EQUIPMENT FOR OPERATION OF BLOWOUT WELLS Russian patent published in 1994 - IPC

FIELD: gas and oil producing industry. SUBSTANCE: freely installed on lower packer mandrel are upper and lower connections accommodating upper and lower pistons same in areas, interacting with tubing and rigidly connected to each other by means of movable sleeve. Installed on sleeve is a set of flexible packer cups. Upper piston taking up pressure from control system keeps constantly the cut-off valve in open position and set of flexible cups in free state. In so doing, lower piston is constantly under action of formation pressure through hole in string, and ensures compression of flexible cup set and closing of cut-off valve only in case of no pressure in control system. EFFECT: simplified design, reduced specific metal content and higher operate reliability of equipment. 2 dwg