Underwater drilling device and method for procuring and analyzing ground samples of a bed of a body of water

Abstract

The invention relates to underwater drilling for procuring and analyzing ground samples of a bed of a body of water. An underwater drilling device placed onto a bed of the body of water. By a drill drive a drill rod composed of at least one tubular drill rod element is drilled into the bed of the body of water in a first drilling step, wherein a drill core is received in a receiving part in the tubular drill rod element. The receiving part with the drill core is deposited in a storage place of a storage area on the base frame. Subsequently, one further drilling step is carried out with a further drill rod element. By means of sensor means at least one physical and/or chemical property of the drill core is determined. data on the storage place of the drill core in the second storage area.

Claims

1. An underwater drilling device for procuring and analyzing ground samples of a bed of a body of water, having a base frame which is designed for lowering into the body of water and for placing onto the bed of the body of water, a drill drive on the base frame for rotationally driving a drill rod which is composed of tubular drill rod elements, wherein the drill drive is supported in a vertically movable manner along a drilling axis between a lower borehole opening and an upper retracted position, a storage area on the base frame for storing the individual tubular drill rod elements for assembly of the drill rod, wherein a receiving part for a drill core is in each case held in a releasable manner in the drill rod elements, and for storing each receiving part with the obtained drill core as a ground sample, a supply device on the base frame, with which individual drill rod elements can be supplied from the storage area to the drilling axis in order to form the drill rod, and a removal device on the base frame for removing each receiving part with the drill core from the drill rod and for depositing in a specific storage place in the storage area, wherein at least one sensor device is arranged on the base frame, which is designed for determining at least one physical and/or chemical property of the drill core, the at least one sensor device has an annular design, the at least one sensor device is provided in an annular housing, the at least one sensor device is coaxially arranged with the borehole opening, a data processing device is provided on the base frame, which is designed for storing data determined on the at least one physical and/or chemical property of the drill core and data on the storage place of the drill core in the storage area, and the determination of the at least one physical and/or chemical property is effected contact-free through a wall of each receiving part, whereby each receiving part passes through an inner opening of the annular sensor during retrieval of the ground sample.

2. The underwater drilling device according to claim 1, wherein a data transmission unit is provided, with which the determined data can be transmitted to a central facility located at a distance.

3. The underwater drilling device according to claim 1, wherein the data processing device has an evaluation unit, in which decision criteria are stored and which is configured to make a decision on a continuation or discontinuation of drilling on the basis of the stored decision criteria.

4. The underwater drilling device according to claim 1, wherein the at least one sensor device is arranged in the area above the borehole opening.

5. The underwater drilling device according to claim 1, wherein the sensor device is designed for measuring an inductance, electrical conductivity, a capacity and/or further physical or chemical quantities.

6. The underwater drilling device according to claim 1, wherein each receiving part is designed in a tubular manner as a core tube catcher, which has at an upper end a connecting device for the removal device.

7. The underwater drilling device according to claim 1, wherein the removal device has a winch with a hoist rope, at a free end of which a locking device is arranged which interacts with a connecting device on each receiving part for the drill core.

8. The underwater drilling device according to claim 1, wherein the base frame is connected via a maritime umbilical to a supply vessel.

9. A method for procuring and analyzing the ground samples of the bed of the body of water with the underwater drilling device according to claim 1, in which the underwater drilling device with the base frame is lowered into the body of water and placed onto the bed of the body of water, having the drill drive which is supported in a vertically movable manner on the base frame, the drill rod composed of at least one tubular drill rod element of the tubular drill rod elements is drilled into the bed of the body of water in a first drilling step, wherein a drill core is formed and received in a receiving part in the tubular drill rod element, the receiving part with the drill core is removed by means of a removal device from the drill rod and deposited in a storage place of the storage area on the base frame, and subsequently at least one further drilling step is carried out, wherein by means of a supply device a further drill rod element with a receiving part for a drill core is supplied from the storage area to the drill rod and a further drilling of the drill rod is effected with the drill drive, wherein by means of at least one sensor device at least one physical and/or chemical property of the drill core is determined, and the data thereby determined are stored in a data processing device together with the data on the storage place of the drill core in the storage area.

10. The method according to claim 9, wherein on the basis of the data determined on the at least one physical and/or chemical property of the drill core a decision is made on a continuation or discontinuation of drilling while the underwater drilling device is still located in the body of water on the bed of the body of water.

Description

(1) In the following the invention is set out further by way of preferred embodiments illustrated schematically in the accompanying drawings, wherein show:

(2) FIG. 1 a schematic perspective view of an underwater drilling device according to the invention;

(3) FIG. 2 a schematic side view of the underwater drilling device according to FIG. 1; and

(4) FIG. 3 a schematic illustration with a plurality of sample drillings.

(5) The structure and function of an underwater drilling device 10 according to the invention are explained in conjunction with FIGS. 1 and 2. The underwater drilling device 10 comprises a box-shaped base frame 12 which is composed of steel girders. In a central area of the base frame 12 a vertically directed drilling guide 24 is provided, along which a drill drive 20 with a tensioning means 22 for tensioning drill rod elements 32 is supported and driven in a vertically movable manner along a drilling axis 21. In addition, the drill drive 20 can be moved away from the drilling axis 21 perpendicularly to the said drilling axis 21 in a horizontal direction along a crossbar 23. The drill drive 20 can serve as a part of a supply means 38 in order to grab drill rod elements 32, which are not depicted and stored in a first storage area 14 of the base frame 12, and guide these into the drilling axis 21. The supply means 38, which is only illustrated schematically, can have further handling means to grab vertically directed, stored drill rod elements 32 and convey these in a known manner to the drilling axis 21.

(6) To form a drill rod 30 a new drill rod element 32 is attached by way of a screw connection to a drill rod element 32 already present. In FIG. 1 only a single drill rod element 32 is shown which has been introduced into the bed of a body of water 5 in a first drilling step. In this initial drill rod element 32 a drill head 31 with ground-removing cutting tools is provided at the lower end. During drilling of the tubular drill rod element 32 a cylindrical drill core is formed by the in-situ ground material. This drill core is received in a tubular receiving part 34 that is arranged in the interior of the drill rod 30.

(7) To remove the tubular receiving part 34 with the drill core arranged and held therein the drill drive 20 is initially moved out of the drilling axis 21. Afterwards, a hoist rope 43 of a removal means 40 is moved by a swivel lever mechanism 41 into the area of the drilling axis 21. At the lower free end of the hoist rope 43 a sleeve-shaped locking means 44 is provided. The hoist rope 43 runs from a winch 42 mounted laterally on the base frame 12 via a lower linkage roller 45 to an upper deflection means 46 of the removal means 40. Through the winch 42 the hoist rope 43 which is deflected several times on the frame is lowered downwards, and in doing so the locking means 44 on the hoist rope 43 engages in a connecting means 36 at the upper end of the sleeve-shaped receiving part 34. As a result, a connection is established, allowing the receiving part 34 with the drill core to be pulled upwards out of the drill rod 30. Subsequently, the sleeve-shaped receiving part 34 with the drill core is conveyed laterally by the removal means 40 to a second storage area 15 on the base frame 12 and deposited there. As is also the case concerning the second storage area 15, the magazine-like storage is not shown in greater detail for the sake of clarity. In the second storage area 15 the sleeve-shaped receiving parts 34 with the drill cores contained therein are stored vertically in holders so that on completion of the drilling operations the drill cores can be conveyed for further examination together with the underwater drilling device 10 to a supply vessel, not illustrated.

(8) For a preliminary examination and analysis of the drill cores an annular sensor means 50 is provided concentrically to the drilling axis 21 directly above the borehole opening 18, on which a tensioning unit 17 for holding the drill rod 30 is arranged. The sensor means 50 is designed with contact-free operating sensors for determining physical and/or chemical properties of the drill core. Furthermore, a data processing means 52 is provided, in which the data determined in each case with regard to a drill core can be stored. At the same time, the data processing means 52 can be used to store the positional data and in particular the storage place, in which the respective drill core is deposited in the second storage area 15. In a subsequent further analysis of the drill cores this makes it possible to selectively fall back on those drill cores which, according to the initial on-site analysis and the data transmitted beforehand by the data processing means 52, are of particular interest for further examination.

(9) After this first drilling step with a securing of a drill core the removal means 40 is moved out of the drilling axis 21 again so that subsequently the drill drive 20 provided with a new drill rod element 32 from the first storage area 14 can be moved into the drilling axis 21 again. The new drill rod element 32 can then be attached to the upper drill rod element 32 of the drill rod 30. Finally, the drill rod 30 can be drilled again by one drilling step by the length of a drill rod element 32 into the bed of a body of water 5. In this process, a new drill core is formed which can be removed from the drill rod 30 and deposited again in the second storage area 15 in line with the previously described method. If desired, further drilling steps can then take place accordingly.

(10) In FIG. 3 a schematic illustration is given of determining a natural resource deposit 7 in a bed of a body of water 5 by means of an underwater drilling device 10 according to the invention and a method according to the invention.

(11) To produce a first drilling 8.1 the underwater drilling device 10 is initially placed onto the bed of a body of water 5. Subsequently, a step-by-step drilling along with procurement and examination of the drill cores is carried out, as has been set out beforehand in conjunction with FIGS. 1 and 2. During the first drilling 8.1 no data concerning a natural resource deposit 7 were established by the underwater drilling device 10 according to the invention in the direct on-site analysis of the obtained drill cores. Accordingly, the first drilling 8.1 has been carried out up to the maximum achievable drilling depth which is illustrated by the drill rod 30 having four drill rod elements 32 in the present case.

(12) After dismantling of the drill rod 30 the underwater drilling device 10 can be shifted to a second position in order to carry out a second drilling 8.2. In the illustrated embodiment, a natural resource deposit 7 is established by the sensor means 50 as early as after the first drilling step. Following the second drilling step during the production of the second drilling 8.2 the in-situ examination of the drill core shows that in this drilling area the natural resource deposit 7 has again come to a halt in this depth position. Since this can be established immediately by an evaluation unit, continuation of the second drilling 8.2 can be brought to an end. The underwater drilling device 10 can then be shifted again to carry out further drillings 8.3, 8.4, 8.5 and 8.6.

(13) The embodiment according to FIG. 3 clearly shows that a direct analysis of the drill cores by the underwater drilling device 10 enables an early termination of drillings e.g. as on leaving an established natural resource deposit 7, as has been the case with the drillings 8.2, 8.3, 8.4 and 8.5. All in all, a time- and therefore cost-efficient method for establishing submarine natural resource deposits 7 can thus be implemented.