TELEMETRY OPERATED CIRCULATION SUB

摘要

A method of drilling a wellbore includes drilling the wellbore by injecting drilling fluid through a drill string extending into the wellbore from surface and rotating a drill bit of the drill string. The drill string further includes a circulation sub having a port closed during drilling. The drilling fluid exits the drill bit and carries cuttings from the drill bit. The drilling fluid and cuttings (returns) flow to the surface via an annulus formed between an outer surface of the tubular string and an inner surface of the wellbore. The method further includes after drilling at least a portion of the wellbore: halting drilling; sending a wireless instruction signal from the surface to a downhole portion of the drill string by articulating the drill string, acoustic signal, or mud pulse, thereby opening the port; and injecting drilling fluid through the drill string and into the annulus via the open port.