Wellbore circulation system

摘要

A tong as may be used for a continuous circulation system in a wellbore. The tong has a housing with a hollow interior. A plurality of spaced apart jaw assemblies reside within the housing's hollow interior for engaging a portion of a tubular to be gripped and rotated by the tong. A gear wheel is secured to the housing for rotating the housing and the jaw assemblies. The gear wheel includes a toothed outer circumference for mating with teeth of a drive shaft of a driving motor. A gear flange is movably mounted on the gear wheel such that rotation of the gear wheel does not rotate the gear flange.