Patent ID: 7048470

Claim:
An offshore drilling installation, comprising at least one drilling riser extending from a floating support to a guide device on the seabed, said drilling riser deflecting progressively from a substantially vertical position at said floating support to a position that is one of substantially horizontal and tangential to the horizontal at the seabed, being characterized in that said guide device comprises a guide pipe in a buried position wherein said guide pipe comprises in succession: a front end resting substantially horizontally on the seabed; a curved intermediate portion of guide pipe buried in the subsoil of the seabed with a radius of curvature being greater than about 500 m; and a substantially linear rear portion sloping at the rear end of said guide pipe buried in the subsoil of the seabed at a given angle of inclination α relative to the horizontal that lies in the range of about 10° to 80°; and controlled burying means for burying said guide pipe in the seabed while said guide pipe is being towed along the seabed from its front end, going from an initial position in which said guide pipe rests entirely on the seabed in a substantially horizontal position, to asaid buried position in the subsoil of the seabed.