MASTER
YOUR
TERRAIN
W
ith the development of diamond-leached cutter
technology and other material advancements, the
industrymade significant improvements in PDC bit
durability over the last few decades. Stability and steerability
improvements were another significant focus, and great strides have
beenmade in the last 30 years.
But little consideration had been given to drill bit efficiency – to
maximise rates of penetrationwhile using the least amount of energy
This became the concept and philosophy for the ReedHycalog™
Tektonic™ drill bit platform.
First, the researchers and engineers at NOV examined every
aspect of the drilling process: how to initiate rock failure as efficiently
as possible; ways tominimise the frictional losses associated with
cuttings movement up the cutter face and along the blade; means
to efficiently distribute cutter loads on the bit body; andmethods to
ensure cuttings are evacuated from the face of the bit as quickly and
efficiently as possible.
Thousands of hours were spent to develop, simulate, test and
validate new designs and bit features aimed at maximising drilling
efficiency and rates of penetration, which were combined with
proven attributes for durability, stability, and steerability.
In order to specifically tailor bits for myriad challenges and
environments around the globe, regional bit design engineers were
provided with a design toolbox so they could use a combination of
features to build the best bit for any given application.
New analysis software was developed, as well. Dynamic rotation
bit modelling software is used to examine cutter forces under
non-concentric bit motion conditions that more accuratelymatch
what is encountered downhole and to optimise each bit’s cutter
loading, transient bit-rock interactions, and wear characteristics.
Advanced fluid flowmodelling software uses techniques to quantify
and improve hydraulic cleaning and cooling performance. Examining
the interaction between cuttings and drilling fluid helps the regional
design engineers maximise hydraulic energy in critical areas,
ensuring quick and efficient evacuation and providing high-velocity
fluid to the cutters to prevent thermal degradation.
Research for the Tektonic platformalso resulted in the
development of the newReflektor™mirror-finish cutters, which
offer improved wear and impact resistance. New cutter geometry,
surface finish, and edge treatments improve cutting efficiency. Lab
tests in sandstone and shale using a pressure chamber to simulate
downhole conditions showed increases in ROP – 85% in shale and
ALEXIS GARCIA, BRAD IVIE AND ANDREW MILLER, NOV, USA, INTRODUCE A NEW
GENERATION OF PDC BITS.
COVER STORY
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