Patent attributes
A system and method for pressure locking a downhole tool in position during a drilling operation includes rotating the drill string to drill a borehole. A fluid is pumped through a passage of a drill string in the downhole direction wherein fluid undergoes a pressure drop at the downhole end of the drill string such that fluid in the passage of the drill string is under higher pressure than the fluid outside the drill string. While fluid is flowing, an uphole portion of the downhole tool, such as a MWD tool, is exposed to the higher pressure fluid and a downhole portion of the downhole tool to the lower pressure fluid, thereby seating the downhole tool in a receptacle member attached to the drill string in the passage. Ceasing flow easily eliminates the locking force created by differential pressure allowing the tool to be retrieved.
