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Oilfield Technology
June
2016
sludge deposits, prevent new deposits from forming, maximise water
injectivity and oil production and provide corrosion inhibition to the
injection infrastructure.
Productevolutionandexpansiontomeetgrowing
marketneeds
Over time, field experience and research teams have evolved the
technology into an array of products tailored to remediate the various
deposit compositions found in the oilfield as well as other complex
operational conditions. As previously mentioned, this technology
was designed to treat systems heavily fouled by hydrocarbon. While
hydrocarbon is often a deposit’s binding agent, system fouling
is regularly compounded by other solids present in the deposit
matrix. To address these additional challenges, several product
line extensions have been developed. The product line contains the
original high performance components for hydrocarbon fouling as well
as chemistries targeting: iron sulfide deposits, paraffin/asphaltene
control, scale inhibition and winterising, water floods, and ongoing
systemmaintenance.
In addition to advanced chemical composition, the technology
incorporates hands-on technical expertise and in-field monitoring
to provide a comprehensive treatment solution. In water injection
wells, it removes deposits from inner pipe walls and filter equipment,
provides continuous cleaning at the formation face, and prevents
aggressive corrosion from taking place. This results in increased
injectivity, more consistent injection rates, and maximum injection
capacity for improved production. For heavily soiled or ageing assets,
the company’s technologies help operators maximise production and
extend asset life. In pipeline applications, it prevents under-deposit
corrosion while reducing maintenance, pigging costs, and associated
downtime and labour. Furthermore, the use of the technology
for injectivity improvement in waterflooding can help operators
accelerate the recovery of their proven reserves and can also clean
the wellbore and enhance the ability of water to enter the formation.
Increasing injection rates will increase offset oil production rates
and accelerate reserves recovery. In addition, using the technology
as a pretreatment or additive should improve the effectiveness of
traditional EOR techniques. Cleaning out the near wellbore will
improve the injectivity of EOR chemicals by allowing the chemicals
to penetrate into areas in the formation previously unaccesable due
to deposits. Increasing water and chemical injectivity during EOR
will accelerate the oil production response resulting in improved
economics.
Provenresults
In one customer’s water injection system, this level of oily sludge
removal translated to 75%more water being injected, resulting in
increased oil production and an 800% return on investment. Once
the oily sludge had been removed, Clean n Cor prevented it from
re-adsorbing. It then protected the pipe surface by providing a
strong and persistent film that acted as a barrier to corrosive fluids.
The required dosage to maintain an acceptably low corrosion rate
was nearly 20% lower than the dosage required for conventional
corrosion inhibitors.
In another case, a midstream gas gathering station operator in
New Mexico was experiencing extensive plugging in a gas stream
inlet line and filter to the booster, first stage scrubber, and the
condensate bullet tanks. Each time the system became plugged,
the result was to shut-in production. Prior to the application of
the technology, the operator was applying up to 20 gal./week of
surfactant at the first stage scrubber and an additional 20 gal./week
of surfactant at the bullet tanks. Frequently, the field had to be
shut in to clean the process equipment and change the filters. This
resulted in a significant loss of revenue for this operator due to lost
production. To combat this problem a trial of the technology was
conducted. At the onset of the trial, only 1 gal./d of chemical was
applied at the inlet and a ½ gal. of chemical was applied at the
bullet tank. In the second stage of the trial, the treatment at the
inlet was reduced to a ½ gal./d and the treatment at the bullet tank
was discontinued. The treat rate reductions were made because
there was no fouling during the first stage. During an 18 month
period while the technology was being continuously applied at this
location, there were zero shut ins.
An operator in Wyoming was experiencing frequent plugging of
injection wells due to the buildup of oily pipeline deposits. These
deposits were increasing well downtime and creating additional
costs associated with screen cleaning and well maintenance. A
two man crew had to perform weekly screen cleanings, which
resulted in one hour downtime per well every week. The operator
had attempted back-flowing the wells and lateral lines but the
results were discouraging. Well downtime and production losses
were a growing concern, in addition to under deposit corrosion.
Four injection wells were selected as a pilot programme to
investigate the results of using Clean n Cor technology. In this case,
a company representative recommended technology that included
winterised multifunctional cleaning capabilities and as well as best
in class corrosion performance. Initially the wells were treated at
a rate of between 5 and 20 ppm. The rates were increased every
three weeks up to 100 ppm, which was then held for three months.
After only three months, injection on all four wells had increased
by 282 bpd, which was a 50% increase over previous injection
rates. This increased injection resulted in 94 additional bpd of oil
production. The weekly screen cleanings were reduced from once
per week to once every six weeks, thus saving 344 man-hours and
172 hours of well downtime. And, as a result of the decreased
amount of pipeline deposition, the risk of under-deposit corrosion
in the system was greatly reduced.
Conclusion
As E&P budgets continue to shrink due to low oil prices, oil and
gas producers demand more out of their producing assets than
ever. Additionally, since much of today’s operating infrastructure
continues to operate beyond original design life, producers will
increasingly turn to novel, multifunctional technologies like
Clean n Cor to keep their systems clean, corrosion-free, and
operating at maximum production levels.
The technology incorporates hands-on technical expertise and
in-field monitoring combined with innovative chemical products
to provide a comprehensive treatment solution. Since it has the
ability to maximise oil production and preserve asset integrity
under a wide range of field conditions, this technology has an
important role to play during the current very challenging market
conditions.
References
1.
Last 18 months price trend for West Texas Intermediate Crude (USD), from
2.
‘Barclays: Global E&P budgets to see double-dip in 2016’, Houston,
Oil & Gas
Journal
, PennWell Corporation, (13 January, 2016).
3.
Moon, T., ‘Corrosion Inhibitor and Cleaner, Rolled into One.’ Posted to
(25 April, 2007).
4.
Horsup, D., (Nalco Company) SPE-108675-MSSPE Annual
Technical Conference and Exhibition, Anaheim, California, U.S.A.
, (11 - 14 November, 2007).
5.
Horsup, D., Dunstan, I., T., S., & Clint, J. S. NACE-07690 ‘A Break-Through
Corrosion Inhibitor Technology For Heavily Fouled Systems’
NACE
International,
(1 January, 2007).
