American Oil and Gas Reporter - March 2016 - 76

SpecialReport: Unconventional Resource Science
drilling and extend the field."

high-resolution temperature and pressure
gauges above and below the bridge plug.
"The bottom-hole temperature and pressure measurements are extremely valuable
for getting a sense of what is going on
during the stimulation in a cost-effective
way," Hummer says.
"The biggest benefit is understanding
zonal isolation," he says. "Ideally, the
pressure reading from the bottom gauge
should stay more or less constant as the
frac is underway. If it rises, there likely is
pressure communication between the zones,
which might mean the stage spacing is
too close. But if the pressure reading stays
the same, there is no communication, so it
may be worth trying tighter spacing."
Hummer adds that the downhole pressure curve the sensors record can replace
the pipe friction-based pressure estimates
traditionally used to improve the accuracy
of frac simulations.
The temperature sensors also detect
communication, Hummer notes. "In a
situation where the pressure communication is too small to be detected, but
temperature communication shows, the
fluid may be traveling through microannuli
in the cement," Hummer says. "Knowing
that will allow the operator to take a
closer look at his cementing procedures
and centralizers."

Field Optimization
With the right data and tools, operators
can optimize completions from well to
well to improve a field's economics, says
Ryan Hummer, vice president of strategy
for NCS Multistage. He says the company's Multistage Unlimited® frac delivery
system simplifies such optimization by
allowing precise, verifiable and repeatable
frac placement.
"With traditional completion methods,
such as plug-and-perf or ball-drop techniques, a stage's performance can be dictated by the formation's heterogeneity,"
he notes. "Our system uses single-point
injection, so we know exactly where the
fluid and proppant are going. By taking
out the unpredictability associated with
the completion itself, we enable more
meaningful well-to-well comparisons that
make it easier to evaluate and improve
completion designs."
Multistage Unlimited is based on a
coiled tubing-deployed, resettable bridge
plug that can be used to open casing
sleeves or isolate an area so an opening
can be created using a downhole sand-jet
perforator, Hummer describes.
To help customers improve their completions, the system now includes tougher,

Top gauge pressure

Top guage temperature

Bottom gauge pressure

Bottom gauge temperature
90

7,000
Sleeve shift

6,000
Pressure
test
85
Bridge plug unset,
pressure equalized

4,000
80
Bridge plug set, isolation
3,000

Temperature (deg F)

Pressure (psi)

5,000

2,000
75

1,000

0
10:00

10:05

10:10

10:15

10:20

10:25

10:30

10:35

10:40

70
10:45

Time

The temperature and pressure gauges installed above and below the resettable bridge plug
that isolates each fracture stage in NCS Multistage's Multistage Unlimited™ system can
help operators identify pressure and temperature communication between each stage. This
image shows data from a typical stage. NCS says the lack of pressure communication can
help the operator determine whether tighter spacing would optimize the next completion.

76 THE AMERICAN OIL & GAS REPORTER

The temperature data also are invaluable
in formulating frac chemicals, he says.
"By knowing exactly how the formation
cools during a completion rather than relying on estimates, completion engineers
can design cross-linkers and breakers that
are more likely to perform as intended,"
Hummer explains
During the completion itself, operators
can monitor the coiled tubing string to
estimate downhole pressures in real time,
Hummer reports. He says this allows
them to adjust pad sizes, pump rates and
proppant concentrations based on the formation's response. They can even anticipate a screen-out and make adjustments
to prevent it, allowing the frac to be completed as designed.
"The temperature and pressure gauges
have been used in every active formation
in the United States and Canada that requires intense horizontal completions, including the Marcellus and Utica, Eagle
Ford, Permian Basin, Powder River Basin
and Bakken, as well as the Cardium,
Viking, and Montney," Hummer says.
In many cases, the system's data have
enabled operators to make significant
changes to their completion designs. As
an example, Hummer offers the company's
work for an operator in the Montney
Shale, "Over the course of 10 wells, the
company reduced its average stage spacing
from 140 to 70 feet without seeing any
pressure communication," Hummer says.
"That helped maximize the wells' net
present value and internal rate of return."
Continuous-Duty Pump
As multiwell pads have become the
norm and completion designs have called
for ever-higher pressures and volumes,
completion companies have had to ask
more from their pumps. Today, many
companies require pumps that can operate
continuously at peak rod loads, says
David Paradis, president of pressure
pumping at Weir Oil & Gas.
In response, Weir introduced the SPM®
QEM 3000, which it describes as the
first high-horsepower frac pump designed
for continuous duty at a 275,000-pound
rod load.
"A traditional pump will not last if it
is run at full rod load for an extended period, so completion companies have had
to sacrifice rate or pressure to keep the
pump on line," Paradis says. "With the
SPM QEM 3000, they no longer have to
make that trade-off."
Chris Buckley, Weir Oil & Gas' vice
American Oil and Gas Reporter - March 2016

Table of Contents for the Digital Edition of American Oil and Gas Reporter - March 2016
