American Oil and Gas Reporter - April 2015 - 148

SpecialReport: Bits & BHAs

By leveraging robust simulation technology to quickly
identify the best design for a
specific application, the engineers behind Halliburton's
GeoTechTM bits are reducing
drilling costs across the United States.

western Shelf of New Mexico, as well as
the San Juan, Powder River, and Piceance
basins, Dalla Betta notes. He says it has
made 500 runs without being pulled as a
result of bit damage.
Deen reports the company is applying
lessons learned from the 83⁄4-inch OneShot
U516M to develop versions with different
diameters, including an 81⁄2-inch model for
the Permian Basin. "The people in the field
where these bits are being run are very,
very excited, because the initial results
have been impressive," he comments.

Simulation's Power
The traditional approach of improving
fixed-cutter bits by developing better materials is slowly reaching the point of diminishing returns, argues Brad Dunbar,
Halliburton's product manager for fixedcutter drill bits.
"While there always will be some
gains from keeping a cutter sharper for
longer and reducing erosion and wear on
the body, the future of optimization is figuring out how to accurately simulate how
a particular set of PDC cutters will drill in
a given hole geometry and rock geology,"
he says.
"Once simulation results become predictably proportional to actual drilling, engineers will be able to test improved cutting structures on the computer," he continues. "Instead of trying new iterations
from one well to the next, they will be able
to test hundreds of iterations and identify
the right design before the well is even
drilled."
According to Dunbar, Halliburton's GeoTech™ fixed-cutter product line embodies that philosophy by combining traditional product improvements with simulation
techniques that are enabling a leap in performance. While the cutters have increased abrasion resistance, impact resist-

ance and thermal mechanical integrity, he
says the key to their performance is to customize the bit design using application-specific knowledge.
"Advances in how PDC cutters are
placed, such as multilevel and two-layer
cutting structures, allow the full use of different components in the specific rock to
be drilled, with parameters to increase efficiency," Dunbar observes.
A new rock interaction energy balancing model integrated into an IBitS™ 3-D
computer-aided design and manufacturing
platform clarifies how these materials
will cut the rock down hole. Dunbar says
this allows engineers to change cutter designs, body materials and placement, and
to modify input parameters to exceed
customer expectations.
Improvements in computational fluid
dynamics automation provide better removal of cuttings, Dunbar continues. He
adds that upgraded depth of cut control
helps place drilling elements where they
are needed to ensure torque and ROP re-

148 THE AMERICAN OIL & GAS REPORTER

sponse are appropriate for the application,
maximizing durability and ROP.
GeoTech bits have been extremely
successful in the Bakken, Dunbar reports. "The bits incorporate advanced
cutter technology with depth-of-cut control that significantly increases the amount
of rock removed with less cutter wear," he
says. "This advance has yielded as much
as 20 percent higher average penetration
rates and up to three times more footage
drilled, compared with offset wells. As a
result, operators are realizing cost savings
as high as 20 percent."

Drilling Jaguar
The speed of the MicroCORE™ bit
from Tercel Oilfield Products has surprised
even its creators, says David Morrissey, the
company's vice president of sales and marketing. "We developed the bit in collaboration with Total to enable drillers to gather miniature cores while drilling, but over
the past two years, we have discovered that
it works extremely well in applications focused on ROP," he clarifies.
Instead of cutting through the center of
the hole, Morrissey says the bit cuts
around it to create a small core, then applies a simple lateral force to break the core
off and send it to the surface alongside
more traditional cuttings.
"The center section of a traditional bit
cuts using an inefficient compression
failure mechanism and takes an unequal
share of the weight on bit available to the
cutters," Morrissey says. "By cutting
around the hole's center, we redistribute
high-energy consumption from the bit's
center to the more efficient areas of the cutting structure."
To maximize the design's inherent ef-

Because it cuts around rather than
through the center of the hole, the
MicroCORETM bit from Tercel Oilfield Products allows more weight
on bit to reach the outer cutters,
providing faster penetration rates.
American Oil and Gas Reporter - April 2015

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