HEAT-INSULATED STRING Russian patent published in 1997 - IPC

FIELD: oil-and-gas producing industry, in particular, units of pipe joints in heat-insulated string which is applicable in oil production with use of injection of heat carrier into formation. SUBSTANCE: string consists of sections of coaxially located internal pipes with union joint and external pipes with heat-insulating material located between them and guide rest. Heat-insulating material is made of basalt cloth and aluminum foil. Guide rests are made in form of rings and rigidly attacked to one of pipes in each section of string. Enclosed pipes in joint unit of external pipes have external beads located under sealing members. Installed on lower pipe is connecting sleeve-nut with bore and thread. Installed on upper pipe is pressure nut connected with internal thread of connecting sleeve-nut. Installed between pipe sides and stop end of pressure nut and internal projection of connecting sleeve-nut are sealing members and intermediate rings. EFFECT: higher efficiency. 1 dwg