EP0819819A1 - Milling head,drilling device and method for underwater drilling - Google Patents

Abstract

A novel cutting head, especially taking seabed sample drillings, has two or more counter-rotating, coaxial cutting wheels. To form an approximately round borehole cross section, the wheel diameter reduces to one side. Preferably, the cutter is implemented as a full-width cutter. The cutters are oppositely-rotating, frustrated-conical wheels. Four such wheels (2) are arranged in pairs on drive plates (6), with drive motors above. Spacer plates on the head (1), co-operating with the cutter wheel teeth (5), reduce the drillings to defined maximum grain size. A suction casing extracts the particles through a suction line. Also claimed are: the drilling equipment used, including the shipboard rig; and the corresponding method of seabed drilling.

Description

The invention relates to a milling head for earth bores, a Drilling device for soil exploration, as well as a seabed drilling device and a method of drilling the seabed, which are used in soil exploration to make soil samples from a defined depth below the drilling surface to collect.

Trench wall cutters are known for earth drilling, which have two offset cutting wheel pairs parallel to the axis, which rotate in opposite directions on horizontal axes, so that the loosened soil in the space between the two Wheels are conveyed where there is a suction device is transported upwards. These trench cutters have a large-volume frame structure and are very heavy. The drilling cross section is rectangular. To support the The borehole must have a supporting liquid, for example that which is known as bentonite, in the borehole be filled in.

Such trench cutters are not suitable for exploring the ground very suitable as the support fluid to the bottom of the drill is present and there with the drilled soil mixed. A neat analysis of the composition of the Drilled soil is no longer possible. In addition the drill cross sections are unnecessarily large and the rectangular ones Drill cross-sectional shape has only moderate inherent stability of depth.

Trench wall cutters of this type are also used by one Supply vessel for ground exploration below sea level used. However, the maximum achievable Limited drilling depth. Seabed exploration such as diamond mining or finding other rare Materials are therefore often used with scrapers carried out. However, this procedure is very imprecise and not particularly powerful.

It is also known to cased the seabed To explore snails. With this procedure you can reach greater drilling depths, on the other hand allows one In principle, the auger only drills relatively soft ground.

The invention has for its object to provide a milling head, a drilling device and a seabed drilling device, and to provide a method for drilling the seabed, which enable efficient soil exploration to great depths and even with hard base material.

The task is characterized by the characteristics of the Part of claim 1 with respect to the milling head Claim 7 with respect to the drilling device, the claim 11 regarding the seabed drilling device and claim 16 with respect to the method for Seabed drilling solved. Advantageous embodiments are described in the subclaims.

By using a milling head with at least two opposing rotating coaxial milling wheels, the diameter of which is to form an approximately round cross-section after a Rejuvenate side, provides, you get one to the special Soil exploration conditions very well adapted Drilling tool.

The drilling device according to the invention provides a drilling sample which accurately reproduces the depth and the amount of the individual material work. An approximately round drilling cross-section achieves very stable conditions in the borehole. The borehole wall area is minimal in relation to the borehole volume. Accordingly, a high level of performance, ie a high yield of conveyed milling material, is achieved in the borehole shape according to the invention.
Although the drilling device can also be used on land, it is particularly suitable for use as a seabed drilling device.

A very good drilling result is achieved when the milling head is designed as a full cut milling head.

The milling head is advantageously made of rotating in opposite directions frustoconical cutting wheels formed. Through this A circular drilling cross-section can very well build up can be achieved. At the same time, the drill head has a very high drilling performance.

It is useful that four cutter wheels in pairs on gear shields are stored and hydraulic drive motors are arranged above the transmission shields.

Good conveying performance is also achieved by scraper plates on Milling head achieved through which the milled material from milling teeth on defined maximum grain size is crushable.

The comminuted milling material is suitably separated by a Suction box can be extracted via a suction line.

A drilling device according to the invention has a Milling head a tube with a roughly the same cross section corresponding cross section.

This ensures that the entire depth is secured. The Depth cannot collapse or due to slipping material be filled in again, so that a precisely definable Floor area with a defined volume can be promoted can. The evaluation of such a test bore is therefore particularly reliable. It is also this way easily possible to generate the milling feed.

Particularly good results are achieved when an inventive Milling head is used and if one is on work surface supporting the drilling surface, which the Pipe recorded with a follow-up system and in the longitudinal direction of the pipe moves, is used. In particular, the work table exercises with the follow-up system a feed force on the Milling head. This arrangement makes it easy to install and safe stabilization of the drilling device possible. Furthermore, when pulling out the drill head and the pipe the forces that occur directly on the Redirected floor surface without further components of the device to charge.

To achieve efficient operation, One massive suction line for removing and supplying the milling head and hydraulic line fixed in the pipe and the Milling head flushing water fed through the pipe. With this advantageous embodiment of the surrounding the drill head Area is a quick and reliable drainage of the Milled material guaranteed. There is also a lasting relief the milling conditions due to the good drainage of given dissolved soil. Training as a massive pipe, for example made of steel or plastic, protects against Damage from contact with sharp-edged ones Projections of the drilled bottom.

Because the area of interest is common when exploring the ground is not directly below the surface is an advantageous one Simplification of drilling operations given that a bypass valve is provided at the top of the tube, through which unneeded milled material from the suction line can be pumped out. This saves you the Effort for pumping the milling material not required by the entire suction line to the supply ship.

An advantageous use of the seabed drilling device is by mounting on a ship with one over a work tower arranged amidships arranged opening guaranteed. The lowerable part of the seabed drilling rig, which mainly comes from the milling head, the worktable and the pipe is through that Opening retractable and extendable. In the work tower it can hoisted pipe securely attached in a vertical orientation will.

Good drilling operations are achieved by going through from the ship the upper opening of the pipe to the milling head for operating the seabed drilling rig Deflection devices are guided at the work table. Thereby it is possible to use these lines relatively strongly at minimal Tension length as well as hustle and bustle in the ocean current avoid without an undesirable through these lines Force is exerted on the drill head and the pipe becomes. The lines only practice on the work table Force upwards, which is due to its high weight, however, generally no impairment experiences its orientation.

Furthermore, advantageous operation is made possible by a rope run over rollers, which the ship, the work tower, a displaceable enclosing the tube Connecting the guide part and the work table, for lowering and pulling up the lowerable part the seabed drilling device is provided. Thereby quick and precise work is guaranteed.

The vertical alignment can be carried out in a particularly advantageous manner of the pipe are taken over by the guide part, if the rope is held steadily with a relatively high tension becomes. As already described above, the work table relatively high due to its high weight exposed to upward forces without being in its alignment to be affected.

• der herablaßbare Teil der Meeresboden-Bohrvorrichtung, welcher hauptsächlich aus dem Fräskopf, dem Arbeitstisch und dem Rohr besteht, wird durch die Öffnung an dem Seil von der schiffseitigen Bergewinde auf den Meeresboden herabgelassen, wobei sich der Arbeitstisch am unteren Ende des Rohres befindet;
• der Fräskopf beginnt damit, in den Meeresboden zu bohren, wobei das Nachfaßsystem seinem Vortrieb entsprechend das Rohr nach unten nachschiebt;
• das Fräsgut wird über eine Absaugleitung zum Schiff hoch befördert;
• nach Beenden des Bohrvorganges zieht das Nachfaßsystem das Rohr aus dem Bohrloch wieder hoch;
• der herablaßbare Teil der Meeresboden-Bohrvorrichtung wird über das Seil von der schiffseitigen Bergewinde wieder auf das Schiff hochgezogen;

In procedural terms, the task is solved by the following steps:

• the lowerable part of the seabed drilling device, which mainly consists of the milling head, the work table and the pipe, is lowered through the opening on the rope from the ship's side winch onto the sea floor, the work table being at the lower end of the pipe;
• the milling head begins to drill into the sea floor, the follow-up system pushing the pipe downwards according to its advance;
• the milled material is transported up to the ship via a suction line;
• after completion of the drilling process, the follow-up system pulls the pipe out of the borehole;
• the lowerable part of the seabed drilling device is pulled up on the rope from the ship's winch back onto the ship;

This enables seabed exploration, which large and easy seabed sample volumes can promote. The process is relatively large Drilling depths possible, especially since the depth through the Pipe is secured and secure alignment through the heavy workbench supported on the sea floor given is.

Optionally, unneeded material can be cut via the bypass valve removed from the suction line at the top of the pipe without being pumped up to the supply ship have to.

The drill head is secured by the pipe throughout the operation with large amounts of trailing sea water as rinse water supplied for milling operation.

Fig. 1

eine Seitenqueransicht eines erfindungsgemäßen Bohrkopfes;

Fig. 2

eine Seitenlängsansicht eines erfindungsgemäßen Bohrkopfes entlang der Linie a-a aus Fig. 1;

Fig. 3

eine Seitenansicht eines Versorgungsschiffes mit darauf angebrachten Arbeitsturm und hochgezogenem herablassbaren Teil der erfindungsgemäßen Meeresboden-Bohrvorrichtung sowie zusätzlich auch der Seitenansicht mit quergeschnittenem Meeresboden des im Bohrbetrieb befindlichen herablassbaren Teils der erfindungsgemäßen Meeresboden-Bohrvorrichtung;

Fig. 4

eine Seitenansicht des herablassbaren Teils einer erfindungsgemäßen Meeresboden-Bohrvorrichtung;

Fig. 5

eine Draufsicht auf den herablassbaren Teil der erfindungsgemäßen Meeresboden-Bohrvorrichtung;

Fig. 6

eine perspektivische Ansicht eines Teils der erfindungsgemäßen Meeresboden-Bohrvorrichtung mit der Darstellung des Verlaufes eines Seiles.

In the following, the invention is further explained by way of example with reference to the figures. They show schematically:

Fig. 1

a side transverse view of a drill head according to the invention;

Fig. 2

a longitudinal side view of a drill head according to the invention along the line aa of Fig. 1;

Fig. 3

a side view of a supply ship with a work tower mounted thereon and the lowerable part of the seabed drilling device according to the invention, as well as the side view with the seabed of the removable part of the seabed drilling device according to the invention in drilling operation;

Fig. 4

a side view of the lowerable part of a seabed drilling device according to the invention;

Fig. 5

a plan view of the lowerable part of the seabed drilling device according to the invention;

Fig. 6

a perspective view of part of the seabed drilling device according to the invention with the representation of the course of a rope.

Figure 1 shows a milling head 1 with an approximately round cross-section. The milling head 1 is made of four pairs in opposite directions revolving frustoconical cutting wheels 2 formed, which are stored in pairs via two gear shields 6 are. The radii of the truncated cones are from the axial center of the milling head 1 starting smaller in the axial direction. The axially outer milling wheels 2 have a smaller one Diameter than the inner cutting wheels 2. they are composed of a larger, axially inner Stump of a cone that is flatter than the cone from which the stumps of the inner cutting wheels 2 are derived, and an axially outer, smaller stump of an even flatter one Cone, the small of which forms the axial termination Area much smaller than the largest diameter of the Milling head 1 is.

The drive motors (not shown) are above the cutting wheels 2. The gear shields 6 are on one Frame 7 attached, which at the end of a tube 12 (Fig. 3) are attached. The milling wheels 2 run in pairs in opposite directions, since each two cutter wheels 2 driven by a gear are, as shown in EP 0 167 090. An emerging torque around the drilling axis is caused by the firm locking of the tube 12 in the circumferential direction in the Depth compensated. On the circumference of the cutting wheels 2 are in the circumferential direction evenly spaced Milling teeth 5 formed, which the area of effect of Milling head 1 except for the boundary line dashed in Figure 1 8 enlarge.

A milling tooth 5 is shown as an example in FIGS. 1 and 2. FIG. 2 also shows a scraper plate 4, which crushes the milled material to a defined maximum grain size. The milled material is through a suction box 3 and Suction line 28 aspirated.

As FIG. 3 shows, a ship 11 is used as a surface-water operations control device provided that a work tower amidships 16 carries, which over an opening 18 in Longstrip is arranged. Through this opening 18 can the lowerable portion of the ocean floor drilling rig, which mainly from the milling head 1 (not shown), the tube 12 and a work table 13, on one Rope 26 can be lowered. Figure 3 shows this part in Rest position and in working position, namely both in the raised position Position, the tube 12 in a vertical orientation is fixed in the work tower 16, as well as in lowered Position, the tube 12 through a follow-up system 14 relative to the work table 13 to the maximum drilling depth is pushed down.

The follow-up system 14 consists of hydraulically driven and in the radial direction and in the axial direction of the tube 12 adjustable brackets. These grip the circumference of the tube 12 and move it in the axial direction. The brackets are counteracted with the hydraulic drive in the radial direction the tube 12 pressed so that it is displaceable on the circumference of the tube 12 abut. The brackets are about evenly distributed over the pipe circumference, so that no resulting Radial moment on tube 12 works. The clamps are used to move the tube 12 hydraulically driven in the axial direction of the tube 12, taking the tube 12 with it and relative to it Move work table 13. If the tube 12 relative to Work table 13 can be moved further than the maximum stroke of the brackets in the axial direction, the brackets loosen when reaching the maximum stroke in the axial direction of the Tube 12 will then be in the opposite direction retracted and then take the tube 12 again by moving in a radial direction. Then take the clamps the tube 12 in turn in the desired direction of movement With.

The tube 12 has a the drilling diameter of the milling head 1 corresponding diameter. Serves during drilling operations via the follow-up system from the work table 13 to the pipe 12 transmitted force in the axial direction of the tube 12 as Feeding force for the milling head 1. Especially when drilling the seabed leads the pipe 12 to improved drilling conditions, because the depth is due to the highly flowable components of the sea floor always exposed to danger is to be buried. Since the tube 12 has no protrusions has and is relatively smooth-walled, its introduction into the depths with relatively little effort possible. Through the tube 12, the milling head 1 is on a kept straight drilling direction. This makes it possible test drilling in precisely defined areas. The milling head 1 and the tube 12 are firmly connected. The tube 12 thus also fulfills a supporting function for the milling head 1. The pipe cross-section is about circular drilling cross section of the milling head 1 adapted. This cross-sectional shape ensures the stability of the pipe 12 very high against indentation or bending.

At the top of the tube 12 there is a bypass valve 15, through which unneeded milled material from the suction line 28 can be pumped out. With this bypass valve 15 it is possible, for example, to cut the milled material the first section of the hole has been drilled out and only the milled material from a greater drilling depth comes to convey up to ship 11. After the end Drilling process, the tube 12 with the milling head 1 through Follow-up system 14 pulled up relative to the work table 13 again. Typical withdrawal forces correspond to the order of magnitude from 500 to 1000 tons. However, these are not included in the Rope 26 initiated between ship 11 and work table 13. Only after the tube 12 is completely relative to the work table 13 has been pulled up, the rope 26 by one recovery winch 25 on the ship side (see FIG. 6) rolled up.

Figures 4 and 5 show the tube 12, on the lower End of the milling head 1 is (not shown). The Tube 12 is via the follow-up system 14 with the work table 13 connected. The pipe diameter is typically around 2 Meters, the pipe length a maximum of about 30 meters. The weight the work table 13 is 120 tons. However, there are larger dimensions can also be implemented. The work table 13 and the tube 12 are via a gimbal 27 connected to one another even with sloping seabed to be able to drill vertically. A hydraulic line 20 and the suction line 28 run from the milling head 1 from upwards inside the tube 12, at the upper end the tube 12 out of this, then parallel to the tube 12th down to deflection devices, which are off at the work table 13 attached pulleys 17 exist, and then further up to the ship 11. The tube 12 also forms one Flushing water line for the flushing water supply to the milling head 1. Inside the tube 12 and on the semicircular Deflection parts at the top of the pipe are the hydraulic line 20 and the suction line 28 designed as metal pipes, because they do not have to be twistable there.

Also located within the upper part of the tube 12 a height adjustment 30 for a guide member 24, which encloses the tube 12.

As FIG. 6 shows, the rope 26 runs from the ship's side Recovery thread 25 on a role on a ship side Work tower upper part 23 through an opening of the guide part 24 to two roles on the work table 13, then again through the guide part 24 to the ship's side Work tower upper part 23, then again to the work table 13 and finally back to the upper part of the work tower 23, on which the rope end is fixed. At the Drilling on the seabed is the distance between the ship-side work tower upper part 23 and the guide part 24 strongly compared to the situation shown in Figure 6 enlarged. For example, the device in FIG a water depth of up to about 200 to 300 meters this The distance then corresponds approximately to the distance between the ship-side work tower upper part 23 and the guide part 24th

The guide part 24 is relative in its height setting adjustable to the tube 12 by means of the height adjustment 30. The height adjustment 30 serves to guide the guide part 24 tube 12 completely raised into the work tower 16 lower. The tube 12 protrudes in a fully raised position Condition the height of the work tower 16 and thus also the height of the ship-side upper part of the tower 23, so that the guide member 24 no longer at the upper end of the Tube 12 can be located. When tube 12 is lowered the guide member 24 generally as far up as possible Pipe 12 to with the relatively high tension Rope 26 to achieve good vertical guidance for the tube 12. The height adjustment 30 consists of two diametrically oppositely arranged deflection rollers 31 on the upper Edge of the tube 12. Inside the tube 12 are close to that upper edge under the two pulleys driven winches 32 (only one winch 32 is shown). From from these a rope goes over the guide roller 31 the outside of the tube 12 down to one each next to the pipe 12 attachment point on the Guide part 24. The guide part 24 is opened and closed Unrolling the ropes of the height adjustment 30 in the axial direction shifted relative to the tube 12.

Below is the function of the seabed drilling rig described using an example. The ship 11 drives over a part of the seabed that explores shall be. The seabed drilling device is in motion pulled up and is in work tower 16. When the ship 11 is stationary and aligned, the lowerable part of the seabed drilling rig by the Opening 18 from the work tower 16 into the water to the Lowered seabed. The work table 13 is located during this process at the lower end of the tube 12. He arrives first on the sea floor and takes due to its high weight, a stable alignment a.

Between the ship 11 and the lowerable part are now the rope 26, the hydraulic line 20 and the suction line 28 excited. The rope 26 runs on the tube 12 through the Guide part 24, which after the tube 12 the work tower 16 left had moved to the top of the tube 12 has been. This is due to the relatively tight rope 26 a vertical alignment of the tube 12 through the Guide part 24 guaranteed. The rope 26 can be relative be very excited without the heavy work table 13 takes off. An uneven seabed can be sloping despite overlying work table 13 a vertical orientation of the Tube 12 can be maintained because these two parts with the gimbal 27 are connected.

Next the actual drilling operation is started, by rotating the cutting wheels 2. The Milling wheels 2 rotate against each other in pairs. The Milled material is gripped by the milling teeth 5 and by the Scraper plates 4 crushed. The shredded milled material is sucked through the suction box 3 and through the suction line 28 and transported up to the ship 11. It is caught there and analyzed.

The drilling feed of the milling head 1 is through the follow-up system 14 accomplished on the work table 13, which the tube 12 corresponding to the drilling rate down shifts. During the drilling process, the hydraulic line 20 drive energy to the milling head 1 and Sea water supplied for rinsing through the tube 12. Optional can be a part of the milled material through the bypass valve 15 on removed the upper end of the tube 12 from the suction line 28 without having to be carried up to ship 11. The maximum drilling depth is due to the length of the tube 12 fixed. The tube 12 from the Nachfaßsystem 14 on his detected at the upper end, the maximum drilling depth is reached and the tube 12 is moved upwards again by the follow-up system 14. After that, the lowerable part of the seabed drilling rig from the rope 26 back to the ship 11 in the Work tower 16 pulled up. The drilling process is finished and the ship 11 can leave the drilling site again.

Claims (18)

Milling head
characterized by
at least two counter-rotating coaxial milling wheels, the diameter of which tapers to one side to form an approximately round cross-section. Milling head according to claim 1
characterized by
that it is designed as a full cut milling head. Milling head according to one of the preceding claims,
characterized by
that it is formed from counter-rotating frustoconical cutting wheels (2). Milling head according to one of the preceding claims,
characterized by
that four cutting wheels (2) are mounted in pairs on gear plates (6) and the drive motors are arranged above the gear plates (6). Milling head according to one of the preceding claims,
characterized by
Scraper plates (4) on the milling head (1), through which the milled material can be reduced to a defined maximum grain size in cooperation with milling teeth (5) on the milling wheels (2). Milling head according to one of the preceding claims
characterized by
a suction box (3) through which shredded milled material can be extracted via a suction line (28). Drilling device with a milling head
characterized by
a pipe (12) arranged above the milling head (1) and having a cross section corresponding approximately to the drilling cross section, which secures the entire depth and via which the feed for the milling head (1) is generated. Drilling device according to claim 7
characterized by
a milling head (1) according to one of claims 1 to 6 and a work table (13) which is supported on the drilling surface and which grips the tube (12) with a follow-up system (14) and supports it so that it can be moved in the drilling direction. Drilling device according to one of claims 7 or 8
characterized in that
through the tube (12) a suction line (28) and hydraulic line (20) which supply the milling head (1) with drive energy or suck the milling material, and that the milling head (1) through the tube (12) can be supplied with rinsing water . Drilling device according to one of claims 8 or 9
characterized by
a bypass valve (15) at the upper end of the tube (12) through which unneeded milled material can be pumped out of the suction line (28). Drilling device according to claim 10,
characterized by
use for seabed drilling. Seabed drilling apparatus according to claim 11,
characterized by
mounting on a ship (11) with a work tower (16) arranged above an opening (18) arranged amidships, the lowerable part of the seabed drilling device being able to be lowered through the opening (18). Seabed drilling apparatus according to claim 12
characterized by
that from the ship (11) through the upper opening of the tube (12) to the milling head (1) extending lines (20, 28) for the operation of the seabed drilling device are guided on the work table (13) deflection devices (17). Seabed drilling apparatus according to one of claims 12 or 13,
characterized by
a rope (26) guided over rollers, which connects the ship (11), the work tower (16), a displaceable guide part (24) enclosing the tube (12) and the work table 13. The seabed drilling apparatus of claim 14
characterized by
that the cable (26) is kept under tension to guide the tube (1) with the guide part (24). Method for drilling the seabed with a seabed drilling device according to one of claims 11 to 15,
characterized by
the following steps: the lowerable part of the seabed drilling device, which mainly consists of the milling head (1), the work table (13) and the pipe (12), is opened through the opening (18) on the rope (26) by the ship-side recovery thread (25) lowering the sea floor with the work table (13) at the lower end of the tube (12); the milling head (1) begins to drill into the seabed, the follow-up system (14) pushing the pipe (12) downward according to its propulsion; the milled material is conveyed up to the ship (11) via a suction line (28); after completion of the drilling process, the follow-up system (14) pulls the pipe (12) out of the borehole again; the lowerable part of the seabed drilling device is pulled up again by the rope (26) from the ship's side winch (25) onto the ship (11). A method of drilling the seabed according to claim 16
characterized by
that milled material that is not required is removed from the suction line (28) via a bypass valve (15) at the upper end of the tube (12) without having to be pumped up to the ship (11). Method for drilling the seabed according to one of claims 16 or 17,
characterized by
that the milling head (1) during the drilling through the pipe (12) trailing sea water is fed as rinsing water.

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