FIELD: machine building.
SUBSTANCE: required values of detachment pressure are determined on the basis of rod size and/or pipe dog type. The upper and lower limits for permissible values of rod detachment pressure may be calculated on the basis of the required pressure of detachment and/or rod size. Values of rod detachment pressure below the lower limit and above the upper limit specify the necessity to analyse the rod condition in order to identify whether this rod may be used repeatedly. The values of rod detachment pressure may be recorded as data of detachment pressure for subsequent assessment, including detection of improper unscrewing of rods and poor condition of a well.
EFFECT: invention provides for identification of pipes that require replacement.
25 cl, 13 dwg
