DE1925959A1 - Connection device for an underwater wellhead assembly - Google Patents

Description

The invention relates to devices for use in connection with deep underwater drilling Extraction of petroleum are intended · More specifically, the invention relates to a wellhead connection device which it enables operational connections between a buoyant vehicle and a wellhead assembly or Manufacture production control device of an underwater deep borehole, so that the buoyant vehicle above the deep borehole from maintenance work and other work on the wellbore and / or the wellhead assembly can be »

A more recent development in the field of building deep wells for the extraction of oil is the downing of deep wells underwater near the coast, these deep wells being provided with a wellhead assembly which is arranged on the sea floor or in its vicinity so that it does not pass through the water Ships can be damaged. However, such devices placed on the seabed are corrosive

909849/0928

BATH ORIGINAL

Exposed to the action of sea water and there is the Danger of living things living in the water sticking to the metal parts under the surface of the water and, for example, encrustations form,

It is therefore necessary from time to time to drill a working deep well in order to carry out certain Making work accessible again »Furthermore, it can required, the underwater botal hole head assembly repair it yourself at certain intervals · Therefore it is desirable to have a wellhead assembly available which is adapted to be easily separated from the subsea wellhead and to the surface of the water can be pulled up. Furthermore, it is desirable to have an assembly of the type mentioned that it enables certain work to be carried out with the aid of a vehicle taking up a position above the deep borehole perform from tools lowered through the assembly.

Until now it is used to carry out maintenance work or other work under water on a deep borehole, it is customary to first arrange a guide device, e.g. guide ropes, between the vehicle and the wellhead. A suitable connecting device is then usually installed with the aid of a strand of floss along the guide ropes or the like lowered to the wellhead assembly, whereupon the required work is carried out from the vehicle be performed. Certain operations can be performed while the wellhead assembly is still running Wellhead is connected, but it is occasionally necessary to disconnecting the wellhead assembly from the subsea wellhead and production lines; and to pull them up to the vehicle with the help of the pipe string along the guide ropes or the like.

90984 9/092

BATH ORIGINAL

1325959

When carrying out work on underwater deep boreholes near the coast, the time required is a factor essential role, since high daily rents are to be paid for the use of the necessary devices, and there is high expenditures for wages etc. «result» also acts A longer interruption in the operation of a deep well for maintenance purposes results in correspondingly high losses regarding the amount of oil extracted from "

Therefore, it is advantageous to enable all repair and maintenance work to be carried out on underwater deep boreholes be carried out as quickly as possible,

It is now the main object of the invention to provide a wellhead connection device disclosed by can be lowered from a watercraft and placed on an underwater wellhead without it it is necessary to first provide a guide device between the vehicle and the deep borehole. Further sees the invention provides a wellhead connection device, the devices for determining the position of the wellhead assembly and other devices to facilitate personnel control of the location of the wellhead assembly determine and to connect the connecting device operationally with this assembly.

To this end the invention provides a wellhead connection device that can be lowered from a watercraft and with sound detection and television equipment which will help ensure the correct placement of the fitting on the wellhead assembly to facilitate. After the connection device is fixed by suitable anchoring devices has been connected to the wellhead assembly, an internally disposed conduit assembly becomes the connector moved with the help of a power actuator and into their operating position with respect to themselves

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production lines extending down into the wellbore brought. Since this internal line assembly is also in constant flow connection with one or more pipe strings extending to the vehicle are in place, the required work on the wellbore and / or the wellhead assembly can be performed from the vehicle will.

The invention and advantageous details of the invention are explained in more detail below with reference to schematic drawings of an embodiment.

Pig. 1 shows schematically in a side view a boat or another buoyant vehicle that is in a position above a subsea wellhead assembly, and at which a wellhead connection device according to the invention is hung

Fig. 2 shows on a larger scale partly in a side view and partly in longitudinal section a with a subsea wellhead assembly, operably connected wellhead connection device according to the invention.

Fig. 3 shows on an even larger scale a part of a connecting device according to the invention in association a cooperating part of a subsea wellhead assembly ·

In Fig. 1 one recognizes a boat or other buoyant vehicle 11 of any suitable construction, that in a body of water 12 has a substantially fixed position above a predetermined point on defc Occupies seabed and through suitable location devices or is held in this position by the fact that it is on the seabed 13 with the help of not shown, is anchored to anchor ropes 14 and 15 attached anchors. Such an arrangement can be used when working

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carried out in a water depth of about 30 to 450 m or more Need to become. Das .Fahrzeug 11 is with a suitable Rig 16 and other auxiliary devices equipped to carry out maintenance work a deep borehole. The derrick 16 is above a vertically in the usual manner the vehicle 11 extending slot 17 is arranged. When using the device according to the invention, the slot 17 can either be arranged in the center of the vehicle 11 or extend inward from one side of the vehicle. However, it is also possible to dispense with the use of the slot 17 and the work concerned to be carried out over the beltline of the vehicle "

Furthermore, one recognizes in Fig. 1 an underwater wellhead with a base plate 18 arranged on the seabed 13, which is firmly connected to a casing 19 having a larger diameter, which extends down into the previously drilled deep borehole and is preferably cemented into it _e is within the casing 19 or the Verrohrunge one or more production tubing strings, for example, the tubing strings shown in FIG. 1, 20 and 21, suspended, extending in the usual manner in the down hole. If necessary, the wellhead construction can comprise two or more vertically arranged guide columns and 23 working together with guide ropes hanging down from the vehicle 11.

A casing head 24 is disposed on the base plate 18 on which a wellhead assembly or a Production control device 25 is attached. normally the assembly 25 is in fluid communication with the Production pipe ranks, and it includes one as a riser head designated arrangement with the required pipelines, Valves, throttles, etc. as well as those required

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hydraulic or electrical devices including pumps, tanks, motors, etc. that require remote control of the valves on the head or mouth hole of the deep hole.

The wellhead 25 comprises one or more conduits, e.g. those shown in Mg. 1 at 26 and 27, as well as an upwardly extending conduit 28 through which the wellhead is accessible. The pipes 26 and 27 are in place in connection with the production tubing strings 20 and 21, and they are uniformly curved so that they allow P Insert tools into the borehole via the tubing strings.

A wellhead connecting device 30 according to the invention is suspended from the vehicle or train 11 with the aid of a pipe string 29, to which devices 32 and 32 for attaching guide ropes and guide ropes 33 and 34 depending from the vehicle 11 can be assigned. It should be noted that when the devices 31 and 32 for securing the guide ropes are fully lowered to the guide pillars 22 and 23, the guide ropes are suitably secured to the pillars. However, the columns 22, 23, the fastening devices 31 _f 32 and the guide ropes 33 »34 do not form a subject of the invention, w, and these are shown only for clarity here. The connection device 30 could optionally also be used without the use of the arrangement comprising the guide ropes.

According to FIG. 2, the connecting device 30 comprises a cylindrical main body or a housing 35 with a through bore 36 into which is located within the pipe string 29 pipe strings extending upward to the vehicle 11 37 and 38 protrude, which preferably each comprise individual pipe sections, the length of which is essentially is equal to the length of the sections of tubing string 29, and which by means of suitable supports so with the sections.

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of the pipe string 29 are connected so that they form individual assemblies together with the latter. If necessary, can however, the pipe strings 37 and 38 also independently of the Pipe string 29 can be arranged in this.

At the lower end of the housing 35, as shown in FIG attached to the outwardly extending frame structure 39, the means for determining the location of the wellhead assembly 25 as well as devices that make it easier for the operating personnel on the vehicle 11, the connection device 30 to be arranged in the correct manner on the assembly 25, as will be explained in more detail below. It it should only be noted that, in addition to the devices mentioned, a hydraulically operated, extendable sound location device 40 and a television camera 41, both of which can serve to carry out the work to be carried out in the area of the deep borehole to be monitored «, the television camera 41 carries a lighting device 42, the observation the work to be carried out underwater. The television camera 41 may be permanently installed, but it will be preferred to store them movably so that they can be adjusted by an operator as required, so that the work to be carried out can be observed more easily. Since the use of television cameras and sound detection devices for the purpose mentioned is known from the patent and technical literature, should be a more detailed explanation their mode of action at this point is superfluous frustoconical component 43 that extends below is attached, which has a cutout 44 which is arranged so that with the help of the television camera 41 the »within the Component 43 playing processes can be observed. The frustoconical component 43 also carries on a still to be explained Vieise to the connection device 30 onto wellhead assembly 25 in the correct manner.

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A cylindrical component 45 is located in the housing 35
arranged coaxially with it and mounted so that it can be extended downwards in the axial direction. The cylindrical component 4-5 is normally biased towards a retracted first position, for example by a spring arrangement (not shown). On the outside of the component 45, a flange 46 is formed, in the circumferential surface of which a sealing ring 47 is installed, which works together with the inner wall 48 of the housing 35 and between the component 45
and an annular chamber 49 delimits the housing 35. Around the housing 35 are several circumferentially spaced apart and suitably connected to the housing
Accumulators 50 are provided. Pipelines 51 serve to establish a flow connection between the accumulators 50 and the chamber 49, and valves (not shown) are switched into these pipelines, which make it possible to interrupt or re-establish the flow connections between the accumulators and the chamber as required. These valves could be from the vehicle 11
operated in a known manner. In the embodiment described here, a cable 52 is provided which comprises several electrical and / or hydraulic lines 53, by means of which energy pulses can be supplied to the connection device 30 from the vehicle 11 from the various valves, anchoring devices, etc. The valves mentioned here can be electrically or pneumatically or hydraulically operated valves.

The mode of operation of the wellhead connecting device 30 according to the invention is explained in more detail below. It is assumed that the vehicle 11 is approximately in
a position above the wellhead assembly 25 where certain work is to be carried out · The
Most common method is to get the vehicle bit
With the help of suitable surveying equipment in the right one
To bring position above the borehole, whose location is known

909849/0928

'is. Once the borehole has been found and the vehicle has been secured with the aid of anchors or the like, the connection device 30 is attached to the pipe string 29 by means of any known coupling device and lowered from the vehicle 11 by the pipe string 29 in a known manner by adding further pipe sections is extended _e These work steps are continued until it is established that the pipe string 29 is composed of such a number of sections that the connecting device 30 is still at a distance from the seabed 13 which is slightly greater than the height of the wellhead assembly 25β

Once this point is reached, the sound detection device will be used 40, the television camera 41 and the lighting device 42 operate from the vehicle 11 set and monitored. The pipe string 29 with the connecting device 30 suspended thereon is then removed from the vehicle 11 from coaxial with the inlet line 28 of the wellhead brought. Then more pipe sections are connected to the upper end of the pipe string 29 to the To lower the connection device 30 further and place it on the To push the inlet line 28 of the wellhead. Here, the truncated cone-shaped component 43 serves dadku, the connecting device 30 to be arranged coaxially with the inlet line 28 while the connecting device is lowered is, and here the operator on the vehicle 11 can do this work with the help of the television camera 41 through the cut-out 44. The connection device 30 is lowered further so that it slides down on the inlet line 28 until the upper end of the inlet line is in firm contact with the underside a stop 54 comes through a shoulder section protruding into the chamber 49 as shown in FIG is formed on the inner wall 48 of the housing 35.

909849/0928

- ίο -

According to Mg. 2, the inlet line 28 is provided with an annular groove 55 on its outside near its upper end. As soon as the upper end of the inlet line 28 has come to rest against the stop 54, hydraulic locking parts 56 and 57 associated with the smaller housings attached to the housing 35 are actuated so that they engage in the annular groove 55 in the manner shown.) Of course suitable hydraulic lines and a source of hydraulic pressure medium are provided so that the locking parts 56 and 57 can be actuated, but these parts are in i'ig. 2 omitted for the sake of clarity. The locking parts 56 and 57 can either be actuated automatically as soon as the upper end of the inlet line 28 comes into contact with the stop 54, or they are actuated from the vehicle 11 Hydraulically operating securing devices 58 and 59 are actuated in order to keep the locking parts 56 and 57 in engagement with the hanging groove 55 in the manner shown in FIG. In order to make the illustration clearer, the complete hydraulic device for actuating the safety devices 58 and 59 has also been omitted in FIG. If necessary, the securing devices 58 and 59 can be actuated from the vehicle 11, or they can be actuated automatically as soon as the locking parts 56 and 57 have been brought into engagement with the annular groove 55

In Fig. 3, the position of the cylindrical component 45 relative to the wellhead inlet line 28 for the Case reproduced in which the locking operations just described have been carried out · Here is located the cylindrical component 45 is in its retracted first position. It is also assumed that the connecting device 30 has been brought into the correct angular position with respect to the inlet line 28, as shown in FIG. 3

90984 9/0928

is shown. For this purpose one can bring the pipe string 29 together with the connection device 30 from the vehicle 11 under observation with the aid of the television camera 41 in the correct ⁷ position, or the connection device and the inlet pipe can be provided with cooperating devices by means of which these parts in the correct Y / angular position to one another. An inner tube assembly is connected to the cylindrical component 45, for example by welding, which comprises a plate 60 and pipe strings or sections 37 and 38. Furthermore, a holding plate 61 connected to the plate 60 by screws 62 and 63 can be provided. The tubes 37 and 38 protrude through openings in the plate 60 and the holding plate 61 arranged coaxially with them and are fixed in the manner shown in FIG Pipes 37 and 38 can, for example, be welded to the holding plate 61 or each installed with a press fit in matching openings in the holding plate protrudes below through the plate 60 and the holding plate 61 · The end of the tube 64, not shown, could be operationally connected to a suitable energy source, e.g. at their lower ends 65 »66 and 67 are preferably provided with annular grooves or the like, in which sealing elements are arranged Cylindrical component 45 can also accommodate electrical cables which enable various types of work to be carried out on the wellhead.Each of these electrical cables would be provided with a suitable connector attached to the holding plate 61 can use. A further explanation should be superfluous.

909849/0928

According to FIG. 3, a support plate 68 is arranged in the wellhead inlet line 28, in which connection pieces 69 and 70 and a pipe coupling 71 are permanently installed in any known manner; these components also have the shape of cylindrical tubes. The connectors 69 and 70 project downwardly into the wellhead assembly and are coaxial and in flow communication with the production tubing strings 20 and 21. If the holding plate 61 is associated with electrical cables and connectors, matching electrical plugs or the like are provided on the support plate 68 to which cables, not shown, are connected down to the wellhead assembly. During the production operation of the deep borehole, valves (not shown) interrupt the flow connection between the pipe strings 16 and 21 on the one hand and the connecting pieces 69 and 70 on the other hand. The pipe coupling 71, on the other hand, is in operative communication with one or more valves, locking devices, etc. (not shown) which are arranged in the wellhead assembly or in the wellbore itself and which enable the wellbore to be closed or other operations to be carried out electrical cables and fittings described above are used for this purpose _o Since the nature of the work to be performed depends on the construction of the particular wellhead assembly used and other factors, no further details are given here. The connection device according to the invention can of course be used as required in connection with tubes of various dimensions and / or electrical cables provided in different numbers.

after the connection device 30 has been anchored to the inlet conduit 28 and rotated so, that the cylindrical component 4-5 according to FIG. 3 on the inlet line 28 is aligned, the not shown

909849/0928

put, in those from Ji ¹ Ig. 2 visible lines 51 switched on valves opened so that the hydraulic pressure medium flowing out of the accumulators 50 builds up a hydraulic pressure in the chamber 49. Instead of these accumulators, a hydraulic line that enables direct actuation could be provided between one of the hydraulic lines 53 and the chamber 49, so that the hydraulic pressure medium could be supplied to the chamber 49 directly from the vehicle 11. Since the hydraulic pressure in the chamber 49 acts on the flange 46, the cylindrical component 45 is pushed down together with the drill string 29 so that all parts of the connecting device 30 including the pipe strings 37 and 38 and the pipeline 64 are shown in FIG Take up the position shown. The cylindrical component is now in its extended position or its second position. After this movement has been brought about, a locking device 72 is hydraulically operated, which cooperates with a flange 73 formed on the outside of the cylindrical component 45 and serves to engage the pipe strings 37 and 38 and the pipeline 64 with a sealing effect associated connecting pieces 69 and 70 or to hold the pipe coupling 71. In a similar way, all of the electrical connection pieces arranged on the holding plate 61 and the plugs or the like provided on the support plate 68 would be brought into engagement with one another.

After the connection device 30 in the FIG has been brought into position and connected to the wellhead assembly 25, the required Work to be carried out. For example, one can use tools or instruments via the pipe strings 37 and 38 insert the connectors 69 and 70 and the production tubing strings 20 and 21 down into the borehole

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If necessary, work steps can be carried out through the tubing strings 37 and 38 in order to close the borehole seal and the entire wellhead assembly 25 or a part of the same with the help of the pipe string 29 up to to pull up the vehicle 11 so that maintenance work is carried out on the vehicle or other work on the assembly 25 can be carried out.

Claims;

909849/0928

Claims (5)

PATENT CLAIMS 1. Wellhead connection device that attaches to a subsea wellhead assembly by means of an on-one The watercraft suspended tubing string can be lowered with the subsea wellhead assembly one after A component protruding above with pipes or pipe strings arranged therein, g e k e η η ζ e i c h η e t by a main body or a ü-ehäuse (35) with a vertical through hole (36), which with the help of the pipe string (29) on the upwardly protruding component (28) can be placed or pushed on, by at least one of these parts supported locking devices (56, 57) for anchoring the parts to one another, wherein in the main body or housing (35) a cylindrical component (45) is mounted in such a way that it can move axially downwards in the through hole in relation to the housing, internal pipelines (37, 38) supported by the cylindrical component, which together with the cylindrical Component can be brought from a first position into a second position, supported by the G-housing Power actuators (50) that cooperate with the cylindrical member (45) to release the internal Bring pipelines from the first position to the second position, as well as by cooperating devices (69, 70} 65, 66) on the pipes or pipe strings (20, 21) of the wellhead assembly (25) or on the inner ones Pipelines for the production of connections sealed to the outside between the associated 0 9 8 4 9/0928 Pipelines or pipelines when the internal pipelines move from the first position into the second position. 2. Connection device according to claim 1, characterized in that opposite the housing (35) a frame structure (39) extends outward, the devices (40, 41, 42) for determining the position of the Wellhead assembly and an orientation device (43) wears these devices to the operator facilitate locating the wellhead assembly (25) and placing the connector (30) in the correct operative position on the wellhead assembly ", 3. Connection device according to claim 1, characterized in that the power actuating devices hydraulically associated accumulators (50) supported by the pipe string (29) to be actuated piston (46) include ", 4. Connecting device according to claim 1, characterized in that the internal pipelines essentially rigid pipe strings (37 »38). include, which are fixed in at one end of the cylindrical member (45) arranged plates (60, 61) are installed, the latter having openings through which the pipe strings protrude. 5. Connection device according to Amspruch 1, characterized in that the inner pipes (37 j 38) are dimensioned so that they are extended downwards and into the pipes or connectors (69, 70) in the upright component (28) of the wellhead assembly (25) can be inserted, the upper ends of the connecting pieces being offset downwards in relation to the upper end of the upright component. 909849/0928 Blank page