The invention relates to a capture device for a bore hole of a fluid source.

Petroleum and/or natural gas exist in a bubble in the ground in a petroleum and/or natural gas deposit. The bubble frequently is located below a cap rock that is gas- and/or fluid-tight, whereby a high pressure predominates in the bubble. To

transport the petroleum and/or natural gas embedded in the bubble, it is known to install a bore into the cap rock via which an access to the bubble is established. To compensate for the high pressure in the bubble, a drilling fluid with a high density is filled into the bore hole during the drilling. The fluid column that thereby results generates a hydrostatic counter-pressure, whereby an uncontrolled escape of petroleum and/or natural gas out of the bubble is suppressed. However, unexpected pressure increases in the bubble can occur during the drilling and in the later transport. If the deposit

pressure is higher than the counter-pressure of the drilling fluid, petroleum and/or natural gas can penetrate into the bore hole, wherein the petroleum and/or the natural gas displaces the drilling fluid in the direction of the surface of the earth and ultimately itself reaches the surface as a blowout. In order to prevent or at least dam such a blowout, the bore hole must be sealed quickly. For this it is known to install a bore hole seal at the mouth of the bore hole. The bore hole seal is mounted at the bore hole and firmly anchored in the ground. The bore hole seal comprises a series of combined barrier devices that are mounted directly over the bore hole.

If the bore hole seal fails to stop the blowout of petroleum and/or natural gas, petroleum and/or natural gas arrives at the earth's surface without any control. The natural gas and/or petroleum that thereby escape out of the bore hole are no longer available to be transported, whereby an economical loss occurs. However, it is more serious, given the outflow of large quantities of petroleum and/or natural gas, a severe environmental pollution is incurred that results in a considerable ecological damage.

Bore holes have previously only been provided with the bore hole seal, wherein a disaster can occur upon its failure. In particular given bore holes in the deep sea, it is difficult to install the bore hole seal at significant depths and even more difficult to seal the bore hole again in the event of disaster. It is an object of the invention to provide a capture device for a bore hole of a fluid source, a method to secure the bore hole with the capture device and a use of the capture device to secure the bore hole, wherein the bore hole can be redundantly secured with the capture device in addition to a conventional device.

The capture device according to the invention for a hole of a fluid source comprises a base plate, said base plate can be anchored over the hole and comprises a base plate opening, through which fluid can stream out of the hole, a funnel, said funnel is attached to the base plate with its large opening and put over the base plate opening, so that the small opening of the funnel is arranged facing away from the base plate opening, an ascending pipe, said ascending pipe can be positioned on the small opening of the funnel with one of its longitudinal ends, and at least two slides, said slides are supported on the inner face of the funnel that they can be displaced longitudinally along the axis of the funnel and are arranged opposing each other such that, when the fluid source is in the normal state, the slides are in the passive state and at the same time arranged inside the funnel around the base plate opening, and, when the fluid source is in the disaster state, in which the fluid uncontrollably escapes out of the hole, the slides are in the active state and lead through the small opening out of the funnel by longitudinal displacement and encompass the

longitudinal end of the ascending pipe, whereby fluid streaming out of the base plate opening can be captured via the slides and can be discharged via the ascending pipe. The capture device can be attached to the hole with the base plate without having to dismantle transport devices and barrier valves that are possibly already present. The funnel and the slides can advantageously be made such thick-walled that they can

withstand the pressure of the fluid escaping out of the hole.

It is inventive that each slide comprises a flank that is arranged facing the base plate and transversal to the axis of the funnel, so that fluid streaming out of the hole to the ascending pipe drags along the slides in direction away from the base plate. Therefore, the capture device can

advantageously close itself in the disaster state. The base plate together with a funnel is preferably made in two pieces consisting of two halves. For mounting the base plate and the funnel on the hole each half is placed on both sides of the hole on the ground and then both halves are brought together, whereby the base plate and the funnel are formed as well as the base plate opening is arranged over the hole. The capture device can thereby be mounted on the hole even when the fluid source is already in the disaster state. In doing so, the capture device with its separated base plate and its separated funnel can thereby be moved laterally to the hole, essentially in the lee streaming out of the hole, so that the installation of the two halves takes place in that zone that is least negatively effected by the escaping fluid.

It is preferred that the slides in the active state are

arranged in circumferential direction laterally lying on each other, whereby the longitudinal end of the ascending pipe is sealed against the funnel by the slides. The slides preferably comprise a sliding surface facing towards the inner face of the funnel, and being parallel to the inner surface of the funnel, and a clamping surface facing away from the sliding surface, and being parallel to the axis of the funnel. It is preferred that the slides in the active state extend from the inner face of the funnel to the outer end of the longitudinal end of the ascending pipe, whereby the radial distance between the inner face of the funnel and the outer face of the longitudinal end is bridged in the active state. In the active state the sliding face of the slides and the inner face of the funnel have a physical contact and the clamping surface and the longitudinal end of the ascending pipe have a physical contact. Thereby a respective sealing surface is formed between the inner side of the funnel and the sliding face of the slides as well as between the clamping surface and the ascending pipe, through which an escape of fluid from inside the funnel to outside the funnel is prevented.

It is preferred that the capture device comprises a driving unit, with which the slides can be driven longitudinally along the inner face of the funnel from the passive state into the active state. The driving unit preferably comprises a linear drive, in particular a worm wheel drive or a hydraulic strut or a step motor. It is preferred that the driving unit comprises a cable winch, said cable winch grabs each slide. The cable winch preferably comprises a main rope and for each slide a

respective pull rope, wherein the pull ropes couple the main rope with the slides. The main rope is preferably arranged inside the ascending pipe and the pull ropes extend on the longitudinal end out of the ascending pipe to the slides. It is also possible to provide both the linear drive and the cable winch, so that redundant driving units are provided for the displacement of the slides.

Each slide preferably comprises a locking device, by which the longitudinal displacement of the slides can be prevented and the longitudinal displacement of the slides can only be made possible, when the ascending pipe with its longitudinal end is positioned on the small opening of the funnel. For example, the locking device can be formed by a bolt, wherein said bolt can be remote controlled. The method according to the invention for securing a hole of a fluid source comprises the following steps: anchoring the capture device on the ground of the fluid source, wherein fluid can be streamed through the base plate opening, wherein the slides are in the passive state; when the fluid source is in the disaster state, in which fluid uncontrollably escapes out of the hole, bringing the slides in the active state, wherein the slides are longitudinally displaced on the inner face of the funnel to the longitudinal end of the ascending pipe, so that the distance between the funnel and the ascending pipe is bridged fluid-sealed. According to the invention, the capture device is used for securing a bore hole of a petroleum and/or natural gas source. It is hereby preferred that a transport apparatus already installed at the bore hole is retrofitted with the capture device.

The capture device according to the invention can already be mounted during the opening of the fluid source, wherein for example a bore hole seal is mounted together with the capture device. It is also conceivable that the capture device

according to the invention is mounted at a later point in time, in order to retrofit the hole with the capture device according to the invention. It is also possible to mount the capture device according to the invention on the hole as soon as the hole is in the disaster state.

In the following a preferred embodiment of a capture device according to the invention is explained on the basis of the schematic drawings. It shows:

Figure 1 a perspective view of the embodiment in the passive state and with an open funnel, Figure 2 a perspective view of the embodiment during the displacement of the slides and with the open funnel,

Figure 3 a perspective view of the embodiment in the active state and with the open funnel,

Figure 4 a view of a longitudinal section through the

embodiment in the passive state and with a fluid source, Figure 5 a view of a longitudinal section through the

embodiment during the displacement of the slides and with the fluid source, Figure 6 a view of a longitudinal section through the

embodiment in the active state and with the fluid source,

Figure 7 a perspective view of the embodiment in the passive state and with a closed funnel,

Figure 8 a perspective view of the embodiment during the displacement of the slides and with the closed funnel,

Figure 9 a perspective view of the embodiment in the active state and with the closed funnel, as well as

Figure 10 a perspective view of a slide.

As it can be seen from Fig. 1 to 9, a capture device 1

comprises a circular base plate 6. The base plate 6 comprises in its centre a circular base plate opening 9, so that the base plate 6 comprises a radial outer edge 7 as well as a radial inner edge 8. The base plate 6 is directly arranged on the ground 4 and anchored in it. A hole 5 is arranged in the ground 4, wherein the base plate 6 is arranged over the hole 5 such that a fluid can escape out of the hole through the base plate opening 9. The capture device 1 further comprises a funnel 10 in the shape of a truncated cone which large opening 11 is facing towards the hole 5 and which small opening 15 is facing away the hole 5. The funnel 10 comprises on its large opening 11 a flange 12. The funnel 10 is attached to the base plate 6 by means of the flange 12 such that the base plate opening 9 is arranged inside the funnel 10. The flange 12 is connected to the base plate 6 with screw connections 13, whereby it is also possible to weld the flange 12 to the base plate 6. A sealing surface is formed between the flange 12 and the base plate 6, so that an escape of the fluid between the flange 12 and the base plate 6 is prevented. The capture device 1 comprises an ascending pipe 2 having a circular cross section, wherein the lower longitudinal end 3 of the ascending pipe 2 is inserted through the small opening 15 into the funnel 10. The capture device 1 further comprises four slides 17 that are arranged inside the funnel 10 pairwise opposing to each other. It is in principle possible to design the invention with an arbitrary number of slides 17, however at least two slides 17, wherein also an uneven number of slides 17 is conceivable. The slides 17 comprise radial outside a sliding surface 21 that is parallel to the inner face 16 of the funnel 10. The slides 17 comprise radial inside a clamping surface 22 that is parallel to the axis of the funnel. The slides 17 are supported in the funnel 10 such that they can be displaced, such that the displacement path of the slides 17 comprises both a component parallel to the axis of the funnel 10 and a component perpendicular to the axis of the funnel 10. For that reason the funnel 10 comprises for each of the slides 17 at least one slide rail 18 arranged on the inner face 16 of the funnel 10, wherein the slide rail 18 is inserted in an according recess in the slide surface 21, so that the slide 17 can be displaced along the inner face 16 of the funnel 10. The slide rail 18 and the recess in the sliding surface 21 can for example be shaped in the form of a dovetail.

In the normal state of the fluid source the slides 17 are in the passive state that is shown in Figs. 1, 4, and 7. In the passive state the slides 17 are arranged around the base plate opening 9 and lie at least partially with their lower faces 19 on the base plate 6. In case a disaster state occurs, during which the fluid uncontrollably escapes out of the hole 5, the slides 17 are lead through the small opening 15 by longitudinal displacement out of the funnel 10. Figs. 2, 5, and 8 show the slides 17 on the way to the active state. The slides 17 in the active state are shown in Figs. 3, 6, and 9. In the active state the slides 17 lie in a circumferential direction

laterally on one another, whereby the clamping surfaces 22 of all of the slides 17 from a cylindrical surface, wherein the longitudinal end 3 of the ascending pipe 2 is arranged inside the cylindrical surface. The clamping surfaces 22 grip around and clamp the longitudinal end 3 of the ascending pipe 2 such that a sealing surface is formed between the slides 17 and the ascending pipe 2, so that no fluid can escape between the slides 17 and the ascending pipe 2. As the slides 17 lie laterally in circumferential direction on one another also no fluid can escape between the slides 17.

The extensions of the funnel 10 and the slides 17 are chosen such that in the active state the slides 17 extend from the inner face 16 of the funnel 10 to the outer face of the

longitudinal end 3 of the ascending pipe 2, whereby the radial distance between the inner face 16 of the funnel 10 and the outer face of the longitudinal end 3 is bridged. Thereby a further sealing surface is formed between the sliding surface 21 and the inner face 16 of the funnel 10, whereby no fluid can escape between the slides 17 and the inner face 16 of the funnel 10. Thereby it is advantageously ensured that in the disaster state fluid can only escape via the ascending pipe 2 out of the funnel 10 and thereby can be captured in a

controlled manner. As it can be seen from Fig. 10, a recess 23 is arranged in the lower part of the slide 17, so that the slide 17 comprises a flank 29 that is facing towards the base plate opening 9 and is substantially perpendicular to the axis of the funnel 10. The fluid streaming in the disaster state out of the hole 5 bounces against the flank 29, so that the slide 17 is dragged along by the fluid in a direction away from the base plate 6. The capture device 1 can thereby advantageously close itself in the disaster state or at least the force necessary for driving the slide 17 can be reduced.

A rib 24 formed vertically is arranged in the recess 23, wherein an eyelet 25 is arranged in the rib 24. It is shown in Figs. 1 to 9 that in each eyelet 25 of each slide 17 a pull rope 26 is fixedly attached. Each of the pull ropes 26 is connected to a main rope 27 by means of a knot 28. The main rope 27 is lead through the ascending pipe 2 to outside the funnel 10. It is therefore possible to bring the slides 17 from the passive state to the active state by pulling the main rope 27.

List of reference signs

1 capture device

2 ascending pipe

3 lower longitudinal end of ascending pip

4 ground

5 hole

6 base plate

7 outer edge of base plate

8 inner edge of base plate

9 base plate opening

10 funnel

11 large opening

12 flange

13 screw connection

14 upper longitudinal end of funnel

15 small opening

16 inner face of funnel

17 slide

18 slide rail

19 lower face of slide

20 upper face of slide

21 sliding surface

22 clamping surface

23 recess

24 rib

25 eyelet

26 pull rope

27 main rope

28 knot

29 flank