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Sand Trap / Sand Separator FAQ
"You have the best sand traps on the market and I’ll be happy to spread the
word."
-- K.P., Appalachian Basin Testing Manager
Q. How do your sand traps work?
A. Our sand separators (aka de-sanders) operate vertically and use gravity, not centrifugal force,
to separate sand from the flow. As the flow enters the sand separator it is radically slowed and the
direction changed 90 degrees by the stinger-diverter. This allows the sand to separate from the
gas and liquids. Sand falls to the bottom of the trap and is kept there by a system of proprietary baffles.
The baffles allow gas and liquids to move up and out while keeping the sand separate. Sand is removed by
opening one of the two sand discharge ports during operation; shut-in is not required.
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Q. What working pressures do you offer?
A. We offer sand traps in a variety of pressures ranging from 3000 psi to 10,000
psi working pressure. Our most common pressures are 5800# and 10,000 psi, but we also offer
7500#, and 3000 psi. Sand traps come in two basic configurations:
mounted in an "L" skid like the one to the right, or mounted on a trailer like the example below.
An "L" skid allows for horizontal transport of the sand trap, then it can be
stood up on the lower portion of the skid to operate vertically (all our sand traps operate vertically). Our sand traps are ASME coded
and registered with the National Board.
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Q. Do you offer trailer mounted sand traps?
A. Yes we offer 5800, 7500 and 10,000 psi versions of our sand
separators that are mated to a dual axle trailer. They feature hydraulic lift/lower
capability for fast and easy set up. This design allows one man using a standard pickup truck to pull,
position, and rig up. Perfect for fast-paced flowback and frac cleanup.
Q.
Do you offer sour service sand traps?
A. Most of our sand traps are NACE certified right out of
fabrication and can be used for sweet or sour service. For instance, all
3000 psi and 5800 psi sand traps are NACE certified and show the NACE
endorsement on the U1A data form.
Q. What size are the Inlet and the Gas Out and Sand Discharges?
A. 3,000 psi sand traps have 2" 1502 connections all around (in/out and sand
discharge ports). The 5800 psi sand traps come in either 2" or 3" 1502.
The 3" in/out 1502 connections also offer greater thoughput and hence are
called "High-flow" units. 10K sand traps come with 3" 1502 in/outs and 2" sand discharge and drain
connections.
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Q. How easy
is it to service your sand traps?
A. After each job, clean the sand trap by flushing it with air or clean water.
There is a drain on the bottom of the sand trap when it is vertical,
designed specially for this
purpose.
Depending on use, remove and inspect the stinger-diverter assembly checking
for wear and tear on the stinger plug. This plug is the main deflector that
forces the inflowing stream
downwards; it is critical to the proper operation of the trap. When re-assembling
the stinger, be sure the stinger flow direction indicator bar is pointing straight
down when the sand trap is in its vertical operational position.
Q. What is the effective lifetime of a sand separator?
A. Provided the de-sander is regularly inspected and
maintained it should last many years.
We have units in our rental fleet over six years old and they still
operate as well as they did in the first year of service.
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Sand Trap Detail
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20" x 8' L skidded Sand Separators fresh off the production line
Q. How much gas can a 20" x 8' x 5800# sand trap clean per day?
A. Depending upon the amount of sand entrained in the natural gas stream and the
average operating pressure, a 20" x 8' x 5800# desander typically cleans
anywhere from 6mm to 10mmscf / day. A High-flow unit can handle 12mmscf /
day.
Q. What are
other common names for sand traps and what type of sand can they handle?
A. Sand traps are also called sand cans, desanders (or de-sanders) and sand separators.
Sand traps are designed to handle naturally occuring reservoir sand, frac sand,
and grit that is left behind from drilling and fracking operations. There
are two main types of de-sander, gravity and centrifugal. Mountain Equipment
specializes in high pressure gravity sand traps that range from 3,000 psi to
10,000 psi (206 bar to 689 bar). |
Q. Should I put the sand trap before or after my choke manifold?
A. A Choke manifold benefits when placed downstream of the sand trap since it is not
exposed to the abrasive sand. However, there are times when it is necessary to place a
choke manifold upstream of the sand trap. The most common reason is that the pressure at
the wellhead is higher than the sand separator rating and must be reduced. Another reason
is that the new well is producing mostly liquid and the manifold is used to shunt the
liquid directly to holding tanks. As the flow from the well dries out, the manifold makes
it easy to change the flow from tanks to sand trap, and from there, into the Test Separator.
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Choke Manifold
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