Title:
METHOD AND DEVICE FOR EXCAVATING OIL WELL OF ABYSS
Document Type and Number:
Japanese Patent JPS63284397
Kind Code:
A
Abstract:
A method and apparatus for drilling subsea wells in water depths exceeding 3000 feet (preferably exceeding 4000 feet). Drilling mud returns are taken at the seafloor and pumped to the surface by a centrifugal pump (81) that is powered by a seawater driven turbine. A low-differential pressure rotating head (70) seats in the upper tapered portion of the longitudinal throughbore of an upper stack package (60) which is attached to the top of the blowout preventer stack and seals against the drill string (12) as it is run in and out of the borehole. The drilling mud returns are pumped to the surface via a mud return line (82), a conventional riser not being used.
Inventors:
KORIN PIITAA RIICHI
Application Number:
JP10744388A
Publication Date:
November 21, 1988
Filing Date:
April 28, 1988
Export Citation:
Assignee:
CONOCO INC
International Classes:
E21B33/064; E21B7/12; E21B21/00; E21B21/08; E21B33/035; E21B33/08; (IPC1-7): E21B33/064
Attorney, Agent or Firm:
Takehiko Suzue (2 outside)