American Oil and Gas Reporter - May 2018 - 50

SpecialReport: Mid-Continent Update

STACK/SCOOP/Merge Turns To Tech
The formula for success in horizontal
resource plays includes four key elements:
high-quality source rock, capital, engineering and technology. While the importance of any one of those elements
relative to the others is debatable, there is
no understating technology's role in transforming a collection of tight rocks into
the marvels of the modern energy world.
The SCOOP/STACK/Merge is a perfect
case in point.
As operators step up activity in the
plays and shift to infill development projects, technology is being called on to
continue to drive down costs while pushing
up productivities and estimated ultimate
recoveries. Oklahoma City-based Thru
Tubing Solutions has developed an "incasing" diversion system, SlicFrac™, that
does both, according to Cliff McKaughan,
business development manager.
"Some of our customers have shared
that they have seen a 40 percent increase
in production in the Woodford (SCOOP).
Another customer says most of his pads
in the STACK have seen a 20 percent increase in production with SlicFrac," McKaughan asserts.
Diverter applications are increasing as
oil and gas companies seek to optimize
the effectiveness of hydraulic fracturing
treatments by selectively diverting fluid
and proppant away from the "paths of
least resistance" to untreated perforation
intervals, thereby maximizing the stimulated
reservoir volume, McKaughan says.
Unlike chemical diverting agents,
SlicFrac is a mechanical diverter system
that deploys "PODs" down hole that preferentially seal perforations taking the
most fluid, and selectively diverting frac
energy to virgin formation to stimulate
the entirety of each stage. "The PODs
efficiently attach to and block perforations,
including irregularly shaped holes. They
are pressure rated up to 10,000 psi,"
McKaughan details.
As an illustration, he points to a hypothetical stage with 36 perforations. "Many
times, only about 50 percent of the holes
in a stage take fluid. With SlicFrac, the
frac crew pumps about half the volume,
and then the PODs are dropped, sealing
the perforations that are taking the fluid,"
he explains. "If 18 are dropped, 18 holes
will be sealed. The frac crew then pumps
the rest of the volume, allowing more
perforations to take the fluid."
50 THE AMERICAN OIL & GAS REPORTER

Contacting More Rock
McKaughan says there are two advantages to using the technology. "First,
you contact more rock," he comments.
"If you have a 250-foot stage, you are
contacting the entire 250 feet instead of
only the first perfs taking the fluid.
Second, the fluid in the initial perforations
does not travel as far to negatively impact
other wells in the field."
The second point is key in infill drilling,
where completing child infill wells can
interfere with the original parent well
and where induced fractures created in
closely spaced wells on a pad could interact. "If the fluid and proppant travel
too far, they can knock the parent or
child wells off line," he continues. "Selectively sealing the perforations at the
casing has made a big difference."
McKaughan says Thru Tubing Solutions is using the SlicFrac system in every
basin in the lower-48. Another advantage,
besides contacting more rock, is that it
eliminates the need for as many bridge
plugs, thus reducing cost.
"If you have 40 stages in a lateral,
you need 40 bridge plugs," he offers.
"With this system, you can go from 40
to 20 stages. That saves 20 plugs. You
also can save one-and-half to two days
on location. If frac crews cost $5,000
an hour, up to $200,000 can be saved in
treatment cost and you get just as good
a well without having to remove as
much fluid."
McKaughan says the company's
chemists also have designed a POD that
is degradable, eliminating the need for
the POD to be milled out. The POD will
degrade in 12 days in 150 degrees with
no fluid movement. If there is any fluid
movement, it will degrade even faster, he
adds. "And it doesn't matter what the
fluid is," McKaughan maintains. "It will
work in freshwater or heavy brine."
He points out that Thru Tubing Solutions also has developed a degradable
POD that works the same way in 350
degree environments. The degradable
POD is especially beneficial when it is
run to the toe of long horizontal laterals.
"Even if the operator is using a plugand-perf method in completing the well,
there is no need to go back in to drill out
a plug near the toe, which could be two
miles out, if a degradable pod is used,"

McKaughan states.
"Operators also tell us that because
they are contacting more rock, the higher-end flow from the initial pressure lasts
longer until the breakover point where
the pressure drops," McKaughan contends.
"They get another 20-30 days of the
higher rate, which means a lot of money."
Greener Approach
EcoStim Energy Solutions Inc. moved
into Oklahoma last year when it opened
a yard in Fairview, between Enid and
Woodward. Headquartered in Houston,
EcoStim's core operating areas are in
Oklahoma and Argentina.
"Fairview is ideally suited for both
SCOOP and STACK work, located on
the northern end of the STACK," describes
Chief Operating Officer Barry Ekstrand.
"Additionally, we can go west into the
Tonkawa and Granite Wash or north into
the Mississippian Lime.
"We moved into our new facility in the
first quarter of 2017 and began fracturing
operations in the second quarter. We expanded with a second frac fleet working
out of Fairview in the fourth quarter," he
says. "EcoStim is very bullish on the
STACK and SCOOP, and we would like
to continue to grow our activities there."
According to Ekstrand, technology is
at the heart of EcoStim's fracturing services, including:
* Computer-controlled natural gaspowered turbine fracture pumps that provide high power with low emissions and
a small, lighter footprint;
* Geo-Predict® analysis to characterize
the subsurface, improve stage and cluster
placement, develop proppant and diverter
strategies, and optimize the overall stimulation program; and
* Reservoir monitoring services, including DFIT, offset pressure interference
monitoring, fiber optic acoustics, temperature and bottom-hole pressure sensing.
By leveraging these technologies, Ekstrand says EcoStim has developed a systematic method to optimize well completions, beginning with rock mechanics
and other subsurface data to determine
the differential stress profile, natural fracture network, fault networks and highprobability production indicators within
a shale formation.
During and after treatment, downhole
fiber optic monitoring (either as perma-

American Oil and Gas Reporter - May 2018

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