Paraffin (wax) Inhibitors and Dispersants
Details
Paraffin is an important and valuable component of
oil and gas hydrocarbon production. It may be present
in trace amounts (<0.5%) up to as much as 50% of the
total hydrocarbon production volume in some fields.
The most critical and difficult aspect of producing
paraffinic crude is to keep the paraffin in solution
from the reservoir to the refinery, where it can be
processed into valuable petrochemical products.
Paraffin has a tendency to crystalize and form
deposits after changes in pressure and temperature.
Every location in the system is at risk for paraffin
deposition downstream of where the oil reaches its
wax appearance temperature (WAT)—the location
where wax crystals first appear. The WAT could be
in the reservoir, in the near wellbore area, past the
perforations in the production tubing, pumps or
valves, in surface flow lines and headers, in tanks
and separation equipment, and so forth. When
wax deposits form, they grow and grow, eventually
blocking pore spaces and production tubing, plugging
valves and pumps, causing separation issues. In
some instances, wax will co-precipitate with mineral
scale and asphaltene, making the removal process
extremely complex.
Inhibitors (crystal modifiers, pour point
depressants/PPDs):
Whenever it is possible,
producers should apply a wax inhibitor prior to the
WAT in the system. Often this means injecting the
inhibitor into the reservoir via a squeeze application.
The inhibitor will latch onto the wax crystal as soon
as it appears, preventing the crystal from adhering
to surfaces and preventing the crystal from further
growth. The wax crystal becomes permanently
inhibited throughout the production system and
passes directly through to the refinery.Certain types
of paraffin inhibitors, pour point depressants, are
applied to lower the WAT. In some cases, reductions
of 10° – 20°F can be achieved, helping to prevent
deposition from occurring. Depending on the situation, the PPD products allow produced fluids
to travel subsea over long distances, assuring flow
until the fluids surface and are out of the danger
zone.In subsea systems, it is also critical to inhibit
the wax crystals to enable easy startup in the event
of a system shutdown, due to a tropical storm or
well workover. Water Technologies & Solutions’
paraffin inhibitors will permanently modify the wax
molecules so that in the event of a system shut
down, flow lines are protected and startup becomes
a non-issue.
Dispersants and Solvents:
In situations where
deposition has already occurred, another type
of chemistry must be used to remove the waxy
deposit—paraffin dispersants. These products
contain chemistries and solvents that penetrate
the deposit and solubilize the paraffins. Water
Technologies & Solutions’ dispersants are widely
used to clean up deposition on surfaces, such as
pipe, equipment and valves; and in tank bottoms.
The solvents applied with the dispersant are
specially selected to solubilize the wax and keep it
in solution.
Water Technologies & Solutions is investing in
superior solutions to paraffin control, with one thought
in mind—providing customers with trouble-free
operations. The bottom line benefits provided by Water
Technologies & Solutions include:
• Reduction or elimination of wax deposition
throughout your production system and a
corresponding reduction of failures due to
wax deposition
• Reduced operating costs and improved HSE performance
• Production improvements due to more system uptime and more wax in solution
• Increased hydrocarbon production
• Reduced operating costs and improved HSE performance
• Production improvements due to more system uptime and more wax in solution
• Increased hydrocarbon production
