Thermally insulated downhole tubing (TK-114-73-350), (Fig. 1) forms part of the heat-resistant facilities and is used for the steam injection and production oil wells. This tubing is used for casings of 168 mm (diameter) or more in oil fields developed by using thermal stimulation technique and with the following wellhead heat parameters:
• Temperature:  630 °K (358°С), max;
• Pressure: 16 MPa, max;
• Operating environment: hot water, moist high-temperature steam, steam-gas ("thermophore").

Technical Specifications:
      Operating thermophore temperature at wellhead, 0K (357°С), max 
 630 (357)
      Operating delivery pressure of thermophore at wellhead, MPa, max   16
      Temporary operating overpressure, MPa, max          20
      Allowed overpressure time, min     5 
      Test pressure, MPa 
 Overall Dimensions:
  • External tube diameter, mm 
  • Tubing internal diameter, mm 
  • Tubing collar outside diameter, mm 
  • Tubing (segment) length, m, max 
      Specified axial tension load, kN, max   900
      Heat loss along the tubing, W/m   150
      Tubing weight per meter, kg      32