INSULATION METHOD OF TROUBLE SOME ZONES IN WELL BY SHAPED COVERING DEVICE Russian patent published in 2011 - IPC E21B29/10 

FIELD: oil and gas industry.

SUBSTANCE: method involves shaping of pipes of covering device, internal threads made on coupling ends and external threads on pin ends, or calibration of shaped end with removal of chamfers for welding, tight screwing of sections of shaped pipes to each other or welding, lowering of covering device to necessary pre-expanded space of the well, radial expansion of shaped pipes by creating hydraulic pressure in them, flaring till they are tightly borne against well walls. Shaping is performed by using cylindrical pipes the inner diametre of which is bigger by 5-8% than inner diametre of well shaft; its installation space is extended to the diametre at which complete expansion of shaped pipes takes place with their simultaneous tightness with well walls. Before the covering device is lowered to well, its upper end is equipped with flaring device with cutter to destruct the shoe and with extensible flaring device, and lower end is equipped with easily drilled shoe. Extensible flaring device has diametre in working position, which allows flaring the inner diametre of covering device at the narrowest points to the diametre which exceeds diametre of well shaft at least by 1.5%.

EFFECT: manufacturing capabilities are enlarged, time and costs for manufacture and assembly are reduced.

1 dwg