METHOD OF OIL WELL TUBING TREATMENT Russian patent published in 2017 - IPC C21D9/08 B23P6/00 B21J5/00 

FIELD: metallurgy.

SUBSTANCE: invention refers to metallurgy, oil machine engineering and repair of subsurface equipment of oil wells, and can be applied for manufacturing and repair (restoration) of oil-well tubing. To increase operation life, efficient use period, bearing capacity of thread joints in onworn tubing, a workpiece is prepared out of onworn tubing with wall thickness deviation of 20-45 % of the rated value, tube workpiece ends are heated to 950-1300 °C for upsetting, the tube is fixated by a clamp, and each tube end is upset to a 60-350 mm length with a horizontal forging machine or hydraulic press with deformation rate of 20-70 %.

EFFECT: enhanced operation life.

4 cl, 1 tbl, 2 ex