EP1076738A4

EP1076738A4 - Method and apparatus for suction anchor and mooring deployment and connection

Info

Publication number: EP1076738A4
Application number: EP99915019A
Authority: EP
Inventors: Billy J Bergeron
Original assignee: Delmar Systems Inc
Current assignee: Delmar Systems Inc
Priority date: 1998-05-06
Filing date: 1999-03-26
Publication date: 2003-08-27
Also published as: WO1999064684A2; WO1999064684A3; CA2331176C; ID27033A; NO20005579L; EP1076738A2; AU743420B2; CA2331176A1; OA11691A; NO20005579D0; AU3363699A; WO1999064684A8; BR9910349A

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

APPLICATION

TITLE: METHOD AND APPARATUS FOR SUCTION ANCHOR AND

MOORING DEPLOYMENT AND CONNECTION

BACKGROUND OF THE INVENTION

The benefit of United States Provisional Application Serial No. 60/045,735 filed on May 6, 1997 by Billy J. Bergeron and entitled Method And Apparatus For Suction Anchor 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 concerns a wire socket connector mechanism which facilitates subsea connection and reconnection of mooring lines of semi-submersible drilling rigs, production and drilling platforms and the like to suction anchor piles and other anchor devices. This invention also concerns deployment and installation of suction anchor piles and a mooring wire assembly with retrieval buoys and sling on one of its ends. The invention also concerns addition of buoys to mooring wire sections and connecting the mooring wire to a vessel to be moored. The procedure also concerns the mooring wire, buoy recovery, wire retrieval and suction anchor pile recovery and a procedure for recovering mooring wires and other apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

The various objects and advantages of this invention will become apparent to those skilled 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 specification and in which: In the Drawings:

Fig. 1 is a plan view showing the stern section of an anchor handling vessel designed for suction anchor deployment, mooring wire deployment and handling and showing four suction anchors in loaded position on the stern of the vessel in preparation for deployment thereof;

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

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

Fig. 4 is an elevational view of the track roller assembly of Fig. 3;

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

Fig. 6 is an end elevational view of the track roller assembly of Figs. 3-5 and showing a hydraulic jacking mechanism for lateral movement of the track roller assembly;

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 rollers during deployment or recovery operations for suction anchor piles;

Fig. 8 is side elevational view of a service vessel showing a suction anchor pile in position for launching over the stern roller of the vessel and showing an initial arrangement of handling lines; Fig. 9 is a side elevational view similar to that of Fig. 8 and showing overboarding of the suction anchor pile and also showing the relationship of the handling lines to the anchor handling vessel and the suction anchor pile;

Fig. 10 is a side elevational view similar to that of Fig. 9 and showing the suction 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 suction anchor pile just under the stem of the vessel and further showing disconnection of the overboarding hook from the sling of the suction anchor pile by remote operating vehicle (ROV) handling; 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 ROV monitoring and directing orientation of the suction pile and having the capability to assist in suction pile installation; Fig. 14 is a side elevational view similar to that of Fig. 13 showing a further step in suction 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 anchor 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 of Fig. 15 and showing movement of the 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 and showing recovery of the ROV to the anchor handling vessel in preparation for connection of the mooring wire to the rig or other vessel being moored;

Fig. 18 is a side elevational view similar to that of Fig. 17 and showing deployment of the mooring line by the anchor handling vessel; Fig. 19 is a side elevational view showing lowering of a primary mooring wire to the sea floor by an anchor handling anchor handling vessel and showing a buoy which suspends the deployment/recovery sling assembly of the mooring line in position for subsea connection;

Fig. 20 is a side elevational view similar to that of Fig. 19 showing recovery of the lowering hook and ROV to the surface and further showing the primary mooring wire extending along the sea floor with its terminal end being positioning by the buoy for subsequent connection with an intermediate mooring wire section;

Fig. 21 is an elevational view similar to that of Fig. 20 showing the primary mooring wire on the sea floor and with the ROV and lowering hook recovered by the vessel; Fig. 22 is a side elevational view similar to that of Fig. 21 and showing a semi- submersible drilling rig at the right hand of the portion of the figure and further showing a lift wire being connected by the ROV to the deployed primary mooring wire by an anchor handling vessel loaded with wire and buoys for rig connection; Fig. 23 is a side elevational view similar to that of Fig. 22, showing heaving of the mooring wire to the stern roller of the anchor handling vessel for connection of an intermediate mooring wire to the primary mooring wire;

Fig. 24 is a side elevational view similar to that of Fig. 23 showing the intermediate mooring wire being connected to the primary mooring wire and showing deployment buoys fixed to the intermediate mooring wire in preparation for connection to a mooring wire of the rig;

Fig. 25 is a side elevational view similar to that of Fig. 24, showing an upper winch wire being paid out of the rig to the anchor handling vessel which is backed into close proximity to the rig; Fig. 26 is a side elevational view similar to that of Fig. 25, and showing a mooring wire of the rig being connected to the anchor handling vessel and further showing the buoys of the intermediate mooring line section being heaved to the anchor handling vessel for connection of the rig wire to the buoy;

Fig. 27 is a side elevational view similar to that of Fig. 26 showing lowering of the buoys and intermediate anchor wire with a J-chaser suspended from the anchor handling vessel by a lowering line;

Fig. 28 is a side elevational view similar to that of Fig. 27 showing the completed mooring line connection from the rig to the suction anchor pile;

Fig. 29 is a side elevational view similar to that of Fig. 28 showing initiation of a rig disconnect procedure where an anchor handling vessel chases out along the rig mooring line section with a J-lock chaser to reach a short chain located above the first buoy of the intermediate mooring line section;

Fig. 30 is a side elevational view similar to that of Fig. 29 showing the buoys of the intermediate mooring line section being heaved to the anchor handling vessel to permit disconnection of the upper mooring line section therefrom; Fig. 31 is a side elevational view similar to that of Fig. 30 showing release of the upper mooring line section of the rig and showing the buoys of the intermediate mooring line section being located below the stern roller of the vessel;

Fig. 32 is a side elevational view similar to that of Fig. 31 and showing lowering of a sub-sea retrieval tool to a position below the second buoy of the intermediate mooring line section;

Fig. 33 is a side elevational view similar to that of Fig. 32 and showing the use of an ROV for connection of the subsea retrieval tool to the intermediate mooring wire section below the buoys; Fig. 34 is a side elevational view similar to that of Fig. 33 showing, after retrieval of the ROV, use of the anchor handling vessel to heave in on the mooring wire below the buoys to thereby permit the buoys to be decked without damage;

Fig. 35 is a side elevational view similar to that of Fig. 34 showing the buoys of the intermediate mooring line being located on the deck of the anchor handling vessel and showing initiation of the recovery of the intermediate mooring line section of the main mooring extension wire;

Fig. 36 is a side elevational view similar to that of Fig. 35 showing installation by the anchor handling vessel of a syntactic buoy with a deployment/recovery sling so that the primary mooring wire can be lowered to the sea floor; Fig. 37 is a side elevational view similar to that of Fig. 36 showing lowering of the primary mooring wire to the sea floor by the anchor handling vessel with the syntactic buoy at the end thereof suspending the deployment/recovery sling assembly;

Fig. 38 is a side elevational view similar to that of Fig. 37 and showing the deployment/recovery hook being disconnected by the ROV; Fig. 39 is a side elevational view similar to that of Fig. 38 showing the anchor handling vessel proceeding to the rig to repeat a suction anchor pile and mooring line deployment procedure after having recovered the deployment wire and ROV;

Fig. 40 is a side elevational showing initiation of a procedure for recovery of mooring wires and anchors, with an anchor handling vessel having heaved on the mooring wire until the mooring wire is located vertically above the suction anchor pile and with the ROV directing the mooring wire as it is guided into the entrapment slot on the suction anchor pile, after which the ROV manipulates the lock of the suction anchor pile for securing the mooring wire thereto;

Fig. 41 is a side elevational view similar to that of Fig.40, showing the ROV being positioned to disconnect the subsea connector from the mooring extension of the suction anchor pile;

Fig. 42 is a side elevational view similar to that of Fig. 41 , further showing direction of the subsea connector to the anchor lift sling by the ROV after having released the lift sling from the mooring line extension of the suction anchor pile;

Fig. 43 is a side elevational view similar to that of Fig. 42, showing the pumping of water into the suction anchor pile by the ROV to dissipate the suction of the anchor while the anchor lift sling is moved upwardly to begin lifting of the ROV from its embedded condition with respect to the sea floor;

Fig. 44 is a side elevational view showing lifting of the suction anchor pile from the sea floor after the suction anchor pile has been moved upwardly to the point that its suction is minimal;

Fig. 45 is a elevational view showing the suction anchor pile being located clear of the sea floor and, at a particular depth below the surface, showing a recovery hook being connected to the recovery sling of the suction anchor pile by ROV control;

Fig. 46 is a sectional view showing the suction anchor pile being supported solely by the recovery hook and line of the anchor handling vessel in preparation for tailboarding of the suction anchor pile over the stern roller of the vessel to its deck;

Fig. 47 is an elevational view showing the suction anchor pile being drawn to the stem roller of the vessel at which point skids of the suction anchor pile are aligned with the track roller assembly of the anchor handling vessel; Fig. 48 is an elevational view showing movement of the anchor handling vessel in the water during tailboarding to permit the force of water action to orient the anchor as the anchor proceeds to the deck of the vessel and becomes located on its cradle;

Fig. 49 is a front elevational view of a socket connector that is adapted for connection to a mooring or heaving line and which is adapted to receive a socket, that is connected to another line section to thus permit quick and efficient connection disconnection of mooring wire sections; Fig. 50 is a plan view of the socket connector of Fig. 49;

Fig. 51 is a sectional view taken along line 51-51 of Fig. 50 and showing the internal geometry of the socket connector as well as the geometry of the connecting eye thereof; 5 Figs. A-A through F-F are sectional views taken along respective section lines

A-A through F-F of Fig. 52 to thereby show the cross sectional configuration of the connection bail at various locations along the lengths thereof;

Fig. 52 is a sectional view of a socket element adapted to be fixed to a wire by zinc or polymer connection and further adapted for seated assembly within the wire 10 socket connector of Figs. 49-51 ;

Fig. 53 is a bottom view of the wire socket element of Fig. 52;

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring now to the drawings and first to Fig. 1 , the stern deck of a anchor

15 handling vessel, also referred to therein to an anchor handling vessel, is shown generally at 10 and incorporates a stern roller 12 over which suction anchor piles and other apparatus is launched. The stern of the anchor handling vessel is pitted to receive 4 suction anchor piles shown at 14, 16, 18 and 20 which are secured to the anchor handling vessel by individual track roller assemblies which are shown in greater

?π detail in Figs. 3-6. The deck of the vessel is provided with transverse beams or rails 22, 24 and 26, one which being shown in Fig. 6. Track roller assemblies are provided as shown in Figs. 3, 4 and 5 with one of the track roller assemblies, shown generally at 28, having parallel track members 30, 32 and 34 which are interconnected by transverse structural members 36. Roller assemblies 38, each including top and

25 bottom rollers, are mounted to the outer parallel structural members 30 and 34 and to the transverse structural members as is more clearly evident from the end view of Fig. 6. Bottom rollers 40 and 42 are connected to the transverse structural members 36 by roller mounting pins 44 and 46 respectively. These bottom rollers are disposed in contact with the upper surface 48 of the transverse I-beam track 22. Upper rollers 50

30 and 52 are mounted to the parallel structural members 30 and 34 for rotation about axes that are oriented in 90° relation with the axis defined by the mounting pins 44 and 46. The rollers 50 and 52 are provided for contact by parallel support members 54 and 56 of an anchor cradle 58 to thereby permit linear movement of the cradle and the suction anchor pile supported thereby for launching the suction anchor pile overboard the stem roller of the vessel. Alternatively, the structural support members 54 and 56 5 may comprise elongate support that are fixed along a side suction anchor pile. The suction anchor pile 58 is supported directly by the rollers 50 and 52 to permit its effective launching and retrieval. Lateral guide members 60 and 62 are welded or otherwise fixed to the outer parallel structural members 30 and 34 and function to establish a proper relationship of the members 54 and 56 to the rollers 50 and 52 as

10 the suction anchor pile is moved linearly during its launching or retrieval.

Referring now to Fig. 8 and subsequent figures, the anchor handling vessel 10 is shown with one of the suction anchor piles 70 located with its lower end at the stem roller 12 of the vessel and with its deployment sling 72 being connected by a wire socket connector shown generally at 74 to the upper winch wire 76 of the vessel winch

15 system. Another winch wire 78 is shown to be connected to a suction anchor pile deployment sling 80 that is located intermediate the upper and lower ends of the suction anchor pile. The suction anchor pile is shown with its main mooring wire extension 82 secured to a mooring wire connector 84 of the suction anchor pile and with its upper end being secured against one side of the suction anchor pile by a

?ⁿ mooring wire positioning lock 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. 52 and 53 thereof. The deployment sling 72 is connected to the suction anchor pile 70 by a deployment connector 73 which may be in the form of a elastomer support to provide a cushioning capability between the suction anchor pile and the anchor lifting

25 and handling sling 72.

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 line 76 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

30 weight is largely supported by the overboarding sling 80 and the support for the anchor begins to transfer from the winch line 78 to the winch line 76. As shown in Fig. 11 , the suction anchor pile is located just under the stern of the anchor handling vessel and its weight is supported by the winch line 76 via the socket connector 74 and the deployment sling 72. At this point, the winch line 78 is not needed and thus its overboarding hook 90 can be disconnected from the overboarding sling 80. A remote operating vehicle (ROV) 92 may be utilized to manipulate the overboarding 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.

As shown in Fig. 21 , after the primary mooring wire has been deployed, as shown, with its syntactic buoy positioning the terminal end for recovery, the ROV 92 and lowering and heaving wire 108 with its lowering hook 110 will be recovered to the anchor handling vessel. After this has been done, the anchor handling vessel is loaded with wire and buoys for rig connection and, as shown in Fig. 22, the ROV 92 functions to connect the hoisting and lowering wire 108 with its hook 110 to the connector 112 immediately above the buoy 106. From the condition shown in Fig. 22, the primary mooring wire section 76 is hoisted to the anchor handling vessel and is pulled over the stem roller of the vessel as shown. With the terminal end of the primary mooring wire located on the anchor handling vessel, an intermediate section of mooring wire is connected to the primary mooring wire section by a connector 114 as shown in Fig. 24. The intermediate mooring wire section 116 is then provided with one or more buoys as shown at 118 and 120 for supporting the intermediate mooring wire 116 and for providing the completed mooring line assembly with support intermediate its length. After the buoys 118 and 120 have been attached to the intermediate mooring wire, the upper winch wire 122 of the anchor handling vessel, which is connected to the intermediate mooring wire 116 above the uppermost buoy 118, will be paid out from the anchor handling vessel to thus allow the vessel back into the rig as shown in Fig. 25 to receive the mooring wire 124 of the rig. The mooring wire of the rig will be paid out from its winch so that, after its connection to the intermediate mooring wire 116, the mooring wire installation from the rig to the suction anchor pile can be controlled by the on-board winch of the rig. At this point of the mooring operation, as shown in Fig. 26, the upper winch wire 122 of the anchor handling vessel is heaved to a position adjacent the stern of the vessel to expose the mooring wire connection. The rig mooring wire 124 is then connected to the intermediate mooring wire section 116 at a connector 126 that is located immediately above the upper buoy 118 of the intermediate mooring wire. The mooring wire installation is completed as shown in Fig. 27 by lowering the rig mooring wire and the intermediate mooring wire with its buoys by a winch line 126 having a J-chaser 128 connected thereto. When the mooring wire installation reaches its proper catenary, the J-chaser will simply become unhooked from the mooring wire and may then be recovered to the vessel. The mooring wire winch system of the vessel will then adjust the mooring wire assembly as is proper for stationing of the rig at its proper location relative to the sea floor.

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 with the mooring wire of the rig. The anchor handling vessel will then move away from the rig, thereby causing the J-chaser 128 to move along the rig mooring wire 124 until it comes into contact with a short chain located immediately above the upper buoy 118 of the intermediate mooring wire section. After this has been done, the heaving line and J-lock chaser is heaved to a position exposing the short recovery chain above the upper buoy 118 as shown in Fig. 30 and thus also exposing the connection between the rig mooring wire 124 and the intermediate mooring wire 116. The rig mooring wire is then disconnected from the intermediate mooring wire at the vessel deck and is recovered to the rig by the rig winch system as shown in Fig. 31. It should be borne in mind that the connector 125 for making the connection of the rig mooring wire 124 with the intermediate mooring wire, may be in the form of a quick release type socket connector which is explained in detail hereinbelow in connection with Figs. 49-53. In fact, each of the connectors along the length of the mooring wire installation may be defined by wire socket connectors, if desired, or may take the form of any other suitable mooring wire connector without departing from the spirit and scope of the present invention. After the rig mooring wire has been disconnected and recovered, as showing in Fig. 32, the anchor handling vessel will lower a subsea retrieval tool 130 to a depth below the lower buoy 120 as shown and will then connect the subsea retrieval tool to the intermediate mooring wire 116 below the buoys. The ROV 92 can be utilized for this purpose. The subsea retrieval tool is then heaved to the deck of the vessel thereby causing the buoys 118 and 120 to be decked without damage because the weight of the intermediate mooring wire 116 will not be present on the buoys are as they are heaved over the stem roller of the anchor handling vessel. After the buoys have been secured on deck as showing in Fig. 35, the intermediate mooring wire section is then recovered by the anchor handling vessel. After the intermediate mooring wire section has been recovered to the anchor handling vessel, as shown in Fig. 6, the vessel will reinstall the syntactic buoy with a deployment/recovery sling and begin to deploy the primary mooring wire section 76. After the syntactic buoy has been connected to the primary mooring wire section, the primary mooring section is then lowered to the sea floor by the winch wire 106. As is then shown in Fig. 38, the ROV 92 is deployed from the anchor handling vessel 10 and is used to disconnect the deployment recovery hook 132 of the winch wire 126 from the sling 134 above the syntactic buoy. After the hook has been disconnected from the sling, the wire 126 and deployment/recovery hook are then recovered to the anchor handling vessel, leaving the primary mooring wire 76 lying on the sea floor with its terminal end being positioned by the syntactic buoy 106 so that its sling 134 will be positioned for immediate reconnection to the intermediate mooring wire section as needed. After this has been done, the anchor handling vessel can then proceed to the rig as shown in Fig. 39 to repeat the suction anchor pile and mooring line installation for another one of the plurality of suction anchor pile and mooring line assemblies of the rig mooring system.

Referring now to Fig. 40 and subsequent figures, it may be appropriate at some point to recover the suction anchor pile 70 so that is may be reinstalled at some other location as may be desired for different stationing of the rig relative to the sea floor. This is accomplished by connecting a vessel winch line to the heaving sling 134 of the primary mooring wire 76 and heaving the primary mooring wire onto the anchor handling vessel until it is oriented substantially vertically above the suction anchor pile 70. With the primary mooring wire so positioned, the ROV 92 is then utilized to direct the mooring wire extension 82 so that it enters an entrapment slot 83 of the suction anchor pile. The ROV will then manipulate a lock on the suction anchor pile to secure the mooring wire extension 82 within the entrapment slot. After this has been accomplished, the ROV 92 will be moved to the subsea connector 74 as shown in Fig. 41 and will disconnect the connector from the mooring wire extension. Since the mooring wire extension will be locked within the entrapment slot of the suction anchor pile, it will remain substantially vertically oriented as shown in Fig. 42, with its socket element 88 positioned for subsequent reconnection to a mooring wire section in simple and efficient manner. As shown in Fig. 42, the ROV will then move the subsea connector 74 from the mooring wire extension to the anchor lift sling 72 in preparation for lifting the suction anchor pile to the deck of the anchor handling vessel. Then, as shown in Fig. 43, the ROV 92 will be maneuvered for connection of its fluid transfer line 96 with the fluid transfer 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 a differential pressure induced force that moves the suction anchor pile upwardly. Simultaneously, a heaving force is applied to the winch wire 126 of the vessel, which, through the wire socket connector 74, lifts the suction anchor pile from its embedded relation within the sea floor until the suction anchor pile is located within the 15' silt line of the sea floor. At this point, the ROV will disengage its fluid transfer conduit 96 from the suction anchor pile coupling 98. After the ROV has been disconnected, the suction anchor pile is heaved upwardly by the winch line 126 until the suction anchor pile is located at a predetermined depth, i.e. about 60' below the anchor handling vessel as shown in Fig. 45. With the suction anchor pile 70 stationary below the stern of the vessel, the ROV 92 will be utilized to connect a recovery hook 132 of a recovery winch line 134 to the deployment/recovery sling 80 of the suction anchor pile. The recovery wire is then heaved as shown in Fig. 46, moving the suction anchor pile upwardly toward the stem of the vessel and causing the deployment/recovery wire 76 to become slack. As shown in Fig. 47, heaving is continued, causing the deployment/recovery sling 80 to pass over the stern roller 12 of the vessel and thus initiating boarding movement of the suction anchor pile over the stem roller as shown. To then assist in maneuvering the suction anchor pile so that it can be decked by a heaving force applied by the winch system to the wire 134, the vessel is moved forwardly in the water as shown by the movement arrow in Fig. 48, thus applying a water drag induced force against the lower portion of the suction anchor pile to assist in its pivot-like movement about the stem roller 12. The winch wire 34 will continue movement of the suction anchor pile until it is slowly brought aboard the vessel and is allowed to rest in a cradle that is positioned by the moveable track system that is mounted on the deck of the vessel. Referring now to Figs. 49-53, the subsea connector shown generally at 74 in the various figures described above, may conveniently take the form of a wire socket connector, which is shown in Figs. 49-53. The wire socket connector 74 incorporates a basket structure 140 having spaced, generally parallel surfaces 142 and 144 which defined a wire access opening 146. A bail structure, shown generally at 148, is formed integrally with the basket structure 140 and defines upwardly extending basket support arms 150 and 152 that are interconnected at the upper ends thereof by a curved bail section 154 of circular cross-sectional configuration as shown in Fig. 51. The cross- sectional geometry along the length of the basket support arms 150 and 152 is indicated by sections A-A through F-F. The basket structure 140 defines a central socket receptacle opening 156 in communication with the wire access opening 146. About the central opening 156, the basket also defines a reverse angled circular shoulder 158 which extends to the wire access opening 146. The conical, reverse angled shoulder 158 provides for seating of a wire socket within the basket as will be discussed hereinbelow. The basket structure also defines a pair of locking tabs 160 and 162 which project downwardly on each side of the wire access opening 146 as is best shown in Fig. 49. These locking tabs define registering through bores 164 and 166 that can receive a bolt, pin or other suitable locking connector for securing a winch line or mooring line, as the case may be, within the central socket receptacle opening 156 of the basket. The bolt or locking pin may be extended through the registering through bores 164 and 166 by the ROV in order to prevent inadvertent disassembly of the wire socket connection assembly in the event the mooring line or other wire should become slack for any reason.

As shown in Figs. 52 and 53, a socket member shown generally at 170 is defined by a socket body 172 having a tapered central passage 174 through which a wireline or mooring line extends. The socket body is fixed to the wireline by zinc, polymer or any other material that is poured into the passage 174 in its molten or uncured liquid state and is then allowed to harden or cure to permanently fix the socket body to the wireline. The socket body also defines a circular conical shoulder, having the same angle as the reverse angled conical shoulder 158 of the socket body 140. After the wireline has passed through the wire access opening 146, and has located the socket body 172 above the central opening 156, the wireline is lowered in relation to the basket structure causing a tapered external guide surface 178 of the socket body to guide the socket into the socket receptacle opening 156, thus causing the conical shoulder 176 of the socket body to seat against the conical shoulder 158 of the basket structure. The wire socket will become unseated from its supported relation within the wire socket receptacle opening 156 of the basket simply by its upward movement relative to the basket structure. After being unseated in this manner, assuming a locking member is not present with the registering openings 164 and 166, the wire and wire socket are moved laterally relative to the basket structure thereby causing the wire to exit from the receptacle opening 156 via the wire access opening 146. It should be borne in mind that the wire socket connector shown in Figs. 49-53 may be of other convenient configuration if desired, it being appropriate only that it have the capability of being quickly assembled and disassembled particularly in the subsea environment and perhaps with the use of an ROV for controlling relative movement of the basket and wire socket structures for accomplishing quick connection or disconnection thereof. In view of the foregoing it is evident that the present invention is one well adapted to attain all of the objects and features hereinabove set forth, together with other objects and features which are inherent in the apparatus disclosed herein.

As will be readily apparent to those skilled in the art, the present invention may easily be produced in other specific forms without departing from its spirit or essential characteristics. The present embodiment is, therefore, to be considered as merely illustrative and not restrictive, the scope of the invention being indicated by the claims of an issued patent based hereon rather than the foregoing description, and all changes which come within the meaning and range of equivalence of such claims are therefore intended to be embraced therein.

Claims

What Is Claimed Is

1. A method for deployment of mooring systems for mobile offshore drilling units and for connecting the same to the mooring lines thereof, comprising:

(a) providing an anchor handling vessel having a stern roller and 5 having at least one suction anchor thereon having a deployment connection for launching and retrieving said suction anchor and having a mooring connection for connecting said suction anchor with a mooring line of the mobile offshore drilling unit said anchor handling vessel having an anchor deployment mechanism 10 incorporating a handling line having a quick-disconnect socket connector for accomplishing movement of said suction anchor over said stern roller for handling line deployment to the sea bottom;

(b) after deployment of said suction anchor, disconnecting said 15 handling line from said deployment connection and moving said anchor handling line from said deployment connection to said mooring connection, said handling line becoming the main mooring line;

(c) connecting syntactic buoy means with said main mooring line for " elevating said main mooring line for recovery; and

(d) repeating said method steps (a)-(c) for each plurality of suction anchors and mooring lines.

2. A method for stationing a mobile offshore drilling rig to a pre-deployed rig mooring system having a plurality of suction anchors to which is connected a plurality

25 of mooring lines having syntactic buoys elevating the ends of the mooring lines above the sea bottom, comprising:

(a) recovering said syntactic buoys with the lifting winch of a service vessel;

(b) connecting said mooring lines to the mooring lines of said mobile 30 offshore drilling unit; (c) attaching a length of chain to each of said mooring lines and installing a J-chaser stopper device to said length of chain, the mooring line, chain and J-chaser stopper being a mooring string;

(d) lowering the mooring string from the service vessel with a J-chaser to permit said mobile offshore drilling unit to accept the weight of said mooring string; and

(e) with said service vessel, sliding said J-chaser along said mooring line toward said mobile offshore drilling unit until said J-chaser moves free of said mooring line.

3. The method of claim 1 , wherein said steps of disconnecting said handling line from said deployment connection and moving said deployment connection to said mooring connection being accomplished by a remote operating vessel.

4. The method of claim 1 , wherein said deployment connection having a first releasable connecting device and said handling line having a second releasable connecting device receiving said first releasable connecting device in releasable connection, said method comprising: maneuvering said second releasable connecting device relative to said first releasable connecting device to disconnect said first and second releasable connecting devices, to move said second releasable connecting device to said mooring connection and to connect said second releasable connecting device in releasable assembly with said mooring connection.

5. The method of claim 1 , wherein said first releasable connecting device being a first tapered socket member fixed to said deployment connection and a second tapered socket member fixed to said mooring connection and said second releasable connecting device being a socket connector defining a lateral slot and having an internal tapered socket receptacle in communication with said lateral slot, said socket connector being supported by an elongate force transmitting member capable of deploying a suction anchor and capable of serving as a component of a mooring string, said method comprising:

(a) maneuvering said elongate force transmitting member in a direction unseating said first tapered socket member from said internal tapered socket receptacle;

(b) maneuvering said elongate force transmitting member laterally through said lateral slot of said socket connector;

(c) maneuvering said elongate force transmitting member and said socket connector laterally to cause said mooring connection to pass through said lateral slot and to position said internal socket receptacle in registry with said second tapered socket; and

(d) maneuvering said elongate force transmitting member in a direction causing seating of said second tapered socket within said internal tapered socket receptacle.

6. The method of claim 5, wherein latch means being provided on said socket connector and being moveable to a latching position to prevent lateral movement of said elongate force transmitting member through said lateral slot and a releasing position permitting lateral movement of said elongate force transmitting member through said lateral slot, said method comprising: (a) with said first socket member seated within said internal tapered socket receptacle, moving said latch means to said releasing position; and (b) after lateral movement of said mooring connection through said lateral slot, moving said latch means to said latching position.-

7. The method of claim 5, comprising: after said releasable assembly of said elongate force transmitting member and said second tapered socket with said socket connector, deploying said elongate force transmitting member as a component of a mooring string.

8. The method of claim 1 , comprising:

(a) deploying a J-chaser stopper in said rig mooring line, said J- chaser stopper having a length of chain connected thereto said main mooring wire, said J-chaser stopper and said length of chain being components of a mooring string extending from the suction anchor; to said rig;

(b) for mooring line recovery, running a J-chaser along said rig mooring line until the J-chaser contacts and is stopped by said J- chaser stopper and engages said length of chain; (c) hoisting the J-chaser and the chain, J-chaser stopper and mooring line to the anchor handling vessel; and (d) performing anchor mooring line and drilling unit connection or disconnection as desired.

9. The method of claim 8, comprising releasing said J-chaser from the rig mooring line by moving said J-chaser along the rig mooring line until the J-chaser falls by gravity therefrom.

10. The method of claim 1 , wherein said anchor deployment mechanism having track roller means for mooring suction relative to the deck of the anchor handling vessel, said method comprising: (a) with said track roller means, mooring a suction anchor laterally from a stored position to a launching position; and (b) moving said suction anchor linearly for launching said suction anchor over the stem roller of the anchor handling vessel.

11. The method of claim 1 wherein a plurality of anchor handling track roller assemblies are provided on the deck of the anchor handling, each anchor handling rack roller assembly having a suction anchor situated thereon, said method comprising: (a) moving a selected track roller assembly laterally from a stored position to an intermediate position; (b) moving the selected track roller assembly linearly to a launching position adjacent the stern roller of the anchor handling vessel; and

(c) moving the selected suction anchor linearly from its track roller assembly over the stern roller of the anchor handling vessel.

12. The method of claim 11 wherein transverse rails are provided on the deck of the anchor handling vessel and are positioned for supporting and guiding engagement with rollers of said track roller assemblies, said method comprising:

(a) moving a selected one of said track roller assemblies laterally along said transverse rails from said stored position to said intermediate position; and

(b) moving the selected suction anchor linearly along its track roller assembly from said intermediate position to said launching position and linearly overboard the stern roller of the anchor handling vessel.

13. The method of claim 12, wherein:

(a) said moving of a selected one of said track roller assemblies laterally being accomplished hydraulically; and

(b) said moving the selected suction anchor linearly along its track roller being accomplished by a winch system of the anchor handling vessel.

14. The method of claim 2, comprising:

(a) after recovering the syntactic buoy and the end of the anchor mooring line to which it is attached to a location on the anchor handling vessel, running a J-chaser along a selected rig mooring line until the J-chaser stopper device is contacted by the J-chaser; (b) hoisting the J-chaser stopper and the rig mooring line to a location on the anchor handling vessel with the J-chaser in hoisting engagement with the length of chain thereof;

(c) connecting the anchor mooring line and the rig mooring line; and (d) lowering the connected anchor mooring line and rig mooring line until the weight of the anchor mooring line is accepted by said rig mooring line.

15. The method of claim 14, wherein: said step of connecting the anchor mooring line and the rig mooring line being accomplished by a quick release socket connection having a first releasable connecting device being a first tapered socket member fixed to one mooring line and a second releasable connecting device being a socket connector fixed to the other mooring line and defining a lateral slot and having an internal tapered socket receptacle in communication with said lateral slot, the tapered socket of said one mooring line being first moved laterally to registering position with the internal tapered socket receptacle of the second releasable connecting device by passing its mooring line through the lateral slot of said second releasable connecting device and then moving the mooring lines linearly relative to one another to seat said first tapered socket member within said internal tapered socket receptacle.

16. The method of claim 15, wherein said second releasable connecting device having a locking member movable to an open position permitting lateral movement of a mooring line through said lateral slot and a locked position preventing movement of a mooring line through said lateral slot, said method comprising:

(a) for assembly of said releasable connecting device, after movement of the mooring line through said lateral slot and said tapered socket member into said internal socket receptacle, moving said locking member from said open position to said locked position; and (b) for disassembly of said releasable connecting device, moving said locking member from said locked position to said open position, moving the mooring lines in relative directions for unseating said tapered socket member from said tapered internal tapered receptacle, and moving the mooring line and tapered socket member laterally for passing the mooring line through said lateral slot.

17. A mooring system for mooring mobile offshore drilling units, comprising:

(a) at least one suction anchor adapted to penetrate into the sea bottom and having an anchor handling connection and a mooring connection each having a tapered socket member;

(b) a socket connector defining a lateral slot and having an internal tapered socket receptacle in communication with said lateral slot and capable of receiving said tapered socket member of said anchor handling connection and said mooring connection in seated relation therein, said socket connector being supported by an elongate force transmitting member capable of deploying a suction anchor and capable of serving as a component of a mooring string; (c) means for deploying said suction anchor from a single anchor handling vessel with said elongate force transmitting member and with said socket connector of said elongate force transmitting member in connection with said anchor handling connection of said suction anchor to embedded relation within the sea bottom; (d) means for shifting said socket connector laterally from said anchor handling connection to said mooring connection; and (d) means for releasably connecting said mooring line to a rig mooring line.