Patent ID: 8720545

Claim:
A method for drilling a wellbore, comprising acts of: drilling the wellbore by injecting drilling fluid into a top of a tubular string disposed in the wellbore at a first flow rate and rotating a drill bit, wherein: the tubular string comprises: the drill bit disposed on a bottom thereof, tubular joints connected together, a longitudinal bore therethrough, a port through a wall thereof, and a sleeve in fluid communication with a hydraulic chamber, operable between an open position where the port is exposed to the bore and a closed position where a wall of the sleeve is disposed between the port and the bore; the drilling fluid exits the drill bit and carries cuttings from the drill bit, and the cuttings and drilling fluid (returns) flow to surface via an annulus defined between the tubular string and the wellbore; moving the sleeve to the open position by injecting hydraulic fluid into the hydraulic chamber; injecting drilling fluid into the port at a second flow rate while adding a tubular joint or stand of joints to the tubular string, wherein injection of drilling fluid into the tubular string is continuously maintained between drilling and adding the joint or stand to the tubular string.