High pressure circulating shoe track with redundant pressure isolation feature

• Main Authors: Andrew, Colin P, Lehr, Douglas J
• Format: Patent
• Language: English
• Published: 25.01.2018
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

A dual barrier system is provided to withstand pressure differentials well above those of the check valves in a float shoe used to allow circulation of a bottom hole assembly on the way to a desired depth. The bottom hole assembly can have screens and an internal wash pipe that pushes a sleeve to hold open a lower flapper for running in. The wash pipe also holds open an upper flapper that has opposed orientation to facilitate circulation when running in. Once on location an annulus packer closes off the producing zones where the screens are located from a lower zone that can have higher pressures. A high pressure packer is set against the shoe track and the wash pipe is retracted through this packer. Retracting the wash pipe allows closure of both flappers. Flow is blocked in opposed directions by the flappers and packer in the shoe track.