American Oil and Gas Reporter - October 2017 - 47

SpecialReport: Oil Field Chemistry
for even low-volume wells," he remarks.
Durham cites the handheld calculator as an example. "In
1974, the first calculators cost $150 for a few simple functions.
Now those functions and much more are available for free on
every mobile phone," he states, adding that he sees automation
and remote monitoring similarly being "built into" chemical
pumps, meters and storage systems as well as virtually all other
types of production equipment. "For production chemicals, that
translates into improved treatment quality, lower cost and
reduced well-site risk."
Completion Fluids
Durham has a unique perspective on completion fluids technology. He helped develop the first fluid systems specifically
designed for hydraulic fracturing in the 1970s while working
for Amoco. He says those early systems were licensed to service
companies and deployed almost exclusively as part of their
broader turnkey well completion services. That same model
was carried into the early days of the shale boom, with completion
services bundling chemicals, pressure pumping horsepower and
proppant.
As more companies entered the market, completion services
and goods were debundled gradually, giving operators more
options and increased pricing transparency, according to Durham.
"The market always moves to be more cost-effective. In the
case of the hydraulic fracturing market, bidding horsepower,
proppant and chemicals separately lowered the cost of everything,"
he states. "Many chemical companies got into the fracturing
chemistry business when it became debundled, expanding the
range of products and services available while simultaneously
reducing prices."
Consequently, operators now are sourcing their own sand
and chemicals and hiring pressure pumping horsepower on a
service fee basis, he explains. "This approach helps stabilize
pricing and leads to operators better understanding the chemical
business," Dunham says. "Oil and gas companies are hiring
people from the chemical industry who understand the benefits
of different completion fluid formulations and know what the
prices should be."
Unlike the production chemicals market, which is defined
by many different types of specialized chemistries usually
ordered at relatively small volumes with high service requirements,
completion chemicals is a lower service market with fewer
products but very high-volume orders. "Rather than complex
chemistries, the focus in fracturing fluids is simplified systems
with minimal additives, such as slickwater with friction reducers,"
notes Durham. "Both the types of fluids and the volumes
required make it easier to commoditize fracturing fluids."
As lateral lengths grow longer, stage counts increase and operators pump more proppant per well, the amount of fluid
required goes up, as do pressure and friction. The toe section of
a horizontal well generally takes more friction reducer on a
concentration basis, with friction decreasing as completion operations progressively work back toward the heel. With laterals
routinely extending to 8,000 feet or more, friction reducer concentrations in the toe section now average 1.5 gallons per 1,000
gallons of treated frac fluid volume or higher.
While low-cost slickwater systems with friction reducers are
the clear preference for hydraulic fracturing in tight oil and
shale gas plays, hybrid treatments that combine slickwater and

cross-linked gel systems are proving advantageous in many
completion designs to place proppant out in the formation and
keep induced fractures propped open, according to Durham.
"Typically, cross-linked gels are tailed in to pump a little larger
proppant mesh size toward the end of the stage to ensure an efficient, conductive fracture network."
Although friction reducers and gels historically have come in
liquid form, Durham notes that Apache is using solid powdered
forms of chemical additives and gels to reduce overall volumes
and the number of trucks on the road, and eliminate the use of
solvents. "The dry products work just as well as the liquid
versions without the solvent toxicity," he says. "Chemical vendors
also are developing powdered versions of scale inhibitors."
Improving Sustainability
Mirroring the trend toward higher proppant concentrations
(some wells are being completed with 2,000 pounds or more of
proppant per foot), operators also are pumping larger volumes of
fluid per well. Considering the high percentage of fluid ultimately
flowed back during the early production phase, Durham notes
that operators are implementing recycling systems as a standard
best practice to capture, treat and reuse flowback fluids. Moreover,
he says Apache and others are also using chemical and mechanical
treatment methods to recycle brackish produced water for use in
well fracturing, particularly in areas such as the Permian Basin
where freshwater supplies are limited.
Sustainability is a major motivator for innovation in completion
chemicals, and Durham says it is imperative for operators and
chemical manufactures to continue to work cooperatively to engineer green chemistries and implement environmentally friendly
best practices for delivering chemical solutions down hole. One
example is the American Chemical Society's Green Chemistry
Institute® Hydraulic Fracturing Roundtable, which Durham
chairs.
"Member companies work together to develop and disseminate
scientific information related to applying green formulations
and engineering principles in the chemical supply chain for hydraulic fracturing," he states. "The goal is to foster more
sustainable practices in hydraulic fracturing."
The biggest risk associated with fracturing chemicals is accidental releases during transportation, Durham adds. "There
has been a lot of misinformation about frac fluids down hole,
but many of the general public's concerns about hydraulic fracturing operations really stem from concerns of materials transport,
well construction, hydrocarbon production or distribution," he
contends.
Through internal best practices and external initiatives such
as the Hydraulic Fracturing Roundtable, Apache is committed
toward being more cost-effective and sustainable over time.
"The fact is, you can accomplish both simultaneously," says
Durham. "They actually go hand in hand. The less chemical
used, the less cost there will be. The greener the chemicals
used, the less risk there will be.
"Our continuous improvement process has helped us reduce
frac chemical usage and the levels of toxins year over year," he
concludes. "We are working hard to apply green chemistries
and reduce the amount of chemicals used in production and
fracturing processes, and that makes wells both more profitable
and more sustainable."
OCTOBER 2017 47

American Oil and Gas Reporter - October 2017

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