Underwater Excavation Device and Method for Forming an Underwater Cased Borehole

Abstract

To provide a drilling rig capable of forming a particularly efficiently cased borehole underwater.SOLUTION: The present invention relates to an underwater drilling device, which comprises a lowerable platform configured to be placed on a bottom of a body of water, at least one support tube axially displaceably and rotatably mounted on the platform, at least one tubular drive unit disposed on the platform and configured to rotationally drive the support tube to rotationally introduce the support tube into the bottom of the body of water, and an in-hole drilling rig disposed within a support tube, which comprises a rig base body, at least one clamping device for clamping and securing a downhole drilling rig within the support tube, and a drill head that is axially displaceable and rotatably attached to the rig base body and can be rotated by a drill drive unit. According to the invention, when the support tube is rotationally driven, the downhole drilling rig is placed within the support tube and clamped in the axial direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an underwater excavation device for forming an excavated hole cased underwater using a platform that can be lowered, as described in claim 1.

[0002] The present invention further relates to a method for forming an excavated hole cased underwater using such an underwater excavation device, as described in claim 12.

Background Art

[0003] Patent Document 1 discloses an excavation device and method for manufacturing the foundation of an underwater structure. The guiding device is installed on the seabed. A support pipe is arranged in the guiding device. An excavation hole for lowering the support pipe is dug by an excavation rig inserted into the support pipe. After removing the in-hole excavation rig, a foundation element can be inserted into the support pipe. Then, the support pipe is pulled, and the intermediate space between the hole wall and the inserted foundation element is filled.

[0004] Patent Document 2 discloses an apparatus and method for making an underwater foundation. In this case, the support pipe is also inserted into the ground, and an in-hole excavation rig is arranged therein. The in-hole excavation rig can remove soil substances and push the surrounding support pipe axially along.

[0005] Another known apparatus and method for manufacturing the foundation of an underwater structure are disclosed in Patent Document 3.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention is based on the object of specifying an excavation device and method capable of forming an efficiently cased excavation hole particularly in water.

Means for Solving the Problems

[0008] According to the present invention, the object is achieved on the one hand by an underwater excavation device having the features of claim 1 and on the other hand by a method having the features of claim 12. Preferred embodiments of the present invention are defined in the independent claims.

[0009] An underwater excavation device according to the present invention for forming an excavation hole cased in water includes a lowerable platform configured to be installed on the bottom of a water area, at least one support pipe axially displaceable and rotatably mounted on the platform, at least one tubular drive unit disposed on the platform and configured to rotationally drive the support pipe and rotationally introduce the support pipe into the bottom of the water area, and at least one downhole drilling rig disposed in the support pipe, the downhole drilling rig including a rig base body, at least one clamping device for clamping and fixing the downhole drilling rig to the support pipe, a drill drive unit attached to the rig base body, a drill head axially displaceable and rotatably mounted on the rig base body and rotationally drivable by the drill drive unit, wherein when the support pipe is rotationally driven, the downhole drilling rig is disposed in the support pipe and axially clamped to the support pipe, and includes.

[0010] A first aspect of the present invention is to provide at least one tubular drive unit on a lowerable platform for rotationally driving a support pipe, the tubular drive unit being configured to rotationally introduce the support pipe into the bottom of the water area in an underwater excavation device.

[0011] According to a further aspect, in an underwater excavation device having a tubular drive unit, a downhole drilling rig disposed within a support pipe is configured to be clamped to the support pipe when the support pipe is rotationally driven and to rotate together with the rotating support pipe. Thereby, efficient step-by-step excavation of the support pipe and the drilling rig becomes possible. Depending on the type of soil at the site, either the support pipe of the drilling rig or the drill head can advance. While the drill head is rotationally driven, the drilling rig can be clamped to the stationary support pipe. After a drilling step by the drill head of the drilling rig, the support pipe can be rotationally introduced into the ground by a further advancement step, whereupon the downhole drilling rig remains rotationally fixed to the support pipe. When the support pipe is rotationally driven, the drill head remains stationary relative to the rig base body. Alternatively, the drill head can be rotationally driven simultaneously with the support pipe in the same or opposite rotational direction.

[0012] In principle, the tubular drive unit of the lowerable platform can be configured to rotationally drive the support pipe in any suitable manner. A preferred embodiment of the present invention is that a collet device for clamping the support pipe is disposed on its outer peripheral side such that it is rotatable or swingable and axially movable in order to form the tubular drive unit on the platform, and that the torque of the tubular drive unit can be transmitted to the support pipe.

[0013] The tubular drive unit can be configured in the same manner as the casing device, in which case releasable gripping of the support pipe on the outer peripheral side can be achieved by a collet. Preferably, a hydraulic cylinder can be used to rotate the collet about the longitudinal axis of the pipe.

[0014] According to a variant of the present invention, it is particularly advantageous that the tubular drive part is configured to transmit a continuous rotational movement to the support tube. Thereby, a continuous rotational drive can be provided. Further, two or more collets can be provided, each collet having a rotating cylinder, and each arrangement having a collet performs a specific twist through a predetermined angular range. By a cooperative and continuous torsion by at least two such arrangements, a continuous or quasi-continuous rotation of the support tube can be achieved.

[0015] Alternatively or additionally, according to a further development of the present invention, the tubular drive part is configured to transmit an oscillating rotational movement to the support tube. This oscillating movement or stepwise rotational movement can be achieved in particular by arranging a single collet device.

[0016] The downhole drilling rig is suspended from the support tube via a suspension cable, and a feed force can be generated only by the dead weight of the downhole drilling rig. According to an advantageous embodiment of the present invention, the downhole drilling rig preferably comprises an axial feed device in which the drill head is axially displaceable relative to the rig base body. The rig base body may be provided with a frame structure that can be fixed in a rotationally fixed manner to the inner wall of the support tube, preferably by a hydraulically expandable clamping cylinder. The feed device may comprise one or more hydraulically actuated cylinders arranged axially. Thereby, the rotationally driven drill head can be axially displaced relative to the rig base body. The drill drive part, which may preferably comprise one or more hydraulic rotary motors, may be provided axially fixed to the base body, and the drill drive shaft is axially extendable and retractable by a toothed structure of corresponding splines or another suitable configuration. Thereby, torque transmission from the drill drive part to the axially displaceable drill head can be achieved.

[0017] In principle, the supply device can have any configuration as long as it is appropriate. According to one variant of the present invention, it is particularly advantageous for the supply device to comprise at least one hydraulic supply cylinder. The supply cylinder can be a single-acting or double-acting operating cylinder.

[0018] According to a further development of the present invention, it is advantageous for two or more support pipes to be rotatably and axially displaceably mounted on the platform for the efficient lowering of the cased borehole. The platform may be configured as a template for positioning the support pipes in a predetermined arrangement on the bottom of the water area. In principle, a dedicated downhole drilling rig can be arranged for each support pipe. Alternatively, a single downhole drilling rig may be provided, and the single downhole drilling rig is first inserted into the first support pipe to form the first borehole. After the first borehole is formed, the downhole drilling rig is released and retracted from the first support pipe and inserted into the second support pipe to form the second cased borehole. This can be repeated according to the number of support pipes present. The tubular drive unit is preferably arranged on the platform according to the number of support pipes to be provided.

[0019] During the drilling operation, the downhole drilling rig is connected to a supply unit on the water surface, in particular a supply vessel, via one or more lines, in particular so-called supply pipelines. Through the one or more lines, energy, in particular electrical energy and / or hydraulic energy, is transmitted. When the downhole drilling rig rotates the support pipe fixed inside, it is necessary to prevent twisting in the one or more lines. For this purpose, at least one line may be connected to the downhole drilling rig in the upper region of the downhole drilling rig by means of a corresponding rotary coupling. In particular, a so-called rotary union may be provided as a passage for the hydraulic fluid.

[0020] A simplified embodiment of the present invention for avoiding the twist of at least one line is that at least one upper clamping device is arranged on the rig base body and at least one lower clamping device is arranged on the drill head. Thereby, the drill head and / or the rig base body can be alternately supported.

[0021] In particular, according to a variant of the present invention, when the support pipe is rotationally driven, at least one lower clamping device on the drill head extends radially and the drill head is clamped to the support pipe, and at least one upper clamping device on the rig base body retracts radially and is released from the support pipe. In this state, the rotational drive unit may be disconnected from the drill head or self-propulsion may be selected. In this arrangement, when the support pipe is rotationally driven, the drill head can rotate together, but the rig base body does not follow the rotational movement because self-propulsion of the drill drive unit is selected. In this way, the rig base body with the line connected can be stationary, but the drill head rotates together with the rotationally driven support pipe. With this arrangement, the twist of at least one connected line can be avoided without providing a special line coupler or rotary union on the line. Alternatively, the rig base body can be clamped and fixed to the support pipe, and the downhole drilling rig can be rotated together with the support pipe.

[0022] When the support pipe is rotated in a rocking manner instead of rotating in the circumferential direction, a special line coupler or rotary union can also be omitted.

[0023] As a further preferred modification of the present invention, the platform at the bottom of the water area is provided with a supply device connected to the water supply unit via at least one main supply line, and at least one tubular drive unit and at least one downhole drilling rig are connected to the supply device of the platform for energy supply, particularly via the supply line. The supply device of the platform can preferably store a certain amount of energy, such as electrical energy from a built-in rechargeable battery or hydraulic energy from a corresponding accumulator. In this way, the platform can be operated self-sufficiently for a certain period of time. This may be necessary, for example, in case of bad weather or when the main supply line is cut accordingly. The supply device of the platform is preferably connected to the water supply unit via a releasable main supply line. The water supply unit may particularly be a ship.

[0024] The present invention further relates to a method for forming a cased borehole underwater, comprising an underwater drilling device according to the present invention, wherein at least one support pipe is arranged on the platform of the underwater drilling device, and at least one downhole drilling rig on which at least one support pipe is arranged, and the platform is lowered to the bottom of the water area, and at least one support pipe is rotationally driven via a tubular drive unit on the platform to drill down into the bottom of the water area. Before and / or after the excavation of the support pipe, while the support pipe is held on the platform in a rotationally fixed manner, the drill head of the downhole drilling rig arranged in the support pipe is rotationally driven to drill down into the bottom of the water area to form a borehole. When the support pipe is rotationally driven, the downhole drilling rig stays in the support pipe and is axially clamped.

[0025] This method can be particularly implemented using the underwater drilling device according to the present invention described above. The advantages described in this context can be achieved. The method according to the present invention includes the method steps defined in claim 1, but is not limited to a specific order of the method steps. The individual method steps can also be implemented before or after another method step.

[0026] The present invention will be further described below with reference to preferred exemplary embodiments schematically shown in the accompanying drawings.

Brief Description of the Drawings

[0027]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0028] In FIGS. 1 to 4, exemplary embodiments of an in-hole boring rig 10 for forming an underwater excavation device 100 according to the present invention are shown. The in-hole boring rig 10 includes a frame-shaped rig base body 12 composed of a first annular frame portion 14. On the upper side of this plate-shaped first frame portion 14, a drill driving portion 40 is arranged. In the illustrated exemplary embodiment, the drill driving portion 40 is formed by three hydraulic rotary driving portions 42 arranged so as to be uniformly distributed around the longitudinal axis or the excavation axis of the in-hole boring rig 10.

[0029] The clamping device 50 is attached to the lower side of the first frame portion 14, and the first frame portion 14 is configured to radially tighten and fix the downhole drilling rig 10 to the support pipe and / or the wall surface of the drilling hole. In the illustrated exemplary embodiment, the annular clamping device 50 includes six non-visible radially directed clamping cylinders, and a plunger-like clamping plate 52 is attached to the outer peripheral side thereof. The clamping cylinders having the clamping plate 52 are uniformly distributed around the longitudinal axis or the drilling axis of the downhole drilling rig 10.

[0030] An upper frame portion 15 is disposed at the upper end of the frame 12. A plate-like ring-shaped intermediate portion 16 is disposed between the upper frame portion 15 and the first frame portion 14 below it. The intermediate portion 16 is connected to the first frame portion 14 via connecting struts 18 directed vertically on one hand, and is connected to the upper frame portion 15 upward on the other hand.

[0031] On the upper side of the upper frame portion 15, a connecting device 28 for cable suspension of the downhole drilling rig 10 is centrally disposed, and two line supply devices 29 are disposed on its sides. The line supply device 29 has a function of supplying a hydraulic hose line on one hand and supplying and holding a drilling slurry discharge line on the other hand.

[0032] Compressed air for the air-lift method, as well as power supply, data lines, and supply devices for supply lines may be provided.

[0033] The control components 19 may be disposed on the plate-like intermediate portion 16. As a whole, the upper region of the rig base body 12 may have a modular structure having the first frame portion 14, the upper frame portion 15, and the intermediate portion 16, whereby the downhole drilling rig 10 can be adapted to different drilling hole sizes and application areas in a simple manner.

[0034] Below the clamping device 50 on the first frame part 14, a supply device 70 with a hydraulic supply cylinder 72 is arranged. The supply cylinder 72 is fixed to the first frame part 14 together with their cylinder housings. On the other hand, by an extendable cylinder piston, the supply cylinder 72 is hinged to the annular plate-like second frame part 20. The annular second frame part 20 is fixed to the outer surface of the tubular bearing sleeve 24, and therein, a tubular drill string 38, which is only partially visible in FIGS. 3 and 4, is attached so as to be rotatable but axially fixed. The drill head 30 is fixed to the lower end of the drill string 38. The drill head 30 includes a central pilot tip 32 and radially directed removal elements 34, and the removal elements 34 are configured to remove soil material. The second frame part 20 is axially adjustably attached to the first frame part 14.

[0035] In the upper end region of the tubular drill string 38, the drive shaft 44 of the drill drive 40 extends into the tubular drill string 38. The drive shaft 44 includes an outer axially extending drive strip 46, and the drive strip 46 cooperates with a corresponding inner drive strip inside the tubular drill string 38 for torque transmission. Through the drive shaft 44, the drill string 38 is rotationally driven together with the drill head 30, whereby the drill head 30 can remove soil material.

[0036] In FIGS. 1 and 2, the downhole drilling rig 10 is shown with the drill head 30 retracted axially. In this state, the downhole drilling rig 10 can be fixed in the drilled hole via the clamping device 50 by the radial extension of the clamping plate 52 with respect to the support pipe. Thereafter, the supply device 70 can be actuated with the drill head 30 rotating, and at this time, the supply cylinder 72 extends downward. Thereby, the second frame portion 20 having the bearing sleeve 24 and the drill head 30 attached thereto can be moved downward and advanced correspondingly during drilling. Alternatively, the drill head 30 and / or the downhole drilling rig may be supported or fixed at a predetermined position when the support pipe 8 is rotated.

[0037] When the maximum extended length of the supply cylinder 72 of the supply device 70 is reached, as shown in FIGS. 3 and 4, by retracting the clamping plate 52, the support by the clamping device 50 can be released. The upper region of the rig base body 12 can be guided downward by slackening the suspension cable fixed to the connecting device 28 until the supply cylinder 72 is retracted and the axially retracted state according to FIGS. 1 and 2 is reached again. Now, after the rig base body 12 is clamped again by the clamping device 50, a further drilling step can be carried out. Alternatively, the clamping plate 52 may extend radially and remain fixed to the support pipe 8. Thus, the support pipe 8 can be rotated towards the ground and guided along it. The supply cylinder 72 may be retracted during this process.

[0038] The soil material generated during excavation is discharged from the frame 12 by a suction pump 36 as a conveying device 35 via a hollow drill string 38 and a hollow drive shaft 44, and is conveyed outside the excavation hole via a partially illustrated conveying line 37. The second frame portion 20 having a bearing sleeve 24 may include a third frame portion 27, and this third frame portion 27 is fixedly attached to the first frame portion 14 and is linearly displaceably attached via a downwardly directed linear guide 26. Since the guide 26 absorbs circumferential torsional forces, the supply cylinder 72 is released from lateral forces.

[0039] As shown in FIG. 5, the underwater excavation device 100 according to the present invention includes a lowerable platform 80 having a work stage 82, and this platform 80 is suspended from a cable arrangement 97 shown only in part, and can be lowered and installed on the bottom 5 of the water area via this cable arrangement 97 having adjustable legs 88.

[0040] As shown in FIG. 5, a plurality of support pipes 8 into which the in-hole excavation rigs 10 are inserted may be arranged on the work stage 82, and two of the in-hole excavation rigs 10 can be seen in the side view of FIG. 5. Four in-hole excavation rigs 10 may be arranged at the corners of the work stage 82 configured as a geometric rectangle, or three in-hole excavation rigs 10 may be arranged at the corners of the work stage configured as an equilateral triangle.

[0041] As described above, the in-hole excavation rigs 10 are substantially identically formed.

[0042] The in-hole excavation rig 10 functions to introduce the support pipe 8 to the bottom 5 of the water area. On the work stage 82, each in-hole excavation rig 10 or a sleeve-shaped linear guide 84 and a tubular drive unit 85 for each excavation hole are arranged. The linear guide 84 guides the support pipe 8 to be displaceable vertically on the work stage 82. The underwater excavation device 100 further includes a collet device 86 for fixing the support pipe 8 in a rotation-fixed manner while rotating and / or axially displacing the support pipe 8 on the work stage 82 to form the tubular drive unit 85. This collet device 86 is arranged below the linear guide 84 on the work stage 82. The collet device 86 may be configured as, for example, a hydraulic clamping device, and also includes means for axially fixing the support pipe 8, that is, means for fixing against vertical displacement. Therefore, the collet device 86 can ensure that the support pipe 8 maintains not only the rotational position but also the axial position with respect to the work stage 82 not only during the descent of the work stage 82 but also during the excavation operation.

[0043] To form an excavation hole into which the support pipe 8 is introduced, the in-hole excavation rig 10 is inserted therein. At the lower end of the in-hole excavation rig 10, a drill head 30 configured as a full-face drill head or another suitable drill head equipped with roller bits may be provided. The drill head 30 may protrude from the lower end of the support pipe 8, whereby the drill head 30 can remove the soil material below the support pipe 8. The support pipe 8 is pressed while rotating axially with respect to the in-hole excavation rig 10 via the collet device 86. When the support pipe 8 is displaced, the in-hole excavation rig 10 is supported within the support pipe 8 and thus is guided together with the support pipe 8. The energy supply can be supplied to the central supply device 90 on the work stage 82 via the main supply line 92.

Explanation of Reference Numerals

[0044] 8 Support pipe 10 In-hole excavation rig 30 Drill head 40 Drill drive unit 50 Clamping device 80 Platform 85 Tubular drive unit 100 Subaqueous excavation device.

Claims

1. An underwater excavation device for forming an excavation hole cased in water, comprising: A lowerable platform configured to be installed on the bottom of the water area; At least one support pipe axially displaceable and rotatably mounted on the platform; At least one tubular drive unit disposed on the platform and configured to rotationally drive the support pipe for rotationally introducing the support pipe into the bottom of the water area; At least one in-hole excavation rig disposed in the support pipe, A rig base body; At least one clamping device for clamping and fixing the in-hole excavation rig in the support pipe; A drill drive unit of the rig base body; An in-hole excavation rig comprising a drill head axially displaceable and rotatably mounted on the rig base body and rotationally drivable by the drill drive unit; When the support pipe is rotationally driven, the in-hole excavation rig is disposed in the support pipe and axially clamped to the support pipe, so that the in-hole excavation rig rotates together with the rotating support pipe; When the support pipe is rotationally driven, the drill head is rotationally driven with respect to the rig base body. An underwater excavation device, characterized in that.

2. A collet device for clamping the support pipe on its outer peripheral side is disposed rotatably or pivotally and axially movably to form the tubular drive unit with the platform, and the torque of the tubular drive unit can be transmitted to the support pipe. The underwater excavation device according to claim 1, characterized in that.

3. The underwater excavation device according to claim 1, characterized in that the tubular drive unit is configured to transmit a continuous rotational motion to the support pipe.

4. The underwater excavation device according to claim 1, characterized in that the tubular drive unit is configured to transmit an oscillatory rotational motion to the support pipe.

5. The underwater excavation device according to claim 1, characterized in that the in-hole excavation rig comprises an axial feed device axially displaceable with respect to the rig base body by the drill head.

6. The underwater excavation device according to claim 5, characterized in that the axial feed device comprises at least one hydraulic supply cylinder.

7. The underwater excavation device according to claim 1, characterized in that at least one supply line is connected to the downhole drilling rig above the rig base body.

8. The underwater excavation device according to claim 1, characterized in that two or more support pipes are mounted on the platform rotatably and axially displaceably.

9. The underwater excavation device according to claim 1, characterized in that at least one upper clamping device is arranged on the rig base body and at least one lower clamping device is arranged on the drill head.

10. When the support pipe is rotationally driven, the at least one lower clamping device of the drill head extends radially, the drill head is clamped to the support pipe, and the at least one upper clamping device on the rig base body retracts radially and is released from the support pipe. The underwater excavation device according to claim 9, characterized in that.

11. The platform on the bottom of the water area is provided with a supply device connected to an above-water supply unit via at least one main supply line. The underwater excavation device according to claim 1, characterized in that the at least one tubular drive part and the at least one downhole drilling rig are connected to the supply device of the platform for energy supply, in particular via a supply line.

12. A method of forming an excavated hole cased in water using the underwater excavation device according to claim 1, At least one support pipe is arranged on the platform of the underwater excavation device. At least one downhole drilling rig is arranged in the at least one support pipe. The platform is lowered to the bottom of the water area. The at least one support pipe is rotationally driven by the platform via a tubular drive part to dig down the bottom of the water area. Before and / or after the excavation of the support pipe, while the support pipe is held on the platform in a rotationally fixed manner, the drill head of the downhole drilling rig arranged in the support pipe is rotationally driven to dig down the bottom of the water area to form the excavated hole. When the support pipe is rotationally driven, the downhole drilling rig remains in the support pipe and is axially clamped, so that the downhole drilling rig rotates with the rotating support pipe, and the drill head is rotationally driven with respect to the rig base body. A method, characterized by...

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