Oxygen Scavenger for boiler usage in dearator

Boiler oxygen scavenger for corrosion on control in boiler water treatment application for industrial usage

1. OXYGEN SCAVENGER
IN OILFIELD REV 02
BONY BUDIMAN
2024
https://www.linkedin.com/in/bony-budiman-39886031/
Bony Budiman

2. DISCLAIMER
•This presentation may be used for research,
teaching, and private study purposes.
•Any commercial/monetize of substantial or
systematic reproduction, redistribution,
reselling, loan, sub-licensing, systematic supply,
or distribution in any form to anyone is
expressly forbidden
Bony Budiman

3. COMMON QUESTIONS
•What is dissolved oxygen?
•How serious is the problem caused by
dissolved oxygen ?
•What is oxygen scavenger, and how is
the mechanism ?
•How to apply oxygen scavenger ?
•Field cases !
Courtesy Picture : https://dragonflytraining.files.wordpress.com/2013/10/man-with-question-01.png?w=640 Bony Budiman

4. •OBJECTIVE
•INTRODUCTION
•MONITORING
•CONTROL
•TREATMENT METHOD
•FIELD APPLICATION
•SUMMARY
OUTLINES
Bony Budiman

5. OBJECTIVES
•Know how dissolved oxygen will cause corrosion
•Sharing hot to monitor dissolved oxygen
•Sharing mitigation of dissolved oxygen especially by
oxygen scavenger
•Field cases study
Courtesy Picture :https://pngimage.net/wp-content/uploads/2018/06/objective-icon-png-3.png Bony Budiman

6. •OBJECTIVE
•INTRODUCTION
•MONITORING
•CONTROL
•TREATMENT METHOD
•FIELD APPLICATION
•SUMMARY
OUTLINES
Bony Budiman

7. DISSOLVED OXYGEN : GENERAL INFORMATION
•Oxygen not common found in the reservoir, the
concentration usually below 20 ppb (0.02 ppm). This
concentration is very low compare to dissolved oxygen in
the seawater (sea graph beside)
•Oxygen may ingress to the production water through
leaking in the topside or when mixed with other liquid
that already contain oxygen.
Bony Budiman

8. VARIOUS DISSOLVED GAS EFFECT TO CORROSION RATE
•Dissolved oxygen (DO) in water can cause
destructive oxygen corrosion to metal pipes
and process equipment
•Corrosion caused by DO is more severe than
corrosion by CO
2and H
2S at similar
concentration
Courtesy Picture :https://www.researchgate.net/figure/Comparison-of-corrosion-rates-of-steel-in-the-presence-of-H-2-S-CO-2-and-O-2-adapted_fig4_328198474
Bony Budiman

9. TEMPERATURE EFFECT
•Corrosion rate will increase when
temperature increase and with
•If the allowable corrosion rate is
less than 5 mpy, the DO shall be
maintained below 45 ppb
•The common specification for DO is
less than 20 ppb.
Courtesy Picture :http://4.bp.blogspot.com/_woBa2hINx6k/SoWAn16141I/AAAAAAAAAHw/AwB0dGwTN7Y/s280/oxygen-steel-pipe-corrosion-diagram.png
Bony Budiman

10. •OBJECTIVE
•INTRODUCTION
•MONITORING
•CONTROL
•TREATMENT METHOD
•FIELD APPLICATION
•SUMMARY
OUTLINES
Bony Budiman

11. MONITORING
•DO could be measured using oximeter, titration, or colorimetric
•One of the most convenient colorimetric analysis procedures
employs an extremely clever unitized reagent and sampling system
called a CHEMet®
•Important during conduct DO test: Shall avoid contact with open air
since oxygen in the air will be easily induced to the open sample
Bony Budiman

12. RAPID TEST METHOD
•Rapid test principle : reaction between DO with reagent will create
change of color. Darker color indicate higher DO. The formed color
compare to standard comparator. One of rapid test method is using
CHEMet
•Each CHEMetis a 7-mm diameter glass ampoule with a tapered,
prescoredtip.
•Color-forming reagents are sealed inside the ampoule under
vacuum.
•When the user snaps the tapered tip of the ampoule in the sample,
vacuum pulls the sample in automatically
•Sampling and analysis was well described at :
https://www.chemetrics.com/measuring-ppb-dissolved-oxygen-in-
boiler-water/
Bony Budiman

13. RAPID TEST OF DISSOLVED OXYGEN
Bony Budiman

14. •OBJECTIVE
•INTRODUCTION
•MONITORING
•CONTROL
•TREATMENT METHOD
•FIELD APPLICATION
•SUMMARY
OUTLINES
Bony Budiman

15. CONTROL
1.Avoid leaking at any facilities
2.Use blanketing such as by nitrogen
3.Use mechanical method such as stripper or deaerator.
4.Work principle of deaerator is by evaporate dissolved oxygen at temperature below
100
o
Cand at vacuum condition. Deaerator could decrease DO below 50 ppb.
5.Using chemical treatment : oxygen scavenger
Bony Budiman

16. BASIC PRINCIPLES OF CHEMICALS TREATMENT
•Chemicals treatment is just like medical drugs
treatment
•WHAT is the type ?
•WHERE is the injection point ?
•WHEN to inject ?
•HOW much the dosage ?
•HOW to inject ?
Courtesy picture : https://www.shutterstock.com/image-vector/drug-addiction-medical-pills-tablets-260nw-776948416.jpg
Bony Budiman

17. OXYGEN SCAVENGER (OS)
•An oxygen scavenger is a chemical substance that is used
to reduce or (near to) completely remove oxygen in
fluids
•OS is chemical that react stoichiometric with DO. The
reaction is usually irreversible
•More D require more OS
•OS may not efficient to decrease DO above 1000 ppb (1
ppm).
•OS could decrease DO to < 10 ppb
+ Oxygen
Scavenger
Bony Budiman

18. CLASSES OF OXYGEN SCAVENGER
(1)
•Bisulfite, metabisulfite, and sulfite salts
•Hydrazines, including 1-
aminopyrrolidine
•Guanidines
•Semicarbazide and carbohydrazides
•Catalytic Hydrogenation
•Hydroxylamines
•Oximes
•Activated aldehydes
•Polyhydroxyl compounds
•Dithionite salts
•An enzyme that catalyzes the reaction
between a substrate material and
oxygen
•Solid sulfided iron reagent
There are many classes of oxygen scavengers that have been used, including :
Bony Budiman

19. SULFITES BASED
•The most common oxygen scavengers in oilfield production are sulfite (M
2SO
3), bisulfite
(MHSO
3), and metabisulfite(M
2S
2O
5) salts, where M = cation such as sodium (Na).
•One of stoichiometric reaction is : 2Na
2SO
3+ O
22Na
2SO
4
•The most common bisulfite salts are ammonium bisulfite (NH
4HSO
3) and sodium
bisulfite (NaHSO
3)
•As a rule, to reduce the oxygen concentration in water from 9 ppm to 50 ppb requires
addition of 60 ppm of 65 wt.% NH
4HSO
3
•Some ions such as Co
2+
danMn
2+
act as catalyst to improve the performance of some
sulfite based
Bony Budiman

20. HYDRAZINE AND GUANIDINE SALTS
(1)
•Hydrazine (RNH
2NH
2) reacts fairly slowly with oxygen, but the reaction rate is accelerated by
transition metal ion catalysts such as Cu
2+
and Mn
2+ions and also by increasing the
temperature.
•Hydrazine is also a suspected carcinogen and requires special handling precautions
•Guanidine salts (H
2NC(=NH)NH
3
+
X
-
) such as guanidine acetate have been proposed as
oxygen scavengers primarily in seawater injection.13 Semicarbazide (H2NNHCONH2) and
carbohydrazides (RCONHNH2) have also been used, especially in boiler water treatment
•Carbohydrazideis a volatile oxygen scavenger, contributes no solids to the system, reacts
readily with oxygen at low temperatures and pressures, and passivates the metal of the boiler
system
Bony Budiman

21. HYDROXYLAMINES
(1)
•Hydroxylaminessuch as DEHA(picture beside) are
currently used in closed-loop water treatment. They are
not temperature dependent, and do not add to the
dissolved inorganic solids.
•4(CH
3CH
2)
2NOH + 9O
2→8CH
3COOH + 2N
2+ 14H
20
•In theory, 1.24 parts of DEHA react with 1 part of oxygen,
but in application, a dosage of 3 : 1 DEHA to O
2is
recommended
Bony Budiman

22. CATALYTIC HYDROGENATION
(1)
•Erythorbicacid (also known as isoascorbicacid) is one
of Catalytic Hydrogenation based.
•The application of erythorbicacid in the oil and gas
industry may provide a strong performing non-
hazardous alternative to commonly used oxygen
scavengers including sulfites to prevent oxygen-based
corrosion issues in transportation pipelines and subsea
equipment
(3)
Bony Budiman

23. COMPARISON OF SOME OS
•The OS selection usually consider
some aspect such as effectiveness,
cost, compatibility, HSE, field
suitability and market availability
•Even the OS react stoichiometry
with the dissolved oxygen, the
actual dosage always higher than
the theoretical. Field dosage could
be 10 –30x of theoretical dosage.
Bony Budiman

24. LABORATORY TESTING
•Chemical reaction of each type Oxygen Scavenger are well known.
Actually laboratory test to select suitable OS in term of performance may
not required except for new type or at specific condition
•The challenge of laboratory test is how to avoid contact between water
and open air since the oxygen in the open air will easily ingress to the
water,
•The equipment is quite specific and customizable and will be explained in
the next slide
Bony Budiman

25. LABORATORY TESTING EQUIPMENT
(4)
•The bench-scale OS testing conducted within this study was
performed using four custom-made glass testing cells fitted with
airtight lids as depicted by figure beside.
•DO sensor has an oxygen detection range of 6 ppb to saturation
with an accuracy of ±1%.
•Each testing cell was fitted with a rubber injection port to allow the
injection of the OS solution via a syringe while preventing O
2
intrusion during experimental trials. A retractable stainless steel tube
was implemented into the test cell to allow spargingof the test
solution with nitrogen (UHP grade) or air to achieve the desired
starting DO concentration.
Bony Budiman

26. •OBJECTIVE
•INTRODUCTION
•MONITORING
•CONTROL
•TREATMENT METHOD
•FIELD APPLICATION
•SUMMARY
OUTLINES
Bony Budiman

27. TREATMENT AND MONITORING METHOD
•OS injected continually to once through production system or batching at closed system.
•At close system with batching method, residual of OS shall be monitor regularly.
•The KPI of OS performance are dissolved oxygen after treatment and residual of OS.
•Excessive injection of OS will cause wastage, corrosion, and incompatibility issue.
•OS is and oxidatorthat may react with other chemicals and lead to decrease the
efficiency for both OS and others chemicals. It is important to keep the dosage and
injection point to avoid incompatibility issue.
Bony Budiman

28. FACTOR AFFECTING TREATMENT DOSAGE
•Dissolved oxygen : At low level of DO, the dosage of OS per part O2 will be higher.
Active content concentration : the chemical manufacturer may provide the OS with
various active content such NH
4HSO
3may available in the market with purity 30-65%
•Temperature : see on next slide
•Compatibility : oxygen scavenger is one of chemicals that may react with others
ions/chemicals such as with Ca
2+
, H
2S, Corrosion Inhibitor and Biocide. The reaction may
decrease performance of OS since it will reduce the concentration of its active content
•pH : see on next slides
Bony Budiman

29. TEMPERATURE EFFECT
•As a general rule, an increase in water
temperature of 18°F [10°C] doubles the
reaction rate.<Catalysis : sulphitebased
require catalyst to speed up the reaction
(2)
•Graph beside show temperature effect to
OS performance at pH 9 with 80 wt% MEG
at temperatures of 10, 20, and 27
o
C.
•Increasing the temperature resulted in an
accelerated reaction rate. At 20 and 27
o
C,
the complete removal of dissolved oxygen
occurred at 9 and 4 hours, respectively
Courtesy picture : https://www.researchgate.net/publication/314271765
Bony Budiman

30. pH EFFECT
(2)
•When any of the sulfite based are dissolved in water, they will ionize to
produce varying amounts of SO2 , HSO3--,and SO32-depending on the
pH of the solution (Figure beside) Since only SO32-reacts with oxygen,
pH is very important as it dictates the percentage of the product available
to react
•At pH values below 4.5, the sulfite scavengers will not react with oxygen.
Reaction rates are not appreciable until pH values exceed 6.0.
•Further increases in reaction rate occur with pH up to a maximum in the
8.5-10.0 pH range, with a rapid decrease in rate above pH 10.5
•The effectiveness of Co++ as a catalyst decreases as the pH of the water
decreases. Distribution of Sulfite Species as a Function of pH
Bony Budiman

31. •OBJECTIVE
•INTRODUCTION
•MONITORING
•CONTROL
•TREATMENT METHOD
•FIELD APPLICATION
•SUMMARY
OUTLINES
Bony Budiman

32. OXYGEN INGRESS
Injection
Point CI Washtank
Watertank
Shipping
Tank
Corrosion
coupon
•Corrosion rate at Alpha GS still
high even injection corrosion
inhibitor increased
•Corrosion rate is > 20 mpy
meanwhile the specification < 5
mpy
Bony Budiman

33. WATER QUALITY ANALYSIS
Sampling PointWash Tank Alpha
GS Level 13’10”
Suction Water Pump
Alpha GS
Suction Water
Pump Alpha GS
Date Analyze 7 Sept 7 Sept 15 Sept
CO
2( ppm ) 40 60 40
SO
3( ppm ) 6.5 6 4.5
H
2S ( ppm ) n.d n.d n.d
SRB ( coll / cc ) 100 100 n.a
Temperature (
o
F ) 130 134 n.a
O
2 ( ppb ) 20 50 >100
Bony Budiman

34. WHY DO INCREASE AT WATER TANK ?
At watertank, water flow through
goose neck called water leg.
Waterlegnot fully close
Hypothesis : oxygen from open
air ingress to the water through
this gapOpen
Bony Budiman

35. RECOMENDATION
•Close the gap
•Inject Oxygen Scavenger at inlet watertank
RESULT AFTER OS INJECTION
•DO decrease to 20-30 ppb
•Corrosion rate decrease < 10 mpy
Bony Budiman

36. PLUGGING OS
•MEG (monoethyleneglycol) injected continuously
to avoid hydrate at gas field.
•Return MEG recovery at topside and the recovered
MEG injected back to the wellhead.
•Sulphitetype Oxygen Scavenger injected
continuously to maintain oxygen level at MEG
below 20 ppb).
MEG Tank
Subsea
Wellhead
Bony Budiman

37. PLUGGING FOUND
•Every 2-4 weeks the injection point was plugged
•The deposit is sulphitesalt and MEG.
•The OS may not compatible with the
temperature, pressure or MEG itself.
•Propose to change the type of OS from sulphite
to carbohydrazidetype
•No plugging issue after chemical replacement.
Bony Budiman

38. OXYGEN STRIPPER -DEAERATOR
•Produced water used as injection
water
•Oxygen scavenger injected at
dosage 50 ppm upstream of
stripper
•DO outlet stripper < 20 ppb
•But why DO outlet water tank >
100 ppb ?Produced
Water
Water Tank
O2 Stripper
To Injection
Well
OS
Bony Budiman

39. OXYGEN STRIPPER -DEAERATOR
•Some gaps found in the roof of
water tank
•Relocate the flow direction of
stripper and OS
•OS dosage decrease to 5 ppm
•DO downstream of OS injection
point < 10 ppb
Produced
Water
Water Tank
To Injection
Well
O2 Stripper
OS
Bony Budiman

40. •OBJECTIVE
•INTRODUCTION
•MONITORING
•CONTROL
•TREATMENT METHOD
•FIELD APPLICATION
•SUMMARY
OUTLINES
Bony Budiman

41. SUMMARY
•Dissolved oxygen is one of corrosive agent and more aggressive than CO
2and H
2S at
same concentration
•Dissolved oxygen usually increase when water contact with the open air.
•Dissolved oxygen could be removed to safe level using mechanical or chemical method
•Oxygen scavenger is chemical that react stoichiometric with the dissolved oxygen
•The effectiveness of OS depend on temperature, concentration, others process and field
condition.
Bony Budiman

42. REFERENCES
1.Malcolm, Kellan., Production Chemicals for the Oil and Gas Industry,Second
Edition, CRC Press
2.Applied Water Technology, Charles C. Patton, C. C. Patton & Associates, Inc.,
Dallas, Texas, 1986
3.https://doi.org/10.1016/j.petrol.2018.06.073
4.https://espace.curtin.edu.au/bitstream/handle/20.500.11937/70113/267799.pdf?
sequence=2
Bony Budiman