magazine

Feature
Grain by Grain:
Drying Frac Sand
A frac sand drying system. Photo provided
by Worldwide Recycling Equipment Sales.
By Savannah Cooper
W
ith the frequent rises
in oil prices and
the increase in oil
and gas exploration
in the United States,
experts anticipate that the demand for frac
sand will increase by at least 4.8 percent
every year until 2016.
In 2009, the average price of industrial
sand was $28.82 per ton, and the average
price of frac sand was $44.33 per ton. With
the addition of transportation costs from
the Midwest to oil and gas sites in places
like Colorado, Texas and Canada, the total
cost of frac sand can be over $300 per ton.
Many wells use more than 2,000 tons of
frac sand, leading oil and gas producers to
look for more cost-effective alternatives.
For years now, frac sands have been
used to augment the production of natural
gas and oil from wells, and frac sand use
will almost certainly become more common
and frequent in the years to come.
The hydraulic fracturing, or “fracking,”
process begins with the drilling of a well
into a rock formation. A high-pressure
fracking fluid is injected into the well.
This fluid, made up of water mixed with
frac sand and a blend of chemicals, acts as
a propping agent, or proppant. The proppant
prevents the fracture from closing
and permits gas to flow through the well.
Frac sand is a natural silica-based proppant.
In 2009, 6.5 million metric tons of
sand were mined to meet the demands of
the fracking industry—an amount worth
a total of $319 million. The United States
Geological Survey estimated that frac sand
mining doubled in 2010.
Frac sand requires pure quartz with as
few contaminating materials as possible.
The American Petroleum Institute (API)
has specific criteria that must be met for
frac sands, including its weight percentage,
sphericity and roundness, crush resistance,
acid solubility and turbidity. To ensure
that the quality of sand is acceptable, mining
companies wash and dry the frac sand
to rid it of all possible impurities.
To meet API standards, frac sand particles
must be well-rounded and relatively
clean of other minerals and impurities.
High-purity quartz sands are common
in the United States but most silica sand
BASIN BITS | Spring 2014 69