Drilling tool, apparatus and method for underreaming and simultaneously monitoring and controlling wellbore diameter

Abstract

A dynamic position sensing Apparatus or Method is used to underream an oil or natural gas well with a variable gauge positioning system incorporating underreamer position or diameter sensing means.

What is claimed is: 
     
         1 . An apparatus for closed loop underreaming to provide a wellbore of a predetermined diameter, sensing a position of extendable blocks using a dynamic position sensor, sensing a property from one of a group comprising flow, rotation, weight, sound transit time, density, pressure, and hydraulic force using a properties sensor, performing the step of comparing block positional data to property data and using said properties data to check underreaming and delivery of the predetermined wellbore diameter. 
     
     
         2 . An apparatus for oil and gas drilling comprising a variable gauge reamer with at least one radially extendable block, at least one dynamic position sensor wherein said sensor indicates a position of radially extendable cutter block positions selected at surface. 
     
     
         3 . Apparatus of  claim 2  further comprising at least one calliper to determine wellbore diameter. 
     
     
         4 . Apparatus of  claim 3  further comprising a processor interlinked to receive positional data and wellbore data and one of the group from: vibration, rpm, torque, pressure, weight, flow, hydraulic force. 
     
     
         5 . Apparatus of  claim 4  further comprising wherein the processor controls the position of the block according to either calliper data, vibration data, rpm, torque, pressure, weight, flow, hydraulic force. 
     
     
         6 . The apparatus of  claim 2  wherein the detected position is sensed by analogue, digital, electrical or mechanical means. 
     
     
         7 . The apparatus of  claim 2  wherein the detected position is based on a direct or inferred measurement. 
     
     
         8 . The apparatus of  claim 1  wherein position data is based on direct or inferred signaling means. 
     
     
         9 . The apparatus of  claim 1  wherein said cutter block positions are locatable within at least three known positions. 
     
     
         10 . The apparatus of  claim 1  wherein sensing or signaling means indicate the radial position of the cutter block. 
     
     
         11 . The apparatus of  claim 2  wherein sensing or signaling means indicate the radial position of the cutter block. 
     
     
         12 . The apparatus of  claim 1  wherein sensing or signaling means indicate the diameter of the cutter block relative to the tool. 
     
     
         13 . The apparatus of  claim 2  wherein sensing or signaling means indicate the diameter of the cutter block relative to the tool. 
     
     
         14 . The apparatus of  claim 2  wherein said dynamic sensing detects reamer diameters