American Oil and Gas Reporter - October 2015 - 99

SpecialReport: Drilling Fluids Technology

Equipment Optimizes Mud Condition
By Colter Cookson

Even the most promising drilling fluid
can fail to deliver if the equipment that is
designed to maintain its condition works
poorly or goes down. Consequently, companies behind everything from flowline
shakers to barite recovery units and
vertical cuttings dryers continue to innovate. Their latest products offer greater
reliability and efficiency while coming
in smaller, more manageable packages.
The right equipment can turn an otherwise troublesome and costly well into a
joy to drill, suggests Jeff Woolums, National Oilwell Varco mud cooling product
champion. Likening mud coolers to the
radiator in a Formula 1® race car, Woolums
says, "The radiator can be 20 percent the
weight of the car, but no one would dare
race without one. Mud coolers do not
have that reputation, but they are highperformance radiators for the drilling rig.
In hot wells, they are easily worth the
cost."
He says NOV's mud coolers offer
several benefits. "The temperature in the
topside tanks goes down, extending the
lives of surface expendables such as mud
pump liners, valves and blowout preventers," he begins.
"Cooling mud improves downhole
tool life as well," he continues. "In a
series of South Texas wells, the cooler
dropped the temperature-related failure
rate from two per well to zero, which enabled the operator to drill three days
faster.
"In hot wells, to avoid paying rebuildtool costs and keep electronics in order,
operators periodically cool their wellbores
by pulling off bottom and circulating for
45 minutes to an hour," Woolums notes.
"With our mud cooler, we can cut that
circulation time to 10-15 minutes."
He says mud coolers offer tremendous
savings, but traditional designs, which
spray water over a bundle of tubes that
contain the mud, can evaporate 8,00010,000 gallons of water a day. "That is
not sustainable, so we developed a closedloop system that cools the mud without
operating water," Woolums says.
The result is the TUNDRATM MAX
land chiller, which has two stages. "The
first stage uses an air cooler to knock 2030 degrees off the approach temperature,
and the second is a chiller that cools the

mud another 20-30 degrees," Woolums
describes.
"Because the chiller is doing most of
the heavy lifting, in high ambient conditions such as a 105-110 degree day in the
Eagle Ford, we can operate as if it was
70-80 degrees," he says. "That allows
for a much smaller footprint than a traditional air-cooled unit and cools the mud
an extra four, five, six or even 10 degrees.
"The TUNDRA is easy to transport
and deploy," Woolums says. "Rather than
needing several trailers, we have one,
and we do not need to offload the equipment. Instead, we back the trailer up to
the mud tank and connect two hoses.
"The closed-loop system eliminates
the cost and logistical hassle associated
with bringing water on site for the cooler,"
he adds. "With the simpler logistics, we
can reduce mobilization times from a
couple days to less than eight hours in
most cases."

Barite Recovery Unit
To help operators reduce their capital
and operating expenditures, Fluid Systems
Inc. has introduced the BarkeeperTM as
an alternative to the centrifuges traditionally
used to recover drilling fluid barite. In
testing, the Barkeeper achieved 85-95
barite recovery, reports Ben Hiltl, FSI's
president and chief executive officer.
"The Barkeeper is an extremely simple
piece of equipment with no moving parts,
so it is easy to maintain," he says. "The
capital cost is less than half that of an
equivalent centrifuge. The volume handling capacity is several times that of a
centrifuge, and it does not lose capacity
as the drilling mud's specific gravity increases."
The Barkeeper weighs only 500
pounds, compared with 10,000 pounds
for an equivalent centrifuge, Hiltl adds.
Because of its light weight and compact
design, he describes the unit as ideal for
offshore applications, including dual den-

With its two-stage design, National Oilwell Varco's TUNDRATM
MAX land chiller can keep mud
cool even in high ambient temperatures, such as those encountered in the Eagle Ford
Shale region. NOV adds that the
chiller does not require a water
supply.

OCTOBER 2015 99
American Oil and Gas Reporter - October 2015

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