DE1301285B - Device for automatically setting the axis of a rigid body on the axis of an underwater structure, e.g. B. a subsea wellhead - Google Patents

Description

1 2

The invention relates to a device. An analogous problem arises when a star-. floating system, which is located above an unruly body on the axis of an underwater structure, a terwasserstructure with a lean on the bottom. B. an underwater borehole head, which is from lowing base or a base plate, which are a floating body, from this structure tensed guide ropes lowered to the underwater 5 successive rigid body, a control device, by stacking the direction for the floating body and a measuring device. Underwater petroleum head is formed,
These successive parts are preferably measured in two planes and the measured values are lowered in that they slide along the control device of the floating body remotely over the guide cables carried by the floating one, which is located after the Connect the reception of the measuring system to the base plate,
signals automatically in the most favorable reference position So that these parts are brought into the correct position. ^J , it is necessary that each of them

When carrying out numerous underwater work, a corresponding axis is set up,

th, for example in the case of underwater drilling, it is 15 which is linked to the preceding element

for attaching and maintaining the delivery heads is already attached to the underwater structure.

of underwater oil wells is floated by one.

Menden plant, for example a ship or in the known devices of the above-mentioned Drilling platform, from necessary to an unlimited type, are the measuring devices on the water structure rigid bodies of various types, 20 floating bodies attached, and they measure the Neiwie Tools, parts of the delivery head, etc., under supply one between the floating body and the To lower water. These rigid bodies are suspended from a tensioned wire in relation to the underwater structure at the end of a flexible rope, and it is customary to project on the vertical axis onto two ebb people Plant with the underwater structure. Seeks depending on the measurement result by at least two guide cables to connect 25 then the control device in the float and to hold the most favorable reference position on the body to be lowered, for example to be attached, which slide along these cables exactly vertically above the axis of the lower slide, water structure, if this axis itself is vertical.

There is the problem of the rigid body. These known devices are with a

when it arrives at the underwater structure or the 30 series of uncertainty factors. On the one hand

To keep the underwater pedestal in place. it is often difficult or even impossible to obtain the

This correct location can be used in the most general way of measuring wire to be really stretched

be defined in such a way that essentially a coincidence, so that the measurement result is falsified

denz between an axis of the rigid body and is and the floating body is not in the most favorable

an axis 35 linked to the underwater structure reaches the reference position. But even if that

will be produced. The most favorable reference position

In the case of a drilling in the sea with a drilling, there is still no certainty that the axis

tool above which an arrangement of several of the rigid body is always on the axis of the axis

rigid tubular elements is attached, the underwater structure of which is aligned, because as a result

upper part with a floating system due to the action of underwater currents, to which

A flexible hose is connected to it, contains the effect of weight all along it

For example, the base, which is added by an arrangement that slides on the guide ropes,

resgrund resting base plate is formed, take these guide ropes, even if they are under

a shaft for the passage of the drilling tool, tension to be held, a certain curvature

the rigid tubular elements and the flexible 45 which changes the orientation of the axes,

seed tubes. Depending on the flow conditions and other

The problem then arises that the axis of the conditions must be the most favorable reference

can be changed by the drilling tool, the basic motor and the position, but this is

if necessary, the drill rods formed rigid th devices is not possible.

Column correctly in the axis of the 5 ° in the base. The object of the invention is to provide a

brought shaft is when the lower part of this device of the type specified to create

Column, the downward movement of which by sliding along, in which the axis of the rigid body, un-

the guide cables takes place at the upper mouth depending on changes in the flow conditions

of the shaft arrives, so that this rigid column in or other conditions, always exactly on the

the shaft can be inserted. 55 axis of the underwater structure is aligned.

Another example is the introduction of According to the invention this is achieved by Engaging tools in a wellhead one in that the measuring device in the vicinity of the fastening operation located oil well, for example points of the guide ropes on the underwater structure of the scraping tools for well tubbing that is attached.

hanging on a cable from a ship

that is always in a reference position essentially vertically above floating bodies.

the drill well, where you bring the tool in which the guide ropes in a

can slide along the guide cables. These works agreed with the direction of the underwater structure

witnesses have an elongated shape with one end. Depending on the prevailing conditions,

Axis, which when it arrives at the upper end of the conveyor, these reference positions differ from one another

derkopfes must lie in the axis of the tubbing, but is always the correct arrangement of the axis

so that the tool can be inserted into the segment Rigid body on the axis of the underwater

think Structure guaranteed.

3 4

One embodiment of the invention is in the hold in the middle between the guide ropes.

Drawing shown. Each of these guide elements contains a central

F i g. 1 is a schematic representation of a sub-bushing 23 or 24, which is fixed with radial arms 17, water deep drilling rig as an example for the application 17a or 18, 18a connected, which in sliding dung of the invention, 5 guides 36, 36 c and 37, 37 a, which end along

F i g. 2 on a larger scale that the guide ropes can slide on the ground,

located underwater wellhead of the plant. Of course, only a single guide could be

of Fig. 1, use guiding element, provided that its

FIGS. 2a and 2b are sectional views of the bushing which is long enough to ensure good centering

Underwater wellhead mounted angle measurement to ensure the rigid drilling assembly. In this

devices and case, the socket would preferably be at least two

3 shows the block diagram of the dynamic pairing of radial arms at different heights

Anchoring system of the plant of Fig. 1 have. However, in order to build up the management

F i g. 1 shows a drilling ship N, from which instructions are not too difficult if pre-water deep boreholes are used. This preferably has at least two guide elements of the type shown as an example in FIG. 2 with the aid of a flexible drilling tube.
28, which is unwound from a supply drum 29 with the aid of In general, each central bushing is provided with as many drive devices, for example one provided by a radial arm, as there are guide cables in front of the motor 4 driven capstans 41. are in hand.

This drilling tube ends in a rigid drilling 20 during the downward movement or upward movement

set, which essentially consist of a base of the rigid drill set, the guide elements

motor 5 which drives a drilling tool 6. on stops or shoulders of the drill string.

The drilling hose goes through one in the ship's hull. One stop 19 is located near the upper one

attached shaft 7. Part of the rigid drill string and the other

In this system there is the problem of the rigid 25 impact 20 essentially at the lower part of the drilling

Drill assembly into the mouth of the into the seabed assembly.

drilled borehole 8 (or in case of renewed) In this way, when moving downwards

to reintroduce the lowering system), d. i.e., to reach or to move the rigid drill string upward

chen that the axis of this rigid drill string to that between the relevant guide elements

the borehole opening substantially along the 30 lying sections 21 and 22 of the guide ropes

Axis ZZ 'of the borehole lies. as well as the rigid drill string parallel to each other

In this embodiment, the drilling ship N is held.

provided with two thrusters H ₁ and H ₂ , which when the drilling tool is near the opening

Thrust forces P ₁ or P ₂ arrives with adjustable strength from the borehole head 9, this settles

practice whose direction in a horizontal plane 35 lower guide element on this, and in the

is adjustable. These thrusters can slide the outboard further downward movement of the tool

engines or any other engine drill assembly through the center sleeve 24 of this guide

with adjustable direction and strength of the shear element.

be powers. When the drill string is completely in the drilling

Furthermore, if an underwater borehole hole 8 has penetrated the bottom, the upper guide head 9 is attached, which in turn rests on the borehole head with an opening 10 to the element and the rigid drill string and the drill hose then slide through the central bushing of the drill hose 28 is provided. This wellhead 23 of this guide element to the extent that it is unrolled with the drilling ship N through two guide ropes drilling hose from the drilling ship.
11 and 12 connected. 45 In the reverse process, i.e. in the case of

These guide ropes are with their upper ends downward movement of the rigid drill string, the

13 and 14 on the drilling ship N and with their lower central bushings 23 and 24 one after the other from this

Ends 15 and 16 attached to the wellhead 9. taken back with them, focusing on the

They are put through suitable devices from schlage 19 and 20, respectively.

possibly of a known type, which are located on the borehole 50 Furthermore, facilities are provided that head it or are on the drilling ship, possibly under tension, the rigid drill string S, 6 when it is adhered to, for example by pulleys and 'leadership in the opening 10 or in their out-counterweights at the drilling ship. pull out of the borehole essentially in the

The number of guide ropes can of course keep more direction of the axis of the opening 10,

than two. 55 These facilities include at the wellhead

Furthermore, the rigid drilling assembly with guide-mounted angle measuring devices, of which at

facilities provided, which are present along the lines of the example shown two, the

ropes can slide. are designated by 30 and 31, respectively. This angle measuring

These guide devices can measure from a few devices in the form of electrical storage

at least two in FIG. 1 and 2 shown guide 60 signals the projection of the angle between the

elements exist, which the rigid drill string section 21 of the guide rope 11 in the vicinity of the

during their downward movement in constant downhole head 9 and the axis ZZ 'of the well

stand by the guide ropes, which are each on a first level or the projection of the angle

because equal to the distances between the axis of the between the section 22 of the guide rope 12 in

Opening 10 and the corresponding fastening 65 near the wellhead 9 and the axis Z-Z '

15 or 16 of the guide ropes point at the borehole - the borehole on a second plane that is perpendicular

head 9 are so that it is the rigid drill string at the first level,

In the example shown (Fig. 2) these electrical signals are essentially transmitted via lines

25, 26, which are combined in a cable 27 An embodiment for the Winkelmeßein-

(or via lines running in at least one of directions 30 and 31 is shown in FIG. 2. Guide ropes 11 and 12 may be included) to As this figure shows, the Winkelmeß-

a computing device CaIc (Fig. 3), the device 30 of two pipes 32 and 33, of which is located on the drilling ship N and of each 5 the lower pipe 32 attached to the wellhead 9 in a suitable, known manner can be. This is that its axis is parallel to the axis of the drilling calculator calculated for the automatic dy- lochkopfes, while the upper tube 33 with the namische anchoring required control signals. lower tube 32 by a double joint

The calculating device CaIc determines depending on the type of a cardan joint with two axes XX ' and TT connected to one another from the axes XX' and TT connected to the signals V _x and Vy the directions Ct ₁ and "", the axis XX ' perpendicular to the drawing (with respect to the longitudinal axis xx! of the drilling ship) plane of FIG.

and the strengths _{P 1} and P _{2 of} the shear forces, which Fig. 2a shows this double articulation in

the thrusters H ₁ and H ₂ must operate in order to bring the larger scale, in a sectional view in a drilling ship N, in such a position that 15 horizontal plane in which the axes XX ' and the Si- T- T'lie. The axis TI "will be zero from the wellhead 9 signals V _x and Vy , that is, that the wear and is firmly connected with a ring 39, cuts 21 and 22 of the guide cables 11 and 12 par- which the axis XX ' which are directed perpendicular to the axis allel to the borehole axis ZZ ' , TT and as a joint for the upper pipe 33

Servo control devices S ₁ and S ₂ regulate the ao serves.

Thrust forces of the engines H ₁ and H _? so that a detector 38 is mounted on the axis TT,

they have the directions Ct ₁ or a ₂ and the strengths P ₁ or which the rotation of the upper tube 33 about this P ₂ . - Measures the axis in the form of an electrical signal V _x ,

3 shows schematically an example of the control of the engines via the line 25 and the transmission cable on the basis of the electrical 25 27 to the computing device CaIc of the drilling ship transmitted signals V _x and Vy, which is transmitted by the angle measuring devices.

lines30 and 31 can be delivered. The angle measuring device 31 is the angle measuring

The device 30 supplied by the two angle tensioning devices is the same, the upper tube 35 being the

Ferten signals are the terminals 1 and 2 of the water device with the lower tube 34 through a

Computing device supplied. 30 universal joint is connected, both of which are perpendicular

The difference between th axes YY ' and UU' from the corresponding one is applied to terminal 3

two voltages Ve and Ve ₀ applied, of which axes XX ' and TT of the device 30 through

the voltage Ve is proportional to the heading angle of the drilling ship a rotation of + 90 ° about the borehole axis ZZ ', which can be derived by a gyrocompass Gyr.

or another suitable device measured 35. The detector 40 of the second angle measuring device is measured while the voltage Fe ₀ on a 31 is working in the same way as the detector 38, potentiometer set target course angle 0 _O, but it measures the rotation of the upper tube 35 proportionally is that the drilling ship should adhere to during drilling around the axis U-U ', which is perpendicular to the axis TT. stands, in the form of the electrical signal Vy, that over

The difference Fe-Fg ₀ can be supplied by a difference 40 line 26 to the computing device Cälc of the drilling _{amplifier D 3 of a} known type. ship is transferred.

The voltages V _x , Vy and Bei are preferably determined above, in particular with reference to FIG. 1

(Fo-Fo ₀ ) not directly to the input terminals 1, 2 explained embodiment, in which the loading

or 3 of the computing device applied, but there are fastening points 13 and 14 of the guide ropes on it previously with hooves of differential amplifiers D ₁ , 45 drilling ship on the linked with the drilling ship

D ₂ or D ₄ subtract the following signals: Axis yy ' on both sides of the center of the ship

, yj _v A (V - ν Λ trunk attached shaft 7 and at the

_Vx = ££, V ₂ , = - ^ r ¹ -, ν _Θ = _A , the axis TT of the angle measuring device 30 parallel

^{di di} ° - ^f lies to the straight line which the attachment points

so that the input terminals 1, 2 and 3 of the rake 50 15 and 16 of the guide cables at the wellhead

the following signals are supplied to the device: binds, the target intended for the drilling ship is

_ "course angle Θ _ο , which is in the form of an electrical

^ΔΧ ~ ^Vx ~ ^Va >> voltage Fq ₀ (Fig. 3) is set, preferably

AY-Vy - Vy, chosen equal to the heading angle chosen by the drillship

_At _ _v _ _v _ 55 has 9 when lowering the wellhead to the

ve ν _Θο v @. lower ends of the guide ropes 11 and 12 depends.

The voltages v _x , v _y and ve, which the temporal In this way one keeps with the drilling ship

Derivatives of the voltages V _x , Vy or Ve-Ve ₀ linked axes x-xf, yy ' essentially par-

are proportional and are supplied by differentiating amplifiers to the fixed axes XX ' and YY' of the core C ₁ , C ₂ and C _{3 of a} known type, 60 wellhead 9.

result in the automatic dynamic process. The signals V _x and Vy, which are a measure of the

kerungssystem a tachometric counter-coupling, rotation of the guide ropes around the axes TT which dampen the vibrations of the drilling or UU ' , the coordinates χ and y ship are then made possible by its equilibrium position. of the opening 10 of the borehole head 9 in the coordinate system x-x ', y-y' linked to the servo control devices S ₁ , S ₂ regulate the Rieh- 65 Bohrschiff linked system and strengths of the thrusters H ₁ and proportionally.

H ₂ exerted thrust forces on the rake detectors 38 and 40 can be of any suitable

Calc gets certain values. Neten known device exist, for example

from a potentiometer device, the rotation of the upper tube 33, for example about the axis TT, being expressed in the adjustment of the tap of a potentiometer.

Each of these detectors could also be formed by the transmitter of a conventional resolver system, the receiver of which is located on the drilling ship. As a result of the cardan suspension of the two angle measuring devices in the embodiment of FIGS. 2a and 2b, it would also be possible to attach the two detectors 38 and 40 to a single angle measuring device because the lower sections 21 and 22 of the two guide cables are parallel to one another. In this way the same angle measuring device would measure the projections of the angle between the lower portion of a guide rope and the direction of the borehole axis Z-Z ' onto two mutually perpendicular planes in the form of electrical signals.

ZO

Claims (2)

Patent claims: 1. Device for automatically setting up the axis of a rigid body on the axis an underwater structure, ζ. Β. an underwater serbohrkopfes, which from a floating body, stretched from this to the underwater structure Guide ropes, a control device for the float and a measuring device consists, which measures the position of the axes to each other in two planes and the measured values on the control device of the float transmits remotely, which after receiving the measurement signals automatically brings it into the most favorable reference position, characterized in that the measuring device is in the vicinity of the attachment points of the guide ropes on the underwater structure is appropriate. 2. Device according to claim 1, characterized in that each measuring device has a lower tube (32, 34) which is attached directly to the underwater structure (9), and an upper tube (33, 35J, which is attached to the lower tube by a Cardan suspension with two mutually perpendicular axes (X-X ', T-T'; Y-Y ', UV) is articulated, and that electrical devices (38, 40) are provided which enable the rotation of the upper tube about at least one of the two Measure mutually perpendicular axes in the form of an electrical storage signal. 1 sheet of drawings 909534/4