Patent ID: 6955503

Claim:
A method for re-deploying an offshore jacket using a plinth, wherein the method comprises the steps of: a. locating an offshore jacket comprising at least three jacket legs, each jacket leg comprising a jacket leg mud mat, and wherein the offshore jacket is connected to a seabed at a first site at a first depth to be re-located to a second site at a second depth, wherein the second depth is deeper below a sea level than the first depth; b. constructing a plinth, comprising: i. a vertical axis; ii. at least three plinth legs each comprising a top end and a bottom end, wherein a number of plinth legs is equal to a number of jacket legs; iii. a skirt pile sleeve disposed on each plinth leg; iv. at least one plinth mud mat secured to each skirt pile sleeve; v. a space frame connected to and providing support for the least three support pile sleeves and the at least three plinth legs; vi. at least one guide cone attached to the top end of each plinth leg and wherein each guide cone is adapted to receive one jacket leg by guiding and aligning each leg; and vii. at least one trestle per plinth leg, each trestle disposed on the space frame; c. placing the plinth at the second site; d. driving one skirt pile into each skirt pile sleeve; e. disconnecting the jacket legs from the seabed at the first site; f. lifting the offshore jacket above the seabed; g. moving the offshore jacket from the first site to the second site; h. lowering the offshore jacket such that each jacket leg stabs into each guide cone on the plinth until each jacket leg mud mat contacts each trestle; and i. inserting pin piles through each jacket leg and plinth leg and grouting the pin piles to effect a permanent structural connection between plinth and jacket.