THREADED CONNECTION OF DRILL PIPES Russian patent published in 2014 - IPC E21B17/42 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to drilling engineering and refers mainly to threaded connection of drill pipe joints used for geological surveying and oil well drilling. The threaded connection consists of a sleeve, a nipple and a slotted spring installed between the sleeve lip and thrust face of the nipple. At that a gap is formed between the sleeve lip and the nipple thrust face, this gap is liquidated in process of the connection tightening and spring compression and it is equal to the spring pitch and according to its parameters it corresponds exactly to the preset axial load to the inner thrust joint. Upon tightening of the connection the exact axial loads is provided to the outer thrust joint. Reliable functioning of both thrust joints allows increasing axial force of the threaded connection 1.5 times and improving its statistical strength and cyclic life.

EFFECT: provision of the exact preset loads to the inner and outer thrust joints, maintenance of their ratio within the whole operational period.

1 dwg