Underwater drilling device and method for procuring drill cores of a bed of a body of water

Abstract

The invention relates to an underwater drilling device and to a method for procuring drill cores of a bed of a body of water, wherein an underwater drilling device with a base frame is lowered in a body of water and placed on a bed of a body of water. A drill string consisting of at least one tubular drill string element is drilled out into the bed of the body of water in a first drilling step with a drill drive, with a drill core being formed in a receptacle in the tubular drill string element and being received in a core barrel in the drill string element. According to the invention, the drill core is enclosed in pressure-tight manner in a receiving container on the basic cradle under water.

Claims

1. An underwater drilling device for procuring at least one drill core of a bed of a body of water, comprising: a base frame which is designed to be lowered in the body of water and to be placed on the bed of the body of water, a drill drive for rotatably driving a drill string about a drilling axis, wherein the drill string includes at least one tubular drill string element and additionally at least one core barrel for receiving the at least one drill core is provided in the drill string, and storage that is spaced apart from the drilling axis and configured to store at least one receiving container for the at least one drill core, the at least one receiving container includes a tubular base body that is closable with at least one receiving opening for introducing the at least one drill core, wherein the at least one tubular drill string element is used as the at least one receiving container, and wherein barrel ends of the at least one tubular drill string element, once it has been removed from the drill string, can be enclosed in a pressure-tight manner in the at least one receiving container on the base frame underwater by a closing device configured to close the at least one receiving opening of the at least one receiving container in the pressure-tight manner with a closure cap once the at least one drill core has been received.

2. The underwater drilling device according to claim 1, wherein the closing device has at least one rotary drive which is designed to turn the closure cap with screw thread relative to the at least one receiving container, in which case a suitable thread being arranged on barrel ends of the at least one receiving opening.

3. The underwater drilling device according to claim 1, wherein the at least one core barrel can be pulled out of the drill string by a manipulator, and the manipulator and the closing device are movable relative to each other.

4. The underwater drilling device according to claim 3, wherein the manipulator is a cable winch with lifting cable, or has at least one lifting cylinder.

5. The underwater drilling device according to claim 1, wherein the base frame is connected to a supply vessel by way of a marine umbilical.

6. A method for procuring at least one drill core of a bed of a body of water with an underwater drilling device, the method comprising: lowering a base frame of the underwater drilling device in the body of water for placement on the bed of the body of water, rotatably driving a drill string about a drilling axis with a drill drive, wherein the drill string includes at least one tubular drill string element and additionally at least one core barrel for receiving the at least one drill core is provided in the drill string, and storing at least one receiving container for the at least one drill core in storage that is spaced apart from the drilling axis, the at least one receiving container includes the at least one tubular drill string element that is closable with at least one receiving opening for introducing the at least one drill core, wherein the at least one tubular drill string element is used as the at least one receiving container, and the at least one drill core, once it has been removed from the drill string, is enclosed in a pressure-tight manner in the at least one receiving container on the base frame underwater by a closing device configured to close the at least one receiving opening of the at least one receiving container in the pressure-tight manner with a closure cap once the at least one drill core has been received.

7. The method according to claim 6, wherein the closure cap is screwed on with a screw thread to close the at least one receiving container.

8. The method according to claim 6, wherein the at least one core barrel is pulled out of the at least one tubular drill string element by a manipulator, the at least one core barrel and the at least one receiving container are moved and axially aligned relative to each other, and after axial alignment of the at least one core barrel and the at least one receiving container, the at least one core barrel with the at least one drill core is moved into the at least one receiving container by relative axial movement of the at least one core barrel and the at least one receiving container.

9. The method according to claim 6, wherein a receiving bore for the at least one receiving container is created beneath the base frame in the bed of the body of water, and the at least one core barrel is introduced into the at least one receiving container in the receiving bore.

10. The method according to claim 6, wherein the at least one receiving container is moved into the drilling axis.

11. The method according to claim 6, wherein the at least one core barrel is moved to the at least one receiving container at the storage and is introduced into the at least one receiving container there.

12. The method according to claim 6, wherein a temperature control means is provided on the tubular base body, with which means an interior of the at least one receiving container is heated and/or cooled.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be described further below with reference to preferred examples of embodiment, which are illustrated schematically in the drawings. The drawings show:

(2) FIG. 1 a first embodiment of an underwater drilling device according to the invention in a first method step;

(3) FIG. 2 a side view of the underwater drilling device of FIG. 1 in a second method step;

(4) FIG. 3 a side view of the underwater drilling device of FIGS. 1 and 2 in a third method step;

(5) FIG. 4 a side view of a second embodiment of an underwater drilling device according to the invention in a first method step;

(6) FIG. 5 a side view of the underwater drilling device of FIG. 4 in a second method step;

(7) FIG. 6 a side view of the underwater drilling device of FIGS. 4 and 5 in a third method step;

(8) FIG. 7 a side view of a third embodiment of an underwater drilling device according to the invention in a first method step;

(9) FIG. 8 a side view of the underwater drilling device of FIG. 7 in a second method step;

(10) FIG. 9 a side view of the underwater drilling device of FIGS. 7 and 8 in a third method step;

(11) FIG. 10 a side view of a fourth embodiment of an underwater drilling device according to the invention in a first method step;

(12) FIG. 11 a side view of the underwater drilling device of FIG. 10 in a second method step; and

(13) FIG. 12 a side view of the underwater drilling device of FIGS. 10 and 11 in a third method step.

DETAILED DESCRIPTION

(14) In a first embodiment of the underwater drilling device 10 according to the invention of FIGS. 1 to 3, a box-like base frame 12 which in its upper region has a drill drive 20 for drilling out a drill string 30 which is constructed of individual tubular drill string elements 32 is illustrated schematically. Within the lowermost drill string element 32 there is a core barrel 34 which receives a drill core during drilling. The drill core while the core barrel is being drawn is held in the core barrel 34 by friction or by special core catching means. The drilling-out of the drill string 30 takes place in individual drilling steps, with, in a manner which is known in principle, a drill string element 32 being picked out of a storage region 14, which in the example of embodiment illustrated is designed as a revolving carousel, by means of a gripper arm 62 of a manipulating means 60 and brought to the drill drive 20. On the lowermost drill string element there is provided a drill head. The drill drive 20 is mounted and driven on the base frame 12 in vertically movable manner in order to sink the drill string 30 by a further drilling step. The base frame 12 is connected to a supply vessel by way of a marine umbilical 21. The marine umbilical 21 may in this case be provided both for supplying power, in particular electric power or hydraulic fluid, and as a data line for data communication. Furthermore, the marine umbilical 21 may also be designed as a cable with which the underwater drilling device 10 can be lowered and raised again in addition to the supplying function.

(15) In the illustration of FIG. 1, the drill drive 20 is pivoted out of a drilling axis 31 of the drill string 30. The upper drill string element 32 of the drill string 30 is held on the base frame 12 by a holding means 16, which preferably comprises clamping cylinders. By means of a lifting cable with a catching means 66, a core barrel 34 is grasped in the drill string element 30, and is pulled out of the drill string 30. The core barrel 34 can alternatively or subsidiarity also be pulled upwards by the vertically movable and pivotable gripper arm 62 or by a lifting cylinder 68 which is illustrated only schematically in FIG. 1.

(16) Once the core barrel 34 has been pulled out of the drill string 30 into an upper position, as illustrated in FIG. 1, the core barrel 34 is separated from the drill string 30 and the upper drill string element 32.

(17) To close a lower barrel end 35 of the core barrel 34, a cap-like or cup-shaped closure cap 46 is picked up from a magazine 56 and pivoted into the drilling axis 31 beneath the core barrel 34 by means of a lower manipulator arm 52 of the closing means 50, as illustrated clearly in FIG. 2.

(18) The closure cap 46 has at its upper end an internal screw thread which corresponds to an external thread on the lower barrel end 35 of the core barrel 34. By actuating the drill drive 20 and the lifting device 68, the core barrel 34 can be screwed into the screw thread of the closure cap 46. This is done in such a way that the lower barrel end 35 is closed in pressure-tight manner. Preferably a corresponding sealing means, in particular a sealing ring, can be provided on the screw connection.

(19) FIG. 3 illustrates the core barrel 34 with the closure cap 46 screwed on at the bottom. In a corresponding or similar manner, the upper barrel end 35 of the core barrel 34 can be closed with a further closure cap. Once the two barrel ends 35 of the core barrel 34 with the drill core arranged therein are closed in pressure-tight manner, this arrangement forms a pressure-tight receiving container 40 with the core barrel 34. This receiving container 40 can then be brought into a storage means 70 on the base frame 12 by way of the manipulating means 60, in particular by means of the gripper arm 62.

(20) If further drill string elements 32 and further core barrels 34 are present, these method steps for pressure-tight enclosing of the drill core in a collecting container 40 can be repeated until all the core barrels 34 with drill cores are obtained. Upon dismantling the drill string 30, the outer drill string elements 32 can likewise be pulled out of a drill hole again in known manner and conveyed back into the corresponding storage region 14 on the base frame 12.

(21) FIGS. 4 to 6 illustrate a further embodiment of an underwater drilling device 10 according to the invention. In these figures, a base frame 12 of the underwater drilling device 10 with fold-out feet 13 which are in principle present is shown, by which feet the base frame 12 is placed on a bed of a body of water 5. In the illustrations of FIGS. 4 to 6, the drilling-out and retrieval of a drill string 30 has already been carried out, with the retrieved individual drill string elements 32 being deposited in a storage region 14 on the base frame 12 and the core barrels 34 with the drill cores arranged therein in a storage means 70, not shown further.

(22) For pressure-tight enclosing of the core barrels 34 with the drill cores located therein, first of all a cartridge-like receiving container 40 is picked up out of the storage means 70, which may also be the storage region 14 for the drill string elements 32, by means of a manipulating means 60 with at least one gripper arm 62 and introduced into a receiving bore 7 in the bed of the body of water 5, as illustrated clearly in FIG. 4. The receiving bore 7 may in this case be in particular the bore from which the drill string 30 has been pulled out. In this case, the receiving bore 40 may also be of enlarged diameter compared with the bore originally created. The receiving container 40 which is open at the top is designed in cartridge-like manner with a cylindrical, tubular base body 41 and with a lower closed base 44. A temperature control means 43 is provided on the base body 41, with which means an interior of the receiving container 40 can be heated and/or cooled. As a result, the temperature and hence the pressure within the receiving container 40 can be influenced directly. On an underside of the base 44 there may be provided a cutting means with which the receiving container 40 can be introduced more easily into the bed of the body of water 5. At its upper end, the cylindrical base body 41 has a receiving opening 42 for receiving a core barrel 34.

(23) By means of a manipulating means 60, which may in particular comprise a lifting cable 67, a core barrel 34 can be removed from the storage means 70 and, once it has been introduced into the drilling axis, can be introduced through the receiving opening 42 into the cup-like receiving container 40, as is illustrated in FIG. 5.

(24) According to FIG. 6 a closure cap 46 can be inserted into the drill drive 20 and the latter can be moved along the drilling axis downwards to the receiving container 40. The upper closure cap 46 may in this case have been removed from a magazine, not illustrated further, on the base frame 12 by a corresponding manipulating means and have been supplied to the drill drive 20. Once the receiving container 40 has been closed in pressure-tight manner by corresponding screwing-on of the upper closure cap 46, and hence the core barrel inserted therein with the drill core is closed off in pressure-tight manner, the closed receiving container 40 can be pulled out of the receiving bore 7 again and be brought back into the storage means 70. Finally, the operation can be repeated until all the core barrels 34 with drill cores which have been obtained are enclosed in pressure-tight manner in a receiving container 40.

(25) A third embodiment of an underwater drilling device 10 according to the invention emerges from FIGS. 7 to 9. In this case, the basic structure with a base frame 12, a drill drive 20 and a storage means 70 largely corresponds to the structure of the underwater drilling devices 10 previously described. Unlike the embodiments previously described, a yoke-like structure 15 is provided in the direction of a drilling axis on the upper side of the base frame 12. The drill string projecting from a bed of a body of water is not illustrated anew in FIGS. 7 to 9.

(26) Once the drilling-out has been terminated, or after each drilling advance which corresponds to the length of one drill string element, the drill drive 20 is moved upwards along the base frame 12 on a corresponding linear guide and then spaced apart laterally from a drilling axis, as can be inferred from FIG. 7. Then a lifting cable 67, which is guided on the yoke-like structure 15 by way of a cable deflection means, is lowered downwards to the end of the drill string which is open at the top. By way of a connecting means, a first core barrel 34 is picked up and pulled out of the drill string upwards into the region of the yoke-like structure 15, this being illustrated in FIG. 7.

(27) Then an empty receiving container 40 can be removed from a carousel-like storage means 70 by way of a manipulating means 60 with a gripper arm 62, and positioned in the region of the drilling axis beneath the core barrel 34 which has been pulled upwards, as can be seen from FIG. 8. In the present case, the manipulating means 60 comprises a plurality of components, which include the lifting cable 67 and also the gripper arm 62.

(28) Once the receiving position of the receiving container 40 illustrated in FIG. 8 has been reached, the upper core barrel 34 is lowered along the drilling axis by the lifting cable 67 by way of a cable winch, not shown, and thus introduced through the upper receiving opening 42 into the receiving container 40 which is closed off at the bottom. Then the lifting cable 67 is detached from the core barrel 34 and pulled back upwards again to the upper portion of the yoke-shaped structure 15, as shown in FIG. 9. Finally, then the drill head 20 can be provided with a closure cap 46 from a magazine, not shown, with a supply element, likewise not shown, and be pivoted back into the drilling axis. Then the drill drive 20 is moved downwards and by turning the closure cap 46 the latter can be screwed onto the upper receiving opening 42 of the receiving container 40, so that the inserted core barrel 34 with the drill core located therein is enclosed in pressure-tight manner in the receiving container 40.

(29) Then the closed receiving container 40 can be brought back into the storage means 70 by way of the gripper arm 62, after which a further core barrel 34 can be introduced into the drill string 30. Prior to or after this, a further drill string element 32 can be placed on the existing drill string 30 and be screw-connected thereto. After renewed drilling, a further method step for closing a further core barrel 34 can be carried out.

(30) One further variant embodiment of the invention emerges from FIGS. 10 to 12. In the underwater drilling device 10 according to the invention illustrated, likewise a base frame 12 with a similar structure as for the previously described embodiments is yielded. The base frame 12 is placed on a bed of a body of water 5 by way of fold-out feet 13.

(31) From this transfer position illustrated in FIG. 10, the core barrel 34 is picked up by means of a manipulating means 60, which in the example of embodiment has two gripper arms 62, and pivoted away laterally out of the drilling axis into a closure position which is illustrated in FIG. 11.

(32) By means of a closing means 50 which has a movable manipulator arm, a receiving container 40 is moved out of a storage means 70 upwards to above the base frame 12 and moved laterally over the core barrel 34 into the closure position.

(33) In contrast to the embodiments previously described, the receiving container 40 has an inverted position, with the closed base 44 of the cylindrical base body 41 being at the top, while the receiving opening 42 is directed downwards to the core barrel 34. Then with a gripping and displacement unit 58 of the closing means 50 the receiving container 40 can be moved downwards over the core barrel 34 which is located thereunder, as illustrated clearly in FIG. 12. After the movement downwards, the receiving container 40 can be screwed onto a closure cap 46 arranged at the bottom by way of a rotary drive 52 on the gripping and displacement unit 58, with the core barrel 34 according to the invention being enclosed in pressure-tight manner in the receiving container 40. Finally, the closed receiving container 40 can be brought back into the storage means 70 by way of the gripper arms 62. Then, after the next drilling step the operation can be repeated for pulling a further core barrel 34 and closing a further receiving container 40.