Horizontal directional drilling can be a challenge
under ideal conditions, but when you get projects that have a number of
environmental agencies on both the state and federal levels involved, things
can get quite interesting and expensive. The added expenses alone need a
thorough examination when bidding a project.
On a recent project in Santa Barbara
County, Calif., a
number of such issues existed. The project consisted of a number of borings
that crossed under a few streams, a major highway and a series of railroad
tracks. The streams presented the most difficult obstacle, as they contained
protected species of fish and other aquatic life. Preventing any drilling
fluids from entering the stream was of the utmost concern.
All necessary precautions needed to be taken; plans and materials needed to be
in place prior to doing any work. If there was a loss of fluid returns or a
frac-out at any time, the drilling operation immediately would shut down, and
the source of the problem found and corrected. For any frac-outs, the drilling
fluids must be 100-percent contained and monitored, and the drilling operation
adjusted to correct the problem. Pumps, storage tanks, Brady/frac barrels, sand
bags, barrier materials and all other necessary containment materials had to be
on-site and ready for use. (See figure 1 above.) Along with the containment
supplies, a 5,000-gallon to 8,000-gallon vacuum truck was required on-site or
on standby at all times while drilling, in the event any fluids surfaced or,
more importantly, were released into the streams.
At the drill site, all stationary equipment (drill rig, fluid tanks, recycling
unit, mixing systems) had to have heavy plastic material placed under them,
with a berm around it, to contain any drilling fluid leaks or spills. (See
figure 2 above.) A minimum 10,000-gallon frac tank was on-site to contain or
store any mixed or contaminated drilling fluid. Roll-off open tanks were used
to contain the spoils off the fluid-recycling unit, and were to be monitored
for any contamination. If earth pits were used to contain the spoils, they also
needed to be lined with a heavy plastic material. During the fueling of any
equipment, a catch basin was placed to contain any fuel that may have spilled.
In addition, any oil leaks – regardless of how small – needed to be addressed
immediately. Every time the drilling operation was shut down, any open pits
needed to be covered and sealed to ensure no protected frog or other animals
could fall in. The open pits were monitored closely in the morning to ensure no
protected species wandered on-site. Several environmental inspectors were
on-site at all times to monitor the area and to ensure operations were in line
with their requirements. They were very specific in awarding the special
permits for the project. Along with inspectors, the project required a
qualified drilling-fluids specialist on-site while any drilling was going on
and to monitor the drilling fluid.
Another requirement on one of the sites was a wash area that required any
vehicle that entered the site be washed off before leaving the site. They
wanted to ensure that anything on-site, which was next to an avocado grove,
would not be carried onto another grove. The wash-down site was set up next to
the road, and required a fresh supply of water and a pressure washer to meet
the requirements, which added additional costs and time to the project.
Drilling fluids for a project with such a high level of environmental concern
also need to be considered very closely. Some projects only will allow for
food-grade bio-degradable fluids, which can add greatly to costs. This project
only allowed for drilling fluids that were NSF/ANSI Standard 60-certified. In
order to use a product on this project, all products needed to have a complete
submittal package submitted. The submittal package contained complete technical
data and MSDS. Complete records were maintained on the drilling fluid
viscosity, weight, pH and grit content during the drilling
operation.
As you can see, there are many added considerations when looking at an HDD
project that has a number of environmental concerns. These projects need a
complete review before bidding, and all the added expenses need to be
considered. These projects also can carry some large fines for not adhering to
the specific requirements. Overall, the projects can be quite profitable when
done properly, and can open the door to your company for other projects of this
nature.
ND
Drilling Fluids: HDD in Environmentally Sensitive Areas
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