Patent ID: 7823658
Filing Date: 2010-11-02
Classification: E21B

Abstract:
1. A method of performing drilling operations, the method comprising: using a drillstring for conveying a bottomhole assembly (BHA) into a borehole; making first measurements with a compressional load on the BHA; making second measurements without a compressional load on the drillstring; using a processor for estimating, from the first measurements and the second measurements, a parameter related to a change between the loaded and unloaded condition of the BHA the parameter being selected from: (i) a time when a drillbit loses contact with a bottom of the borehole, (ii) a time when a drillbit makes contact with a bottom of the borehole, and (iii) a stretch of the drillstring; and continuing further drilling operations based on the parameter; wherein the first measurements and the second measurements comprise a formation evaluation measurement made at a plurality of toolface angles.