41664-Phase-1-Final-Report.pdf

DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM PHASE I FINAL REPORT Starting date: October 1, 2002 Ending Date: May 31, 2004 Principal Author: Martin E. Cobern Date Issued: August 31, 2004 DOE Award Number: DE-FC26-02NT41664 Submitting Organization APS Technology, Inc. 800 Corporate Row Cromwell, CT 06416 ABSTRACT The deep hard rock drilling environment induces severe vibrations into the drillstring, which can cause reduced rates of penetration (ROP) and premature failure of the equipment. The only current means of controlling vibration under varying conditions is to change either the rotary speed or the weight-on-bit (WOB). These changes often reduce drilling efficiency. Conventional shock subs are useful in some situations, but often exacerbate the problems.