EP2562348A1 - Underwater drilling assembly and method for producing a borehole - Google Patents

Abstract

The underwater drilling arrangement (10) has a retractable platform (20) for placement on the seabed, that is provided with a guide tube (22). A drill drive (52) is arranged on the working platform. A drill string (70) is provided with a drilling head (78) that is rotationally driven by drill drive. A linear guide is arranged inside the guide tube of retractable platform, for guiding drill drive axially. The guide tube is held in a receptacle of the work platform in adjustable and fixable manner. An independent claim is included for method for constructing borehole.

Description

The invention relates to an underwater drilling arrangement for producing a well in a river bed according to the preamble of claim 1. Furthermore, the invention relates to a method for creating a well in a riverbed according to claim 10.

The underwater drilling assembly comprises a submersible working platform for placement on the river bed, a drilling drive, which is arranged on the working platform, and a drill pipe with drill head, which is rotatably drivable via the drill drive.

The underwater drilling arrangement and the drilling method are used in particular for the creation of foundations or foundation piles in the river bottom, for example for anchoring offshore wind turbines, flow turbines of tidal power plants or oil and gas conveyors in the sea.

An underwater drilling assembly is for example from the EP 2 322 724 A1 known. In this drilling arrangement, the drill drive is placed on an upper tube collar of a tubular foundation element to be introduced into the body of the water, which remains after the drilling process in the riverbed. The foundation element to be introduced into the body of water is guided along a sleeve-like linear guide, which is arranged above the water bottom at the working platform.

Another underwater drilling assembly is in the GB 2 448 358 A described. The drilling assembly comprises a work platform with a plurality of hollow support feet, through which fastening piles can be introduced for fixing the platform at the bottom of the water in the ground.

An apparatus and a method for producing a cased deep hole is in the DE 43 08 856 C1 described. The device comprises a drill pipe, which is rotationally driven by means of a pipe lathe with simultaneous application of a feed force, wherein for excavating Bohrkerngut a Imrohrbohrgerät is used, which is retractable to a rope in the drill pipe and extendable from this. The Imrohrbohrgerät can be fixed to the drill pipe and entrained by the drill pipe in rotary drilling motion and thereby drivable.

A further device for producing a cased bore with a rotatable drive which can be fixed in the drill pipe is disclosed in US Pat DE 27 34 185 C2 described.

The invention has for its object to provide an underwater drilling assembly and a method for creating a hole in a body of water, which allow a particularly economical creation of a subsea well.

The object is achieved by an underwater drilling assembly having the features of claim 1 and a method for creating a hole in a riverbed with the features of claim 10. Preferred embodiments of the invention are specified in the respective dependent claims.

The underwater drilling arrangement according to the invention is characterized in that the working platform has a guide tube, on the inside of the tube at least one linear guide is arranged, along which at least a portion of the drill drive is guided axially movable, and that the guide tube mounted adjustable and fixable in a recording of the working platform is.

The inventive method, which can be carried out in particular with an underwater drilling arrangement according to the invention, comprises the following method steps: A working platform with a guide tube is sunk and placed on the bottom of the water. In the guide tube, a drill string with drill head is arranged and guided axially, wherein the drill string is driven to rotate by means of a drill drive. After creating the hole, the work platform becomes with the guide tube again removed from the water body and lifted.

A first basic idea of the invention can be seen in guiding the drill drive along an inner side of a tubular guide structure, namely the guide tube, of the working platform. The guide tube thus assumes the function of a leader, along which the drill drive is movably guided. By arranged and guided in the interior of the guide tube drill drive this is largely protected against external influences such as currents of the water. In particular, the guide tube allows guided movement of the drill drive along the direction of drilling progress.

For guiding the drill drive, the guide tube has a guide device extending in the axial direction of the guide tube, which is designed as a linear guide. The linear guide may in particular comprise a guide groove extending in the axial direction of the guide tube and cooperate with a corresponding guide element of the drill drive. The guide element of the drill drive, for example, a guide shoe, this is preferably provided on the outside of a housing of the drill drive.

The linear guide tube guide ensures a guided, exclusive axial movement of the drill drive inside the guide tube. Due to the linear guide, the housing of the drill drive can be secured against rotation with respect to the guide tube, so that reaction forces, in particular rotational forces, can be absorbed by the guide tube during a rotary operation of the drill drive and be derived therefrom.

A second basic idea of the invention is that the guide tube is adjustable, in particular axially displaceable and / or rotatable, to be supported in the receptacle of the working platform, so that the guide tube can be moved and in particular lowered and raised or rotated during the creation of the bore. Furthermore, the invention provides that the guide tube can be fixed to the receptacle. When fixed guide tube this is secured against rotation and / or axial movement with respect to a base body of the platform.

The fixed guide tube can serve as an abutment or support for the drill drive during operation of the drill drive. This allows the derivation of reaction forces via the guide tube to the base body of the platform and on this further to the body of water. Furthermore, the guide tube can be tracked in the drilling direction due to its adjustable mounting on the base body of the working platform, in particular during an interruption of the operation of the drill drive. Thus, the leadership of the drill drive can be extended down to allow a greater depth. Alternatively or in addition to the axial movement, a rotational movement of the guide tube relative to the main body of the working platform is possible.

According to the invention, it is particularly preferred to at least partially introduce the guide tube into the body of water in order to allow guidance of the drill drive both above and below the body of the water.

The guide tube as part of the working platform of the underwater drilling assembly is raised again after creating the bore and removed together with the base of the work platform from the bottom of the water.

In a preferred embodiment of the invention, it is provided that the drill drive has a drill drive upper part and a drill drive lower part, which are axially movable relative to one another. Preferably, both the drill drive upper part and the drill drive lower part have a passage for the drill pipe. Furthermore, it is preferred that the drill drive lower part is equipped with a driver device, which causes a coupling of drill drive lower part and drill pipe for a common axial movement. The Bohrantriebsoberteil and / or the Bohrantriebsunterteil are preferably fixed to the guide tube and releasably mounted. The Bohrantriebsunterteil may have at least one outwardly facing guide element which cooperates for axial guidance with the at least one linear guide.

Preferably, the Bohrantriebsoberteil and / or the Bohrantriebsunterteil is adjustable relative to the guide tube. Due to the adjustable, in particular axially movable storage Bohrantriebsoberteil and / or Bohrantriebsunterteil can be moved along the entire length of the guide tube to create a fixed guide tube with a bore approximately the length of the guide tube. Preferably, the Bohrantriebsoberteil and the Bohrantriebsunterteil are independently fixed to the guide tube. In order to carry out a drilling step, it is particularly preferred that the drill drive upper part can be fixed in the guide tube and the drill drive lower part can be moved axially in the guide tube together with the drill pipe when the drill drive upper part is fixed.

The feed movement of the drill string with drill head can basically be achieved by gravity. However, it is particularly preferred that an axial actuator is arranged for moving the bottom drill drive part relative to the drill drive top part. The actuator, which can also be referred to as a feed device, allows a demand-optimized control of the load on the drill head, in particular by increasing or decreasing the load caused by gravity.

To control the ballast or the pressure force is particularly provided to brace the Bohrantriebsoberteil in the guide tube and exert an axial force on the Bohrantriebsunterteil by the actuator, so that a defined pressure force is transmitted to the drill head.

An advantageous axial actuator is given by having at least one, preferably three, hydraulic cylinders. The hydraulic cylinder or cylinders can be arranged to save space within the guide tube. Preferably, a plurality of hydraulic cylinders are arranged symmetrically about a central longitudinal axis of the drill pipe.

In particular for screwing in the guide tube into the body of the water, it is preferred that the guide tube is rotatably and axially movably mounted in the receptacle and that a rotary drive for rotating the guide tube is arranged on the working platform. For a deep screwing in of the guide tube into the body of the water, it is preferred that the guide tube can be extended upward, if appropriate so far that it projects beyond the water surface.

A particularly robust rotary drive, which at the same time allows a secure fixing of the guide tube on the main body of the working platform, is given by the fact that the rotary drive has at least one hydraulically tensionable collet for clamping the guide tube and that the collet with at least a horizontal cylinder is rotatable. For this purpose, the horizontal cylinder is articulated, on the one hand, to the collet and, on the other hand, to the main body of the working platform. The rotary drive thus formed allows intermittent rotation of the guide tube by tensioning the collet, rotating the collet by means of the horizontal cylinder, loosening the collet, returning the collet and re-tightening and turning.

The introduction of the guide tube in the body of water can be facilitated by the fact that the guide tube has a cutting device on its underside. The cutting device may in particular comprise a cutting ring with cutting teeth formed on the axial end face of the guide tube.

To increase the load on the drill bit, it is preferred that load plates are disposed on the drill string above the drill bit. The load plates can in particular be releasably attached to the drill string, in particular attached to this. For this purpose, the load plates comprise a central passage for the drill pipe. Preferably, a variable number of load plates can be attached to the drill pipe.

For a secure setting or bracing the Bohrantriebsoberteils and / or Bohrantriebsunterteile on the guide tube, it is preferred that the Bohrantriebsoberteil and / or the Bohrantriebsunterteil has at least one locking device with an adjustable locking element. Preferably, a plurality of supporting elements, for example inwardly projecting wedges or indentations formed in the inner wall of the pipe, are provided on the guide pipe over its length, which optionally interact with the locking element to form a form-locking connection. This allows an axial fixation of the corresponding drive part at different points of the guide tube. By releasing the locking element, an axial movability of the corresponding drive part can be ensured.

The support elements are preferably arranged in the region of the linear guide on the guide tube. The adjustable locking elements on the drill drive are preferably arranged in the region of a guide element of the drill drive, which interacts with the linear guide. Preferably, a locking cylinder, in particular a hydraulic cylinder is provided for adjusting the locking element.

It is preferred in the method that the drill drive upper part of the drill drive is fixed to an upper side of the guide tube and that the drill drive lower part is guided along at least one linear guide on a tube inner side of the guide tube and moved axially together with the drill pipe. The drill head arranged on the drill string creates a bore, preferably leading the guide tube.

The pressure force of the drill head can basically be effected by the weight of the drill head and drill pipe and the optionally arranged load plates. However, it is particularly preferred that the pressing force of the drill head is controlled by means of an axial actuator, which is arranged between the Bohrantriebsoberteil and the Bohrantriebsunterteil. The axial actuator, for example, at least one hydraulic cylinder, can either increase or decrease the pressure provided by the weight of the drill string and the optionally arranged Auflastplatten pressure force. As a result, a predetermined pressure force can be selectively generated and changed during the drilling operation.

The borehole depth at a given length of the guide tube can be increased according to the invention in an advantageous manner that the drill string is telescoped or extended by inserting an intermediate piece. To insert the intermediate piece, the drill drive is pulled out of the guide tube remaining in the bottom, connected to the intermediate piece and re-introduced into the guide tube.

In a further preferred embodiment of the method according to the invention it is provided that for performing a drilling step, the drill drive lower part is extended by a defined stroke relative to the Bohrantriebsoberteil and then tracked the guide tube in the well and thereby the Bohrantriebsunterteil is retracted into the Bohrantriebsoberteil, so that a further drilling step is feasible.

In this embodiment of the method so drill head and guide tube are gradually and alternately driven into the body of water. In this case, preferably, the drill head leading the guide tube introduced into the ground. Since the guide tube thus only has to widen the borehole, the feed force is for lowering the guide tube comparatively low. After the maximum penetration depth of the guide tube is reached, the guide tube can continue to serve as a guide device for the drill drive and the drill drive can be moved along the guide tube to the lower end of the guide tube. The maximum drilling depth thus corresponds approximately to the sum of the lengths of the guide tube and the optionally extended drill string.

To create the wellbore with a fixed guide tube, the procedure is as follows: After the drill drive base moves down and the at least one hydraulic cylinder is maximally extended, the drill drive base is fixed to the guide tube and the drill drive shell detached from the guide tube and moved in the direction of the Bohrantriebsunterteil. By re-setting the drill drive shell on the guide tube and loosening the drill drive base, another drilling step can be performed. In this way, with a fixed guide tube, a bore can be made approximately with the length of the guide tube, with the drill drive upper part and the drill drive lower part being moved stepwise and alternately in the manner described. This method can be carried out independently of the position of the guide tube, that is also in the case of a guide tube which is not or not completely screwed in.

A further preferred embodiment of the method is that the drilled soil material is conveyed out of the borehole via a flushing channel in the drill pipe and ejected above the drill drive. Such a so-called Spülbohrverfahren allows a comparatively simple removal of the drilled soil material. For introducing rinsing liquid, a feed channel is provided in addition to the flushing channel.

Fig. 1

eine Seitenansicht einer Unterwasser-Bohranordnung;

Fig. 2

eine perspektivische Ansicht eines Führungsrohres;

Fig. 3

eine Querschnittsansicht des Führungsrohres aus Fig. 2;

Fig. 4

eine perspektivische Ansicht einer Bohreinheit in einer Grundstellung;

Fig. 5

die Bohreinheit aus Fig. 4 mit einem gegenüber einem Bohrantriebsoberteil ausgefahrenen Bohrantriebsunterteil;

Fig. 6

eine Schnittdarstellung der Bohreinheit aus Fig. 4;

Fig.7

eine perspektivische Ansicht eines Bohrantriebs in einer Grundstellung;

Fig.8

den Bohrantrieb aus Fig. 7 mit einem gegenüber einem Bohrantriebsoberteil ausgefahrenen Bohrantriebsunterteil;

Fig. 9

eine perspektivische Ansicht eines Bohrantriebsoberteils;

Fig. 10

das Bohrantriebsoberteil aus Fig. 9 in einer Schnittansicht;

Fig. 11

eine in einem Führungsrohr angeordnete Bohreinheit mit einem durch ein Zwischenstück verlängerten Bohrgestänge;

Fig.12

eine Bohreinheit mit einem teleskopierbaren Bohrgestänge und

Fig. 13

eine Bohreinheit mit einem durch eine Kellystange verlängerten Bohrgestänge.

The invention will be further described by means of preferred embodiments, which are illustrated in the attached schematic drawings. In the drawings shows:

Fig. 1

a side view of an underwater drilling assembly;

Fig. 2

a perspective view of a guide tube;

Fig. 3

a cross-sectional view of the guide tube Fig. 2 ;

Fig. 4

a perspective view of a drilling unit in a basic position;

Fig. 5

the drilling unit off Fig. 4 with a drill drive base extended relative to a drill drive shell;

Fig. 6

a sectional view of the drilling unit Fig. 4 ;

Figure 7

a perspective view of a drill drive in a basic position;

Figure 8

the drill drive Fig. 7 with a drill drive base extended relative to a drill drive shell;

Fig. 9

a perspective view of a drill drive shell;

Fig. 10

the Bohrantriebsoberteil from Fig. 9 in a sectional view;

Fig. 11

a drilling unit disposed in a guide tube having a drill string elongated by an intermediate piece;

Figure 12

a drilling unit with a telescopic drill pipe and

Fig. 13

a drilling unit with a drill string extended by a kelly bar.

Equivalent elements are identified in all figures with the same reference numerals.

Fig. 1 shows an underwater drilling assembly 10 according to the invention with a mountable on a body of water platform 20 and guided on the platform 20 drilling unit 50. The platform 20 includes a base body 30, which may also be referred to as a base frame. The main body 30 has a plurality of Aufstellfüße 32 for placement on the bottom of the water. The feet 32 are preferably designed to be adjustable, so that unevenness in the body of water can be compensated and the platform 20 in the desired orientation, in particular horizontally, can be placed on the bottom of the water. The main body 30 further includes a plurality of struts 34 and a central receptacle 36 for a guide tube 22. The guide tube 22 as part of the working platform 20 is adjustably mounted in the receptacle 36.

For rotating the guide tube 22 relative to the base body 30, a rotary drive 40 is provided on the base body of the working platform 20. The rotary drive 40 comprises a hydraulically tensionable collet 42, which is rotatable by means of a horizontal cylinder 44. For applying a vertical force to the guide tube 22, a vertical cylinder 46 is further provided.

An inventive guide tube 22 is in the Figures 2 and 3 shown. The guide tube 22 has at its lower end a cutting device 28 with a plurality of cutting teeth, which are arranged in a ring. The guide tube 22 has a cylindrical outer circumferential surface. On the outer circumference of the guide tube 22 a plurality of securing elements 23 for securing the guide tube 22 relative to the base body 30 are arranged.

On the inner lateral surface or inner wall of the guide tube 22, a linear guide 24 is formed, which comprises in the illustrated embodiment, three extending in the longitudinal direction of the guide tube 22 grooves. Furthermore, 22 wedge-shaped support elements 26 are provided on the inner circumferential surface of the guide tube, which can also be referred to as a locking pin, locking wedges or guide wedges. A plurality of support elements 26 are arranged at equal intervals along the longitudinal direction of the guide tube 22. In the illustrated embodiment, the support members 26 are in the region of the linear guide 24, that is in the longitudinal grooves of the guide tube 22. The radial extent of the support elements 26 is less than or equal to the depth of the formed in the guide tube 22 grooves, so that the support elements 26 not beyond the cylindrical inner lateral surface of the guide tube 22 protrude.

On the guide tube 22, a drilling unit 50 can be arranged, which in more detail in the FIGS. 4 to 6 is shown. How the particular Fig. 1 can be seen, the drilling unit 50 can be placed on the guide tube 22 via a not shown rope or at least partially inserted into this.

The drilling unit 50 comprises a drill drive 52 for driving a drill pipe 70 with a drill drive head element 51 which can be placed on the guide tube 22 and a drill drive upper part 54 which can be axially moved in the guide tube 22 and a likewise drivable drill drive lower part 56. The drill drive 52 serves on the one hand to drive the drill pipe in a rotating manner 70 and on the other hand, the axial feed of the drill pipe 70 for creating a hole in the riverbed. At the lower end of the drill string 70, a drill head 78 is arranged on which drilling tools 79 are attached. The drilling unit 50 can be equipped with drilling tools 79 of many kinds, for example, roller bits, cross cutters, both optionally with air lift, auger or drilling bucket. In the drill pipe 70, a scavenging passage 74 is formed to perform a scavenging operation.

The contact force required for drilling is applied via ballast weights, in particular load plates 76. The Auflastplatten 76 are disposed between the drill drive 52 and the drill head 78 on the drill pipe 70, in particular the so-called drill collar. The drilling unit 50 can thus also be referred to as a gravity drilling unit, in which the loading of the drill head is largely provided by gravity.

Details of the auger top 54 and auger bottom 56 are shown in FIGS FIGS. 7 to 10 shown.

Both the auger top 54 and bottom auger 56 have a central opening 53 as a passageway for the drill string 70.

The Bohrantriebsoberteil 54 includes a plurality of, in the illustrated embodiment, three guide members 58 which can be brought into engagement with the guide grooves 22 of the guide tube. Drill drive base 56 includes respective guide elements 60.

In the area of the guide elements 58, locking devices 61 are arranged on the drill drive upper part 54, with which the drill drive upper part 54 can be locked in a form-fitting manner with respect to the guide tube 22. The locking devices 61 each include an adjustable locking element 64 and a hydraulic latching cylinder 66 for actuating the locking element 64. In a corresponding manner arranged on the Bohrantriebsunterteil 56 locking devices 62 with locking element 64 and latch cylinder 66.

By means of the locking devices 61, 62 arranged on the drill drive upper part 54 and on the drill drive lower part 56, the drill drive upper part 54 and the drill drive lower part 56 can be clamped or fixed independently of one another in the guide tube 22. The locking devices 61, 62 can therefore also be referred to as clamping or tensioning devices.

The guide elements 58, 60 and the locking devices 61, 62 are respectively arranged on transverse members 55 of the drill drive upper part 54 and the drill drive lower part 56.

In order to move the bottom drill drive part 56 relative to the top drive drive part 54, an axial drive 80 is arranged between the top drive part 54 and the bottom drive drive part 56. The actuator 80 includes a plurality of, in the illustrated embodiment, three feed cylinder, which are designed as a hydraulic cylinder 82. The drill pipe 70 is axially fixedly coupled to the drill drive base 56. By moving the drill drive lower 56 relative to the drill drive upper 54, a feed force can be exerted on the drill pipe 70 and the drill head 78. As a result, the load on the drill head 78 can be controlled.

The length of the guide tube 22 does not limit the drilling depth, since the drill pipe 70 can be extended. Fig. 11 shows a drilling unit 50 arranged in a guide tube 22 with Bohrantriebsoberteil 54, Bohrantriebsunterteil 56, drill pipe 70 and drill head 78. The drill string is extended by means of an intermediate piece 72 which is disposed between the drill drive 52 and the drill head 78. Thus, the drill head 78 protrudes downwards over the guide tube 22 with the drill drive 52 arranged above in the guide tube 22. Due to the extended drill pipe 70, a greater drilling depth can be achieved.

To extend the drill string 70, the drilling unit 50 is taken out of the guide tube 22, the linkage is extended and the drilling unit 50 is again lifted into the guide tube 22.

A drilling unit 50 with a telescopic drill string is shown in FIG Fig. 12 shown. The drill pipe 70 is constructed telescopically above the load plates 76. On the outer circumference of the telescoping part of the drill string 70, there are disposed tappets or retainers 73 which engage the drill drive base 56 to axially move the drill string 70.

Fig. 13 shows a drill pipe with a kelly extension. The driver elements or retaining wedges 73 are arranged here on the outer circumference of an extendable Kelly bar 69.

In the following, a drilling method according to the invention for producing a bore in a body of water will be described.

First, the work platform 20 including guide tube 22 by means of a rope (not shown) by a arranged on the water surface support means, such as a platform or a ship, lowered and placed on the bottom of the water. The platform 20 is then aligned and can be additionally attached to the ground.

After the work platform 20 is arranged in the desired orientation at the bottom of the water, a drilling unit 50 with a drill drive 52, a drill string 70 and a drill head 78 is inserted into the guide tube 22. The drill drive upper part 54 is clamped in a form-fitting manner by means of the upper locking device 61 in the guide tube 22. The drill string 70 is rotationally driven by the auger drive 52 and a first drilling step is performed. By the drilling progress, which is controlled by the load control, the drill head 78 moves down with fixed guide tube 22 together with the Bohrantriebsunterteil 56 down to the hydraulic cylinder 82 of the feed device 80 are fully extended.

In a first embodiment of the method now drill head 78 and guide tube 22 are drilled alternately stepwise in the ground. For this purpose, when the hydraulic cylinders 82 are fully extended, the drill head 78, which hangs by means of the upper locking device 61 in the guide tube 22, again withdrawn from the bottom of the hole. The hydraulic cylinders 82 are retracted again. The Bohrantriebsunterteil 56 is by means of the lower locking means provided thereon 62 positively clamped in the guide tube 22, so that the drilling unit 50 is fixed again in the guide tube. The guide tube 22 is screwed by means of the rotary drive 40 approximately to the bottom hole. The lower locking device 62 is released, so that the Bohrantriebsunterteil 56 is again axially movable and a further drilling step can be performed.

In a further embodiment of the method, the drill head 78 is screwed into the ground in a plurality of successive drilling steps with the guide tube 22 stationary. When the hydraulic cylinders 82 are fully extended in the first drilling step, the drill drive lower part 56 is clamped in a form-fitting manner by means of the lower locking device 62 provided thereon in the guide tube 22. Subsequently, the upper locking device 61 is released and the Bohrantriebsoberteil 54 along the guide tube 22 moved down until the hydraulic cylinder 82 are retracted again. It is now again the Bohrantriebsoberteil 54 braced within the guide tube 22 and the tension of the Bohrantriebsunterteils 56 solved. Thus, a further drilling step can be performed.

Once the drill drive 52 has reached the lower end of the guide tube 22, the guide tube 22 can be sunk by operating the rotary drive 40 along the created wellbore. In this case, the drilling unit 50 is preferably withdrawn within the guide tube 22, thus preferably does not protrude downwards.

Claims (15)

Underwater drilling assembly for making a hole in a riverbed with - a submersible working platform (20) for placing on the bottom of the water, - A drill drive (52) which is arranged on the working platform (20), and a drill rod (70) with a drill head (78), which is rotationally drivable via the drill drive (52), characterized, - That the working platform (20) has a guide tube (22), on the tube inside at least one linear guide (24) is arranged, along which at least a portion of the drill drive (52) is guided axially movable, and - That the guide tube (22) in a receptacle (36) of the working platform (20) is mounted adjustable and fixable. Underwater drilling assembly according to claim 1,
characterized,
that the drill drive (52) has a drill drive upper part (54) and a drill drive lower part (56) which are axially movable relative to one another, and
in that at least the drill drive lower part (56) has at least one outwardly pointing guide element (60) which cooperates with the at least one linear guide (24) for axial guidance. Underwater drilling assembly according to claim 2,
characterized,
in that the drill drive upper part (54) and / or the drill drive lower part (56) are adjustable relative to the guide tube (22). Underwater drilling assembly according to claim 2 or 3,
characterized,
in that an axial actuating drive (80) is arranged relative to the upper drive drive part (54) for moving the lower drive part (56). Underwater drilling assembly according to claim 4,
characterized,
that the axial actuator (80) has at least one, preferably three, hydraulic cylinder (82). Underwater drilling arrangement according to one of claims 1 to 5,
characterized,
that the guide tube (22) is rotatably and axially movably mounted in the receptacle (36) and
in that a rotary drive (40) for rotating the guide tube (22) is arranged on the work platform (20). Underwater drilling assembly according to claim 6,
characterized,
that the rotary drive (40) has at least one hydraulically clampable collet chuck (42) for clamping the guide tube (22) and
that the collet chuck (42) is rotatable with at least one horizontal cylinder (44). Underwater drilling assembly according to one of claims 1 to 7,
characterized,
that the guide tube (22) on its underside, a cutter (28). Underwater drilling assembly according to one of claims 1 to 8,
characterized,
that on the drill pipe (70) above the drill head (78) Auflastplatten (76) are arranged. A method of creating a well in a body of water, in particular with an underwater drilling assembly according to any one of claims 1 to 9, wherein - a working platform (20) with a guide tube (22) sunk and placed on the bottom of the water, - In the guide tube (22) a drill string (70) with drill head (78) is arranged and guided axially, wherein by means of a drill drive (52), the drill string (70) is rotationally driven, and - That after the creation of the bore, the platform (20) with the guide tube (22) again removed from the water body and lifted. Method according to claim 10,
characterized,
that a Bohrantriebsoberteil (54) of the drill drive (52) is fixed to an upper side of the guide tube (22) and
in that a drill drive lower part (56) is guided along at least one linear guide (24) on a pipe inside of the guide tube (22) and moved axially together with the drill pipe (70). Method according to claim 11,
characterized,
that a pressing force of the drill head (78) by means of an axial actuator (80) is controlled, wherein between the Bohrantriebsoberteil (54) and the Bohrantriebsunterteil (56) is arranged. Method according to claim 11 or 12,
characterized,
in that, to perform a drilling step, the drill drive lower part (56) is extended by a defined stroke distance relative to the drill drive upper part (54) and
that then the guide tube (22) tracked into the borehole while the Bohrantriebsunterteil (56) is retracted into the Bohrantriebsoberteil (54), so that a further drilling step is feasible. Method according to one of claims 10 to 13,
characterized,
that the drill pipe (70) is telescoped or extended by inserting an intermediate piece (72). Method according to one of claims 10 to 14,
characterized,
that the drilled soil material is conveyed out of the borehole via a flushing channel (74) in the drill string (70) and ejected above the drill drive (52).

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