Valved jet device for well drills

摘要

A column of drill collars have holes or jets extending radially from the collar bore through the collar wall. A wash pipe extends full length through the bore of the perforated collars, so sized as to leave an annular flow space between the wash pipe and the collar bore wall. A remote control selector valve is situated such as to receive drilling fluid from the upwardly continuing drill string and direct the fluid through the wash pipe to the drill bit for regular drilling, or on cue from the earth surface, direct fluid to the annulus to be expelled through the drill collar perforations to help free stuck pipe or to prevent such sticking.