PACKER Russian patent published in 2003 - IPC

FIELD: oil and gas industry, well bore sealing. SUBSTANCE: technical result of invention consists in increased reliability of setting of packer in any point of casing string including box joints displaying axial clearance between butts of linked casings and in enhanced pressure difference endured by packer thanks to alignment of unit with extendible dies by means of spring and to more uniform distribution of forces over their lengths. Packer has shaft, upper and lower substitutes put on it, sealing member confined between conical rings and placed between substitutes. Spring-loaded extendible dies interact with their conical surfaces with conical rings. Additional conical rings with which conical surfaces of dies interact are set between substitutes. Extendible dies are knock-down dies assembled with formation of internal spaces where circular springs are placed. Axial size of dies exceeds size of clearance between butts of casings in box joint by factor of 3 or more. EFFECT: increased reliability of setting of packer. 2 dwg