Drilling vessel with well for drill tube string in outer tube - has inflatable bags between outer tube and sides of well to protect sides and partly retracted tube e.g. during heavy storm

摘要

The system is intended for an underwater drilling vessel or platform to prevent contact of the outer drilling tube with the sides of an open well (''moon pool'') extending between deck and keel e.g. during a heavy storm. System comprises a number of inflatable bags which are arranged such that, in inflated condition, they fill the space between the sides and the tube to the extent that tube contact with the sides is prevented. At least two such bags may be secured to opposite sides or one or more such bags may be carried by (e.g. a collar on) the tube. Pref. four such bags are arranged as two vertically spaced pairs secured to two pairs of opposed sides of a rectangular well.