SPE Drilling & Completion
Volume 24, Number 2, June 2009, pp. 293-300

SPE-107289-PA

Gauge, Cutting Structure, Torque Control Components--What Really Counts for Optimal Tool Face Control With FC Drill Bits?

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DOI  More information 10.2118/107289-PA http://dx.doi.org/10.2118/107289-PA

Citation

  • Barton, S., May, H., and Johnson, S. 2009. Gauge, Cutting Structure, Torque Control Components--What Really Counts for Optimal Tool Face Control With FC Drill Bits? SPE Drill & Compl  24 (2): 293-300. SPE-107289-PA. doi: 10.2118/107289-PA.

Discipline Categories

  • 1.4 Drilling Equipment and Operations

Keywords

  • torque control, motor steerable, tapered gauge, depth-of-cut control, torsional stability

Summary

Tool-face control is widely regarded as one of the greatest challenges when drilling directionally with an FC (fixed cutter) drill bit on a positive displacement motor (PDM).

Tool-face offset is proportional to the torque generated by the bit. FC bits, by nature, generate high levels of torque. If an external force acting on the bit causes an FC bit to over-engage, a large change in downhole torque is typically produced, which causes rotation of the drillstring and loss of tool-face orientation. It is therefore desirable for an FC bit to produce a torque response that does not vary greatly with changes in the external forces applied.

This paper examines the effect of varied components of an FC drill bit to determine the key design requirements to deliver a smooth torque response and improved directional performance. This includes evaluation of the results from a comprehensive series of laboratory tests to determine the effectiveness of a number of varied, removable torque controlling components (TCC). The goal was to establish a configuration that would provide predictable torque response to applied weight on bit (WOB), allowing cutting structures to be independently optimized for overall higher penetration rates.

A novel gauge geometry was engineered to reduce drag and deliver a smoother borehole. This would provide less torque when sliding and beneficial gauge pad interaction with the borehole when in rotating mode.

Field performance studies clearly demonstrate that matching TCC, an optimized cutting structure, and gauge geometry to a steerable assembly delivers smooth torque response and improved directional control. Benefits within rotary vertical applications are also demonstrated. Successful application has resulted in significant time and cost savings.

© 2009. Society of Petroleum Engineers

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History

  • Original manuscript received: 15 February 2007
  • Meeting paper published: 16 April 2007
  • Revised manuscript received: 23 July 2008
  • Manuscript approved: 25 August 2008
  • Published online: 1 June 2009
  • Version of record: 1 June 2009