Patent ID: 8511404
Filing Date: 2013-08-20
Classification: A01N,B26B,E21B

Abstract:
1. A wellbore underreaming tool for use in oil and natural gas drilling arranged for attachment to a rotary drill-bit and associated drill-pipe to enlarge the wellbore to a diameter greater than a pass-through diameter of a wellbore restriction, the underreaming tool comprising: at least one radially extendable cutter block to form the enlarged wellbore diameter; at least one caliper to determine the wellbore diameter; a position sensor to sense a relative position of the cutter block to a tool body; at least one calibration sensor to measure and detect changes in fluid properties, the at least one calibration sensor sensing fluid properties from one of a group comprising flow, rpm, weight, and hydraulic force; and at least one processor inter-connecting the at least one caliper and the at least one calibration sensor, said processor providing verification and control of a desired wellbore diameter by comparing simultaneous measurements from the caliper measuring wellbore diameter and from the position sensor for sensing the relative position of the extendable cutter block to the tool body, and compensating the measurements using said calibration sensor.