Patent ID: 9057235
Filing Date: 2015-06-16
Classification: E21B

Abstract:
1. An apparatus for continuously flowing drilling fluid along a drill string, comprising: a continuous circulation device having at least a first fluid path in fluid communication with a top drive and a second fluid path in communication with a diverter in selective fluid communication with a pipe stand associated with the drills string; a circulation sub configured to selectively isolate at least a portion of the pipe stand at a rig floor, the circulation sub receiving the drilling fluid from the diverter and including: an upper hydraulic chamber, an upper port in selective fluid communication with the upper hydraulic chamber, a lower hydraulic chamber, and a lower port in selective fluid communication with the lower hydraulic chamber; and at least one pressure sensor in pressure communication with at least one of: (i) the upper hydraulic chamber, and (ii) the lower hydraulic chamber; and