American Oil and Gas Reporter - April 2018 - 131

SPECIAL REPORT: DRILLING TECHNOLOGY
The work described in this article focuses on a methodology to derive a drilling
optimization index. This index and the
dysfunction beliefs allow drilling software
to calculate an operational cone that depicts
optimal drilling parameter suggestions.
A case study on the use of such cones for
drilling optimization is being prepared.
One of conclusions drawn from this
work is that when a holistic, normalized
index automatically aggregates all drilling
dysfunctions, the driller is freed from the
task of monitoring trends. Drillers are
then able to focus on determining optimal

WOB and rpm operating points.
Because of large uncertainties that
undermine the ability to accurately
assess formation properties, hole geometry, wellbore tortuosity, bit conditions
and other drilling conditions, the work
demonstrates that optimal drilling regions within a WOB-rpm plot vary
widely, even among wells drilled on
the same pad. Therefore, it is difficult,
if not impossible, to arrive at such regions through models.
The drilling optimization index and
dysfunction belief values enable the driller

to move toward a better solution, but
global optimality is not guaranteed because
drilling dynamics are highly nonlinear.
Determining drilling parameters
through post-well analysis should be done
with caution. Those parameters may serve
as starting points only, but real-time data
better reflect reality and provide pointers
for better drilling parameters.
Operational cones can be calculated
and provided to the driller in a visual
format to help implement drilling parameters that attenuate dysfunctions and
improve drilling efficiency.
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PRADEEPKUMAR ASHOK

Pradeepkumar Ashok is the chief technology officer of Intellicess Inc., an Austin, Tx.-based company that develops
drilling data-related technologies for oil and gas operators and drilling contractors. He also is a research scientist
in the rig automation and performance improvement in drilling (RAPID) group at the University of Texas at Austin.
There, he utilizes his research experience in the robotics industry to focus on improving data quality in the upstream
petroleum space to advance drilling automation throughout the well delivery life cycle. Ashok holds a Ph.D. in mechanical engineering from the University of Texas at Austin.
ADRIAN AMBRUS

Adrian Ambrus is a research scientist in the drilling and well modeling group at the International Research Institute
of Stavanger. He holds a Ph.D. in mechanical engineering from the University of Texas at Austin and is an alumnus
of the RAPID group at UT. Ambrus also has worked for Intellicess Inc., where he helped develop and integrate
software for drilling data quality validation, rig activity classification and detection of drilling dysfunctions and other
drilling-related incidents.
TAYLOR THETFORD

Taylor Thetford is a drilling engineer at Apache Corporation with a background in field drilling operations. He works
in the drilling data services group supporting the deployment and operations of a real-time data analytics and advisory
system to land and offshore drilling rigs. Thetford holds a B.S. in petroleum engineering from Texas Tech University.
BRIAN NELSON

Brian Nelson is a drilling engineer at Apache Corporation with a background in research and development, manufacturing and engineering design. Within Apache's drilling data services group, he has supported the development
and deployment of a real-time data analytics and advisory system to land and offshore drilling rigs. Nelson holds a
B.S. in mechanical engineering from Rose-Hulman Institute of Technology.
MICHAEL BEHOUNEK

Michael Behounek is a senior drilling adviser with Apache Corp. in Houston, working in worldwide drilling, supporting global operations and engineering, and pursuing technology advancement that can be leveraged to drive improvement and increase value to Apache. His 33 years of expertise include drilling engineering, operations,
performance improvement and contracting work in more than two dozen countries. Recent technology developments
include three years in drilling automation, and he now leads efforts to improve performance leveraging data, including
data quality, integration, transformation, analytics-visual, advanced and predictive. Behounek is a degreed mechanical
engineer and holds an M.B.A.
APRIL 2018 131

American Oil and Gas Reporter - April 2018

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