) arranged between them, the ribs (66) being larger than in the radial direction the open spaces (68). Device (12) according to one of the preceding claims, characterized in that the receiving body (46, 146, 246) comprises several different closure elements (58, 60),
wherein, as an optional feature, the different closure elements (58, 60) assume the open and the closed state at a different pressure difference between the interior space and the surroundings. Device (12) according to one of the preceding claims, characterized in that the receiving body (46, 146, 246) comprises several sections which are separated from one another by closure elements (58, 60), the closure elements (58, 60) preferably being designed for this purpose are to adopt the open and the closed state at a different pressure difference between the adjacent sections. Device (12) according to one of the preceding claims, characterized in that the device (12) comprises a plurality of receiving bodies (46, 146, 246) which preferably have different closure elements (58, 60), the plurality of receiving bodies (46 , 146, 246) assume the open and the closed state at a different pressure difference between the respective interior space and the environment. Method for pressure protection of deep boreholes (10), in particular geothermal, oil, gas and / or cavern boreholes, preferably with a device (12) according to one of Claims 1 to 14, at least one receiving body (46, 146, 246) for this purpose is designed to receive a compressible medium (72) in an interior space, and wherein at least one closure element (58, 60) is designed to have one as a function of a predetermined pressure difference between the interior space of the receiving body (46, 146, 246) and an environment to assume an open and a closed state, the method comprising the steps of: Subjecting the receiving body (46, 146, 246) to a predetermined pressure; Arranging the receiving body (46, 146, 246) in the deep bore (10); Pressure equalization of a pressure difference between the interior space and the surroundings of the receiving body (46, 146, 246), the closure element (58, 60) at least temporarily assuming an open state.

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