METHOD OF CIRCULATING WHILE RETRIEVING DOWNHOLE TOOL IN CASING

摘要

Retrieving a down hole tool at a lower end of a string of casing can be performed with drill pipe during a casing-while-drilling operation. The operator suspends the casing in the well from a drilling rig floor opening. A string drill pipe is lowered into the casing while the casing is suspended for engaging and retrieving the down hole tool. When circulation is desired, the operator secures a circulation tool to an upper end of the drill pipe, then lowers the drill pipe and the circulation tool to close off an upper end of an inner annulus between the drill pipe and the casing. The operator circulates fluid down the circulation tool and the drill pipe and back up an outer annulus surrounding the casing. The connection between the circulation tool and the casing allows the operator to reciprocate the casing.