FACILITY FOR LOWERING AND EXPANSION OF PIPES IN WELL Russian patent published in 2009 - IPC E21B29/00 

FIELD: mining.

SUBSTANCE: facility consists of case with central channel, of threads for connection with well equipment and indentations on external surface, wherein rotating rollers are installed. In its upper part the case is equipped with a circular recess for pressure tight connection with expanded pipes. Indentations of the case are equipped with lengthwise grooves in the zone of contact with rollers; some of the grooves are filled with solid and wear resistant relative to the case material, while others are filled with solid lubricating material. Top of each roller of a lower row is set off along circumference forward along motion of rotation of the case.

EFFECT: increased reliability and wear resistance.

1 dwg