American Oil and Gas Reporter - December 2018 - 72

SpecialReport: Well Stimulation & Completion Technology

These white buckets contain solid chemical carriers that can be delivered down hole
during completion. Once there, they mitigate production issues by slowly releasing corrosion, scale or paraffin inhibitors. According to Energy & Environmental Services, their
provider, these carriers generally last 18-36 months.

in formations as frac fluid flows back.
Donald Lindblad, who directs the company's production chemicals division,
says solid chemicals also can be applied
during the production phase. "For example,
we use them to treat wells in Kansas and
eastern Oklahoma," he relates. "To do
that, we put the solids down each well's
rat hole. As the well produces, these
solids gradually release corrosion, scale,
paraffin or hydrogen sulfide treatments,
which get carried up the wellbore.
This approach allows operators to
treat a well without paying drivers to
bring chemical trucks on site or installing
an injection pump, which can cost
$1,000, Lindblad says. He describes the
chemicals as a big improvement over
soap sticks, which have lower concentrations and contain wax that can contribute to paraffin issues.
The solid chemicals are easy to transport,
Lindblad adds. "If they spill, they can be
cleaned up with a broom and dust pan.
There is no need to file a report," he says.
Recycling Produced Water
Reusing produced water in completions
can reduce costs greatly, observes Mark
Patton, the president of Hydrozonix LLC.
He says the cost savings are becoming
more significant as water treatment technologies improve and the industry refines
reuse best practices.
"We have seen operators complete
wells using 100 percent produced water,
but blends with 30-50 percent produced
water and 50-70 percent freshwater are
more common," he says. "More aggressive blends increase chloride levels,
which can cause incompatibilities with
traditional friction reducers, forcing the
operator to use higher concentrations or
72 THE AMERICAN OIL & GAS REPORTER

switch to catonic friction reducers, which
cost more."
Operators need not worry that produced
water fracs will be less effective than
freshwater, Patton assures. "Numerous
studies show that even at 100 percent,
produced water is as effective as freshwater
and may even slightly improve production," he reports.
Produced water can reduce the need
for clay stabilizers, Patton continues.
Like the potassium chloride typically
used as a clay stabilizer, the produced
water's sodium chloride content keeps
clay from absorbing water and swelling,
he explains.
To reuse produced water in a completion, Patton says operators need to remove
oil and solids, a task most operators

already perform on their produced water.
Recycling also means removing bacteria,
iron and sulfide, which he says can be
done easily with an oxidizer.
For most applications with flows exceeding 5,000 barrels a day, Patton recommends ozone as the oxidizer of choice.
"It is a strong oxidizer, so it reacts quickly
with almost everything," he says. "This
allows us to verify it is working in real
time, which means we can zero in on the
minimum effective concentration in order
to reduce costs."
Ozone's rapid degradation also keeps
it from interfering with friction reducers
and other components of the completion
fluid, Patton reports. Because ozone is
made on demand by passing air through
an electric current, he adds, it does not
carry the risks and costs associated with
transporting and storing chemicals on site.
Patton points out that ozone breaks
down into oxygen rather than hazardous,
long-lasting byproducts associated with
disinfectants such as chlorine dioxide
and sodium hypochlorite (bleach). "This
is a big benefit if the operator might
want to sell the produced water to agricultural companies or treat it for discharge
once completion activity moves away,"
he comments.
"Oxygen acts as mild oxidizer, so if
the produced water needs to be stored,
the oxygen left behind by the ozone can
help maintain water quality," Patton says.
"It is like a booster shot for the aeration
systems generally used for that purpose."
To reduce treatment costs, Patton says

Before produced water can be reused in completion ﬂuids or waterﬂoods, it must be
treated to remove bacteria, iron and sulﬁde. Water treatment specialist Hydrozonix recommends using ozone, a strong oxidizer that can be generated on site and degrades too
quickly to interfere with friction reducers and other chemicals in the completion ﬂuid.

American Oil and Gas Reporter - December 2018

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