American Oil and Gas Reporter - April 2019 - 75

SpecialReport: Drilling Technology

By splitting bits' primary
blades into two halves, Ulterra creates the space for
extra nozzles. The company
says this gives the blades
dedicated hydraulics for the
cone and shoulder, which
helps the bits excel in a variety of formation types-from
soft, easily-sheared shales to
hard and interbedded formations-by improving cuttings
evacuation and keeping the
cutters sharp and cool.

pyrite and limestone. That combination
makes the Cotton Valley so challenging
to drill through that many cutter test programs use it as a proving ground for new
abrasion-resistant cutters."
Ulterra discovered the bit's exceptional
durability by accident, Casad notes. "Ulterra was asked to design a bit to drill
through 2,000-4,000 feet of rock above
the Cotton Valley as fast as possible," he
relates. "The bit initially missed the instantaneous ROP we were targeting, but
when it transitioned past 10,000 feet into
the Cotton Valley, it drilled at record
footages and speeds to surpass our expectations for the entire section."
The bit's durability comes, in part,
from the enhanced hydraulics, which
keep the cutters cool to reduce thermal
wear, Casad says. "However, there are
other factors at play. For example, the
blades' patented geometry enables bit
designers to lay out cutters in unique
configurations that allow them to overlap
and support one another. This enhances
both footage and ROP by keeping the
cutters sharp."
Other benefits occur because the bit
geometry pushes the cone forward in the
junk slot, Casad contends. "This means
that the cutters in the cone engage the
formation farther ahead of the cutters on
the shoulder than normal," he notes. "The
cone's bite into the formation stabilizes
the bit and pre-fractures the rock, making
it easier for the other cutters to drill
through once they arrive. This minimizes

torque fluctuations, which improves tool
face control and allows the driller to
apply more energy to the bit without
worrying about excessive vibration."
The cone's forward position contributes
to faster ROPs in at least one other way,
Casad adds. "When the cone grabs the
formation as the bit moves through the
curve, it becomes a 'lever' that applies
the weight on bit more directly to the
formation," he explains. "This means the
driller can cut more rock with the same
amount of energy."
How much SplitBlade improves tool
face control and ROP will vary with the

application, but Casad says the improvement can be significant. "In one Rocky
Mountain application, the blade geometry
reduced sliding percentages 30 percent
and increased ROP while sliding, also
by 30 percent," he reports.
Other SplitBlade bits have set footage
records in West Texas and statewide
ROP records in Oklahoma, Casad reports.
The bits also are performing well in
Canada, the Middle East and the Asia
Pacific, he says.
"In a hard and abrasive formation in
Egypt, the technology allowed us to
replace a two-bit run with a single-bit
run at 30 percent higher ROP," Casad
concludes. "This took two days off the
drilling time, providing almost $50,000
in cost savings and bottom-line value for
that customer."
Durability Through Engineering
Sound engineering can turn a multiple-bit run into a one-bit run, says Yemi
Lipede, sales manager at Drilformance.
As an example, he points to Midland
Basin vertical wells, many of which are
8,000-9,000 feet deep and start with a
five-seven degree kick out.
"Because the bits must drill through
several zones with rocks that are almost
as hard as carbonates, this application
generally destroys six-blade bits, especially
if the driller makes mistakes while handling

This 12¼-inch bit from Drilformance has enabled Midland
Basin operators to complete
challenging vertical intervals
that once required two or three
bits in a single run. The company attributes the bit's durability and speed in part to
carefully-engineered improvements in the cutting structure
that enhance cuttings evacuation and tool face control.

APRIL 2019 75
American Oil and Gas Reporter - April 2019

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