Depressurization system of annuli between casings in producing wells

摘要

A depressurization system for the annular spaces (3) between casings in the drilling activity for wells producing oil or other fluids, so as to guarantee effective hydraulic communication between the pressurized annular space (3) and the base of the exposed rock zone (4) to be broken during depressurization, which has the solid deposit with the consequent hydraulic isolation. The system is made up of a flow control device (11); a conveyance pipe (12) between two points of the annular space (3); and an isolation device (13) linked to a centralizer in the shallow casing string (1), allowing the pressurized fluid outlet and the well wall to be close together, whereby the system used will not become clogged with solid deposits over time during the sinking of these well casings.