American Oil and Gas Reporter - November 2016 - 76

SpecialReport: Drilling Fluids Update

Drilling Muds Meet Lateral Challenges
By Dan Holder
Oil and gas operators continue their
search for the perfect drilling fluid, a
quest made more difficult as technology
improvements allow for wells with everlonger lateral sections. To drill greater
horizontal reaches and longer offsets, the
industry requires fluids that meet all the
geologic and rheological challenges while
also mitigating damage to production
zones and satisfying ever-stricter environmental requirements. In addition, of
course, any drilling fluid solution must
be cost effective to deploy, given the industrywide focus on capital efficiency.
"Those are significant concerns," says
Marc Matthiesen, general manager of
Drilling Specialties Co., a division of
Chevron Phillips Chemical Company LP,
a drilling fluids company that has served
the oil industry for 70 years. "Drilling
fluids manufacturers are not only meeting,
but beating those expectations with advanced water-based mud (WBM) and
nonaqueous fluids (NAF) systems.
"WBM can be just as efficient as NAF
systems in shale formations, if you know
how to operate them," Matthiesen says.
"The big hurdle the industry has seen the
past couple of years is the limited number
of people who really understand how to
run and adjust WBM systems. One of
the benefits of using WBMs is that you
don't have a lot of the environmental
issues and disposal problems that are associated with many NAF systems."
Operators are striving to find the most
economical fluid systems to achieve op-

timal drilling performance and hole condition, considering rig time and more demanding wellbore architectures, Matthiesen
says. "Fluid economics always play a role
in determining the type of system ultimately
selected. Sometimes, it does not necessarily
mean using the cheapest per-pound or
per-barrel product. Like everything else,
you typically get what you pay for."
Historically, the trade-off between water-based and nonaqueous systems boiled
down to simpler (and cheaper) cleanup
versus drilling performance, with WBMs
holding clear advantages in handling and
disposal costs, and NAFs offering better
performance in water-reactive shales, according to Matthiesen. However, he says
the latest generation of high-performance
water-based systems provide performance
attributes that rival NAFs.
Shale formations can feature dissimilar
properties from one well site to another,
and because of the rock's geological
properties, different types of shale require
different types of fluids, he says. Sitting
atop operators' wish list is wellbore stability. Matthiesen notes that drilling fluids
are getting better at minimizing their impact on the surrounding rock, which is
encouraging news as operators extend
lateral segments and thereby increase hydraulics demands and expose the rock to
prolonged contact with the drilling fluid.
"There are some limitations on horizontal segments regarding carrying capacity, but that has a lot to do with
pumping and equipment capacity," he assesses. "Finding the right drilling fluid
helps to extend well length, but there are

In addition to mitigating drilling
risks under extreme overbalanced conditions, the BRIDGEFORM™ additive from Baker
Hughes increases rate of penetration in deviated and lateral
wells, and minimizes induced
losses in depleted, fractured
and permeable formations.

76 THE AMERICAN OIL & GAS REPORTER

equipment limitations. Drilling muds are
a limiting factor, to the point where when
you are, say, 10,000 to 12,000 feet horizontally, you have a lot of pipe in the
ground and a lot of friction at the bottom-hole assembly, so you have to continue to move drill cuttings out of the
well by circulating the fluid."
Looking Ahead
Like distance runners constantly striving for new personal bests, the competitive
nature of the business drives oil and gas
companies to continually reduce drilling
times and costs while improving well
productivity and recovery metrics. To
that end, in addition to improvements in
drilling fluid formulations and chemistries,
Matthiesen points out that service companies also are developing new products
and harnessing instrumentation advances
such as microsensors to expand the capabilities of their new fluid lines.
"The question is how new products
may fit into the environment and whether
they are environmentally friendly products
that can enhance performance, especially
in extended-reach wells," he poses. "The
big challenge for the industry is figuring
out what products can provide that extra
performance while meeting environmental
requirements. A lot of the products in
that area, unfortunately, can be costly at
the moment, but the cost of any new
technology tends to come down in time.
"Technology has advanced so much
over the past 10 years, it still amazes me
what they can do down hole," he applauds.
"The improvements are step changing,
and the innovations will continue to
evolve."
International markets are becoming
more of a factor for Drilling Specialties
and other mud manufacturers, Matthiesen
says. The company sells its products globally, and has to deal with a range of regulatory environments. "Those regulations
are not all the same. Working the dynamics
of environmental regulations continues
to be more and more onerous," he assesses.
Some countries use U.S. drilling regulations as a model, while many others
follow Europe's lead, including North
Sea regulations, which are some of the
most stringent in the world, he judges.
Several South American governments
have decided to adopt regulations similar
to U.S. Gulf of Mexico standards.

American Oil and Gas Reporter - November 2016

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