Ranking Asset Integrity of Oilfield-Water Systems in Two Production Lifecycles

Abstract

Microbiologically influenced corrosion is the degradation of a material under the influence of environmental factors complicated by the metabolic activities of microorganisms. Microbiological attack on process equipment used in the petroleum industry results in increased operating expenses and reduced income. This article discusses treatment options for various production streams to prevent corrosion and downtime of assets.

Full text

CM
CORROSION MANAGEMENT
R
Microbiologically inuenced corro-
sion is the degradation of a material
under the inuence of environmental
factors complicated by the metabolic
activities of microorganisms. Microbi-
ological attack on process equipment
used in the petroleum industry results
in increased operating expenses and
reduced income. This article dis-
cusses treatment options for various
production streams to prevent corro-
sion and downtime of assets.
Recent focus on the mitigation of micro-
biologically influenced corrosion (MIC)
damage relies on a judicious selection of
treatment chemicals targeting specific
microoranisms, identified to the genus or
species level by means of recombinant DNA
sequencing.1 In an earlier publication,2 five-
year monitoring data of sessile bacteria
population density, general, and pitting
corrosion were used to establish a ranking
of asset integrity risk for four oilfield water-
handling systems. During the subsequent
five years, a production shift from primary
to secondary recovery method occurred. In
what follows, the same methodology is
used to delinieate the differences in the
ranking of asset integrity risk occasioned
by the production shift.
Field Data
The oilfield water-handling systems are
depicted on Figure 1. The brackish water
Ranking Asset Integrity
of Oileld-Water Systems
in Two Production Lifecycles
olaGoKe olabisi, Infra-Tech Consulting,
Sugar Land, Texas, USA
ameR jaRRaGh aNd ashoK matheW,
Kuwait Oil Co., Ahmadi, Kuwait
(BRW) stream, from the water wells with a
total dissolved solids (TDS) of ~3,000 ppm
at ambient temperature, is used for wash-
ing the almost desalinated and dehydrated
hot wet crude in the second stage desalter.
Consequently, the recycle water (RCW)
stream that emerges from the second stage
desalter has an increased TDS (5,000 to
6,000 ppm) and a higher temperature (70 to
80 °C). This stream is then used to “wash”
the hot wet crude in the first stage desalter,
further extracting the highly salty produced
water (PDW). The effluent water (EFW)
stream that emerges from the first stage
desalter has a higher TDS (35,000 to 45,000
ppm) at approximately the same tempera-
ture as RCW. Further down, the EFW is
mixed with the PDW stream that exits from
the wet tank, and the resulting stream
(final effluent water) has a significantly
high TDS (135,000 to 150,000 ppm) occa-
sioned by the fact that the stream is com-
posed of ~95% PDW that has a TDS of
~150,000 ppm.
Kuwait Oil Co.’s (KOC) internal corro-
sion monitoring plan includes online moni-
toring2 of corrosion, fluid chemical charac-
teristics, sessile, and planktonic bacteria.
During a ten-year period, from 2006 to
2016, bacteria growth analyses for sulfate
reducing bacteria (SRB), general aerobic
bacteria (GAB), and general anaerobic bac-
teria (GAnB) were performed, based on the
serial dilution test method outlined in
NACE TM0194-2014.3 Additionally, in 2015,
16S ribosomal RNA characterization was
commissioned based on a molecular
38 FEBRUARY 2020 WWW.MATERIALSPERFORMANCE.COM

microbiological method (MMM) of quanti-
tative polymerase chain reaction for the
enumeration of specific bacteria species
that contribute to MIC in the facilities.4
However, company-wide adoption of the
MMM awaits the development of a NACE
consensus standard. Meanwhile, the in-
house guideline (Table 2 of reference 2) for
quantifying sessile and planktonic bacteria
proliferation continues to be based on the
serial dilution test method.3 In that guide-
line, measured bacteria population density
higher than the maximum allowable value
of 102 counts/cm2 is considered unaccept-
able. This limitation is utilized to interpret
the bacteria field data in this study.
Data Analysis
Coupon corrosion rates were deter-
mined based on NACE SP07755 with ASTM
procedure G1-03.6 The corrosion severity
classification (Table 1 of reference 2) is in
terms of corrosion rates in mm/y or mils/y.
The field data of oilfield water-handling
systems from 19 facilities were analyzed.
For each of the water-handling systems, the
incidents of low, moderate, high, and severe
corrosion for each production lifecycle
appear in Table 1 in this article, including
the percentage changes of high and severe
corrosion incidents. The corresponding
numbers of sessile bacteria incidents
higher than 102 counts/cm2 for SRB, GAB,
and GAnB for each fluid type are also pre-
sented in Table 2, including the percentage
changes of incidents higher than 102
counts/cm2 for each production lifecycle.
The relative changes of fluid chemical char-
acteristics during the primary and second-
ary production lifecycles appear in Table 3.
The incidents of high and severe pitting,
together with the incidents of sessile bacte-
ria population higher than the maximum
allowable value, are summarized in Table 4.
During the primary and secondary pro-
duction lifecycles, 20 to 40% of the coupons
retrieved for oilfield water systems had cor-
rosion deposits as well as sessile bacteria.
In BRW and RCW streams, the incidents of
high and severe pitting corrosion rates and
sessile bacteria population density were
high during the 10-year period studied.
Generally, there was 80 to 90% correlation
of excessive sessile bacteria with high and
severe pitting corrosion rates for BRW and
RCW streams during the primary lifecycle.
On the other hand, the correlation was
>90% during the secondary lifecycle. In
EFW ( four GCs) and the EFW (EWDP-1)
streams, the correlation was >90%. There
was, however, a reduction in the percent-
age of bacteria incidents during the sec-
ondary production lifecycle in EFW. For the
seawater streams, there was a definite
increase in the incidents of sessile bacteria
as well as pitting corrosion rates during the
secondary production lifecycle. For the
PDW stream, the incidents of sessile bacte-
ria and pitting corrosion rates were quite
low during both primary and secondary
lifecycles, possibly because of the oil wet-
ting of corrosion coupons installed in PDW
streams.
The importance of GAnB as the major
cause of MIC in oilfield water systems is
well documented.7 In this study, the mor-
phologies of severe localized corrosion on
coupons installed in BRW, RCW, PDW, and
EFW streams suggest the presence of MIC
in all the water-handling systems.8 Sessile
GAnB predominated in all the water sys-
tems during the primary and secondary
production lifecycles. In the EFW (EWDP-
1) stream, the percentage of GAnB
FIGURE 1 A simplied generic b lock diagram of sel ected KOC faci lities.
39MATERIALS PERFORMANCE: VOL. 59, NO. 2 FEBRUARY 2020

CM
CORROSION MANAGEMENT
TABLE 1. GENERAL AND PITTING CORROSION INCIDENTS DURING THE PRIMARY/SECONDARY PRODUCTION
LIFECYCLES
Period
(Primary/
Secondary
Production
Cycle) System
Total
Monitoring
Incidents
General Corrosion Pitting
Low Mod. High Sev.
During
Lifecycle
Change, Pri.
to Sec. Low Mod. High Sev.
% Age
of High
& Sev.
Incidents
% Age
Change,
Pri. to
Sec.
Primary GC-09, PDW 162 133 27 2 0 1.2 292 97 933 23 34.6 –69
Secondary 149 129 13 5 2 4.7 129 4 5 11 10.7
Primary GC-10, PDW 96 67 23 0 6 6.3 165 48 816 24 41.7 –41
Secondary 114 82 13 514 16.7 82 4 9 19 24.6
Primary GC-20, PDW 53 32 7 0 14 26.4 –52.7 23 2 9 19 52.8 –100
Secondary 8 6 1 1 0 12.5 6 2 0 0 0
Primary GC-22, PDW 76 56 15 5 0 6.6 1.5 45 114 16 39.5 –66.3
Secondary 120 99 13 7 1 6.7 96 8 7 9 13.3
Primary GC-09, BRW 198 31 54 43 70 57.1 –3.5 56 916 117 67.2 24.2
Secondary 176 18 61 44 53 55.1 23 629 118 83.5
Primary GC-10, BRW 40 911 14 650 –27.8 4 7 10 19 72.5 –3.8
Secondary 119 33 43 29 14 36.1 29 731 52 69.7
Primary GC-20, BRW 84 11 22 34 17 60.7 –0.74 9 2 0 73 86.9 –7.8
Secondary 166 14 52 67 33 60.2 25 816 117 80.1
Primary GC-22, BRW 82 420 21 37 70.7 6.2 2 0 8 72 97.6 –25
Secondary 157 930 71 47 75.1 32 10 15 100 73.2
Primary GC-09, RCW 172 45 52 23 52 43.6 78.2 48 514 105 75 26.1
Secondary 130 623 16 85 77.7 6 1 3 120 94.6
Primary GC-10, RCW 34 812 8 6 41.2 95.4 10 0 0 24 70.6 35.3
Secondary 44 211 22 970.5 2 0 0 42 95.5
Primary GC-20, RCW 20 010 4 6 50 —6 0 0 14 70 —
Secondary — — — — — — — — — — —
Primary GC-22, RCW 48 627 13 231.3 84.3 10 1 3 34 77.1 27.8
Secondary 130 946 29 46 57.7 0 2 9 119 98.5
Primary GC-09, EFW 251 64 36 15 136 60.2 189 14 5143 59 18.8
Secondary 268 64 41 24 139 60.8 73 719 169 70.1
Primary GC-10, EFW 85 29 14 17 25 49.4 –20.9 22 3 3 57 68.2 3.1
Secondary 327 110 89 45 83 39.1 84 13 30 200 70.3
Primary GC-20, EFW 104 28 26 545 48.1 4.4 33 1 4 66 67.3 –9.1
Secondary 263 96 35 38 94 50.2 96 618 143 61.2
Primary GC-22, EFW 152 37 34 32 49 53.3 –3.9 40 5 7 100 70.4 3
Secondary 383 68 119 68 128 51.2 89 17 42 235 72.3
Primary EWDP1, EFW 493 118 132 71 172 49.3 31.6 118 16 36 323 72.8 9.3
Secondary 686 87 164 71 364 64.9 134 611 535 79.6
Primary SWTP, SW 110 175 30 430.9 131 66 511 28 35.5 6.2
Secondary SWTP SW 77 121 37 18 71.4 47 1 7 22 37.7
Primary CIPF-SWIHW 1000 545 353 70 32 10.2 85 679 98 88 135 22.3 53.8
Secondary CIPF-SWIHW 747 201 405 82 59 18.9 419 72 96 160 34.3
Note: BRW—Brackish Water, RCW—Recycle Water, EFW—Efuent Water, PDW—Produced Water, SWTP—Seawater Treatment Plant, SW—Seawater, CIPF—Central Injection Plant Facility,
EWDP—Efuent Water Disposal Plant
High & Sev Incidents (%)
40 FEBRUARY 2020 WWW.MATERIALSPERFORMANCE.COM

TABLE 2. SESSILE BACTERIA INCIDENTS DURING PRIMARY/SECONDARY PRODUCTION LIFECYCLES
2006-2011 and 2012-2016 Sessile Bacteria Monitoring Data
Period (Primary/
Secondary Production
Cycle) Water System
Total Monitoring
Incidents
No. of Incidents with
>100 counts/cm2
% of Incidents with Bacteria
Level
>100 counts/cm2
GAB GAnB SRB GAB GAnB SRB
Primary
GC-09 BRW
66 60 65 55 90.9 98.5 83.3
Secondary 43 43 43 38 100 100 88.4
% change, pri. to sec. —–17 –22 –17 9.1 1.5 5.1
Primary
GC-10 BRW
5 5 3 3 100 60 60
Secondary 22 22 22 18 100 100 81.8
% change, pri. to sec. —17 19 15 040 21.8
Primary
GC-20 BRW
27 26 26 24 96.3 96.3 88.9
Secondary 45 44 43 35 97.8 95.6 77.8
% change, pri. to sec. —18 17 11 1.5 –0.7 –11.1
Primary
GC-22 BRW
22 20 18 18 90.9 81.8 81.8
Secondary 46 44 46 38 95.7 100 82.6
% change, pri. to sec. —24 28 20 4.8 18.2 0.8
Primary
GC-09 RCW
56 41 46 26 73.2 82.1 46.4
Secondary 28 25 27 19 89.3 96.4 67.9
% change, pri. to sec. —–16 –19 –7 16.1 14.3 21.5
Primary
GC-10 RCW
5 4 4 3 80 80 60
Secondary 11 810 10 72.7 90.9 90.9
% change, pri. to sec. — 4 6 7 –7.3 10.9 30.9
Primary
GC-20 RCW
8 7 8 8 87.5 100 100
Secondary — — — — — — —
% change, pri. to sec. — — — — — — —
Primary
GC-22 RCW
9 8 8 7 88.9 88.9 77.8
Secondary 44 42 39 38 95.5 88.6 86.4
% change, pri. to sec. —34 31 31 6.6 –0.3 8.6
Primary
GC-09 EFW
104 39 61 27 37.5 58.9 26
Secondary 69 23 44 13 33.3 63.8 18.8
% change, pri. to sec. —–16 –17 –14 –4.2 4.9 –7.2
Primary
GC-10 EFW
34 16 32 12 47.1 94.1 35.3
Secondary 65 23 43 835.4 66.1 12.3
% change, pri. to sec. — 7 11 –4 –11.7 –28 –23
Primary
GC-20 EFW
52 30 46 15 57.7 88.5 28.8
Secondary 66 34 54 18 51.5 81.8 27.3
% change, pr. to sec. 4 8 3 –6.2 –6.7 –1.5
Primary
GC-22 EFW
53 27 49 16 50.9 92.5 30.2
Secondary 101 42 75 21 41.6 74.3 20.8
% change, pr. to sec. 15 26 5–9.3 –18.2 –9.4
Primary
GC-09 PDW
24 815 033.3 62.5 0
Secondary 10 6 9 1 60 90 10
% change, pr. to sec. –2 –6 126.7 27.5 10
Primary
GC-10 PDW
18 11 14 861.1 77.8 44.4
Secondary 15 611 240 73.3 13.3
% change –5 –3 -6 –21.1 –4.5 –31.1
Primary
GC-20 PDW
13 10 11 676.9 84.6 46.2
Secondary 7 3 7 2 42.9 100 22.2
% change –7 –4 –4 –34 15.4 –24
Primary
GC-22 PDW
13 612 646.2 92.3 46.2
Secondary 18 13 15 572.2 83.3 27.8
% change 7 3 –1 26 –9 –18.4
Table 2 conti nued on page 42
Ranking Asset Integrity of Oilfield-Water Systems in Two Production Lifecycles
41MATERIALS PERFORMANCE: VOL. 59, NO. 2 FEBRUARY 2020

CM
CORROSION MANAGEMENT
TABLE 3. RELATIVE CHANGES OF FLUID CHEMICAL CHARACTERISTICS DURING THE PRIMARY/SECONDARY
PRODUCTION LIFECYCLES
Period Sample pH Conductivity (µs/cm)
Hardness, as
CaCO3 (mg/L) Chloride (mg/L)
Sulfate
(mg/L)
Bicarbonate
(mg/L)
Primary
PDW GC-09
6.3 311,000 32,449 106,100 50 243
Secondary 5.9 332,500 36,000 100,110 30 85
Primary
PDW GC-10
6.4 328,000 35,000 101,361 12.5 143
Secondary 6.4 285,000 33,000 87,600 261
Primary
PDW GC-20
6.1 323,000 35,000 98,000 10 117
Secondary 6.3 322,500 37,000 99,970 4100
Primary
PDW GC-22
6.4 324,000 37,000 98,108 25 61
Secondary 6.2 327,500 36,000 93,720 10 73
Primary
BRW GC-09
7.2 4,460 1,400 750 1,150 142
Secondary 7.2 5,080 1,600 901 1,300 90
Primary
BRW GC-10
6.7 4,490 1,560 901 1,281 110
Secondary 7.2 4,400 1,600 801 1,250 70
Primary
BRW GC-20
74,250 1,600 871 1,275 137
Secondary 7.1 4,340 2,000 849 1,425 67
Primary
BRW GC-22
6.4 5,260 1,400 821 1,325 92
Secondary 7.1 5,020 1,600 900 1,280 110
Primary
RCW GC-09
7.1 7,380 1,800 1,925 1,200 129
Secondary 6.8 7,920 1,800 1,900 1,300 85
Primary
RCW GC-10
6.5 8,120 1,800 2,250 1,220 110
Secondary 7.2 8,300 2,300 2,500 1,300 110
Primary
RCW GC-20
6.8 5,850 2,240 1,654 1,300 139
Secondary 7.2 5,160 2,800 1,150 1,400 73
Primary
RCW GC-22
7.2 7,400 2,000 1,802 1,050 98
Secondary 7.3 9,840 2,400 2,250 1,300 122
Primary
EFW GC-09
6.2 298,000 33,000 97,497 310 195
Secondary 6.2 318,750 34,500 90,730 70 110
Primary
EFW GC-10
6.2 288,000 35,500 102,612 210 175
Secondary 6.7 287,500 34,000 87,600 10 60
Primary
EFW GC-20
6.1 261,250 32,800 102,613 145 115
Secondary 6.6 291,250 36,000 90,600 20 98
Primary
EFW GC-22
6.2 282,000 33,500 106,000 162 112
Secondary 6.2 321,250 36,500 93,720 50 146
Primary
EWDP-1
6.2 308,000 37,000 92,497 115 160
Secondary 6.1 291,250 35,500 87,840 35 171
Primary
SWTP SW
80 73 75 60 91.3 93.8 75
Secondary 55 53 55 50 96.4 100 90.9
% change –20 –20 –10 5.1 6.2 15.9
Primary
CIPF-SWIHW
591 451 463 324 76.3 78.3 54.8
Secondary 405 345 373 249 85.2 92.1 61.5
% change –106 –90 –75 8.9 13.8 6.7
Primary
EWDP-1
245 134 240 74 54.7 98 30.2
Secondary 236 161 226 56 68.2 95.8 23.7
% change 27 –14 –18 13.5 –2.2 –6.5
The change in sessile bacteria population density from primary production cycle to secondary production cycle is given in the table above. The positive (+) values indicate an increase in percentage of incidents with
bacteria levels >100 counts/cm2 and negative (–) values indicate a decrease in percentage of incidents.
TABLE 2. Continued
2006-2011 and 2012-2016 Sessile Bacteria Monitoring Data
Period (Primary/
Secondary Production
Cycle) Water System
Total Monitoring
Incidents
No. of Incidents with
>100 counts/cm2
% of Incidents with Bacteria
Level
>100 counts/cm2
GAB GAnB SRB GAB GAnB SRB
42 FEBRUARY 2020 WWW.MATERIALSPERFORMANCE.COM

TABLE 4. INCIDENTS OF HIGH AND SEVERE PITTING AND SESSILE BACTERIA HIGHER THAN 102 COUNTS/cm2
Primary Production Lifecycle Secondary Production Lifecycle
Coupon Tests Bacteria Tests Coupon Tests Bacteria Tests
System
No. of
Coupon
s Tests
% High
and
Severe
pitting
No. of
Sessile
Bacteria
Tests
% High
Bacteria
No. of
Coupon
s Tests
% High
and
Severe
pitting
No. of
Sessile
Bacteria
Tests
% High
Bacteria
GC-09, BRW 198 67.2 66 98.5 176 83.5 43 100
GC-10, BRW 40 72.5 5100 119 69.7 22 100
GC-20, BRW 84 86.9 27 96.3 166 80.1 45 97.8
GC-22, BRW 82 97.6 22 81.8 157 73.2 46 100
GC-09, RCW 172 75 56 82.1 130 94.6 28 96.4
GC-10, RCW 34 70.6 580 44 95.5 11 90.9
GC-20, RCW 20 70 8100 — — — —
GC-22, RCW 48 77.1 988.9 130 98.5 44 95.5
GC-09, EFW 251 59 104 58.9 268 70.1 69 63.8
GC-10, EFW 85 68.2 34 94.1 327 70.3 65 66.1
GC-20, EFW 104 67.3 52 88.5 263 61.2 66 81.8
GC-22, EFW 152 70.4 53 92.5 383 72.3 101 74.3
GC-09, PDW 162 34.6 24 62.5 149 10.7 10 90
GC-10, PDW 96 41.7 18 77.8 114 24.6 15 73.3
GC-20, PDW 53 52.8 13 84.6 8 0 7 100
GC-22, PDW 76 39.5 13 92.3 120 13.3 18 83.3
SWTP, SW 110 35.5 80 93.8 77 37.7 55 100
CIPF-SWIHW, SW 1,000 22.3 591 78.3 747 34.3 405 92.1
EWDP1, EFW 493 72.8 245 98 686 79.6 236 95.8
TABLE 5. TREND OF BACTERIA INCIDENTS >102 COUNTS/cm2 FOR TWO FLUID GROUPS FROM PRIMARY TO
SECONDARY PRODUCTION CYCLE
Changes in Bacteria Incidents >102 counts/cm2
Fluid Type
Total Number of
Streams GAB Incidents GAnB Incidents SRB Incidents
PDW, EFW, EWDP Nine Five streams had a negative
trend
Six streams had a negative
trend
Eight streams had a negative
trend
BRW, RCW, SW Nine Eight streams had a positive
trend
Seven streams had a positive
trend
Eight streams had a positive
trend
incidents with excessive population density
ranged within 96 to 98%, the range for GAB
was 55 to 68%, and for SRB, it was 24 to 34%.
Population Dynamics
within Bacteria Consortia
Table 3 reflects the effects of produc-
tion shift on the oilfield fluid characteristic
parameters for PDW, BRW, RCW, EFW (the
four GCs), and EFW (EWDP-1) streams.
The data for 2006 marks the beginning of
the primary production lifecycle while the
data for 2016 marks the end of the second-
ary production lifecycle. The sulfate con-
tent in PDW, EFW (the four GCs), and EFW
(EWDP-1) significantly decreased from
2006 to 2016 as follows: PDW (40 to 85%
reduction for the four GCs), EFW (70 to 95%
reductions in the same four GCs), and 70%
reduction in EFW (EWDP-1).
The observed decrease is presumed due
to the depletion of soluble sulfate minerals
in the reservoir. Table 2 reflects a 30 to 70%
reduction in SRB population density in
PDW, EFW (four GCs), and EFW (EWDP-1)
systems from primary to secondary pro-
duction cycles. No sulfate depletion was
observed in BRW, RCW, and SW streams
and no SRB decrease.
Table 5 presents the trend of bacteria
population incidents >102 counts/cm2 from
primary to secondary production in two
groups of water-handling systems. EFW
and EWDP-1 have essentially similar char-
acteristics as PDW in terms of conductivity,
chlorides, bicarbonates, sulfates, etc.
Ranking Asset Integrity of Oilfield-Water Systems in Two Production Lifecycles
43MATERIALS PERFORMANCE: VOL. 59, NO. 2 FEBRUARY 2020

The MP Buyers Guide is an exclusive
directory of manufacturers, suppliers,
and consultants worldwide that
provide products and services for the
prevention and control of corrosion.
To access the online version of the
MP Buyers Guide, as well as add or edit
your company’s listing, please go to
www.mpbuyersguide.com.
CM
CORROSION MANAGEMENT
Consequently, they are grouped together.
On the other hand, the characteristics of
BRW, RCW, and SW are dissimilar to PDW
and are, therefore, grouped separately.
Except for bicarbonate and sulfate con-
tents, Table 3 illustrates that the character-
istic parameters vary within the expected
margin of error during the primary and sec-
ondary production lifecycles. For the bicar-
bonate contents, the differences between
primary to secondary are not consistent.
Consequently, the variation in bicarbonate
content may not be a useful distinguishing
parameter for this study. However, the dif-
ferences between the sulfate contents in
the primary to secondary production life-
cycles are consistent. There is a definite
reduction in sulfate content during the sec-
ondary production lifecycle. The negative
changes in bacteria incidents, especially
that of SRB in the PDW, EFW, and EWDP-1
streams, correlates nicely with the
observed sulfate reduction.
The TDS of BRW and RCW streams
ranges within 3,000 to 5,000 ppm; however,
the RCW stream makes direct contact with
wet crude oil, and hydrocarbons are an
excellent energy source for a variety of
microbes. Consequently, the incidents of
severe general and pitting corrosion rates
are generally higher in RCW than BRW
streams. Such incidents were higher during
the secondary production cycle than dur-
ing the primary production cycle.
The BRW and SW streams are at ambi-
ent temperature and the food/carbon
sources in both fluids are non-crude
organic in nature. The range of tempera-
ture for PDW and EFW streams is non-
ambient (70 to 80 °C) and the two fluids
make direct contact with wet crude oil,
which supplies enhanced nutrients to the
prevalent bacterial population.
Ranking Asset Integrity Risk
The risk assessment process9 identifies
the conditions that could lead to asset fail-
ure. For the oilfield water-handling sys-
tems, the leak impact factor, representing
the consequence, is essentially identical.
That is, the probability of failure could be
used as a surrogate to establish a relative
risk ranking for maintenance action. The
question then arises: which of the oilfield
water-handling systems has the highest
probability of failure, and therefore, the
highest relative risk of negative outcome,
occasioned by bac teria population and the
attendant corrosion?
Based on the data presented in Tables 1
to 4, the risk to each downstream water sys-
tem during primary production lifecycle is
in the following decreasing order: BRW >
RCW > EFW > SW. However, during the sec-
ondary production lifecycle, the risk to each
downstream water system is in the follow-
ing decreasing order: RCW > BRW > EFW >
SW. That is, RCW, which consists of a sig-
nificant amount of PDW, became more cor-
rosive than BRW after the production shift
from primary to secondary. Aside from the
enhanced corrosivity of the PDW, the reser-
voir changes, after the production shift,
apparently induced bacteria population
dynamics resulting in enhanced MIC.
References
1 A. Vigneron, et al., “Succession in the Petro-
leum Reservoir Microbiome through an Oil
Field Production Lifecycle,” ISME J. 11, 9
(2017).
2 O. Olabisi, et al., “Ranking Asset Integrity
Risk of Oilfield Water Handling Systems,” MP
56, 12 (2017): pp. 58-62.
3 NACE TM0194-2014, “Field Monitoring of
Bacteria Growth in Oil and Gas Systems”
(Houston, TX: NACE International, 2014).
4 O. Olabisi, et al., “Rib osomal RNA Character-
ization of Bacteria: Linkage with Field Data
Based on Culture Media,” CORROSION 2015,
paper no. 5591 (Houston, TX: NACE, 2015).
5 NACE SP0775-2013-HD2013-SG, “Prepara-
tion, Installation, Analysis, and Interpreta-
tion of Corrosion Coupons in Oilfield Opera-
tions” (Houston, TX: NACE, 2013).
6 ASTM G1-03, “Standard Practice for Prepar-
ing, Cleaning, and Evaluating Corrosion Test
Specimens” (West Conshohocken, PA: ASTM
International, 2011).
7 Tyngyue Gu, B. Galicia, “Can Acid Producing
Bacteria be Responsible for Very Fast MIC
Pitting?" CORROSION 2012, paper no. 1214
(Houston, TX: NACE, 2012).
8 A.R. Al-Shamari, et al., “Some Empirical Ob-
servations About Bacteria Proliferation and
Corrosion Damage Morphology in Kuwait
Oil Field Waters,” CORROSION 2013, paper
no. 2748 (Houston, TX: NACE, 2013).
9 API RP 580, “Risk Based Inspection,” 1st ed.
(Washington DC: API, 2002).
OLAGOKE OLABISI is the chief consultant
at Infra-Tech Consulting, Sugar Land,
Texas, USA, email: olagokeolabisi@ infra-
techconsulting.com. He is a NACE-certi-
fied Corrosion Specialist and Chemical
Treatment Specialist, was director of
Internal Corrosion Engineering at Corrpro
for 10 years, and was on contract for two
years working with DNV GL on the Kuwait
Oil Co. Internal Corrosion Monitoring Ser-
vices Project. Olabisi was the lead devel-
oper of the NACE Pipeline Corrosion
Integrity Management course and is a
NACE instructor. He has a Ph.D., FNSChE,
and published the Handbook of Thermo-
plastics, 2nd ed., in January 2016 with
CRC Press. He is a 23-year member of
NACE.
AMER JARRAGH is a team leader (pipe-
lines) within the Inspection & Corrosion
Team at Kuwait Oil Co., Ahmadi, Kuwait.
He has been with the company for 17
years, primarily involved in all aspects of
internal and external corrosion. He is a
NACE-certified Cathodic Protection (CP)
Specialist, Senior Internal Corrosion Tech-
nologist, Coating Inspector Level 3, and
API Piping Inspector. Jarragh is an instruc-
tor for NACE CP1 and ICP-Basic, and API
510 Pressure Vessel. He has been a mem-
ber of NACE for 15 years.
ASHOK MATHEW is Corrosion Chemist
within the Inspection & Corrosion Team at
Kuwait Oil Co., email: ashokmathew40@
hotmail.com. He has 35 years of R&D
experience in chemical field, 19 of which
are devoted to all aspects of Internal Cor-
rosion in coordination with the Corrosion
Laboratory, Research and Technology.
Mathew is a NACE certified Chemical
Treatment & Corrosion Specialist and
CEng (Engineering Council, UK). Mathew
has been a member of NACE for 15 years.
44 FEBRUARY 2020 WWW.MATERIALSPERFORMANCE.COM