OA11691A - Method and apparatus for suction anchor and mooring deployment and connection. - Google Patents

Abstract

A method for deployment of mooring systems for mobile offshore drilling units and for connecting the same to the mooring lines (76) thereof. An anchor handling vessel (10) having a stern roller (12), one or more suction anchors (70), a deployment connection (73) and a mooring connection (88). The anchor handling vessel has an anchor deployment mechanism incorporating a handling line having a quick-disconnect socket connector (74) for accomplishing movement of the suction anchor over the stern roller to the sea bottom. After deployment of the suction anchor, the handling line is disconnected from the connection and the anchor handling wire (78) is moved from the deployment connection to the mooring connection for mooring the suction anchor to the offshore drilling unit. A plurality of mooring strings are deployed in this matter to properly station the drilling unit.

Description

'1169 1 -1-

TITLE : METHOD AND APPARATUS FOR SUCTIÔN ANCHOR AND

MOORING DEPLOYMENT AND CONNECTION

BACKGROUND OF THE INVENTION

The benefit of United States Provisional Application Serial No. 60/045,735 filed onMay 6, 1997 by Billy J. Bergeron and entitled Method and Apparatus For Suction Anchor 5 And Mooring Deployment And Connection, is hereby claimed.

FIELD OF THE INVENTION

This invention'relates generally to mooring line connections for subsea operations,particularly for suction anchor pile moorings. More particularly, this invention concems a wire socket connecter mechanism which facilitâtes subsea connection and reconnection of 10 mooring lines of semi-submersible drilling rigs, production and drilling platforms and the liketo suction anchor piles and other anchor devices. This invention also concems deploymentand installation of suction anchor piles and a mooring wire assembly with retrieval buoys andsling on one of its ends. The invention also concems addition of buoys to mooring wiresections and connecting the mooring wire to a vessel to be moored. The procedure also 15 concems the mooring wire, buoy recovery, wire retrieval and suction anchor pile recoveryand a procedure for recovering mooring wires and other apparatus.

DESCRIPTION OF THE PRIOR ART

Présent procedures for installing subsurface anchors and establishing mooring theconnection between the anchors and a semisubmersible drilling rig has required the presence 20 of two service vessels, one an anchor handling vessel equipped with an Α-frame type hoistfor transporting the anchor and for lifting the anchor. The second service vessel is used to 11 δ 9 1 -2- pull the hoisted anchor from the anchor handling vessel and to assist the anchor handlingvessel in deployment of the anchor. When a large A-frame type hoisting mechanism isutilized for lifting the anchor ffom the anchor handling vessel, particularly in rough seaconditions, the heavy and bulky anchor and its peripheral equipment may swing to and from 5 and may strike and damage other equipment in the immédiate vicinity of the A-frame typehoisting mechanism. Additionally, since personnel will typically be required to ascend theA-frame type hoisting mechanism, such as to string wire rope and conduct other activities,the heavy swinging load of an anchor that is supported by the hoist constitutes and themovement of the A-frame hoist along with the vessel présent significant hazards to the safety 10 of workers whether présent on the deck of the vessel or on the A-frame hoist or in the rigging of the hoist. It is désirable therefore to provide a System for transportation and deployment of ·» subsea anchors and mooring lines which does not constitute a safety hazard for workers. It isalso désirable to provide a System for transportation and deployment of subsea anchors andmooring lines and which minimizes the potential for damage to the vessel and its equipment 15 even under circumstances where the sea conditions are rough during anchor deployment andrecovery and during deployment and recovery of mooring lines. It is also désirable toprovide a System for the handling, deployment and recovery of subsea anchors andinstallation and recovery of mooring lines which effectively minimizes the cost of stationingand mooring a semisubmersible vessel such as a drilling rig for well drilling operations. 20 Another significant disadvantage of using two service vessels for anchor transportation, handling and deployment is simply the duplication of costs when two vesselsare utilized rather than a single vessel. It is désirable therefore to provide a System, utilizinga single anchor handling vessel, which is capable of transporting, deploying and retrievingsubsea anchors in deep water conditions and is also capable of accomplishing connection and 25 disconnection of mooring lines to permit drilling vessels to be quickly and efficiently 116 9 1 -3- stationed and restationed, thus conserving not only service vessel time and conséquent costbut also conserving drilling vessel time and conséquent cost.

SUMMARY OF THE INVENTION

It is a principal feature of the présent invention to provide a novel System for anchor5 transportation, handling deployment and recovery which is accomplished by a single anchor handling vessel.

It is also désirable to provide a System for anchor transportation, handling deploymentand recovery and which enables a plurality of subsea anchors to be simultaneouslytransported and permits the anchors to be individually deployed and recovered even under 10 conditions of rough seas.

It is another feature of the présent invention to provide a novel System for anchor* * transportation, handling, deployment and recovery wherein the anchors, particularly suctionpiles, are moved over the stem roller of a single anchor handling vessel during deploymentand retrieval operations. 15 It is an even further feature of the présent invention to provide a novel System for anchor transportation, handling, deployment and recovery which facilitâtes a unique singlevessel handling System enabling anchor connections and disconnections with a minimum ofexpended time and with a minimum of cost.

The common feature of the présent invention is the installation of a mooring anchor 20 without the mooring line attached at the time of deployment and embedment in the seabottom. Prior to the invention of the subsea connector shown in Figs. 21-25 hereof it was notpossible to install an anchor in deeper water without the mooring line being attached to theanchor at the time of deployment. Heretofore, there has been no practical means ofconnecting a mooring line to an anchor embedded in the sea bottom in water depths that 25 could not be manually accessed. 116 9 1 -4-

There is considérable advantage in being able to install mooring anchors without themooring line attached. Several styles of advanced high holding power anchors for use indeeper water depths need to be deployed and embedded with a deployment line that has anattachment point apart from the preferred point of attachment of the mooring line.Previously, it had been necessary to deploy such anchors with both a deployment lineextending from the principal deployment vessel and a separate mooring line extending from asecond deployment vessel in order to prevent the two lines from becoming entangled withone another. The requirement for the use of two anchor handling and deployment vessels hasadded considérable cost and logistical difficulty to the anchor and mooring Systemdeployment process. The method of mooring set forth herein is designed to specificallyavoid this difficulty. In vessel anchoring situations such as is disclosed in U.S. Patent No.4,347,012 of Glidden the basic anchor base structure “A” must be deployed and installed atthe sea bed with the pull line “P” attached or by threading the pull line P about the pulleys 18and 19 and through the side opening 25 after the anchor base has been installed. While thisactivity can be accomplished in shallow water conditions, such as by a diver, it cannot beaccomplished when water depth exceeds the working depth of divers. Thus, for deep wateranchor deployment and installation, the anchor System of Glidden would require the use totwo vessels, one vessel to handle the anchor base and another vessel to manipulate the pullline and prevent rotation of the anchor base due to cable unwinding during deployment and tothus keep the pull line from tangling with the anchor deployment line. The présent inventionis designed to promote anchor deployment with a single anchor handling and without any linebeing attached other than the anchor deployment line. Consequently, wound cable may beused for anchor deployment and anchor rotation by cable unwinding during deployment doesnot detract from the deployment procedure, since no cable fouling can be caused by anchorrotation. The présent invention permits efficient single vessel, single line anchor deployment 116 9 1 -5- and also facilitâtes simple and efficient deployment line disconnection and mooring lineconnection via the use of ROVs. Later, when vessel mooring is no longer needed, the présentinvention also facilitâtes mooring line disconnection and anchor retrieval, again through theuse of a single vessel and a single lifting line which permits rotation of the anchor during 5 recovery from the sea bed.

There are several principal features of the mooring method of the présent inventionthat prove to be practical and advantageous, the most simple of which is the deployment ofthe anchor with a single line from a single vessel with no mooring line attached as shown inFigs. 14 and 15. Once the anchor is embedded, the mooring line is attached as shown in 10 Fig. 16 by the same or another vessel and laid on the sea bed or attached to a buoy which canbe retrieved later, or the mooring line is attached to the anchor at some later date. Thismethod provides the most efficient installation of the anchor and the most flexible arrangement for mooring line attachment to the anchor and connection to the marine structure to be moored. 15 The présent invention envisions the use of Remote Operated Vehicles, called ROV’s to operate the connector that connects the mooring line to the installed anchor. In fact, theconnector is specifically designed to handle the mooring loads and be operated by the ROV.As such, the connector is a unique invention and this method of mooring that it enables isalso a unique invention. 20 Briefly, the various objects and features of the présent invention are realized by providing an anchor handling vessel which is equipped to mount a plurality of subsea anchorsalong the sides of the deck, leaving the central part of the deck for anchor handling. Thevessel is equipped with a track mechanism which is used to move a selected anchor laterallyfrom its tethered position along a side of the vessel and to position the anchor in substantial 25 alignment with the longitudinal centerline of the vessel deck. The track mechanism is also 115 9 1 -6- operated to move the selected anchor linearly toward the stem roller of the vessel and tolaunch the anchor over the stem roller so that it is suspended by a support and handling lineor lines. The suction pile type anchor is lowered to its desired position and installed inconventional manner. The anchor handling line may be utilized as a section of the mooring 5 line, in which case its connection for lifting and supporting the anchor is released and the lineis moved to a mooring connection of the anchor and reconnected. A remote operating vehicle(ROV) may be used for this purpose or a remotely operated quick-release connector may beutilized to release the anchor support and handling connection and to establish the mooring connection.

10 BRIEF DESCRIPTION OF THE DRAWINGS

The various objects and advantages of this invention will become apparent to thoseskilled in the art upon an understanding of the following detailed description of the invention,read in light of the accompanying drawings which are made a part of this spécification and inwhich: In the Drawings: 15 Fig. 1 is a plan view showing the stem section of an anchor handling vessel designed for suction anchor deployment, mooring wire deployment and handling and showing foursuction anchors in loaded position on the stem of the vessel in préparation for deploymentthereof;

Fig. 2 is a plan view similar to that of Fig. 1 and showing one of the suction anchors 20 having been maneuvered to its deployment position with respect to the stem roller of thevessel in préparation for suction anchor deployment;

Fig. 3 is a plan view of a track roller assembly for on deck handling of a suctionanchor pile for deployment or retrieval operations;

Fig. 4 is an elevational view of the track roller assembly of Fig. 3; 116 9 1 -7-

Fig. 5 is a partial plan view of the track roller assembly of Fig. 3 showing the top andbottom roller arrangements thereof in detail;

Fig. 6 is an end elevational view of the track roller assembly of Figs. 3-5 and showinga hydraulic jacking mechanism for latéral movement of the track roller assembly; 5 Fig. 7 is a plan view similar to that shown in Figs. 1 and 2 and showing I-beam tracks mounted on the anchor handling vessel deck to permit transverse movement of track rollersduring deployment or recovery operations for suction anchor piles;

Fig. 8 is side elevational view of a service vessel showing a suction anchor pile inposition for launching over the stem roller of the vessel and showing an initial arrangement 10 of handling lines;

Fig. 9 is a side elevational view similar to that of Fig. 8 and showing overboarding of s the suction anchor pile and also showing the relationship of the handling lines to the anchorhandling vessel and the suction anchor pile;

Fig. 10 is a side elevational view similar to that of Fig. 9 and showing the suction15 anchor pile leaving the stem roller of the vessel in route to its proposed site in the sea floor;

Fig. 11 is a side elevational view similar to that of Fig. 10 and showing the suctionanchor pile just under the stem of the vessel and further showing disconnection of theoverboarding hook from the sling of the suction anchor pile by remote operating vehicle(ROV) handling; 20 Fig. 12 is a side elevational view similar to that of Fig. 11 and showing the suction anchor pile being lowered with a mooring wire to a point near the sea floor;

Fig. 13 is a side elevational view of the anchor handling vessel similar to that of Fig.12 and showing self-penetration of the suction anchor pile into the sea floor with the ROVmonitoring and directing orientation of the suction pile and having the capability to assist in 25 suction pile installation; 1 1 b 9 1 -8-

Fig. 14 is a side elevational view similar to that of Fig. 13 showing a further step insuction anchor pile deployment as water is evacuated from the suction anchor pile by the ROV;

Fig. 15 is a side elevational view similar to that of Fig. 14 showing the suction anchor5 pile fully deployed and showing release of the hook of the lowering line from the suction anchor pile by ROV assistance;

Fig. 16 is a side elevational view similar to that Fig. 15, showing the [ROV] suctionanchor being connected to the main mooring extension wire which is suspended substantiallyvertically from the vessel to the suction anchor and showing movement of the 10 lowering/mooring wire from the suction anchor pile support and reconnection of the mooring wire to the main mooring wire extension of the suction anchor pile; ·»

Fig. 17 is a side elevational view similar to that of Fig. 16, showing intermediatemooring wiring installed in connection with the suction anchor mooring wire and showingsubsurface buoys being connected to the intermediate mooring wire and also showing a 15 surface buoy, if needed, being connected to the intermediate mooring view;

Fig. 18 is a side elevational view similar to that of Fig. 17 a semi-submersible drillingvessel, mobile offshore drilling unit (M.O.D.U.), showing the M.O.D.U, being moved to asite where subsurface anchors and mooring wires hâve been previously deployed andshowing an anchor handling vessel recovering the surface buoy connected to a rig wire, 20 utilizing a short section of chain and also installing a J-chaser stopper device in the mooringwire System;

Fig. 19 is a side elevational view similar to that of Fig. 18 showing the anchorhandling vessel winch wire lowering a mooring string utilizing a J-lock chaser device, withthe J-lock chaser device being stripped back to the M.O.D.U., i.e., rig until ffee; 118 9 1 -9-

Fig. 20 is a side elevational view similar to that of Fig. 19 showing final connection ofthe mooring string to the rig.

Fig. 21 is a front elevational view of a socket connector that is adapted for connectionto a mooring or heaving line and which is adapted to receive a socket that is connected to 5 another line section to thus permit quick and efficient connection and disconnection ofmooring line sections;

Fig. 22 is a sectional view taken along line 22-22 of Fig. 21 and showing the internaigeometry of the socket connector as well as the geometry of the connecting eye thereof;

Fig. 23 is a plan view of the socket connector of Fig. 21 ; 10 Figs. 22A-22A through22F-22F are sectional views taken along respective section fines 22A-22F of the socket connector of Fig. 22 to thereby show the cross-sectional * configuration of the connection bail at various locations along the length thereof;

Fig. 24 is a sectional view of a socket element adapted to be fixed to a mooring fine or mooring connector by zinc or polymer connection and further adapted for seated assembly 15 within the wire socket connector of Figs. 21-23; and

Fig. 25 is a plan view of the socket element of Fig. 24, with undercut and bottom surfaces thereof being shown in broken line.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 20 Referring now to the drawings and first to Fig. 1, the stem deck of an anchor handling vessel, also referred to therein to an anchor handling vessel, is shown generally at 10 andincorporâtes a stem roller 12 over which suction anchor piles and other apparatus is launched.The stem of the anchor handling vessel is pitted to receive 4 suction anchor piles shown at14, 16, 18 and 20 which are secured to the anchor handling vessel by individual anchor 25 handling assemblies which are shown in greater detail in Figs. 3-6. The deck of the vessel isprovided with transverse beams or rails 22, 24 and 26, one which being shown in Fig. 6 at 22. -10-

Track roller assemblies are provided as shown in Figs. 3, 4 and 5 with one of the track rollerassemblies, shown generally at 28 in Fig. 3, having parallel track members 30, 32 and 34which are interconnected by transverse structural members 36. Roller assemblies 38, and 39 are mounted to the outer parallel structural members 30 and 34 and to the transversestructural members as is more clearly évident from the end view of Fig. 6. Rollers 50 and 52 are mounted to the parallel structural members 30 and 34 for rotation and are provided forcontact by parallel support members 54 and 56 of an anchor cradle 58 to thereby permit linearmovement of the cradle and the suction anchor pile supported thereby for launching thesuction anchor pile overboard the stem roller of the vessel. Altematively, the structuralsupport members 54 and 56 may comprise elongate supports that are fixed along a side of thesuction anchor pile. The suction anchor pile 58 is supported directly by the rollers 50 and 52 s to permit its effective launching and retrieval. Latéral guide members 60 and 62 are weldedor otherwise fixed to the outer parallel structural members 30 and 34 and function to maintaina proper relationship of the support members 54 and 56 to the rollers 50 and 52 as the suctionanchor pile is moved linearly during its launching or retrieval. Guide members 42 and 42 aredisposed in guiding engagement with the upper flange 40 of the I-beam 22 and thus permitthe track roller assembly to be moved laterally relative to the deck of the anchor handlingvessel 10 to position a track roller assembly for launching an anchor device or for receivingan anchor device during its recovery. This latéral positioning movement of the track rollerassembly is controlled by at least one latéral positioning actuator such as a hydraulic jackassembly 44 shown in Fig. 6. One or more lift assemblies, such as the hydraulic liftassemblies 45 and 46, connected to the track roller assemblies, are positioned for actuatingengagement with the upper surface 48 of the I-beam 22 and are controllably energized to liftthe roller track assembly and the anchor device supported thereby sufficiently to permit theactuator assembly 44 to accomplish latéral movement of the track roller assembly.

-11-

Referring now to Fig. 8 and subséquent figures, the anchor handling vessel 10 isshown with one of the suction anchor piles 70 located with its lower end at the stem roller 12of the vessel and with its deployment sling 72 being connected by a wire Socket connectorshown generally at 74 to the upper winch wire 76 of the vessel winch System which is the 5 lifting and lowering winch 77. Another winch wire 78 is shown to be connected to a suctionanchor pile deployment sling 80 that is located intermediate the upper and lower ends of thesuction anchor pile. The suction anchor pile is shown with its main mooring wire extension82 secured to a mooring wire connector 84 of the suction anchor pile and with its upper endbeing secured against one side of the suction anchor pile by a mooring wire positioning lock 10 86. At the upper end of the main mooring wire extension, there is provided a tapered Socket member 88, which may be of the type shown in Figs. 12 and 13 thereof. The deployment s sling 72 is connected to the suction anchor pile 70 by a deployment connector 73 which maybe in the form of an elastomer support to provide a cushioning capability between the suctionanchor pile and the anchor lifting and handling sling 72. 15 From the position of the suction anchor pile shown in Fig. 8, the suction anchor pile is moved over the stem roller 12 until such a time as its weight is supported by the winch line76 via the socket connector 74 and the lifting and handling sling 72 as shown in Fig. 9.Movement of the suction anchor continues as shown in Fig. 10 until its weight is largelysupported by the overboarding sling 80 and the support for the anchor begins to transfer from 20 the winch line 78 to the lifting and lowering winch line 76 of the lifting and lowering winch77. As shown in Fig. 11, the suction anchor pile is located just under the stem of the anchorhandling vessel and its weight is supported by the winch line 76 via the socket connector 74and the deployment sling 72. At this point, the winch line 78 is not needed and thus itsoverboarding hook 90 can be disconnected from the overboarding sling 80. A remote 25 operating vehicle (ROV) 92 shown in Fig. 11, may be utilized to manipulate the overboarding -12- 11 δ 9 1 hook and release it from the overboarding sling. The ROV is operationally and controllably coupled with the vessel 10 via a power and service cable 94 under control by personnel of the vessel.

After the primary mooring wire has been deployed, as shown, with its syntactic buoy5 positioning the terminal end for recovery, the ROV 92 and lowering and heaving wire 76with its lowering hook 90 will be recovered to the anchor handling vessel. After this hasbeen done, the anchor handling vessel is loaded with wire and buoys for rig connection andthe ROV 92 functions to connect the hoisting and lowering wire 76 with its hook 90 to aconnecter of the mooring line as shown in Fig. 18. From the condition shown in Fig. 18, the 10 primary mooring wire section which can be the deployed anchor handling line 76 is hoistedto the anchor handling vessel and is pulled over the stem roller of the vessel as shown. With s the terminal end of the primary mooring wire located on the anchor handling vessel, anintermediate section 116 of mooring wire is connected to the primary mooring wire sectionby a connecter 114. The intermediate mooring wire section 116 is then provided with one or 15 more buoys as shown at 118 and 120 for supporting the intermediate mooring wire 116 and for providing the completed mooring line assembly with buoyant support intermediate itslength. After the buoys 118 and 120 hâve been attached to the intermediate mooring wire116 as shown in Figs. 17 and 18, a winch line of the anchor handling vessel, which isconnected to the intermediate mooring wire 116 above the uppermost buoy 118, will be paid 20 out from the anchor handling vessel to thus allow the vessel to back into the rig to receive the mooring wire 124 of the rig. The mooring wire of the rig will be paid out from its winch sothat, after its connection to the intermediate mooring wire 116, the mooring wire installationfrom the rig to the suction anchor pile can be controlled by the on-board winch of the rig. Atthis point of the mooring operation, as shown in Figs. 18 and 19, the upper winch wire 122 of 25 the anchor handling vessel is heaved to a position adjacent the stem of the vessel to expose 11 6 Ο 1 -13- the mooring wire section at a connector 126 that is located immediately above theconnection. The rig mooring wire 124 is then connected to the intermediate mooring wiresection 116 at a connector 126 that is located immediately above the upper buoy 118 of theintermediate mooring wire as shown in Fig. 18. The mooring wire installation is completed 5 by lowering the rig mooring wire 124 and the intermediate mooring wire 116 with its buoysby a winch line 126 having a J-chaser 128 connected thereto as shown in Fig. 19. When themooring wire installation reaches its proper catonary, the J-chaser will simply becomeunhooked from the mooring wire and may then be recovered to the vessel. The mooring wirewinch System of the vessel will then adjust the mooring wire assembly as is proper stationing 10 of the rig at its proper location relative to the sea floor B.

When it is appropriate to disconnect the rig from its mooring wire installation, the > anchor handling vessel 10 will position its heaving wire with the J-chaser 128 in contact withthe mooring wire 124 of the rig. The anchor handling vessel will then move away from therig, thereby causing the J-chaser 128 to move along the rig mooring wire 124 until it cornes 15 into contact with a short chain located immediately above the upper buoy 118 of theintermediate mooring wire section. After this has been done, the heaving line and J-chaser isheaved to a position exposing the short recovery chain above the upper buoy 118 and thusalso exposing the connection between the rig mooring wire 124 and the intermediate mooringwire 116. The rig mooring wire 124 is then disconnected from the intermediate mooring wire 20 116 at the vessel deck and is recovered to the rig by the rig winch System. It should be borne in mind that the connector 126 for making the connection of the rig mooring wire 124 withthe intermediate mooring wire, may be in the form of a quick release type socket connector.In fact, each of the connectors along the length of the mooring wire installation may bedefmed by wire socket connectors, if desired, or may take the form of any other suitable 25 mooring wire connector without departing from the spirit and scope of the présent invention. -14- 116 9 1

After the rig mooring wire has been disconnected and recovered, the anchor handling vesselwill lower a subsea retrieval tool to a depth below the lower buoy 120 shown in Figs. 18 and19 and will then connect the subsea retrieval tool to the intermediate mooring wire 116 belowthe buoys. The ROV 92 can be utilized for this purpose. The subsea retrieval tool is thenheaved to the deck of the vessel thereby causing the buoys 118 and 120 to be decked withoutdamage because the weight of the intermediate mooring wire 116 will not be présent on thebuoys are as they are heaved over the stem roller of the anchor handling vessel. After thebuoys hâve been secured on deck, the intermediate mooring wire section 116 is thenrecovered by the anchor handling vessel. After the intermediate mooring wire section hasbeen recovered to the anchor handling vessel, as shown in Fig. 18 so that the mooring line connecter 114 is on the deck of the vessel the connecter will be disconnected and the vessel crew will reinstall a conventional syntactic buoy with a deployment/recovery sling (notshown) and begin to deploy the primary mooring wire section 76 to the océan bottom. Thesyntactic buoy connected to the primary mooring wire section, the primary mooring line isthen lowered to the sea floor B by the winch wire 78 and deployment and recovery hook 90.The ROV 92 is deployed from the anchor handling vessel 10 and is used to disconnect thedeployment recovery hook 90 of the winch wire from the sling above the syntactic buoy.After the hook 90 has been disconnected from the sling, the winch wire 78 anddeployment/recovery hook 90 are then recovered to the anchor handling vessel, leaving theprimary mooring wire 76 lying on the sea floor with its terminal end being positioned abovethe océan bottom by the syntactic buoy so that its sling will be positioned for immédiatereconnection to the intermediate mooring wire section 116 as needed. After this has beendone, the anchor handling vessel can then proceed to the rig as shown in Figs. 18 and 19 torepeat the section anchor pile and mooring line installation for another one of the plurality ofsuction anchor pile and mooring line assemblies of the rig mooring System. 116 9 1 -15-

It may be appropriate at some point to recover the suction anchor pile 70 so that itmay be réinstallée! at some other location as may be desired for different stationing of the rigrelative to the sea floor B. This is accomplished by connecting a vessel winch line to theheaving sling of the primary mooring wire 76 and heaving the primary mooring wire onto the 5 anchor handling vessel until it is oriented substantially vertically above the suction anchorpile 70. With the primary mooring wire so positioned, the ROV 92 is then utilized toessentially pivot the mooring wire connector extension 82 about its connection 84 with thepile so that it enters an entrapment slot 83 of the suction anchor pile. The ROV will thenmanipulate a lock on the suction anchor pile to secure the mooring wire extension 82 within 10 the entrapment slot 83 so that the mooring line extension 82 is retracted to its subséquent vertical orientation. After this has been accomplished, the ROV 92 will be moved to the * subsea connector 74 and will disconnect the connector from the mooring wire connectorextension 82. Since the mooring wire connector extension will be locked within theentrapment slot of the suction anchor pile, it will remain substantially vertically oriented with 15 its socket element 88 positioned for subséquent reconnection to a mooring wire section insimple and efficient manner. The ROV will then move the subsea connector 74 from thesocket 88 of the mooring wire extension 82 to the anchor lift sling 72 in préparation forlifting the suction anchor pile to the deck of the anchor handling vessel. Then the ROV 92 will be maneuvered for connection of its fluid transfer line 96 with the fluid transfer 20 connection 98 of the suction anchor pile. The pumps on the vessel are then energized,forcing water through the connection 98 into the suction anchor pile and thus developing adifferential pressure induced force that moves the suction anchor pile upwardly.Simultaneously, a heaving force is applied tôt he winch wire 76 of the vessel, which, throughthe wire socket connector 74, lifts the suction anchor pile from its embedded relation within 25 the sea floor until the section anchor pile is located within the 15’ silt line of the sea floor. At -16- this point, the ROV will disengage its fluid transfer conduit 96 from the suction anchor pilecoupling 98. After the ROV has been disconnected, the suction anchor pile is heavedupwardly by the winch line 76 until the suction anchor pile is located at a predetermineddepth, i.e. about 60’ below the anchor handling vessel. With the suction anchor pile 70 5 stationary below the stem of the vessel, as shown in Fig. 11, the ROV 92 will be utilized toconnect a recovery hook 90 of a recovery winch line 76 or 78 as the case may be 78 to thedeployment/recovery sling 80 of the suction anchor pile. The recovery winch line 76 or 78 isthen heaved moving the suction anchor pile upwardly toward the stem of the vessel andcausing the deployment/recovery wire 76 to become slack. Heaving is continued, causing the 10 deployment/recovery sling 80 to pass over the stem roller 12 of the vessel and thus initiatingboarding movement of the suction anchor pile over the stem roller as shown. To then assist s in maneuvering the suction anchor pile so that it can be decked by a heaving force applied bythe winch System to the wire 76 or 78, the vessel is moved forwardly in the water, with theanchor pile positioned as shown in Fig. 10, thus applying a water drag induced force against 15 the lower portion of the suction anchor pile to assist in its pivot-like movement about thestem roller 12. The winch wire 78 will continue movement of the suction anchor pile until itis slowly brought aboard the vessel and is allowed to rest in a cradle that is positioned by themoveable track System that is mounted on the deck of the vessel.

The subsea connector shown generally at 74 may conveniently take the form of a wire 20 socket connector shown in Figs. 21-25, which incorporâtes a basket structure defming atapered internai réceptacle for receiving the tapered wire socket of a wire line or other type ofconnector device and having a slot through which a line is literally movable. The connector74 incorporâtes a wire socket body structure 140 of generally circular cross-sectionalconfiguration having spaced, generally parallel surfaces 142 and 144 which define a wire or 25 connector access opening 146. The generally parallel surfaces 142 and 144 are disposed in -17- 11 δ 9 1 generally parallel relation with the longitudinal axis 145 as shown in Fig. 21. A bail structureshown generally at 148 is formed integrally with the wire socket body structure 140 anddefines upwardly extending body support arms 150 and 152 that are interconnected at theupper ends thereof by a curved bail section 154 of circular cross-sectional configuration as 5 shown in Fig. 22. The cross-sectional geometry along the length of the connector bodysupport arms 150 and 152 is indicated by sections 22A-22A through 22F-22F as shown inFig. 22 and in Figs. 22A-22F.

The connector body structure 140 defines a central socket réceptacle opening 156which is in communication with the wire access opening 146. About the central opening 156 10 the connector body 140 also defines a reverse angled circular seat shoulder 158 which extends to the wire access opening 146. The conical, reverse angled seat shoulder 158* provides for seating of a wire socket element, such as shown in Figs. 24 and 25, within theconnector body as will be discussed below. The connector body structure also defines a pairof locking tabs 160 and 162 which project downwardly on each side of the wire access 15 opening 146 as is best shown in Figs. 21-23. These locking tabs define registering throughbores 164 and 166 that can receive a boit, pin or other suitable locking connector for securinga winch line or other force transmitting line, as the case may be, within the central socketréceptacle opening 156 of the connector body. The boit or locking pin may be extendedthrough the registering through bores 164 and 166 by manual operation or by a robot or 20 remote operating vehicle (ROV) in order to présent inadvertent disassembly of the wiresocket connection assembly in the event the wire line should become slack for any reason.

As shown in Figs. 24 and 25 a socket member shown generally at 170 is defined by asocket body 172 having a tapered central passage 174 through which a wire line or mooringline extends. The socket body is permanently fixed to the wire line by zinc, cadmium, 25 polymer or any other material that is poured into the through passage and about the wire line -18- in its molten or uncured liquid State and is then allowed to harden or cure to permanently fïxthe socket member 170 to the wire line. The socket body also defines a circular conicalshoulder 172 having the same angle as the reverse angled conical seat shoulder 158 of thesocket body 140. 5 After the wire line has passed laterally through the wire access opening 146, and has located the socket body above or in registry with the central opening 154 of the socketconnector body 140, the wire line is lowered in relation to the connector body structure 140 causing a tapered extemal guide surface 178 of the socket body 172 to guide the socketmember 170 into the socket réceptacle opening 154, thus causing the conical shoulder 176 of 10 the socket body to seat against the conical shoulder 158 of the connector body structure 140.As linear force is then applied to the wire line, the socket member 170 will be restrained by s its seated relation within the socket réceptacle of the connector body 140 and the reverseangled conical surfaces 158 and 176 will interact to minimize potential spreading of theconnector body by the wire socket member, thus enabling the connector to withstand 15 significant forces such as are encountered during mooring of M.O.D.U.’s and other marine vessels. When connector disconnect is desired the wire socket 170 will become unseated from its supported relation within the wire socket réceptacle opening 154 of the connectorbody 140 simply by its upward or linear movement relative to the connector body structure,depending upon its orientation. After being unseated in this manner, assuming a locking 20 member is not présent within the registering openings 164 and 166, the wire line and wiresocket are moved laterally relative to the connector body structure 140 thereby causing thewire to exit laterally from the réceptacle opening via the wire access opening 146. It shouldbe borne in mind that the wire socket connector shown in Figs. 21-25 may be of otherconfiguration as desired, it being appropriate only that it hâve the capability of being quickly 25 assembled and disassembled particularly in a remote environment such as the subsea 116 9-] -19- environment and perhaps with the use of a ROV or other actuating mechanism for controllingrelative movement of the connector body and wire socket structures for accomplishing quickand simplified connection or disconnection thereof.

When force is applied by urging the socket connector relative to the wire socket,5 which occurs as lifting or mooring force is applied to the socket connector of Figs. 21-25, themating tapered reverse angled shoulder surfaces 158 and 176 of the wire socket body andwire socket develop a résultant force which is directed radially inwardly rather than radiallyoutwardly as is typical of conventional wire socket connectors. When conventional taperedwire socket connectors are employed, application of seating force of the wire socket within 10 the connector body places the body structure under hoop stress. When the hoop stress is ofhigh magnitude, the conventional connector body structure can become radially yielded to the s point that it may split. According to the principles of the présent invention, the inwardlydirected résultant force developed by the mating reverse angled shoulder surfaces 158 and176 under load, minimizes the potential for hoop stress induced yielding or splitting of the 15 socket body and thus enhances the load carrying characteristics of the wire socket connectormechanism of the présent invention.

In accordance with the preferred method of deployment of the preferred embodiment,the suction anchors will be deployed in the manner set forth above in connection with Figs. 8- 15. No mooring wires will be installed. The anchor handling vessel may retum at a later 20 time with mooring wires and accomplish installation of ail of the main mooring wires of thestationing System. If needed, sub-surface marker buoys can be inserted into the mooringstring to relieve the weight of the interconnected mooring components. Once ail mooringcomponents hâve been installed, a surface suspension/market buoy 123 is installed as shownin Fig. 17. -20- 11 δ 9 Ί

The mobile offshore drilling unit, “rig” 139 is then moved to the stationing site orlocation as shown in Fig. 20. The surface buoys are recovered and the mooring wires areattached to the rig mooring wires 76 and 116 which are connected to the mooring wirehandling system of the rig, with short sections of chain 121 inserted between the predeployed 5 mooring wires and the rig mooring wires. A J-chaser stopper device 128 is then installed ineach mooring string by connecting the J-chaser stopper device to the short section ofdeploy/recover chain. The J-chaser stopper device 128, as shown in Fig. 20, has a bodystructure 130 defining a first stopper connector 132 for connection to the mooring line 116,typically above the buoys 118 and 120, and a second stopper connector 134 for connection to 10 the short length of deployment/recovery chain 121. The chain 121 is connected to the mooring line 124 of the buoyant marine structure, MODU or rig 139. From the body* structure 130 a pair of hook-like projections 136 and 138 extend laterally to provide forcatching the J-chaser in the event it should pass over the chain 121 without becomingmechanically engaged with one of the links of the chain. 15 The connected mooring string is lowered beneath the surface with a J-Chain Chaser (Locking Style). Once the mobile offshore drilling unit has accepted the weight of themooring string, the J-Chain Chaser is forced by the anchor handling vessel to slide along therig mooring wire until it is free. This mooring line attachaient is now complété and is in theform shown in Fig. 20. 20 The preferred embodiment of the présent invention is shown pictorially in Figs. 17- 20. In Fig. 17 the mooring wire is shown to be extended from an installed suction anchor andwith a quick-disconnect connector device 114 interconnecting an intermediate mooring linewith the main mooring line. After the intermediate mooring wire 116 has been installed, asshown in Fig. 17, at least one and preferably a plurality of syntactic buoys 120 are connected

25 to the intermediate mooring line to thus provide for its positioning below the sea surface S -21- υ s g 1 but in position for efficient recovery when disconnected form the mooring line of the drillingrig or other vessel 140. If desired, a surface buoy 123 may be installed at the upper end of theintermediate mooring line 116 so as to provide means for simple and efficient location of themooring line. 5 When the mobile offshore drilling unit. M.O.D.U. 11, has been moved to the mooring site or location, it is then necessary to connect the preinstalled moorings. The anchorhandling vessel then recovers the surface buoy and connects to the rig mooring wire as shownin Figs. 18 and 19, using a short section, 25’ or so, of mooring chain 121. At this time theanchor handling vessel then installe a J-chaser stopper device 128 in the mooring string, the Ι- ΙΟ Chaser Stopper being connected to the mooring line of the rig by [a] the short section ofchain 121. As shown in Fig. 19, the anchor handling vessel winch wire is utilized to lower s the mooring string, utilizing a J-lock chaser. The J-lock chaser is then stripped back to thedrilling vessel until free of the mooring wire. Fig. 20 illustrâtes the final mooring connectionbetween the suction anchor and the drilling vessel. A plurality of mooring strings such as is 15 shown in Fig. 20, typically eight, are utilized to properly station the mobile offshore drilling unit.

In view of the foregoing it is évident that the présent invention is one well adapted toattain ail of the objects and features hereinabove set forth, together with other objects andfeatures which are inhérent in the apparatus disclosed herein. 20 As will be readily apparent to those skilled in the art, the présent invention may easily be produced in other spécifie forms without departing from its spirit or essentialcharacteristics. The présent embodiment is, therefore, to be considered as merely illustrativeand not restrictive, the scope of the invention being indicated by the daims of an issuedpatent based hereon rather than the foregoing description, and ail changes which corne within 1 1 δ 9 1 -22- the meaning and range of équivalence of such claims are therefore intended to be embraced therein.

Claims (15)

116 9 1 -23- I CLAIM:

1. A method for deployment of a mooring System having mooring lines for a buoyantmarine structure and for connecting the mooring lines of the mooring System to the mooring 5 lines of the buoyant marine structure, comprising: (a) providing an anchor handling vessel having at least one mooring anchorthereon having a deployment connection for launching and retrieving said mooring anchorand having a mooring connection for connecting said mooring anchor with a mooring line ofthe buoyant marine structure, said anchor handling vessel having an anchor deployment 10 mechanism incorporating an anchor handling line having a quick-disconnect connector for accomplishing deployment movement of said mooring anchor from said anchor handling* vessel for anchor handling line deployment of said mooring anchor to the sea bottom; and (b) after deployment of said mooring anchor, disconnecting said quick disconnectconnector of said anchor handling line from said deployment connection and moving said 15 anchor handling line from said deployment connection to said mooring connection; (c) connecting a mooring line with said mooring connection; and (d) selectively deploying said mooring line for connection with a mooring line ofsaid buoyant marine structure. 20 2. A method for deployment of a mooring System having mooring lines for a buoyant marine structure and for connecting the mooring lines of the mooring System to the mooringlines of the buoyant marine structure, comprising: (a) providing an anchor handling vessel having at least one mooring anchorthereon having a deployment connection for launching said mooring anchor and having a 25 mooring connection for connecting said mooring anchor with a mooring line of the buoyant -24- 11 6 9 1 ï marine structure, said anchor handling vessel having an anchor deployment mechanismincorporating an anchor handling line having a connector for accomplishing deploymentmovement of said mooring anchor from said anchor handling vessel for anchor handling linedeployment of said mooring anchor to the sea bottom; (b) after deployment of the mooring anchor, disconnecting said connector of saidanchor handling line from said deployment connection and recovering said anchor handling line; (c) connecting a mooring line with said mooring connection; and (d) selectively deploying said mooring line for mooring connection with thebuoyant marine structure. *

3. A method for mooring a buoyant marine structure, comprising: (a) embedding an anchor in the sea bottom, said anchor having a first mooringline having first and second ends and having said first end thereof attached to said anchor andbeing of sufficient length to extend above the sea bottom and of insufficient length to extendto the sea surface, a first mooring line connecting element being located at said second end ofsaid first mooring line; (b) deploying a second mooring line being a component of a mooring string forsaid buoyant marine structure, said second mooring line having first and second ends andbeing of sufficient length to extend from said first mooring line to the sea surface, a secondmooring line connecting element being located at said first end of said second mooring line; and (c) with a ROV connecting said first and second mooring line connecting éléments. -25- 116 9 1

4. The method for mooring of claim 3, comprising: (a) with said first and second mooring connectors in assembly, leaving saidsecond mooring line attached to the anchor for future connection with the mooring System ofsaid buoyant marine structure; and 5 (b) retrieving said second mooring line when mooring of the buoyant marine structure is desired and connecting said second mooring line with said mooring System of thebuoyant marine structure.

5. The method for mooring of claim 4, comprising: 10 with said first and second mooring lines connected by interconnection of said first and second connectors and with said second mooring line connected with the mooring System of* the buoyant marine structure, accomplishing disconnecting manipulation of said first andsecond connectors by said ROV for releasing mooring connection of the buoyant marine structure from said anchor. 15

6. The method for mooring of claim 5, wherein said first connector being a socketmember having a selected extemal profile and said second connector defining a connectorréceptacle defining a Socket access opening and defining an internai socket seat and having alatéral slot permitting latéral movement of said first mooring line therethrough as said socket 20 member is moved to and from alignment with said internai socket seat, said socket memberbeing movable linearly into and from said internai socket seat, said method comprising: (a) during assembly of said socket member and said second connector, with saidROV causing relative latéral movement of said socket member and said connector réceptaclefor moving said socket member laterally through said socket access opening and moving said -26- 1 1 6 9 Î first mooring line through said latéral slot and positioning said Socket member in registry with said internai socket seat; and (b) causing relative linear movement of said socket member and said secondconnector for seating said socket member on said internai socket seat.

7. The method for mooring of claim 6, comprising; (a) during disassembly of said first and second connectors, with said ROV causing relative linear movement of said socket member and said internai socket seat for unseating said socket member from said internai socket seat and positioning said socketmember in registry with said socket access opening; and (b) with said ROV causing relative latéral movement of said socket member andsaid connector réceptacle for moving said socket member through said socket access openingand moving said first mooring line.through said latéral slot.

8. A method for mooring a buoyant marine structure having at least one mooring line toa mooring System having at least one anchor to which is connected at least one anchormooring line, comprising: (a) recovering said mooring line of the buoyant marine structure and said anchormooring line to a service vessel; (b) attaching a J-chaser stopper device to said anchor mooring line; (c) with a J-chaser controlled by a winch line of the service vessel, lowering the J-chaser stopper device from the service vessel until said buoyant marine structure accepts theweight of the mooring line of the buoyant marine structure and the anchor mooring line; and (d) by moving the service vessel, sliding said J-chaser device along said mooringstring toward said buoyant marine structure until said J-chaser device falls free of saidmooring line. -27- « 1 1 S 9 1

9. The method of claim 8, comprising: (a) deploying a J-chaser stopper in said mooring line, said main mooring line andsaid J-chaser stopper being components of a mooring string extending ffom the mooring 5 anchor to said marine vessel; (b) for mooring line recovery, running a J-chaser along said mooring line until theJ-chaser contacts and is stopped by said J-chaser stopper; (c) hoisting the J-chaser, the J-chaser stopper and mooring line to the anchorhandling vessel; and 10 (d) performing an anchor mooring line and marine vessel mooring line connection or disconnection as desired.

10. The method of claim 9, comprising releasing said J-chaser ffom the marine vesselmooring line by moving said J-chaser along the marine vessel mooring until the J-chaser falls 15 by gravity therefrom.

11. A method for establishing an ROV opérable mooring line connection with an anchordevice fixed to the océan bottom, comprising: (a) providing a mooring connector on the anchor device, said mooring connector20 having a first connector element; (b) providing a mooring line having a second connector thereon for connectingengagement with said first connector element; and (c) with an ROV, selectively moving one of said first and second connector éléments into releasable connection with the other of said first and second connector 25 éléments. -28- 11 6 9 1 -

12. The method of claim 11, comprising: (a) with said first and second connectors in releasable connection, with the ROV,moving said second connector element for unseating said first and second connector éléments; and (b) with the ROV moving said second connector element and the mooring lineaway from said first connector element.

13. A method for establishing an ROV opérable mooring line connection with an anchordevice fixed to the océan bottom and having a mooring connector extending therefrom,comprising: s (a) for assembly of said mooring line connection locating the mooring connectorof the anchor device, the mooring connector having a first connector element thereon being located remote from the anchor device; (b) with an ROV, moving a mooring line having a second connector elementthereon to a connecting position relative to said first connector; (c) moving said second connector into releasable assembly with said first connector element; and (d) for disassembly of said mooring line connection, with said ROV causing < relative unseating movement of said first and second connector éléments and moving themooring line and second connector element to a position ffee of said first connector element.

14. A ROV opérable mooring System for mooring a buoyant object to an anchor devicelocated on the océan floor and having a mooring connector extending from the anchor device,said mooring system comprising: -29- (a) a first connecter element being provided on said mooring connecter and located remote from the anchor device; (b) a mooring line for the buoyant object having an end thereof for releasable connection to the anchor device; and 5 a second connecter element being connected to said end of said mooring line and adapted formechanically interfitting connecting relation with said first connecter element by a ROVcausing relative movement of said first and second connector éléments and said mooring line,said first and second connector éléments, when releasably interconnected, conductingmooring forces from said mooring line to said anchor device. 10

15. A mooring System for mooring buoyant marine structures, comprising: (a) at least one anchor adapted to be fixed to the sea bottom and having an anchorhandling connection and a mooring connection; and (b) a ROV actuated connector device being connected to a line and adapted for 15 sélective ROV actuated connection with said anchor handling connection for anchor deployment and recovery and adapted for sélective ROV actuated connection anddisconnection with said mooring connection for mooring of a buoyant marine structure.

16. The mooring System of claim 15, comprising: (a) said anchor handling connection having a first tapered Socket member thereon; (b) said mooring connection having a second tapered socket member thereon; and (c) said ROV actuated connector device having a body structure defining a socketréceptacle therein for receiving either of said first and second tapered socket members andhaving a latéral slot therein permitting movement of said anchor handling connection or said 20 -30- 1169 1 mooring connection through said latéral slot during relative movement of said first and second tapered socket members to and from said Socket réceptacle.