SELF-SUPPORTED DRILLING RISER

摘要

Apparatus and method for drilling a well into a submerged bottom from a floating drilling vessel while employing a riser pipe having positive buoyancy is disclosed. The riser pipe extends between the vessel and the well and is comprised of an upper and a lower section. Means are connected to the lower section for imparting a buoyant force to it of sufficient magnitude to render it positively buoyant. Means are provided extending between the submerged bottom and the upper end of the positively buoyant riser section for restraining the lower section against upward movement. The upper section of the riser pipe may be disconnected from the lower section so that the vessel may abandon the well site. The lower riser section is left self-standing, connected to the wellhead.