Oil drilling pipe is a geological drilling with steel made by hot or cold.Domestic steel with “geological” (DZ) said. Petroleum drill pipe steel gradeDZ40, DZ50, DZ55, DZ65 and DZ75 (DZ40 and DZ50 are eliminated).Geological drill pipe steel grade DZ50, DZ55, DZ60, DZ65, DZ75, DZ85and DZ95. Oil drilling and geological drilling with seamless steel pipe is theimportant equipment for drilling. Mainly includes the drill pipe, tube andpipe, drill collar and small diameter drilling pipe.

Used in petroleum, geological drilling. Due to the deep undergroundthousands of meters deep, extremely complex. Work pressure, tension,torsion and impact load stress, the tube wall by mud, wear particles of rock, strength, hardness, requirements of pipe with wear resistance andgood impact toughness.

Drill pipe is thickened and external upset ends at two ends, and threading and not threading division. With the tools of threading pipe butt weldingmethod is not joint (drill pipe end and joint called “pipe”).