Patent · US Active

Arrangement and method for controlling and regulating bottom hole pressure when drilling deepwater offshore wells

US7497266B2 · kind B2 · utility

55Cited by

30References

30Claims

0Family size

Assignee

Ocean Riser Systems AS · NO

Inventor

Borre Fossli · Oslo, NO

Key dates

Filing date	Sep 4, 2007
Grant date	Mar 3, 2009
Priority date	—
Expiry date	Sep 4, 2027

Classification

Technology area (CPC E)Fixed Constructions
CPC primaryE21B21/10
WIPO fieldCivil engineering
WIPO sectorOther fields

Abstract

An arrangement and method for controlling and regulating bottom hole pressure in a well during subsea drilling in deep water involves adjustment of a liquid/gas interface level in a high pressure drilling riser up or down to change the slope and offset of the pressure gradient in the well. The arrangement may include a surface BOP and gas bleeding outlet at the upper end of the drilling riser, a lower BOP with a by-pass line, and an outlet at a depth below the water surface that is connected to a pumping system with a flow return conduit running back to a drilling vessel or platform.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.