Case Study: CH-0037
Case History: Oilfield Chemicals
WELLBORE SOLIDS AND
FLUID QUALITY IMPROVED BY
RenewIQ™ SOLUTION ANNULAR CLEANUPS
SITUATION
CHALLENGE
Conventional plays throughout the US often experience
iron sulfide deposition issues throughout the production
fluid stream. Iron sulfide species are especially prevalent in
downhole equipment and fluids, which can lead to problems
with wells utilizing rod pumps. Historically, remediation
methods were often large scale acid or cleanup treatments,
which were costly and increased asset integrity concerns.
When iron sulfide deposition occurred, producers often
witnessed a vast decrease in well performance through
pumping conditions and dynamometer scans. Residing
within the annular working fluid column, iron sulfide
would fraction from the oil/water interface into the
hydrocarbon phase and become oil-wet. This viscous, solidsladen emulsion would stick to critical pump components
resulting in restriction of pump fillage, delayed standing
valve closures, increase or erratic pump friction, increased
restriction of fluid flow-through, pump sticking, and delayed
traveling valve closures.
nalcochampion.com
CH-0037-V2
INSIGHT
RESULTS
During field evaluations with Nalco Champion BIOC16734A
biocide, a peracetic acid-based RenewIQ™ solution
chemistry, the chemistry oxidized the emulsifying iron
solids and broke the surface tension enough to resolve the
emulsion. Nalco Champion utilized this knowledge to design
downhole treatments that performed this same task in
annular fluids feeding the pump.
Baseline dynamometer scans and wellhead grindouts
performed on a trial well indicated significant downhole
pump issues. Grindouts indicated approximately 1.0% oil-wet
iron sulfide within the production fluids, while pump and
surface dynamometer cards indicated poor pump fillage
along with subsequent rod stacking. The data highlighted
the likely cause of the decreased pump performance to
be solids-laden emulsions residing within the annular fluid
column. To assist in cleaning this fluid column, consecutive
annular batch treatments utilizing 1 gallon of BIOC16734A
biocide and 1 gallon of FESD11088A surfactant/chelant were
performed. Follow up wellhead grindouts were completed and
data showed a shift from oil-wet to water-wet iron sulfide,
indicating a positive effect from the treatment. Additional
samples were gathered in the subsequent days, and they
showed a continual reduction in the amount of oil-wet and
total iron sulfide. (See Figure 1 below).
SOLUTION
Wells exhibiting pump performance issues were first baselined via wellhead fluid grindouts and dynamometer scans.
From this information, candidates were selected for trial
annular cleanups. Treatments utilizing BIOC16734A biocide
and FESD11088A combination surfactant/iron chelant
product, were designed to focus on removing iron solids
from the near wellbore fluids, resolving the associated
emulsions, and moving the negative fluids through the
pump. This approach was implemented to restore pump
performance and reduce the risk of failure.
Wellhead
Grindouts
Before/After
Wellhead Grindouts
Before/After
TreatmentTreatment
1.4%
Water-Wet FeS
Oil-Wet FeS
Treatment
1.2%
Percent FeS/BS
1.0%
0.8%
0.6%
1.2%
1.0%
1.0%
0.4%
0.8%
0.6%
0.2%
0.4%
0.0%
0.0%
7/8/14
0.2%
0.2%
7/9/14
7/10/14
7/11/14
Date Sampled
Date
Water-Wet FeS
Oil-Wet FeS
7/8/14
0.0%
1.0%
7/9/14
0.2%
1.0%
7/10/14
1.2%
0.8%
7/11/14
0.4%
0.6%
7/12/14
0.2%
0.0%
Figure 1 – Wellhead Grindouts Before/After Treatment
0.0%
7/21/14
entering the pump, improved the overall pump efficiency of
the well and cost much less than conventional remedies.
After the second treatment, dynamometer scan results
were again positive, with a noticeable improvement in both
surface and pump dynamometer cards. A pump fillage of
100% was noted, improving 64% from the baseline level.
(See Figures 2 and 3 below). The Nalco Champion RenewIQ
solution, which focused on improving the quality of fluids
This solution is a breakthrough in mitigating stress-related
failures, which tanslates into reductions in equipment
replacement and workover costs.
Trial Trial
Well Well
Before
Treatments
andand
SPM
Change
Before
Treatments
SPM
Change
Dynamometer Cards
Card #2
16000.00
15000.00
May 28th 2014
Unacceptable Load
Variances to Peak Load
14000.00
Normal
Operation
13000.00
12000.00
11000.00
Load (lbs.)
10000.00
9000.00
Rod Stacking
8000.00
7000.00
6000.00
5000.00
4000.00
Compression
3000.00
56-61% Pump
Fillage
2000.00
1000.00
0.00
0
2
4
6
8
10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Position (inches)
Figure 2 – Trial Well Before Treatments and SPM Change
TrialTrial
WellWell
After
Treatments
andand
SPM
Change
After
Treatments
SPM
Change
Dynamometer Cards
Card #2
15000.00
July 17th 2014
14000.00
13000.00
12000.00
11000.00
Load (lbs.)
10000.00
9000.00
Improved Load
Transitions
8000.00
7000.00
6000.00
5000.00
4000.00
3000.00
100% Pump
Fillage/Fluid
Pound Position
2000.00
1000.00
0.00
0
2
4
6
8
10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60
Position (inches)
Figure 3 – Trial Well After Treatments and SPM Change
Together, We’re Taking Energy Further
TM
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and related services for upstream, midstream and downstream oil and gas operations. Through onsite
problem solving and the application of innovative technologies, we deliver sustainable solutions to
overcome complex challenges in the world’s toughest energy frontiers. Together, we’re taking energy
further. nalcochampion.ecolab.com
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7705 Highway 90-A
Sugar Land, TX 77478
Telephone: +1-281-263-7000
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