CONSTRUCTION OF CASING STRING Russian patent published in 1999 - IPC

FIELD: oil and gas production industry. SUBSTANCE: construction of casing string relates basically to completion of well. Casing string incorporates perforated pipes which are preliminarily plugged by stoppers. Stoppers are arranged with their bottoms facing pipe axis. Internal hollow in stoppers is of round or slot-like cross-section. Length of internal hollows of sleeves is larger than thickness of pipe wall. Stoppers are made of material which meets conditions for bringing to ground surface by washing solution of broken particles of stoppers. Density of material of stoppers must meets requirements brought forth in formula included in description of invention. Aforesaid construction of casing string allows for maintaining strength characteristics of casing string pipes together with enhancing operational reliability of production equipment. EFFECT: higher efficiency. 4 dwg