THERMO-ISOLATED PIPE (VARIANTS) Russian patent published in 2005 - IPC

FIELD: oil extractive industry.

SUBSTANCE: device has inner and outer pipes, placed coaxially with forming of ring-shaped space between them. Ring-shaped space is pressurized by vacuum seams, thermo-isolation is placed therein and vacuum is formed, on both sides of outer pipe thread is made, on one end thereof sleeve is screwed with isolating bushing. Vacuum seams are made at even spaces from ends of outer pipe, calculated from formula L=K·β, where L - distance between vacuum seam and end of outer pipe, mm; K - number of predicted maintenances of threads of thermo-isolated pipe; β - value of shortening of thermo-isolated pipe after single thread maintenance, mm. Also described is another variant of thermo-isolated pipe, wherein vacuum seams are made at different spaces from ends of outer pipe. Distance on side of sleeve is calculated from formula: L_M=K_M·β, where L_M - distance between vacuum seam and end of sleeve end of outer pipe, mm, K_M - number of predicted maintenances of thread of sleeve end of thermo-isolated pipe; β - value of shortening of thermo-isolated pipe after single thread maintenance, mm; and on nipple side space is calculated from formula: L_H=K_H·β, where L_H - distance between vacuum seam and end of nipple end of outer pipe, mm; K_H - amount of predicted maintenances of thread of nipple end of thermo-isolated pipe, while K_M<K_H.

EFFECT: higher efficiency.

2 cl, 1 dwg