Underground Construction - April 2022 - 18

Modern Mud Systems
System elements
Designs and capabilities vary by market
and manufacturer, but all of them rely on
the same essential pieces and processes
to recycle drilling fluid, rather than continuously
remix and dispose of waste
according to strict regulation.
Mud tank - The mud tank contains
the drilling fluid that is pumped
downhole during drilling. All of
the other equipment is connected
to the mud tank.
Shale shaker - The shale shaker
is the first step in the solids
separation process for drilling
fluid after it returns to the surface
carrying solids. It uses vibration
and screening panels to remove
the largest debris.
Vacuum degasser - Gases can form
during the drilling process, causing
bubbles to appear in the drilling
fluid. The vacuum degasser separates
the gases from the fluid.
Desander and desilter - Also called
a mud cleaner, the desander and
desilter remove respectively smaller
solids that survived the shale shaker.
Centrifuge - The centrifuge is the
final hydro cyclone in the process
and is used to remove the finest
solids before the clean drilling fluid
is pumped back into the mud tank
for recycling.
Ray Pietramale of Elgin Separation
Solutions explained that shale shakers,
which have been in use since the 1930s,
might reduce solids down to around 80
microns, as an example, based on screen
configuration.
" Then, if you put a hydro cyclone
manifold into the next line of operation,
that's going to cut solids down to 25
microns. So, anything that's 26 microns
or higher gets disposed of and hauled
away, " Pietramale said.
" That's the perfect kind of (solids
size) range, because you have additives
like barite and bentonite in the fluid,
and the idea is not to strip that out,
because then you'll have to throw a lot
more back into the fluid. "
Systems are rated according to their
cleaning capacity in gallons per minute,
with different brands offering units ranging
from 100- to 1,500-gallons per minute
(GPM). Those measures are based
on hydrostatic testing with water, so
rates in the field will vary depending on
specific fluids and operating conditions.
HDD rig operators can adjust the angle
of shale shakers to control how long
it takes material to pass over the trays, a
measure known as " residence. " This allows
more time for solids separation when
dealing with, say, gumbo soil in Southeast
Texas, versus sandier soil farther west.
" When I think about these systems
overall, including equipment made by
my competitors, I think all of us believe
that the reclaimer and solids control industry
adds real value to drilling, whether
it's a water well or HDD, " said Triflo's
Jerry Turk, describing the environmental
benefits of mud recycling as leaving a
" green footprint " on jobsites.
It's a common refrain among manufacturers
to tout the environmental benefits
of mud recycling, and for good reason.
Modern solids control systems can
reduce the need for chemical reagents by
15-20 percent, lowering operating costs
and potential
environmental
impact.
By removing solids in drilling fluid and
mud, less waste ends up in landfills.
Market trends
Just as contractors are under pressure
in the current market, manufactures of
mud cleaning systems also are recovering
from the pandemic downturn and
lower midstream capital spending - including
the loss of several major pipeline
projects that were delayed to death
or killed outright through environmental
and political opposition.
Triflo mud system
18 APRIL 2022 | UCONonline.com
Now, rising costs for raw steel and
other materials and pricier supply chains
are driving manufacturers to seek operating
efficiencies to help keep a lid on
equipment prices.
" It's been a cycle that has definitely
challenged all of us to look at ways to
streamline our manufacturing to keep
costs down, so that we're not having to
impose a drastic increase that it ends up
hurting the customer, " said Pietramale.
Manufacturers say business is gradually
improving and somewhat diversifying
since the pandemic downturn
reduced energy demand and several ma
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Underground Construction - April 2022

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