FIELD: petroleum industry.
SUBSTANCE: claimed is a group of inventions: a system of an expandable metal packer with a pressure control apparatus. System for expanding a metal packer in a borehole comprises a tubing string with a main tube with an inner part of the main tube. The tubing string is located in the wellbore so as to form an annular space between the tubing string and the surrounding wall surface. The system also includes an expandable metal packer installed around the main tube. The expandable metal packer has an expandable metal sleeve installed along the main tube by means of end elements. The expandable metal packer additionally comprises a pressure control apparatus. The pressure control apparatus is configured to be activated to provide different flow positions by applying input pressures along the inner side of the main tube. The pressure control apparatus comprises a valve retained in the first flow position establishing fluid communication between the annular space and the inner part of the packer and preventing fluid communication between the inner part of the main tube and the inner part of the packer when the tubing string is being lowered into the wellbore. The valve is configured to be activated in order to provide a second flow position by applying an input pressure. The second flow position prevents fluid communication between the annular space and the inner part of the packer and establishes fluid communication between the inner part of the main tube and the inner part of the packer in order to expand the expandable metal sleeve. The valve comprises an opening piston configured to slide in the first piston passage of the hydraulic circuit located in the body of the valve, and a closing and compensatory piston configured to slide in the second piston passage of the hydraulic circuit. The opening piston and the closing and compensatory piston are initially retained in place by means of a first retaining element and a second retaining element, respectively.
EFFECT: increase in the tightness of seal with the surrounding wall of the wellbore and increase in the quality of controlling the pressure acting on the metal sleeve.
14 cl, 17 dwg
