Acoustically controlled electro-mechanical circulation sub

摘要

This invention relates to a self-contained circulation sub which may be operated upon control from the surface. It may be in the shape of a short section of drill collar and utilizes a sleeve valve to cover the circulation ports. Upon reception of an acoustic signal from the surface, a control valve directs fluid from the pipe bore onto a pressure face on the sleeve valve. The sleeve valve then moves down and exposes the circulation ports thereby allowing drilling fluids to pass from its interior to its exterior.