SECURING OF STRUCTURES TO THE SEA BED

摘要

IMPROVEMENTS IN OR RELATING TO THE SECURING OF STRUCTURES TO THE SEA-BED Structures such as free standing oil production platforms or subsea templates are secured to the sea bed by inserting a tubular pile (1) (31) in the seabed so as to form, with a part (2)(30) of the structure, a pair of nested members. Fluid is then introduced into the innermost of the members to plastically deform the innermost member radially so that it engages with the outermost member and forms a mechanical connection between the members. A tool for effecting the plastic deformation comprises a mandrel (4) for insertion into the innermost member and carrying a means to form a chamber (11) (13) (16) (20) (23) within the innermost member adjac?ent to its inner surface. The tool also includes a means (9) of introducing fluid into the chamber to expand it radially and thereby deform the innermost member.