Fil: Guiamet, Patricia Sandra. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA). Departamento de Química. Facultad de Ciencias Exactas. Universidad Nacional de La Plata; ArgentinaFil: Gómez de Saravia, Sandra Gabriela. Cátedra de Zoología Invertebrados I. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

Guiamet, Patricia Sandra

Gómez de Saravia, Sandra Gabriela

Naturalis

  
INTERCORR2012_033 
 
 
 
Copyright 2012, ABRACO 
Trabalho apresentado durante o INTERCORR 2012, em Salvador/BA no mês de maio de 2012.  
As informações e opiniões contidas neste trabalho são de exclusiva responsabilidade do(s) autor(es). 
 
∗ a INIFTA, Departamento de Química, Facultad de Ciencias Exactas, UNLP, CCT. La Plata - CONICET. CC 
16, Suc. 4 (1900), La Plata, Argentina. 
b Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, CONICET. pguiamet@inifta.unlp.edu.ar 
c Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, CICBA. 
sgomez@nifta.unlp.edu.ar 
 
 
Operating problems in secondary oil injection plants. Its impact on microbiological 
corrosion processes. 
 
∗Patricia Guiamet a
 
,b, Sandra Gómez de Saraviaa,c 
Abstract  
 
The first mention of corrosion involving microorganisms was made in the early twentieth 
century, however, only in the 80's it was worldwide recognized that the microbiologically 
induced corrosion (MIC) creates serious problems in the oil industry associated, mainly to the 
presence of sulfate-reducing bacteria (SRB). The presence of operational problems for poor 
performance of operators in charge in these facilities, may favor the development of MIC, 
which leads among other things, the replacement pipe failure, pressure loss in pipes, etc. In 
this paper we present several case studies of MIC found in three plants of extraction and 
secondary oil injection, due to operational problems. The plants are located in the provinces 
of Neuquén and Mendoza, Argentina. These sites have serious problems caused by high 
concentrations ranging from 104-108/mL SRB high H2S concentrations of biological origin, 
plugging of wells (greater than 40% per year), high injection pressure and corrosion on 
valves, poor effectiveness of treatment biocides, etc. It presents a comprehensive analysis and 
interpretation of the problem of corrosion present in the deposits using information obtained 
from microbiological and physicochemical fields in order to propose strategies for diagnosis, 
evaluation of solutions in laboratory and field. 
 
Key words: MIC, biofilms, microorganisms, oil plants, sulfate reducing bacteria. 
 
Introduction 
 
The first descriptions of corrosion by microorganisms were provided at the beginning of the 
twentieth century; however, only in the eighties it was worldwide recognized that the 
Microbiologically Induced Corrosion (MIC) causes serious problems in the oil industry (1), 
what means a 50 to 90% of the localized corrosion (2).  
In many oil industries the production is obtained by water injection during secondary oil 
recovery processes. MIC is controlled mainly by studying the presence of sulfate reducing 
bacteria (SRB) (3, 4). Damages in these systems are mainly due to the H2S reaction with the 
carbon steel, the most important component of these distribution systems, iron sulphide 
products are formed (FeS), which reduce the flow area of the lines and block the injector 
wells causing a production decrease (3-5). 
                                                 
 
  
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The H2S content in these secondary recovery systems can be the result of abiotic reactions 
since the crude accompanies the formation water and/or bacterial activities (4-6), involving 
mainly the SRB as they are H2S producers in their respiratory metabolism (1, 7, 8)]. 
Nevertheless, Magot (9) and Crolet (10) reported strains that are not of SRB H2S producers, 
involved in the corrosion products from the water pipes of crude production in Africa, 
highlighting the capacity of these bacteria to produce significant amounts of H2S and organic 
acids from thiosulphate and peptides, which can be the only source of carbon and energy of 
some bacterial species. These processes can be more corrosive than the sulphate reduction by 
the SRB because of the acidification gradient generated (10, 11). 
Problems arising within these systems can be often avoided as in many cases there is 
biofouling and corrosion problems are due to a monitoring and a study of the system not 
careful enough along the time by the operators of the plant. Frequently, when the problem 
arises, the fact of applying the wrong measures to solve biofouling and biocorrosion comes on 
top of the lack of training of the plant operators.  
The aim of this paper is to present several case studies of MIC found in three plants of 
extraction and secondary oil recovery by water injection, due to operating problems as well as 
to suggest able solutions for this question. These plants are located in the provinces of 
Neuquén (systems 1 and 2) and in Mendoza (system 3), Argentina, which will be described 
below.  
 
System 1 
 
The 93 to the 95% of the production is water. Wells of this system are mature; it means that 
their oil production average 7%, the rest is water. They presented sulphate reducing bacteria 
(SRB) with a concentration up to 100 times higher than the maximum value of 104, generating 
then H2S.  
The most important problem was connected with the use of a non oxidizing biocide (acrolein) 
because as soon as it was not injected in the plant, a blockage in the wells took place.  
Hypochlorite and glutaraldehyde and later acrolein were used. It was started with two 
patching per week of 1100 ppm of acrolein, each of them during one hour. The basin where 
the water of the treatment plant passed through was modified and from that moment when 
passing through the basin the acrolein concentration decreases at the exit as it get mixed up 
with the whole water of the basin. Then, the biocide concentration was modified to one 
patching per week of 2200 ppm during four hours.  
At the end of 2004 a dispersant plus biocide was used. The disincrustant caused the blockage 
of the wells and the consequent pipe bursting. Pressure increased so much that serious 
damages occurred in the system. Face to this situation the use of these chemical products was 
suspended and acrolein was used again. Probably an excessive dilution of the acrolein was 
used and this could have decreased its effectiveness. It is a system physically difficult to gain 
access to place a side stream with coupons. Some 15m3/hr of fresh water from the Colorado 
river enter to the water treatment system into the washing tank. This could be a source of 
nutrients for the SRB.  
 
Solutions 
It is necessary to replace acrolein by a safer biocide. A previous dose of disincrustant must be 
used before starting with other biocide. Once the suitable biocide is determined and after 
starting to apply it, a long-term monitoring program must be carried out. The aim of the 
  
INTERCORR2012_033 
 
 
 
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treatment with biocides is to reduce as much as possible the H2S in the wells. A decrease of 
the SRB counting must be reached. It is important that the test do not end abruptly, since once 
the results expected are obtained, the dose must fall up to a maintenance level.  
Studies about the microbial charge of the Colorado River at the different seasons of the year 
were performed, incorporating a sampling protocol.  
Bioremediation is applied to lower processes (for example, petroleum spills on soils or water). 
Here the system is very fast and there would not be enough time to do bioremediation. With 
wastes, it could be possible to carry out bioremediation of the petroleum by-products by 
activating nitrate reducing bacteria (NRB) and SRB in aerobic and anaerobic way.  
 
System 2 
 
There is a great environmental problem since there is no place to throw wastes removed from 
water. In the water treatment plant wastes are reinjected so the contamination reenters into the 
system generating a feedback system. Very high countings of SRB (1015 mo/ml) were 
obtained. In a liquid medium the maximum concentration expected is of 1010 mo/ml. (Figure 
1). These high values observed in different systems are frequently due to staff dismissals 
caused by socioeconomic problems or to operators working without the suitable training.  
When the Northern Plant is working and water is sent there to be processed, the concentration 
of microorganisms decreases but when it is not, the concentration increases.  
Tetrakishydroxymethyl phosphonium sulphate (THPS) was applied.  
There are high H2S concentrations of genetic and microbiological origin. The treatment of 
water to be reinjected is not very effective. There are too much solids.  
 
 
SRB  
0 
2 
4 
6 
8 
10 
12 
14 
16 
Jan. Feb. Mar. Apr. May. June July Aug. 
B
ro
th
s 
Plant input  Plant exit Injection well 
  
 
Figure 1- SRB countings 
 
The well was closed. Sulphydric is generated by SRB. The system has a lot of genetic H2S as 
water is not injected, only gas. There always was sulphydric in the wells.  
 
There are three water treatment plants: 
o Plant of water collection: it treats the river water. 
o Center Plant: it treats the saltwater for injection 
  
INTERCORR2012_033 
 
 
 
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o Northern Plant: it treats the washing water (it does not work) 
 
At the Center Plant quaternary salts and glutaraldehyde (GA) were injected together with 
alcohol. The GA is added at the both patchings per week, 200 ml/min during 4 hours. THSP 
was also used, 150 ppm-160 ppm, at two patchings per week.  
 
Solutions 
 
One of the solutions would be to carry out a pilot testing in the wells, a producer one and an 
injector one, in order to evaluate the biocompetence. The growth of nitrate reducing bacteria 
will be helped to stop the growth of the SRB and to reduce the sulphydric. Countings and 
microbiological studies must be performed. The concentration of H2S diluted in water and 
gas, ions such as: nitrate, sulphate, phosphate, volatile fat acids, injection water salinity, etc., 
must be determined.  
Another solution would be to run the Northern Plant and implement the waste recycling that 
provides a microbial charge to the system. This could decrease the SRB and H2S 
concentrations. Lines cleaning and well interventions are also recommended.  
 
System 3 
 
The big problem is the blockage of the wells by solids (>40% per year), that started with the 
Secundary Recovery in 1967. The well blockage causes a significant injection pressure 
increase. It started with 160-180 kg and they are now of 210 kg.  
The sulphide content at the entrance of the injector wells is very high. Lagged pipes are 
employed, where is paradoxally supposed not to have corrosion nor biofilms formation. The 
water treatment plant works discontinuously as there is a generalized problem of corrosion in 
the valves, (Figure 2). 
 
 
Figure 2-Valves show corrosion problems  
 
The oil field extension is of 100 x 30 km. It is a mature field. The 93% is water. There are 
different formations within the oil field and oil is extracted from different layers. The water 
possesses solids that pass through filters as they retain particles greater than 5 μ. When an 
  
INTERCORR2012_033 
 
 
 
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“Acid stimulation” of the well is carrying out the injection increases (the pressure decreases) 
but after a short time the pressure increases again.  
During a period when fouling inhibitor was not used, lagged piping started to be used. But 
later a film of about 1.5-2 mm thickness was observed, slimy and lumpy, what indicated 
biofouling and biofilms.  
The processes of the plant are not automatics. It is an operator who regulates the pumps and 
he did other operations manually, so the smallest lapse of concentrations is enough to cause 
problems.  
Other problem connected to the discontinuous working is that data obtained can be no reliable 
if they have been taken before the stop of the plant, since after the stop, the conditions are not 
the same and neither does the water quality. There are high concentrations of sulphides. 
Sulphides would be deposited on the pipes. Biocides used were glutaraldehyde, acrolein and 
others.  
 
Solutions 
 
The replacement of the valves could allow the continuous working of the plant.  There is not a 
microbiological study of the system, so it is necessary to analyze which of the bacteria are 
mesophilic, thermophilic, barophilic, SRB ones, etc. Besides, to do a mapping of sulphides, to 
discriminate how much is originated in the reservoir and how much in the piping system and 
in the water treatment plant. It is also recommended to do a sulphydric mapping. There is not 
sampling of sessiles, but countings must be performed.  
 
Global solution proposal for problems of the systems 1, 2 and 3  
 
It is expected to give a solution for the biofouling, biofilms and biocorrosion problems 
through the following global proposal: service of microbiological management of the systems 
and a set of consultancies and specific services. The general proposal is to collect, organize 
and display all the information related with microorganisms, as a tool for monitoring, 
controlling and preventing the bacteria presence in the oil systems.  
The aim of the service: It will be to train the operators and responsible staff of the plants in 
order to decrease at the maximum mistakes when making decisions when unsuitable effects 
caused by the presence of microorganisms in the systems come out. It will be also possible to 
have a service and a methodological microbiological managemet of the systems.  
Theoretical and practical courses on biofouling, biofilms and biocorrosion issues will be 
provided to the operators to acknowledge and train them on taking, preserving and 
transporting the samples.  
A handbook of procedures for the operators will be creating on the management of the 
microbiological works to do in the field and at the laboratory.  
Collecting qualitative-quantitative data of the reservoir, production installations and water 
injection will be carried out, as well as gathering and/or measuring of variables and 
parameters of interest necessary to characterize the system.  
A daily monitoring of the microbiological state of the system (planktonic and sessile bacteria 
producing biofilms); identification and characterization for the microorganisms present 
potentially dangerous; use of kits for detecting and molecular techniques application are also 
expected.  
As well, observing through Scanning Electron Microscopy (SEM) biofilms adhered to the 
metallic substrates (coupons) and XRD (X-ray diffraction energy). Monitoring through 
  
INTERCORR2012_033 
 
 
 
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sampling devices with coupons of the metal constituent of the system to study corrosion, 
biocorrosion and sessile bacteria (biofilms forming). 
Among other possibilities, it is proposed here to solve the problem by the use of the suitable 
biocides in their suitable proportion according to studies performed by authorized staff.  
 
Acknowledgements: The authors thank the National University of La Plata (UNLP 11N 578 
and 11X 506), CONICET PIP 0200, CIC-1535/10, and Lic. Patricia Battistoni for the 
technical support.  
 
References 
 
(1) PRASOD, R. Assessment and control of MIC in the Oil Industry in the 20th century. 
CORROSION/2000. Paper Nº 390 p. 1-4, 2000.  
(2) JONES, J.; LITTLE, B.; MANSFELD, F. ESEM/EDS, SEM/EDS and EIS studies of 
coated 4140 steel exposed to marine, mixed microbial communities including SRB. 
International Power Generation Conference, Atlanta-Georgia. p. 1-2, 1992.  
(3) ANDRADE, S.; BARILLAS E. Control y Monitoreo de Bacterias Sulfato Reductoras 
en aguas de Formación y agua del Lago de Maracaibo. Tesis Ingeniería, Universidad 
del Zulia, Venezuela, p. 5-6, 1992.  
(4) ÁVILA, A. Elaboración de estrategias para el control de corrosión en una plataforma 
de producción de crudo ubicada en el Lago de Maracaibo. Tesis Ingeniería, 
Universidad del Zulia, Venezuela, p. 26-32, 1999.  
(5) FARQUHAR, G. Review and update of technology related to formation souring. 
CORROSION/97. Paper Nº 210. p. 1-9, 1997.  
(6) REVIE R.W. Uhlig´s “Corrosion Handbook”. 2da. Edition. (Electrochemical Society 
Series, John Wiley & Sons, INC, p. 482-483, 2000.  
(7) NEMATI, M.; VOORDOUW, G. Identification and Characterization of Sulfate-Reducing 
Bacteria involved in Microbially Influenced Corrosion in Oil Fields. CORROSION/2000. 
Paper No 126. pp. 1-2, 2000.  
(8) RAINHA, V.; FONSECA, T. Kinetic studies on the SRB Influenced Corrosion of Steel: A 
first approach. Corrosion Science, Vol. 39, Nº 4. p. 807-813, 1997.  
(9) MAGOT, M.; CARREAUL, L.;CAYOL, J.; OLLIVIER, B.; CROLET, J. Sulphide-
Producing, not Sulphate-Reducing Anaerobic Bacteria Presumtively Involved in Bacterial 
Corrosion. Proceedings of the 3rd International EFC workshop on Microbial 
Corrosion. The Institute of materials. London. p. 293-300, 1994.  
(10) CROLET J., MAGOT M. Observations of Non SRB Sulfidogenic Bacteria from Oilfield 
Production Facilities. CORROSION/95. Paper Nº 188, 1995. 
(11) LIE, T.; GODCHAUX, W.; LEADBETTER E. Sulfonates as Terminal Electron 
Acceptors for Growth of Sulfite-Reducing Bacteria (Desulfitobacterium spp.) and Sulpate-
Reducing Bacteria: Effects of Inhibitors of Sulfidogenesis. Applied and Environmental 
Microbiology, Vol. 65, Nº 10. p. 4611-4617, 1999.  


Operating problems in secondary oil injection plants. Its impact on microbiological corrosion processes

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