JPS59209989A - Method of replacing tension leg of tension leg mooring type ocean floating construction - Google Patents

Abstract

PURPOSE:To replace a tension leg, connected to an anchor anchored in the sea bottom ground, not by means of a diver but automatically, by a method wherein a tension leg mounting and demounting device is suspended and supported in the lower containing chamber of the column of a floating construction by means of a suspension rope. CONSTITUTION:A tension leg mounting and demounting device 4, suspended and supported by means of a suspension rope 6 unwound from a winch 5, is installed in a lower containing chamber 3 of a column 2 located around a floating construction. In an installation work of a tension leg 8A, a guide line 30A, pulled up to a sea surface from an anchor anchored in a position by means of a buoy, is drawn off and wound by a winch 23 to stretch it. Thereafter, the first tension leg 18 from a reel 11 is inserted through the column 2, and after a socket at the forward end thereof is held in a retainer arm 33, the mounting and demounting device 4 is lowered along the guide line 30A, the socket at the forward end is inserted through an insertion hole in an anchor. Operation to draw off the tension leg 18 is effected by approximately reversing the above procedures.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for replacing a tension membrane in a tension leg moored marine floating structure used for oil production membrane 'l#11 on the seabed, natural gas production equipment, and other underwater equipment. It is something.

Conventionally, a tensile membrane attachment/detachment device for attaching/detaching a tensile membrane in a marine floating structure with a tension leg mooring type is transported on a separate barge from the marine floating structure (hereinafter simply referred to as a floating structure).
It is then submerged directly below the column in the floating structure,
A tension arm made of wire rope suspended from the column was connected to an anchor on the bottom of the water by underwater work.

For this reason, setting the tension arm to the tension body attaching/detaching device requires a die-cutting operation, and the setting operation takes a long time. However, there were disadvantages in that the operating rate of the dieper work could be reduced depending on sea conditions, and a crane ship was required to lower the tensioning shell attachment/detachment device.

In addition, in the case of a device that attaches and detaches multiple tension arms, the device becomes larger because the part that makes the tension arms into cylinders protrudes.
In addition, there is a drawback that the necessary equipment such as a lifting and unloading device becomes large in size.

The object of the present invention is to provide a method for replacing a tension arm in a tension leg anchorage type floating structure tJ which can eliminate the above-mentioned drawbacks.

Next, the present invention will be explained in detail using illustrated examples.

The drawing shows an embodiment of the present invention, in which a column deck 10 of a steel floating structure 1 having a plurality of columns 2 around the column deck 10 is provided with a tension 1 or 8 made of anti-corrosion coated parallel cable or wire rope. Four reels 11 with tension arms are mounted on each column, and the reel stopper 3 is fixed to the column deck 10.
7) - It is temporarily fixed to the lever 11 by a removable connector 38.

In the opening above the column in the column deck 10,
A turntable 7' wheel 15, which is rotated by the drive device 12 via the pinion 1 and the annular gear 14, is rotated several times, and the upper V? of the turntable 15 is turned. -, two parallel to the turntable diameter line (7) Movable L/-ru 1
Furthermore, fixed rails 17 to be opposed to the movable rails 16 are attached to both sides of the tension leg inspection reel mounting portion of the column deck 10, and the wheels of the winch 18 with a truck are mounted on the movable rails 16. The carriage winch 18 and the tension arm winding reel 11 constitute a tension arm lifting device.

On the floor of the operation chamber 19 provided in the middle part of the column 2,
The annular rail 20 is fixed, and a large number of wheels attached to the lower part around the swivel table 21 are mounted on the annular rail 20F,
A swing drive device 22, a guideline winch 26, and a winch 5 for lifting and lowering the attachment/detachment device are fixed to the swivel base 21, and a hanging rope made of a wire rope is fed from the winch 5 for raising and lowering the attachment/detachment device. 6
hangs down through the part near the center of the swivel base 21, and the tension trunk attaching/detaching device 4 is attached to the lower end of the rope (7).
are connected to each other, and the tension trunk attaching/detaching device 4 is housed in a lower storage chamber 6 within the column 2.

A pair of left and right bottom lids 7 for opening and closing the lower end opening of the lower storage chamber B are pivotally attached to the opposite edges of the lower end openings by horizontal shafts, and between each bottom lid 7 and the periphery of the lower end opening. is provided with a sealing material 25, and the sealing material 25 is fixed to the bottom lid 7 or the column 2. Furthermore, a guideline insertion recess 69 is provided in the center of the opposite end of each bottom lid 7, and each The opposing ends of the bottom lids 70 are configured to overlap in the vertical direction ((), and a sealing material 40 made of a rubber plate that closes the recess 69 is attached to the overlapping end of one of the bottom lids 7 by pasting or other means. It is fixed.

A lid closing fluid pressure cylinder 26 is provided around the lower end opening.
is fixed, and the piston rod 27 of the hydraulic cylinder 26
A locking member 29 is fixed to each bottom lid 7 and has a locking hole 28 that faces the piston rod 27 when the bottom lid 7 is closed. When the bottom lid 7 is closed and the piston rod 27 is inserted into the locking hole 28, the bottom lid 7 is held in a closed state.

The guideline filter OA consisting of a wire rope let out from the guideline winch 2 passes through a through hole in the center of the swivel table 21 and hangs down entirely on the center line of the column 2, and also hangs down on the center line of the tension trunk attachment/detachment device 4. Guide hole filter 1f: penetrates through the guide hole filter OA, and is then fed out from the column 2 into the seawater, and the buoy filter 2 is connected to the drawn-out end of the guide hole filter OA.

A socket holding arm 6 is provided in the lower part of the attachment/detachment device main body 41 of the tension trunk attachment/detachment device 4, and is moved laterally by a fluid pressure cylinder 42 for insertion/exit.
6 is fitted through a guide roller 46, and a vertical guide member 44 is fixed to both left and right sides of the tip of the arm 66, and the guide member 44 is moved up and down by a lifting hydraulic cylinder 45. A socket clamp 65 is fixed to a piston rod of a clamp fluid pressure cylinder 47 fixed to each lift support member 46 via a guide roller.

A guide post insertion vertical hole 48 is provided at the lower center of the attachment/detachment device main body 41, and a guide post clamp 66 is fixed to the piston rod of a clamp fluid pressure cylinder 49 fixed to the lower part of the attachment/detachment device main body 41. An azimuth setting arm 64 with a hydraulic cylinder that protrudes laterally is slidably fitted into the lower part of the attaching/detaching device main body 41, and one end of the arm 64 is connected to a central portion of the attaching/detaching device main body 41. ing.

A tensile film guide loam 64 is fitted into the upper part of the attachment/detachment device main body 41 via guide rollers 66 and is moved laterally by a fluid pressure cylinder 65 for moving in and out. The moving direction is set to be deviated by 90 degrees, and each arm 64 is arranged in a multi-stage manner in the vertical direction, and a gripping fluid pressure cylinder 67 is fixed to both left and right sides of the tip of the arm. ,
A grooved roller 36 for guiding the tension arm is attached to the piston rod of the cylinder 67.

A fluid pressure unit 68 is fixed to the upper part of the attaching/detaching device main body 41, and the power supply cable 69 of the wire rope with power supply cable is connected to the electric motor of the fluid pressure unit 68.

A vertical shaft 71 is fixed to the center of the tensioner chamber 70 in the upper part of the operation chamber 19, and its vertical axis 11! A dog diameter driven gear 76 is fixed to a holding member 72 which is rotatably fitted in the tensioner chamber 70, and a rotational drive device 74Kj which is fixed to the tensioner chamber 70 is connected to the large diameter driven gear. 76 and further engaged with the holding member 72,
Two tensioning drive devices 77 are fitted which are laterally moved forward and backward by a forward and backward hydraulic cylinder 76.

A plurality of annular rails 78 are fixed to the circumferential wall of the tensioner chamber 70 at intervals in the downward direction, and a rotating member 79 that rotates while being guided by the annular rails 78 includes a rotating drive device 80 and a tensioning drive device 77. A pinion 81, which is fixed and rotated by a swing drive device 80, is meshed with an annular gear 82 fixed to the peripheral wall of the tensioner chamber 700.

The tensioning drive device 77 is composed of a large number of rollers arranged close to each other in the vertical direction, an endless belt 86 wound around each roller, and a roller drive device 84.
The six tensioning drives 77 constituting the tensioner 61 are arranged around the tension arm 8 at equal angular intervals.

A connector mounting trolley 86 is fitted into the swivel base 21 and is moved in the diametrical direction of the swivel base by a hydraulic cylinder 85 for loading and unloading. We are prepared.

Upper end unfixed chamber 8 provided above the tensioner chamber 70
Inside 9 is a screw 90 for adjusting the level of the upper end of the tension leg.
An upper end unfixing device 96 is arranged, which consists of an openable and closable upper end socket socket 91 attached to one end of the jack 90 and a fluid pressure cylinder 92 that suspends and supports the jack 90. pressure cylinder
The upper end of the gloss 92 is fixed to the upper end and the second part of the fixing chamber 89, and a steady rest member 94 fixed to the floor is slidably inserted into the lower part of the gloss 90.

The lower part of the azimuth setting post 51 is fixed to the anchor 9, and the lower part of the azimuth setting post 51 is fixed to the anchor 9, and the recall buoy 5 is fixed to the support member 52. A guideline filter OB made of wire rope is attached to the reel 54, and a guideline filter OB made of wire rope is rotatably attached thereto.
The end of the guideline filter DB let out from the guide post 50 is connected to one end of the guide post 50, and the trench anchor 9 and the support member 52 are connected via an ultrasonic separation type connector 55. Four socket insertion holes 56 are provided at equal angular intervals around the guide post 50, and a socket locking device for the socket insertion holes 56 is provided.

Next, the case of installing the tension legs will be explained.

The floating structure equipped with the above-mentioned equipment is towed to the destination by a tugboat, then guided to the position directly above the installed anchor 9 using methods such as radio ranging, and then mounted on the floating structure. The position of the floating structure 1 is maintained by a known fixed point holding device.

Next, the ultrasonic separation type coupling device 5 attached to the anchor 9
5 is separated by ultrasonic control, and the reel 54 floats up via the support system 52 due to the buoyancy of the recall buoy 5, and the guide line 30B is let out from the reel 54.

After the recall buoy 53 has surfaced on the sea surface, the reel 5
The guideline 30B is removed from column 4, and the guideline filter OA drawn out from the bottom of column 2 is attached to buoy 2.
The ends of each guideline filter OA and 30B are connected at sea.

Next, the guideline winch 26 is operated in the winding direction to wind up the guideline, and the guideline filter OA,
The guide line from RoOB is the winch 26.
There is tension between the two and Anchor 9.

Next, the movable rail 1 fixed to the turntable 15
The winch 18 with a dolly on the upper part of the reel 110, which has all the tension legs removed from the movable rail 16, is moved to the second part of the fixed rail 17 at the bottom of both sides, and the reel 11 is set on the winch with a dolly 18. .

Next, the carriage winch 18 is operated in the rewinding direction,
The tip side of the first tension leg 8A is connected to the turntable 1.
It is inserted into the column 2 through the through hole 5 and suspended into the upper end unfixed chamber 89.

Next, after the gloss 90 is set at the lower end of the stroke and the socket support 91 is opened, the tension leg 8A is further lowered, and the tip socket 57 of the tension leg 8A is inserted into the socket support, the IP plate 91, and the jack 90. After passing, the socket support 91 is closed.

Next, the tip socket 57 of the tension leg 8A is inserted into the tensioner chamber 70.
At the same time, the track of the tensioner 61 is opened, and after the tip socket 57 passes through the tensioner 61, the track is closed and the tension leg 8A is gripped.

Next, the tip socket 57 is lowered into the operation room 19, and the connector mounting cart 86 is stored in the swivel base 21.
is pushed out and set in a predetermined position, and then the connector block 58 and the bell mouth 59 are attached to the tip socket 57 on the connector mounting trolley 86 by the pole l-, and then the connector mounting trolley 86 is placed on the swivel base 21. Retracted and tipped with a pull leg connector block 58. A tension leg 8A fitted with a bell mouth 59 is suspended through a tension leg tunnel 60 within the column 2 and delivered from the bottom of the column 2.

Next, after water is poured into the lower storage chamber B in the column 2, the bottom lid 7 of the lower storage chamber B is opened, and the winch 5 for lifting and lowering the attachment/detachment device is operated in the rewinding direction, and the tensile membrane attachment/detachment device 4 is opened. The socket clamp 65 in the tension membrane attachment/detachment device 4 is lowered by the suspension 17, and the tension membrane attachment/detachment device 4 is rotated by the thruster 95 installed on the upper part of the device 4 and the swivel table 21 is rotated. The orientation of the tensile membrane attachment/detachment device 4 is adjusted so that it faces the target.

Next, after the socket holding arm 6 is protruded, the socket clamp 65 holds the tip socket 57, and the lower end of the tensioning leg 8A is fixed to the tensioning membrane attachment/detachment device 4.

Next, since the winch 5 for lifting and lowering the attachment/detachment device and the tensioner are not synchronized, the tension membrane attachment/detachment device 4 is suspended. In this case, Guideline 60. The orientation of the tension membrane attachment/detachment device 4 is adjusted by the thruster 95 so that the hanging rollers and the tension legs 8A do not become entangled with each other.

Next, when the guide post 50 of the anchor 9 is fitted into the vertical hole 48 in the center of the tension leg layer removal/removal ft 4, the tension membrane attachment/detachment device 4 is slightly lifted from the anchor 9.
- The phlegm suspension is stopped and then the tensile membrane attachment/detachment device 4
After the azimuth setting arm 64 is projected, the tension membrane attachment/detachment device 4 is rotated at a slow speed by the thruster 95, and the tension membrane attachment/detachment device 4 is rotated at a small speed at a position where the arm 64 hits the azimuth setting post 51 of the anchor 9. The rotation is stopped, and the orientation of the tensile membrane attachment/detachment device 4 is maintained in a predetermined direction.

Next, the tensile membrane attaching/detaching device 4 is lowered again and the anchor 9
After the tension membrane attachment/detachment device 4 is seated on the anchor 9 , the guide post clamp 66 in the tension membrane attachment/detachment device 4 grips the intermediate small diameter portion 96 of the guide post 50 , and the tension membrane attachment/detachment device 4 is attached to the anchor 9 .
completely fixed against the

Next, the socket clamp 65 is pressed down by the fluid pressure cylinder 45 in the tensile membrane attaching/detaching device 4, and the connector block 58 is inserted into the locking hole 56 of the anchor 9, and the locking device provided in the locking hole 56 is inserted into the locking hole 56 of the anchor 9. The connector block 5B is locked to the anchor 9, and therefore the tensile membrane 8A
The distal end portion of the anchor 9 is locked to the anchor 9. Next, after the socket clamp filter 5 is opened, the socket holding arm 36 is retracted into the attachment/detachment device main body 41.

Next, the guide post clamp 6 of the tension membrane attachment/detaching device 4 is released, and then the tension membrane attachment/detachment device 4 is lifted up by the lifting winch 5. In case, guideline 60 and hanging rope 6
The orientation of the tension membrane attachment/detachment device 4 is adjusted by the thruster 95 so that the membranes do not become entangled with each other. After the tensile membrane attachment/detachment device 4 is hoisted up to near the bottom of the column 2, the tensile membrane attachment/detachment device 4 waits underwater until the next tensile membrane installation starts.

Next, in the second terminal fixing chamber 89, after the socket support 91 in the upper end unfixed device 9B is closed,
The clamp the port 91 is pushed up by the screw jack 90 until it hits the upper end socket 97, and then the socket support 9 is pushed up until the tension is equal to or greater than the weight of the tension leg.
1 is lifted, and then the discarded wire row connected to the reel 11 on the column deck is removed from the reel 11, and the tensioner 61 in the tensioner chamber 70 is removed.
track is opened.

When installing the second tensile membrane one after another, the turntable 15 is rotated 90 degrees with the winch 18 with a dolly placed on the movable rail 16 on the turntable 15, and the tensioner is rotated 90'. After being rotated, the second tensile membrane 8B is suspended so that its tip side portion protrudes from the bottom of the column 2 in the same manner as when the first tensile membrane is installed.

Next, the swivel base 21 is rotated approximately 90 degrees, and the thruster 9
5 is operated and the direction of the tension membrane attaching/detaching device 4 is aligned with the tension membrane, the lower tension leg force guide arm roller 4 is pushed out, and the tension leg guide roller roller 6 is used to pull the first tension membrane. The membrane 8A is gripped, and the socket holding arm 6 is pushed out, and the socket clamp 5 holds the membrane 8A.
The tip socket 56 of the first tensile membrane 8B is gripped, that is, the tip of the second tensile membrane 8B is fixed to the tensile membrane attachment/detachment device 4.

Next, the tension membrane attachment/detachment device 4 and the second tension membrane 8B are suspended while the winch 5 for lifting and lowering the attachment/detachment device and the tensioner 61 are synchronized. In this case, the tensile membrane attaching/detaching device 4 is guided by the guideline 60 and the first tensile membrane 8A and is lowered while maintaining a predetermined orientation, so there is no need to operate the thruster 95.

Next, in the same manner as in the case of the first tensile membrane 8A, the tensile membrane attachment/detachment device 4 is seated on the anchor 9 and fixed to the guide post 50, and as described above, the lower end of the second tensile membrane 8B is is locked to the anchor 9, the socket clamp filter 5 is released, and the socket holding arm 66
is retracted, and then the tensile membrane attachment/detachment device 4 is hoisted up near the bottom of the column 2 with a lever.

Even if the tensile membranes 8C and 8D can be installed sequentially after the third grain,
Installation is carried out in the same manner as when installing the second tensile membrane, but when installing the sixth tensile membrane 8Bk, the middle tension leg guide arm 64 is protruded and the arm 64 is
The second tension film 8B is held by the tension film guide roller 36 attached to the tension film guide roller 36, and when installing the fourth tension leg 8D, the upper tension leg guide arm is protruded and the tension film attached to that arm is held. The tensioning leg 8C of the filter main mouth is gripped by the leg guide roller.

As shown in FIG. 61, after all the lower ends of the four tension legs 8A to 8D are locked to the anchors 9, the guide rod 1 inlet O is cut by an appropriate means near the upper end of the guide post 50. The guideline button is wound up and recovered by the guideline winch 2, and is then returned to the guidepost) 5
After the fixation of the tensile membrane attachment/detachment device 4 to 0 is released,
The tension membrane attachment/detachment device 4 is suspended from the winch 5Vc for lifting and lowering the attachment/detachment device. In this case, the tension membrane attaching/detaching device 4 is lifted up while being guided by the tension legs 8C of the filter main opening.

Note that the upper ends of the second to fourth main opening tension legs are also processed in the same procedure as in the case of the first tension leg.

Next, when the tensile membrane attachment/detachment device 4, which is guided and lifted up by the tension legs 8C, reaches near the bottom of the column 2, it is stopped at that position, and then, after the tension leg guide rollers 6 are released, the - After the pulling arm 34 is retracted and the tension film attachment/detachment device 4 is adjusted to a predetermined orientation by the operation of the thruster 95 and the rotation of the swivel table 21, the tension membrane attachment/detachment device 4 is adjusted to a predetermined direction by the lifting winch 5v. The device 4 is suspended and stored in the lower chamber 6, and after the bottom lid 7 is closed, the seawater in the lower storage chamber is discharged.

The screw jacks 90 in each upper end unfixing device 96 are then operated to apply a uniform predetermined tension to each tension leg.

When the floating structure 1 swings due to an external force such as waves after all the tension legs 8A to 8D have been erected, the impact force acting on the tension legs is absorbed by the fluid pressure cylinder 9 of the upper end unfixed device 9.
2.

Next, the case of replacing the tension leg will be explained.

First, the winch 18 with a trolley is moved from the movable rail 16 on the turntable 15 to the fixed rails 17 at the bottom of both sides of the reel 11 corresponding to the tension leg to be replaced, the reel 11 is set on the winch 18 with a trolley, and then The unwrapped wire rope of the receptacle for pulling up the pulling leg is suspended from the through hole of the turntable into the upper end unfixed chamber 89, and then the end of the unwrapped wire rope is connected to the upper end socket 97 of the pulling leg to be replaced. Thereafter, in the tensioner chamber 70, the tensioner 61 is set on the tension leg to be replaced and the track of the tensioner 61 is closed.

Next, after water is poured into the lower storage chamber B of the column 2, the bottom lid 7 of the lower storage chamber 6 is opened, and the winch 5 for lifting and lowering the attachment/detachment device is operated in the unwinding direction, and the tensile membrane attachment/detachment device 4 is moved to the column. The tensile membrane attachment/detachment device 40 is lowered to a position slightly below the bottom of the membrane 2, and then the tension membrane attachment/detachment device 40 is operated by the thruster 95.
By rotating and rotating the swivel table 21, the tensile membrane attachment/detachment device 4
direction is adjusted.

Next, after the tension leg guide arm 4 corresponding to the six tension legs 8B to 8D (see Figure i32 and Figure 66) that are to be replaced is protruded, each of the three tension legs is It is gripped by a tension leg guide roller roller 6 provided on the arm roller 4, and then the winch 5 for lifting and lowering the attaching/detaching device is operated in the rewinding direction, and the tension gallstone removal device 4 is pulled by the various tension legs as it is replaced. She is being lowered while being made to cum.

After the vertical hole 48 at the center of the tension membrane attaching/detaching device 4 is fitted into the guide post 50 of the anchor 9 and the tension leg small detachment device R4 is seated on the anchor, the small diameter of the guide post 50 is removed by the guide post clamp 6. H%96 is grasped and the tensile membrane attachment/detachment device 4 is fixed to the anchor 9.

Next, after the socket holding arm 6 is protruded, the socket clamp 5 grips the tip socket 57 corresponding to the tension ra++ to be replaced, and then the tensioner of the tension leg to be replaced becomes about the weight of the tension leg itself. Until the socket support 91 is moved downward by the screw jack 90, the weight of the tension leg to be replaced is transferred to the tensioner 6.
Supported by 1VC.

Next, while the tensioner 61 suspends and lowers the tension leg by the required stroke for separating the tension leg, the socket clamp 65 is pushed down by the lifting fluid pressure cylinder 45.

Next, after the socket locking device in the insertion hole 5B of the anchor 9 and the guide post crank groove 3 are released, the winch 5 for raising and lowering the carriage lifting winch 189 and the tensioner 61 are operated in synchronization, as shown in FIG. As shown in FIG.

Next, after the socket clamp filter 5 is opened, the tip of the tensile membrane is lifted up by the tensioner 61 until it reaches the operation chamber 19, and then the cart 86 is pushed out from the swivel base 21 and set in a predetermined position, and then the The connection block 58 and the bell mouth 59 are removed from the tip socket 57 on the trolley 86, and then the trunk of the tensioner 61 and the socket supports 1 and 91 are opened and wound onto the reel 11 rotated by the winch 18 with the trolley. taken and recovered.

Next, in the same manner as when installing the second tensile membrane,
The new tensile membrane is locked to the anchor] 1. Afterwards, the tensile membrane attachment/detachment device 4 is lifted up. In this case, the four tensile membrane attachment/detachment devices are moved while being guided by six tensile membranes that are not replaced.

Next, the upper end of the new tensile membrane is fixed as described above, and the tensile membrane attachment/detachment device 4 is moved to the lower storage chamber 3V as described above. - Stored.

When carrying out the present invention, the tensioner 61 may have any structure other than that shown in the drawings.

According to the present invention, in the tension leg mooring type marine floating structure in which the column 2 of the floating structure 1 is connected to the anchor 9 installed on the seabed ground by a plurality of tension membranes 8, the lower part of the column 2 The tensile membrane attachment/detachment device 4 placed in the storage chamber 3 is suspended and supported by a hanging rod extended from the attachment/detachment device hole R and the lowering winch 5.
The tension membrane attachment/detachment device 4 is lowered toward the anchor 9 while being guided by at least one tensile membrane by operating the tension membrane attachment/detachment device 4 in the feeding direction.
Using the tension membrane 8 as a guide, the anchor 9 can be easily lowered to a predetermined position, and then the tension membrane to be replaced can be fixed to the tension membrane attaching/detaching device 4, and the anchor 9 and After untying the coupling, the long-leg elevating device and the winch 5 for elevating the attachment/detachment device are operated in the winding direction, and the tension membrane attachment/detachment device 4 is guided by the non-replaceable tensile membrane to move the bottom part of the column 2. By lifting it up close, the tensile membrane attaching/detaching device 4 can be removed using the non-replaceable tensile membrane as a guide.
The lower part of the tensile membrane to be replaced can be easily lifted up to the lower part of the column 2 in a stable state, and then the tensile metal to be replaced can be removed from the tensile membrane attachment/detachment device 4, and the lower part of the new tensile membrane can be attached to the tensile membrane attachment/detachment device. 4, and then the tensile membrane attachment/detachment device 4 is lowered to the anchor 9 while being guided by the tensile membrane, and then the lower end of the new tensile membrane is attached to the anchor 9.
After the new tensile membrane is locked, the tensile membrane attaching/detaching device 4 is removed from the new tensile membrane and lifted while being guided by the tensile membrane, so that it can be lowered and locked in a stable state toward the new tensile metal anchor 9. Moreover, after a new tensile membrane is secured to the anchor 9, the tensile membrane attachment/detachment device 4 can be easily lifted into the column 2 and recovered.

[Brief explanation of the drawing]

The drawings show one embodiment of the invention, in which FIG. 1 is a perspective view of a floating structure equipped with a reel wrapped with a tensile membrane, FIG. 2 is an enlarged perspective view of a part of the structure, and FIG. 4 is a vertical sectional side view showing an enlarged part of FIG. 6, FIG. 5 is a sectional view taken along line A-A in FIG. 6, and FIG. A cross-sectional plan view showing a part of the figure enlarged, No. 7
The figure is a sectional view taken along the line B-E in Figure 6, and Figure 8 is a cross-sectional view taken along the line C-C in Figure 6.
9 is a bottom view of FIG. 6, FIG. 10 is a vertical sectional side view of the bottom lid handle, FIG. 11 is a plan view showing the joint between the bottom lids, and FIG. 12 is a tensile membrane. FIG. 16 is a longitudinal side view showing the state in which the attachment/detachment device is fixed to the anchor; FIG.
4 is a sectional view taken along the line E-E in FIG. 12, FIG. 15 is a longitudinal sectional front view of a part of the tensile membrane attaching/detaching device, FIG. 16 is a perspective view showing the anchor and accessories, and FIGS. 17 to 19. 20 is a side view showing the order of connecting and lowering the tip socket, the connector block, and the bell mouth, and FIGS. 20 to 61 are perspective views showing the order of attaching the tension legs. FIGS. 62 and 66 are perspective views showing the order in which the tensile membrane is replaced. In the figure, 1 is a floating structure, 2 is a column, 6 is a lower storage chamber, 4 is a tension adhesive/removal device, 5 is a winch for lifting and lowering the attachment/detachment device, 6 is a hanging rope, 7 is a bottom lid, 8 is a tensile membrane, 9 is an anchor, 11 is a tension leg observation reel, 15 is a turntable, 18 is a winch with a trolley, 21 is a swivel base, 2 is a guideline winch, ', 60 is a guideline, 62 is a buoy, and a roller is for holding a socket. An arm, 64 is a loam for a tension guide, 5 is a clamp for a socket, 6 is a roller for a tension guide, 42 is a fluid pressure cylinder for moving in and out, 45
48 is a hydraulic cylinder for lifting and lowering, 48 is a vertical hole for inserting a guide post, 61 is a tenon/jona, 63 is a runzo for a guide post, 64 is an arm for setting an orientation, 65 is a fluid pressure cylinder for moving in and out, 67 is a gripping fluid A pressure cylinder, 80 is a swing drive device, 9 is a partially unfixed end device, and 95 is a thruster. Figure 22

Claims (1)

[Claims] In a tension leg moored marine floating structure in which the column 2 of the floating structure 1 and the anchor 9 installed on the seabed ground are connected by a plurality of tension membranes 8, the floating structure is arranged in the lower storage chamber 6 of the column 2. The tensile membrane attaching/detaching device 4 is suspended and supported by a hanging rope drawn out from a winch 5 for lifting and lowering the attaching/detaching device, and the winch 5 is operated in the payout direction to move the tensile membrane attaching/detaching device 4 to at least one tensile membrane. Next, the tensile membrane to be replaced is fixed to the tensile membrane attaching/detaching device 4 and disconnected from the anchor 9, and then the tensile membrane lifting device and the winch 5 for lifting/lowering the attaching/detaching device are lifted. is operated in the winding direction, the tensile membrane attachment/detachment device ftt4' is lifted up to near the bottom of the column 2 while being guided by the non-replaceable tensile membrane, the tensile membrane to be replaced is removed from the tensile membrane attachment/detachment device 4, and a new tensile membrane is installed. The lower end of the winch 5 is fixed to the tension chest release device 4, and then the winch 5
is operated in the feeding direction to suspend the tensile membrane attachment/detachment device 4 from the anchor 9 while being guided by at least one tensile membrane, and then lock the lower end of the new tensile membrane to the anchor 9. A method for replacing a tension membrane in a tension leg moored marine floating structure, which comprises removing the tension membrane attachment/detachment device 4 from the new tension membrane and hoisting it up while being guided by the tension membrane.