Tension leg means and method of installing same for a marine platform

In a tension leg means for a marine platform, said tension leg means including a tension pipe string comprising a plurality of pipe string members and couplings interconnecting said members, the provision of:

• means for installing anchor means on the sea floor for connection to said pipe string including
• anchor template guide frame means comprising peripheral frame members and internal frame members providing a rigid template anchor structure;
• a plurality of anchor pile conductor members in spaced relation around the periphery of said frame means;
• a pile anchor member adapted to be set in the sea floor through each of said anchor pile conductor members;
• and connector means on each anchor pile member at the associated conductor member for connection to the bottom pipe member of said tension pipe string.

In a tension leg for a marine platform, said tension leg means including a tension pipe string having a plurality of pipe string members, the upper end of said pipe string extending to a deck on the platform, the provision of:

• a quick latch means for connecting the uppermost pipe string member to said platform, said latch means comprising
• a cylindrical latch body member arranged coaxially with said pipe string member;
• means securing said latch body member to said platform;
• an annular piston within said latch body member coaxial with said pipe string member and said body member and movable axially thereof;
• a latch top cap member above said annular piston;
• a wedge actuator member between said cap member and piston member;
• a plurality of arcuate segmental slip elements carried between said cap member and wedge actuator member, said slip elements having threads engageable with threads on said pipe string member;
• means carried by said cap member and connected to said wedge actuator member for causing relative axial movement therebetween for release and engagement of said arcuate slip elements;
• and means for releasably securing said wedge actuator member against axial relative movement with respect to said annular piston member.

A means for connecting a tension member to a support member and for adjusting tension therein comprising:

• means for securing a latch body member to said support member;
• a wedge slip assembly engageable with said tension member, said wedge slip assembly providing relative axial and rotative movement with respect to said tension member;
• said wedge slip assembly comprising a plurality of slip elements adapted for threaded engagement with threads on said tension member,
• a annular piston member,
• a wedge actuator member releasably secured to said piston member;
• fluid actuating means for forcing said wedge actuator member against said slip assembly to wedge said slip elements into tight engagement with threads on said tension member;
• and means for actuating said annular piston member for adjusting tension in said tension pipe string.

In a method of installing a tension leg from a floatable marine platform having a hawse pipe;

• the steps of:
• lowering a tension pipe string comprising a plurality of tension pipe members including a connector means at the bottom end thereof;
• attaching said connector means to a fixed anchor pile member and locking said connector means against relative rotation with respect to said anchor pile member;
• connecting the upper end of said tension pipe string to a latch connector means carried by said platform;
• and applying fluid pressure to said latch connector means to adjust tension in said pipe string.

In a method of installing anchor pile members in the sea floor and connecting a tension leg to said anchor pile members comprising the steps of:

• lowering an anchor template pile guide structure having a plurality of anchor pile conductors thereon to the sea floor;
• lowering a guidance means over a guidepost provided on said anchor pile structure;
• said guidance means including arm means;
• rotating said arm means about said guide post and indexing their position with respect to an anchor pile conductor guide;
• and extending said arm means to position a pair of guidelines adjacent said conductor guide to facilitate guidance of anchor pile members into and through said anchor pile conductors.

A method of installing a tension leg between a floatable marine platform having a hawse pipe and an anchor means on the sea floor, the steps of:

• lowering a tension pipe string comprising a plurality of tension pipe members including a bottom connector means at the bottom end thereof;
• attaching said bottom connector means to said anchor means;
• connecting the upper end of said tension pipe string to an upper connector means carried by said platform;
• applying fluid pressure to said upper connector means at said platform to adjust tension in said pipe string;
• and gripping and holding the upper end of said pipe string by the upper connector means after adjusting tension therein.

In a method of installing anchor means in the sea floor and connecting a tension leg to said anchor means comprising the steps of:

• lowering an anchor template pile guide structure having a plurality of conductor guides thereon to the sea floor;
• lowering a guidance means over a guide post provided on said anchor template structure;
• said guidance means including arm means;
• rotating said arm means about said guide post and indexing their position with respect to a conductor guide;
• and positioning the end of said arm means adjacent to said conductor guide to facilitate conducting said tension leg to said anchor means.

In a tension leg for a marine platform, said tension leg including a tension pipe string comprising a plurality of pipe string members and couplings interconnecting said members, the provision of:

• means for installing anchor means on the sea floor and for connecting the bottom pipe string member thereto including:
• anchor template guide frame means comprising peripheral frame members and internal frame members providing a rigid template anchor structure;
• a plurality of anchor conductor members in spaced relation on said frame means;
• a pile anchor member adapted to be set in the sea floor through said anchor conductor members;
• and means at said template anchor structure for connecting the bottom pipe member of said tension pipe string to said anchor means.

In a tension leg for a marine platform having a hawse pipe and anchor means fixed in a seabed, the combination of:

• a tension pipe string comprising a plurality of pipe string members;
• couplings interconnecting said pipe string members;
• lower connector means for connecting the lower end of the lowermost pipe member to said anchor means at a conductor member on said anchor means;
• said pipe string extending into said hawse pipe;
• upper connector means on said platform for connecting the upper end of said pipe string to said platform, said upper connector means including
• fluid pressure means at said platform for adjusting tension in said pipe string,
• and means for gripping and holding the upper end of the pipe string at a selected tension.