DE102005058952A1 - Hydraulic heave compensation device for marine engineering, has compensation system with hydropneumatic storage supporting load and active cylinder device integrated in hydropneumatic storage - Google Patents

Abstract

The device has a compensation system (4) including a hydropneumatic storage (6) supporting a load and an active cylinder device (8) staying in working connection with the storage. The cylinder device includes two control spaces, which are loaded with pressure to actuate the cylinder device. The cylinder device is integrated in the hydropneumatic storage, and a common piston arrangement is accommodated in a common cylinder housing.

Description

The The invention relates to a hydraulic sea state compensation device according to the generic term of claim 1.

such Seegangskompensationseinrichtungen be, for example, in the Marine technology used when a load from a ship to an am Seabed supported Object, for example, a platform to be discontinued, wherein For example, a crane is arranged on the ship. In reverse The crane can also work on a platform supported on the seabed be arranged so that the load on a ship or a corresponding Floating object is sell. A similar task lies Also, for example, if a drill string from a floating Platform is lowered off and these are raised by the sea and lowered. In research, for example, heavy Measuring device or supply stations for Robots or the like from a ship over a winch to great depths lowered, causing by the sea, the holding cable considerable Tensile loads is exposed. In some applications it can too occur that both the target object and the load due of the sea run movements, but then in principle the same conditions as in the above Cases exist.

The The movements of the load caused by the sea are to be controlled by sea state compensation devices be compensated, which ensure that the relative position of the load to the target object substantially is kept constant.

In the US 3,946,559 there is disclosed a sea state compensation device (Heave Compensation System) in which the load, in the present case a drill string, is attached to an actuator embodied as a cylinder, which in turn is mounted on a ship or platform. A pressure chamber of the actuator is subjected to the pressure of a passive hydropneumatic accumulator, which has a piston, via which a gas space is separated from a pressure medium space. The piston can be moved by means of an active cylinder. This has two control chambers, which can be acted upon in response to a control signal via a control valve device and a pressure medium source with a flow to control the change in position in the actuator. A similar solution is also in the US 5,209,302 disclosed. In such systems, the hydro-pneumatic accumulator compensates for the static load while compensating for the position and pressure changes due to the sea via the active cylinder. It has been shown that such systems have a much better sea state compensation behavior than systems in which the static load is supported only by a comparatively simple passive system (hydropneumatic accumulator).

At the subject of US 3,946,559 If the load (drill string) is held by a linear actuator (actuator) - in principle, the load can also be held by a winch, in which case the winch must be appropriately controlled in order to compensate for the sea state. For example, in the region between the winch and the load, a hydraulically displaceable roller may be arranged, which is moved in dependence on the sea state, in order to keep the position of the load to the target object constant. Such solutions are described, for example, in the publication "Efficient Heave Motion Compensation For Cable-Suspended Systems" (www.oceanworks.cc).

One Problem exists in the known solutions in that the systems are comparatively complex and have a lot of space.

Of the Invention is based on the object, a sea state compensation device to create, with a simple structure, a reliable compensation of sea-induced movements.

These Task is by a hydraulic sea state compensation device solved with the features of claim 1.

According to the invention Seegangkompensationseinrichtung (Heave Compensation System) Compensation system, which in principle consists of a hydropneumatic Memory (passive cylinder) and an active cylinder device consists. The active cylinder device is in the hydropneumatic accumulator integrated, wherein a common piston assembly within a common cylinder housing is arranged. Through the two outer piston bottom surfaces and the adjacent housing end faces becomes each limited to a pressure chamber, one of which is preferably a Gas space of the hydropneumatic accumulator is.

In the prior art according to the US 3,946,559 on the other hand, the active cylinder device is attached to the hydropneumatic accumulator, so that such a solution requires considerably more installation space and device complexity.

The Unit of hydropneumatic accumulator with integrated therein active cylinder device can be in operative connection with a linear actuator (hydraulic cylinder) or operate a winch, of which the load is held.

at The first alternative thus becomes the load of the hydraulic cylinder executed actuator supported in the support direction the load effective pressure chamber over a pressure line connected to the second pressure chamber of the common cylinder housing is. This working space forming a pressure chamber and the above mentioned Gas space then form the two end portions of the common cylinder housing.

The in this common cylinder housing guided piston assembly has two the piston bottom surfaces forming piston collars, which are connected by a piston ridge. This penetrates sealingly a partition wall of the cylinder housing, so that through the ring end faces the piston collars on the one hand and the housing partition on the other hand the two control rooms the active cylinder device are formed.

to Sealing these two control rooms with each other and the control rooms to the adjacent gas space or working space are on the outer circumference the collars and in the passage opening of the housing partition Arranged seals.

at the second alternative mentioned above is the load on a winch supported. This is preferably over a hydraulic motor driven, the pressure side with a working space of the cylinder housing is connected, so that a pressure medium connection between the hydraulic motor and the active cylinder device.

The Unit of hydrodynamic storage and active cylinder device has in this embodiment Preferably, a piston assembly with two end piston collars and a middle ring collar that over two piston webs are connected to each other. Each of these Piston web passes through a housing partition of the cylinder housing, so next to the two outside lying cylinder chambers (one of which is the gas space) in the cylinder housing by two adjacent Ring faces the above-described piston collars and the intermediate housing partition, the two control rooms the active cylinder device and the other two annular end faces of the piston frets as well as the intermediate housing partition of the working space and another working space are formed.

According to the above Finishes are frontally in the cylinder housing a gas space and another pressure chamber limited, the latter can in a preferred embodiment be subjected to ambient pressure.

Of the provided for driving the winch hydraulic motor can in a closed or open pressure medium circuit to be performed.

in the the former case (closed pressure medium circuit) is the Hydromotor over a variable displacement pump driven by a motor supplied with pressure medium, wherein a suction port of the pump via a Suction line with a low-pressure connection of the hydraulic motor as well a pressure connection of the pump over a high pressure line connected to a pressure port of the hydraulic motor is. In this embodiment the high pressure line is over a pressure line with the former working space and the suction line via a Low-pressure line connected to the other working space, so that the hydraulic motor optional or superimposed over the Pump or workrooms can be supplied with pressure medium.

Either the frets the common piston and the piston webs can with be executed different diameters.

to Hedging can be done in the pressure line between the pressure chamber of the Actuator (hydraulic cylinder) and the working space of the cylinder housing or between the working space and the pressure line of the hydraulic winch drive a fast switching shut-off valve (Isolation Valve) be arranged so that the connection between the actuator or the winch drive and the compensation system (hydropneumatic Memory / Aktivzylindereinrichtung) are interrupted in no time can.

The Piston assembly may be in one piece or be formed of a plurality of pistons.

other advantageous developments of the invention are the subject of further Dependent claims.

in the The following are preferred embodiments of the invention explained in more detail with reference to schematic drawings. Show it:

1 a hydraulic sea state compensation device for a load held on a linear actuator;

2 a sea state compensation device for a load held on a winch and

3 a concrete application of the sea state compensation device according to 1 at a drilling device.

1 shows a functional diagram of a sea state compensation device (Heave Compensation System) 1 in which a load L by means of a hydraulic cylinder 2 executed linear actuator is movable. It is assumed that this hydraulic cylinder 2 is stored stationarily on a ship or a floating platform and the load L is to be held in a predetermined relative position with respect to a fixed target object, for example a platform supported on the seabed. The compensation of the static load and the sea state takes place via a dot-dash line indicated compensation system 4 with hydropneumatic accumulator, over which the hydraulic cylinder 2 is controllable such that the load L retains the predetermined relative position to the target object.

The designed as a differential cylinder hydraulic cylinder 2 has a differential piston 35 that is the hydraulic cylinder 2 in a penetrated by the piston rod annulus 36 and a bottom-side cylinder space divided. At least the annulus 36 is via a pressure medium supply, not shown, for extending and retracting the piston rod 39 connectable to a pump or tank to raise or lower the load L. Such a linear drive is designed only for relatively small strokes.

The compensation system 4 consists essentially of a hydropneumatic accumulator 6 and an active cylinder designed as a synchronous cylinder 8th which is integrated in the hydropneumatic stores. The unit of hydropneumatic accumulator 6 and active cylinders 8th is called active storage. The hydropneumatic accumulator 6 is designed so that it is able to support the load L static, ie without supporting the dynamic changes due to the sea state, while the active cylinder is intended to compensate for the dynamic alternating loads such as friction and other parasitic factors and a position control of the load to allow high speed.

The one from the store 6 and the active cylinder 8th existing active storage has a common cylinder housing 10 in which a piston 12 is guided axially displaceable. This has two outer piston collars 14 . 16 passing through a piston ridge 18 connected to each other. This passes through a housing partition 20 of the cylinder housing so that this through the bottom of the piston collar 16 in a gas room 22 and the bottom of the piston collar 14 in a workroom 24 is divided. Through the annular end face of the piston collar 16 and the partition 20 becomes a first control room 26 and through the annular end face of the piston collar 14 and the housing partition 20 a second control room 28 limited. In the area of carrying out the piston rod 18 through the housing partition 20 and on the outer circumference of the two piston collars 14 . 16 are in the illustration according to 1 not shown arranged seals over which the aforementioned spaces of the cylinder housing are separated from each other. The gas space 22 is over a gas pipe 30 with a gas storage 32 connected so that on the bottom surface of the piston collar 16 the gas pressure acts. The two control rooms 26 . 28 are connectable via terminals A, B with a control valve means described in more detail below and a pressure medium source or a tank, so that the annular end face of the piston federal 16 or the annular end face of the piston collar 14 Active pressure is applied to the piston 12 depending on the movement of the load L to move. The terminals A, B can also be short-circuited to put the active cylinder in "clearance"; then the system works as a passive memory.

The workroom 24 is via a pressure line 34 with an annulus 36 of the hydraulic cylinder 2 In order to prevent shock loads when lifting loads from a moving location (eg deck of a ship at sea), in the pressure line 34 a dashed line indicated fast switching shut-off valve 38 be provided, via which the oil side of the active reservoir from the hydraulic cylinder 2 is separable. About this shut-off valve 38 The memory function can also be disabled.

In the embodiment according to 1 thus becomes the passive hydropneumatic storage through the gas storage 32 , the gas space 22 and the workroom 24 formed while the active cylinder through the two annular control chambers 26 . 28 is formed by the housing partition 20 are separated from each other and can be acted upon via the terminals A, B with pressure medium.

It is now assumed that the load L due to the seaway relative to the cylinder housing supported on the ship 2 to the right (view after 1 ) emotional. As a result, pressure medium from the annulus 36 via the pressure line 34 in the workroom 24 displaced, leaving the piston 12 of the active storage in the illustration according to 1 is moved to the left, the pressure in the gas space 22 and thus in the gas storage 32 the displacement of the load L counteracts. In the case where the two working ports A, B are connected to each other, the active reservoir acts as a passive, conventional hydro-pneumatic accumulator. The load position is not directly influenced here.

In the case where the compensation control is active, the control rooms can 26 and 28 in 1 be acted upon via the connections A and B with pressure medium. By the displacement of the piston 12 to the left or right is the workspace 24 actively increases or decreases, so that the pressure medium from the annulus 36 overflowed and the load L maintains its desired relative position. The regulation of the pressure medium supply and pressure medium discharge to and from the two control chambers 26 . 28 is done so that the load L moves according to a predetermined speed profile or held in their relative position.

In the 1 shown solution shows compared to the above-mentioned prior art, in particular the US 3,946,559 considerable advantages. Thus, in the prior art four seals are required (two on the piston collars, one on a partition wall and a fourth on the passage of a piston rod of the piston through the end face of the active cylinder housing), while in the 1 shown solution only three seals (piston collars 16 . 14 and partition 20 ) must be provided. Since no piston rod projects out of the cylinder, the solution according to the invention also builds up considerably shorter. The piston is guided in the prior art along four sliding guides (two piston collars, passage through housing bulkhead and passage through the active cylinder face), while the in 1 illustrated embodiment, only three sliding guides (piston collars 14 . 16 , Housing partition 20 ) are provided. Another advantage is that in the prior art according to the US patent an external movable part (piston rod) is provided, while in the solution according to 1 the active storage device does not require any external moving parts.

The above-described embodiment with a linear drive is designed for comparatively small paths of the load L. In the event that the load L is to be moved over long distances, a winch is used instead of a linear drive. Such an embodiment is in 2 shown.

In this case, the load L by means of a winch 40 moves, via one or more hydraulic motors 42 is driven. In the illustrated embodiment, the hydraulic motor 42 arranged in a closed circuit and is powered by a motor M variable 44 supplied with pressure medium. Here is a pressure port P of the variable 44 via a high pressure line 47 with a pressure port P 'of the hydraulic motor and a suction port S of the variable 44 via a suction line 49 with a low pressure port T of the hydraulic motor 42 connected.

Of course, instead of the closed circuit and an open pressure fluid circuit can be used, wherein the variable pressure fluid from a tank T sucks and the pressure medium via the low pressure port T of the hydraulic motor 42 is returned to the tank T.

The compensation system 4 In essence, it consists of a hydropneumatic accumulator 6 and an active cylinder designed as a synchronous cylinder 8th , which in turn are implemented as a unit (active storage). In the common cylinder housing 10 is a piston 12 guided, in the illustrated embodiment, for example, two outer piston collars 14 . 16 as well as a middle ring collar 46 having. The ring collar 46 and the piston collar 14 are from a first piston ridge 48 and the ring collar 46 and the piston collar 16 via a second piston bridge 50 connected to each other, for example, this has a smaller diameter than the first piston land 48 Has. The piston bridge 48 passes through a first housing partition 52 and the second piston land 50 passes through another housing partition 54 , Through the pistons with three collars 12 becomes the cylinder housing 10 thus divided into six pressure chambers, the in 2 right pressure chamber of the gas space 22 is. The two control rooms 26 . 28 are through the housing partition 52 and the ring collar 46 or the piston collar 14 limited. Another workspace 56 is through the other housing wall 54 and the middle ring collar 46 as well as the work space 24 through the housing partition 54 and the right piston collar 16 limited. The gas space 22 is like the above-described embodiment via a gas line 30 with the gas storage 32 connected so that the gas pressure on the bottom surface of the piston collar 16 acts. Through the bottom surface of the other piston collar 14 and the inner end surface of the housing 10 becomes a space 58 limited, the z. B. connected to the environment or the low-pressure room or can be completed.

According to 2 is the workspace 24 via the pressure line 34 with the high pressure line 47 and the other workspace 56 via a low pressure line 60 with the suction line 49 connected. In the low pressure line 60 and / or the pressure line 34 can turn fast closing shut-off valves 38 be provided. Through these check valves 38 For example, the transmission of shock loads that may occur when picking up a load from a moving deck, for example, can be prevented. About the shut-off valves 38 The memory function can also be disabled.

The two control rooms 26 . 28 can be in turn, as in the above embodiment via the terminals A, B and a control valve assembly, not shown, connect to a pressure medium source or a tank to perform an active position control of the accumulator piston, and thus the load.

For lifting or lowering a load under normal operating conditions, ie without sea state compensation, these two ports A, B are closed and / or the shut-off valves 38 closed, leaving the active cylinder 8th is ineffective and the speed and direction of rotation of the winch by the tilt angle of the variable 44 is predetermined.

In the case where no lifting or lowering of the load is required but sea state compensation is required to hold the load in a predetermined relative position to a target object, the variable displacement pump will assist 44 no pressure fluid to the hydraulic motor 42 , The piston 12 However, the regulation of the active cylinder 8th shifted depending on the vertical movement of the ship, so that accordingly from the work spaces 24 or 56 Pressure medium to the engine 42 is guided so that this the winds 40 drives accordingly to allow the compensation movement. The load L due to the pressure in the hydropneumatic accumulator 6 supported. The active cylinder must apply pressure differences due to gas characteristics, friction and dynamic influences.

In the case in which the sea state compensation should be carried out simultaneously to a raising or lowering of the load Runaway - this is the most common application - superimposed on the control of the variable 44 the activation of the active storage (active cylinder 8th Hydro-pneumatic storage 6 ) and vice versa.

As mentioned above, the gas pressure should be designed so that it can support the load. In the case in which very different loads are to be handled, it may be advantageous if the gas pressure in the gas storage 32 is variable depending on this load. For this purpose, for example, a compressor with the associated control devices for adjusting the gas pressure should be provided.

Alternatively or additionally, the adjustment of the compensation force to the load to be handled can also take place in that the hydraulic motor 42 the winch 40 is designed with a variable displacement volume or that several hydraulic motors 42 be connected in parallel with variable displacement. The displacement volume is then adjusted as a function of the load, wherein the pressure at the gas side of the active storage, ie the pressure in the gas space 22 and in the gas storage 32 can be kept constant, so that no separate compressor and no gas pressure regulating device are required.

The pump 44 and the hydraulic motor 42 containing hydraulic circuit is still running with all conventional devices, such as pressure relief valves, rinse cycle, coolers, filters, as used in conventional closed circuits. Leakage can be compensated in the same way as conventional systems.

In principle, the functions of the individual pressure chambers of the active storage can be exchanged. For example, the control room 28 with the workspace 24 be reversed.

In the above-described embodiment, the piston 12 executed in one piece, in principle, this piston could also be designed in several parts.

3 shows a concrete application of in 1 illustrated seaway compensation device for a load L forming the drill string, wherein a drill head of a ship 62 should be discharged to the seabed, for example, to take a seabed sample or to drill for oil. In the concrete embodiment is a hydraulic cylinder assembly 2 formed by two or more parallel hydraulic cylinders, wherein the piston rods 39 at one on the ship 62 supported drilling rig 64 stored and the load L (drill string) is attached to the vertically displaceable cylinders. At the drill rig 64 is a laser measuring device in the illustrated embodiment 66 arranged, over which the position of the ship is detectable. The position of the cylinders 2 is about transducers 68 detected.

3 shows the essential components of the control unit for controlling the active cylinder 8th over which the movements, or the pressure fluctuations on the hydraulic cylinders 2 be actively compensated because of the sea. As related to 1 mentioned, the load L, ie the weight of the cylinder and the drill string through the hydropneumatic accumulator 6 statically supported by the gas pressure in the gas space 22 and thus in the gas storage 32 is set accordingly. The setting of the gas pressure in the gas storage 32 via a gas pressure regulating unit 70 about which the gas storage 32 with a reserve store 72 is connectable, in turn, via a compressor assembly 74 can be charged. Of course, the gas storage 32 also directly via the compressor unit 74 and the gas pressure regulating unit 70 be charged, the gas pressure in Depending on the weight of the drill string and possibly the sea state is changeable.

The pressure medium supply of the active cylinder 8th , the hydraulic cylinder 2 and the workspace 24 via a variable pump 76 sucked via the pressure fluid from a tank T and into the pressure line 34 can be promoted. This pressure line 34 is over a lift valve 78 with one with the pump 76 connected pump line 80 and a sink valve 82 with a tank line connected to the tank T. 84 connectable. Both valves 78 . 80 are preloaded biased in a locked position. The lifting valve 78 is a switching valve, while the lowering valve 82 a continuously adjustable directional control valve is in which a drain aperture is proportionally adjustable.

From the pump line 80 branches a supply line 86 and from the tank line 84 a drain line 88 to two input ports P, T of a proportionally adjustable active storage control valve 90 to lead. Two working connections A, B of the active storage control valve 90 are via a supply line 92 and a drain line 94 with the working ports A and B of the active cylinder 8th connected. The supply line 92 and the drain line 94 can have a bypass valve 97 be switched short, so that the active cylinder 8th then it is ineffective and the memory 4 only works as passive storage. Via the proportionally adjustable active accumulator control valve 90 can the two control rooms 26 . 28 of the active cylinder 8th be acted upon by pressure medium or connected to the tank T as a function of the ship's movement. The active storage control valve 90 is executed in its spring-biased basic position with a floating position and can be adjusted via proportionally adjustable electromagnets so that either the control room 26 or the control room 28 with the variable pump 76 is connected, while the pressure medium is displaced from the other pressure chamber to the tank T out.

The filling of the working space 24 hydropneumatic accumulator 6 and the annuli 36 the hydraulic cylinder assembly 2 via a filling control valve 96 , Its only working port A via a filling line 98 with a connection line 100 between the workspace 24 and the pressure line 34 connected is. In this connection line 100 is the above-described check valve 38 arranged over which the connection between the work space 24 and the hydraulic cylinder assembly 2 can be shut off or opened. A pressure port P of the filling control valve 96 is via a pump branch line 102 with the pump line 80 and a tank port T of the filling control valve 96 over a tank branch line 104 with the tank line 84 connected, in the further still facilities for cooling, filtering, etc. of the pressure medium are provided.

To the better understanding Below is the lowering and catching up a drill head explained.

In a first preparatory phase of the hydropneumatic storage 6 initially moved to a starting position and the gas pressure in the gas space 22 adjusted as a function of the weight of the drill string, this setting being adjusted in proportion to the expected weight to be lowered minus the desired feed force acting on the drill head. This setting of the active storage 8th via the filling control valve 96 about which the workroom 24 is supplied with pressure medium, while the check valve 38 , the lifting valve 78 , the drain valve 82 are closed and the bypass valve 97 is open, leaving the two control rooms 26 and 28 of the active cylinder 8th are connected.

In a second phase, the drill head is lowered to the seabed. The shut-off valve remains 38 closed and the valves 78 and 82 are used to retract and extend the hydraulic cylinder assembly 2 to facilitate the assembly of the drill string and to lower the drill bit. The hydraulic cylinder assembly 2 should be set with lowered drill head so that there is still enough travel path for sea state compensation remains. During this lowering process, the pressures in the gas space 22 and in the workroom 24 still according to the filling valve 96 or the gas pressure control unit 70 adjusted to balance the weight of the drillstring.

At the moment when the drill head reaches the seabed, a passive sea state compensation is first switched on, wherein the load pressure of the hydraulic cylinder arrangement 2 is detected. During this passive control the valves become 78 . 82 moved to its locked position, the active storage control valve 90 is still in its home position and the check valve 38 it is open. The active storage 8th is still ineffective as the bypass valve 97 still remains in its passage position.

• 1. Beim sogenenannten Normalbohren wird der Bohrdruck passiv "geregelt". Es werden Bohrdruckschwankungen aufgrund der Schiffsbewegungen und deshalb Zylinderbewegungen und Speicherkolbenbewegungen sowie Gasdruckschwankungen bewußt zugelassen. Bei dieser Bohrart ist der Aktivzylinder kurzgeschlossen, in dem das Bypassventil 97 in seine Durchgangsstellung und das Aktivspeicherregelventil 90 in seine Neutralstellung (Auf) gebracht werden.
• 2. Beim "verbesserten Normalbohren" werden die Bohrdruckschwankungen und entsprechend Drehmoment- und Drehgeschwindigkeitsschwankungen und der Bohrkopf verschleiß sowie ein Bohrkopfabheben reduziert oder weitestgehend vermieden, in dem der Druck im Arbeitsraum 24 oder, bevorzugt, im Ringraum 36 konstant gehalten wird. Dies erfolgt durch eine Druckregelung des Aktivzylinders 8, wobei das Bypassventil 97 in seine Sperrstellung gebracht wird und das Aktivspeicherregelventil 90 auf der Basis eines geeigneten Regelprozesses so angesteuert wird, dass der Druck in den genannten Druckräumen 24 oder, 36 praktisch konstant bleibt.
• 3. Beim sogenannten "Kernbohren" werden mit einem am Bohrstrang befestigten Sondergerät Bodenproben gebohrt. Bei diesem Vorgang müssen die Positionen mit relativ hoher Genauigkeit geregelt werden, um den Seegang und eventuelle Schiffsbewegungen zu kompensieren. Das Gesamtgewicht des Bohrstrangs wird, wie bereits erläutert, in etwa durch den Gasdruck im Gasraum 22 kompensiert. Die Position der Hydraulikzylinder 2 wird durch den Aktivzylinder 8 so geregelt, dass die Schiffsbewegung kompensiert wird, dabei befindet sich das Bypassventil 97 in seiner Sperrstellung und das Aktivspeicherregelventil 90 wird entsprechend geregelt.

The actual drilling distinguishes three methods:

• 1. In so-called normal drilling, the drilling pressure is passively "regulated". Drill pressure fluctuations due to ship movements and therefore cylinder movements and accumulator piston movements as well as gas pressure fluctuations are deliberately allowed. In this type of drilling the active cylinder is short-circuited, in which the bypass valve 97 in his passage position and the active storage control valve 90 be brought into its neutral position (on).
• 2. In "improved normal drilling" the Bohrdruckschwankungen and according to torque and rotational speed fluctuations and the drill head wear and a Bohrkopfabheben be reduced or largely avoided, in which the pressure in the working space 24 or, preferably, in the annulus 36 is kept constant. This is done by a pressure control of the active cylinder 8th , where the bypass valve 97 is brought into its blocking position and the Aktivspeicherregelventil 90 is controlled on the basis of a suitable control process so that the pressure in said pressure chambers 24 or, 36 remains virtually constant.
• 3. In so-called "core drilling", soil samples are drilled using a special device attached to the drill string. In this process, the positions must be controlled with relatively high accuracy to compensate for the sea state and possible ship movements. The total weight of the drill string is, as already explained, approximately by the gas pressure in the gas space 22 compensated. The position of the hydraulic cylinders 2 is through the active cylinder 8th regulated so that the ship's movement is compensated, there is the bypass valve 97 in its blocking position and the Aktivspeicherregelventil 90 is regulated accordingly.

To Upon completion of the drilling operation, the drill head becomes off the ground pulled out and raised. This extraction can in principle also according to the three methods described above. In that case, in a continuous extraction of the drill head or of it mounted device required The active sea state compensation control can be used in a position control be switched to compensate for the ship movements.

This controlled extraction of the drill head from the ground is effected by the fact that via the filling control valve 96 with opened bypass valve 97 Pressure medium in the annuli 36 the hydraulic cylinder assembly 2 is encouraged so that the drill head is pulled out of the ground at a constant speed. As I said, there is an active sea state compensation by means of the setting of the active storage control valve 90 , via which the pressure required in the control chambers for the sea state compensation 26 . 28 is set to pull the drill head out of the ground at a constant speed.

After the drill head is pulled out of the ground, can be prevented on the above-described types of control that this is raised in an uncontrolled manner. The time of extraction of the drill head from the ground can be very easily detected, since then the required pull-out force drops abruptly. In order to prevent a collision of the drill head with the ground, this is then brought relatively quickly in a distance to the ground. As soon as the piston 12 the active accumulator has reached its preset starting position, the sea state compensation is switched off, thereby the check valve 38 closed and the filling control valve 96 as well as the Aktivspeicherregelventil 90 back to their basic positions. The bypass valve 97 is brought into its passage position, so that the active cylinder 8th is switched off. The two valves 78 . 82 stay closed.

The drill string is then removed and the drill head is raised back to the ship. During this lifting, the check valve remains 38 closed, the bypass valve 97 is open and the two control valves 96 . 90 remain in their basic position. During the lifting of the drill head and the disassembly of the drill string takes place the necessary lifting and lowering of the cylinder jackets of the hydraulic cylinder assembly 2 attached, the drill string bearing guide bar via the lifting valve 78 or the drain valve 82 , In this case, the gas pressure in the gas space 22 again via the gas pressure control unit 70 adapted to the decreasing weight of the drill string.

Disclosed is a sea state compensation device (Heave Compensation System), in which the compensation of a relative movement generated by the sea state a load related to a desired position via a passive hydropneumatic Memory and an actively controlled active cylinder takes place. According to the invention Active cylinder integrated into the hydropneumatic accumulator so that the compensation device extremely compact and is simple.

1

Seegangskompensationseinrichtung

2

hydraulic cylinders

4

compensation system

6

hydropneumatic Storage

8th

active cylinder

10

cylinder housing

12

piston

14

piston collar

16

piston collar

18

piston land

20

housing partition

22

headspace

24

working space

26

control room

28

control room

30

gas pipe

32

gas storage

34

pressure line

35

differential piston

36

annulus

38

check valve

40

winch

42

hydraulic motor

44

variable

46

collar

47

High-pressure line

48

1. piston land

49

suction

50

Second piston land

52

1. housing partition

54

Second housing partition

56

Another working space

58

room

60

Low-pressure line

62

ship

64

drilling rig

66

Laser measuring device

68

transducer

70

Gas pressure control unit

72

storage reservoir

74

compressor unit

76

pump

78

raise valve

80

pump line

82

reducing valve

84

tank line

86

supply line

88

drain line

90

Active Memory control valve

92

supply line

94

drain line

96

Füllregelventil

97

bypass valve

98

filling line

100

connecting line

102

Pumps branch line

104

Tank branch line

Claims (14)

Hydraulic sea state compensating device for compensating for sea-induced relative movements between a load (L) and a target position, with a compensation system ( 4 ) supporting a load (L) hydropneumatic accumulator ( 6 ) and an active cylinder device ( 8th ), the two control rooms ( 26 . 28 ), which is used to actuate the active cylinder device ( 8th ) can be acted upon by a pressure, characterized in that the active cylinder device ( 8th ) in the hydropneumatic accumulator ( 6 ), wherein a common piston arrangement ( 12 ) in a common cylinder housing ( 10 ) is accommodated, which defines with its two-sided housing end faces and adjacent piston bottom surfaces in each case a pressure chamber, one of which a gas space ( 22 ) of the hydropneumatic accumulator ( 6 ). Swell compensation device according to claim 1, with a hydraulic cylinder ( 2 ) for moving the load (L), the at least one pressure chamber ( 36 ), which via a pressure line ( 34 ) with the second, a work space ( 24 ) forming pressure chamber is connected in the cylinder housing. Sea gear compensation device according to claim 2, wherein the piston arrangement ( 12 ) two end, the piston crown surfaces forming piston collars ( 14 . 16 ), which by a piston ridge ( 18 ) having a housing partition wall ( 20 ) sealingly interspersed, so that through the annular end faces of the piston collars ( 14 . 16 ) on the one hand and the housing partition ( 20 ) On the other hand, the two control rooms ( 26 . 28 ) of the active cylinder ( 8th ) are limited. Seegangskompensationseinrichtung according to claim 3, wherein at the two piston collars ( 14 . 16 ) and the housing partition ( 20 ) Seals are arranged. Sea gear compensation device according to claim 1, with one of a hydraulic motor ( 42 ) driven, the load (L) supporting winds ( 40 ), wherein a pressure side of the hydraulic motor ( 42 ) with a work space ( 24 ) is connected in the cylinder housing. Sea gear compensation device according to claim 5, wherein the piston arrangement ( 12 ) two end piston collars ( 14 . 16 ) and a central annular collar ( 46 ), which has two piston webs ( 48 . 50 ), each having a housing partition wall ( 52 . 54 ), so that through a housing partition ( 52 ) and the adjacent annular end faces of the piston assembly ( 12 ) the two control rooms ( 26 . 28 ) of the active cylinder ( 8th ) and through the further housing partition ( 54 ) and the adjacent annular end faces of the working space ( 24 ) and another workspace ( 56 ) are limited. Seegangskompensationseinrichtung according to claim 8, wherein the gas from the space ( 22 ) remote pressure chamber ( 58 ) is subjected to ambient pressure. Swell compensation device according to one of the claims 5 to 7 , wherein the hydraulic motor ( 42 ) with constant or variable displacement volume. Sea gear compensation device according to claim 8, wherein the hydraulic motor ( 42 ) in one closed nen or open pressure fluid circuit is arranged. Seegangskompensationseinrichtung according to claim 9, the first alternative, wherein a pump ( 44 ) is driven by a variable displacement of an electric motor (M) and a suction port (S) of the pump ( 44 ) via a suction line ( 49 ) with a low-pressure connection (T) of the hydraulic motor ( 42 ) and a pressure port (P) of the pump via a high pressure line ( 47 ) with a pressure connection (P ') of the hydraulic motor ( 42 ) connected is. Seegangskompensationseinrichtung according to claim 10, wherein the working space ( 24 ) via a pressure line ( 34 ) with the high pressure line ( 47 ) and the further working space ( 56 ) via a low-pressure line ( 60 ) with the suction line ( 49 ) are connected. Sea swell compensation device according to one of the preceding claims, wherein the piston collars ( 14 . 16 ) or piston webs ( 48 . 50 ) are each designed with different diameters. A sea state compensation device according to any one of claims 5 to 12, wherein the two control spaces ( 26 . 28 ) by means of a bypass valve ( 97 ) are connectable or separable from the hydraulic motor circuit. Seegangskompensationseinrichtung according to claim 2 or 11, wherein in the pressure line ( 34 ) or the high pressure / suction lines ( 47 . 49 ) fast switching shut-off valves ( 38 ) are arranged.