US 5,219,451 AGranted

Offshore deck to substructure mating system and method

AssigneeAtlantic Richfield Company

InventorsBisuddha N. Datta, Russell L. Baldwin, Junius D. Allen

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Abstract

An offshore deck or platform unit is provided with depending legs having shock absorbing stabbing tip assemblies for engagement with the upstanding columns of a marine substructure to transfer the weight of the deck to the substructure by positioning the deck relative to the substructure with a barge and ballasting down the barge to move the deck into engagement with the substructure. The barge also carries a deck support structure comprising plural sand jack assemblies which provide for disengagement of the barge from the deck. The stabbing tip assemblies include coaxially arranged primary locating pins which are dropped into position to hold the location of the deck relative to the columns and annular resilient collars for transferring vertical and lateral shock loads between the columns and the deck during the transfer process. Final steel-to-steel engagement of the deck legs with the columns and final disconnection of the vessel from the deck is carried out by actuation of sand jacks which are interposed between the stabbing tip assemblies and the columns and between the deck and deck support structure on the barge.

Claims15

Dependent claims

In an offshore platform, in combination, a deck for installation to be supported by a substructure including a plurality of upstanding column members, said deck including a corresponding plurality of depending legs, the improvement characterized by:

at least one of said legs including a stabbing tip assembly for engagement with a corresponding column member, said stabbing tip assembly comprising an outer body for engagement with said column member to transfer permanent weight of said deck to said column member, a generally vertically moveable locating pin disposed in said body for movement to stab into receiver means including means forming a receptacle on said column member for locating said deck with respect to said column member, and resilient means supported by said body for accommodating lateral and vertically-imposed loads acting between said column member and said leg during placement of said deck on said substructure to minimize the imposition of peak forces on said deck and said substructure;
said receiver means comprising a generally cylindrical receiver shoe forming said receptacle, said shoe comprising part of a jack assembly supported on said column member and said shoe being operable to be moved to a position to permit contact of said leg with said column member to provide supporting relationship therebetween;
and
said jack assembly comprising a generally cylindrical body member supported on said column member and forming a chamber with said shoe for receiving particulate material to support said shoe in a first position for receiving said locating pin, said shoe being moveable to a second position in response to removing said particulate material from said chamber to permit movement of said leg into engagement with said body member.

1 more element

A method for transferring a deck comprising a plurality of depending legs to a marine substructure characterized by a corresponding plurality of upstanding column members, comprising the steps of:

providing each of said legs with a stabbing tip assembly including a locating pin for engagement with corresponding receiver means on said column members, respectively, and resilient shock absorbing means to permit at least vertical shock-absorbed movement of said legs during transfer of said deck to said substructure;
supporting said deck by a floating vessel with respect to said substructure;
providing jack means interconnecting said vessel with said deck;
positioning said vessel with respect to said substructure so that said legs are substantially coaxial with said column members;
inserting said pins into receptacle means to maintain the location of said deck relative to said substructure;
lowering said deck into initial engagement of said shock-absorbing means with said substructure;
disconnecting said vessel from said deck by actuating said jack means to disengage support means on said vessel from said deck;
and
further lowering said deck to engage said legs with said column members for support of said deck by said column members.

6 more elements

Dependencies are inferred from the claim text.