American Oil and Gas Reporter - April 2021 - 70

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SpecialReport: Fluids Chemistry
30 wells drilled with first-generation oilbased muds, the water-based wells had
16% lower total fluid costs and were
ready for completion an average of 4.5
days sooner.
" The water-based muds enabled faster
ROPs in the laterals, but that is not the
only reason they sped well construction, "
Vordick says. " Drilling the entire well
with a water-based mud also eliminates
the need to switch from a water-based
mud to an oil-based mud between the
vertical and lateral sections, which saves
time and pit cleaning costs. "
Vordick adds that water-based muds
simplify cuttings disposal and reduce
rental costs for some tools. " From conversations with Midland Basin operators,
we think replacing oil-based muds with
water-based translates to significant perwell savings. "
Progress Offshore
The demands placed on drilling and
completion fluids in the Gulf of Mexico
are growing, notes Samy Helmy, vice
president of fluids and completion services
at TETRA Technologies Inc. " As producers go into deeper waters and plan
longer step-outs, managing pressures and
circulating densities has required more
creativity and collaboration, " he reports.
To reduce capital and operating costs,
operators increasingly share production
facilities, Helmy adds. He says this trend
has helped create a need for more envi-

ronmentally friendly completion fluids.
" The production facility likely will
comingle fluids from the fields it serves,
so if any of them contain something that
imposes environmental restriction, that
restriction will apply to all the fluids.
For example, if one of the wells uses
zinc, a priority pollutant that cannot be
discharged, all the produced water will
need to be either treated-if feasible-off
shore or more likely shipped on shore
for treatment, " he warns.
Zinc bromide completion fluids are
still used despite zinc's status as a priority
pollutant because they offer the high
densities needed to hold back extreme
pressures, Helmy says. " Cesium formate
can deliver those high densities with a
more benign environmental profile, but
because it is mainly produced in one facility and has been mined for decades,
it is almost depleted and therefore expensive, " he says.
To offer a more affordable alternative
to zinc bromide, TETRA worked with an
operator in the Gulf of Mexico, where the
use of zinc bromide was not feasible on a
challenging project, to develop a new fluid
that contains neither zinc nor formate.
" We are really proud we were able to
come up with an innovative fluid system
that has never been used before, " he says.
The fluid was commercialized in 2015.
In the Gulf of Mexico, the first-generation
iteration was applied seven times, Helmy
relates. " We are on the fourth generation, "

This TETRA Technologies Inc. facility in Port Fourchon, La., delivers clear brine fluids,
specialty fluid blends and chemical additives, as well as lube oils and drilling fluids.
The company says it is improving its manufacturing processes and pushing the
envelope on which fluids can be reclaimed as part of a broader effort to help operators
reduce costs.

70 THE AMERICAN OIL & GAS REPORTER

he shares. " Today, we can offer both divalent and monovalent versions, including
an extremely dense divalent fluid that
can go above 17 pounds per gallon. "
For Europe, Helmy says TETRA is
designing and validating variants that
are stable from minus 40 degrees F to
375 degrees F, enabling their use in
both winter and summer and during
HP/HT projects. " Our novel fluid has
the capabilities for almost every offshore
application, but we believe we can
always do something better, " Helmy
says. " Much of our attention is on
finding ways to reduce the fluid's cost
and improve performance. "
Saving Money
While cost savings can come from optimizing completion fluids' design and
manufacturing process, Helmy stresses
that it is critical to look at ancillary activity
as well. " Time is money, " he notes. " If
we can improve those activities' efficiency,
we can provide value to our clients and
help make their fields viable, which will
create wealth for the country. "
One process on which TETRA has
focused is displacing drilling mud from
the well and replacing it with clean brine
for the completion. " This involves using
displacement fluids between the drilling
mud and clean brine, " Helmy notes. " In
an ultra-deepwater well, the interface between the mud and brine may have 800900 barrels of contaminated fluid. "
In response, Helmy says TETRA developed an alternative displacement system. " This system uses radical chemistries
that shorten the interface and cut waste
by 50%-70%, which saves rig time and
reduces overall costs, " he says.
Optimizing logistics is a key part of
controlling costs in deepwater wells, mentions Joey Detiveaux, TETRA's area manager for U.S. offshore completion services
and fluids. " A deepwater well may require
10,000 or 15,000 barrels of fluid, 10
times as much as a shelf job, " he says.
To shrink required fluid volumes,
Helmy says TETRA is modifying its
manufacturing process to produce more
concentrated additives. " The other key
is maintaining the on-site fluid without
losing rig time, " he relates. " A few years
ago, if a well required completion fluids
to be pumped at 40 barrels a minute, no
filtration unit would have been able to
keep up. We have created filtration units
that use a unique design to handle twice
the volumes with a small increase in

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