ANNULAR BARRIER WITH SAFETY METAL COUPLING Russian patent published in 2017 - IPC E21B33/127 

FIELD: machine engineering.

SUBSTANCE: annular barrier is designed to expand in the annular space between the tubular well structure and the inner wall of the wellbore to insulate the zone between the first zone and the second zone of the wellbore and comprises a tubular portion for mounting as part of the tubular well structure, an expansion metal coupling surrounding the tubular portion and having an inner surface, facing the tubular portion, and an outer surface, facing the inner wall of the wellbore. Each end of the expansion metal coupling is connected to the connecting portion connected to the tubular portion. The annular barrier comprises a space between the inner surface of the expansion metal coupling and the tubular portion, and an expansion hole in the tubular portion, through which fluid can enter the space in order to release the expansion metal coupling. The annular barrier comprises the first safety metal coupling surrounding the tubular portion for providing resistance to pressure influence upon the existence of a hole in the expansion metal coupling. The first safety metal coupling has the first inner surface abutting against the surface of the expansion metal coupling. Each end of the first safety metal coupling is connected to the connecting portion connected to the tubular portion.

EFFECT: reduced possibility of expansion metal coupling cracking during expansion without significant increase in the total thickness of the annular barrier.

14 cl, 9 dwg