FIELD: oil and gas industry.
SUBSTANCE: invention relates to oil and gas industry, mainly to devices for sealing of production strings and disconnection of formations. Equipment includes one or several plasters in the form of thin-walled pipes with the possibility of their radial expansion, which are connected in series by means of threaded connections. On external surface of each of plasters there is a row of vulcanised elastic sealing rings, which can be deformed at expansion of plaster, and expansion assembly with conical mandrel. Lower plaster has a pre-expanded funnel-shaped section, into which a drilled shoe with a check valve and a saddle for a bung plug discharged from the surface is hermetically inserted. Conical mandrel of the expansion assembly serves as a piston at supply of liquid under pressure and at the same time is rigidly connected by means of a rod to a lifter. Outer surface of the plaster is coated with a layer of elastic bituminous paste, the thickness of which is less than the thickness of the elastic sealing ring until radial expansion of the patch or is equal to it, but larger than the thickness of the same ring after radial expansion of the plaster.
EFFECT: higher reliability and efficiency of device operation.
1 cl, 4 dwg
