APPARATUS AND METHOD RELATING TO TONGS, CONTINUOUS CIRCULATION AND TO SAFETY SLIPS

摘要

Apparatus for inserting or removing a string of tubular from a borehole includes upper and lower closed head power tongs to make up/break out connections with the lower tong as rotary back-up. It also includes a continuous circulation system to keep fluid circulating during tripping operations and a safety slip to prevent tubulars slipping therein comprising two arrangements of grips which are coupled to one another.