| 1. |
- Comanescu, Iulian, et al.
(author)
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Assessment of MIC in carbon steel water injection pipelines
- 2012
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In: Society of Petroleum Engineers - SPE International Conference and Exhibition on Oilfield Corrosion 2012. - 9781622760800 ; , s. 227-234
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Conference paper (peer-reviewed)abstract
- The present study compares corrosion mass loss and pit depth measurements on carbon steel corrosion coupons exposed under similar operating parameters, but with different biological consortia. One set of data were obtained from standard flush disc corrosion coupons used to monitor corrosion rates in a water injection pipeline on the North Sea continental shelf. The coupons were exposed on average for 6 months over 6 years operational time. These data are compared with published corrosion data of coupons exposed in abiotic district hot water systems from several power plants situated in Europe. The exposure time for these coupons was 9 months. Both systems were anoxic and in the same temperature range and are comparable. Observations regarding relationship between MIC and bacterial consortia, bacterial numbers and type, water quality and corrosion products are also made. The corrosion rate of the water injection pipeline is approximately 10 times higher compared with the corrosion rate in the abiotic district hot water system. It is concluded that the increased corrosion on the carbon steel coupons in the early stage is caused by MIC. This is also supported by the chemical and biological information available for the pipelines. The results reported here constitute the first step of an overall study to improve the level of understanding of the bacterial contribution to the total corrosion rates of carbon steel in water injection flowlines. Such understanding is expected to improve management and operational decision-making for practical control of corrosion in the field, by providing predictions of expected life time as a function of control of biotic consortia (e.g. through pigging, and biocide treatments). Further, it will facilitate decisions concerning choice of pipeline construction materials for future design. Copyright 2012, Society of Petroleum Engineers.
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| 2. |
- Comanescu, Iulian, et al.
(author)
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Corrosion and durability of offshore steel water injection pipelines
- 2015
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In: Ships and Offshore Structures. - : Informa UK Limited. - 1744-5302 .- 1754-212X. ; 11:4, s. 424-437
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Journal article (peer-reviewed)abstract
- Carbon steel pipelines are widely used for injection of sea and other waters into oil and gas wells so as to increase the rate of recovery, particularly from mature fields. Internal corrosion usually is mild. However, cases of very aggressive channelling corrosion along the bottom of the pipeline have been observed. Practical experience and anecdotal observations have attributed this to microbiologically influenced corrosion even though extensive use is made of preventative measures including biocides, oxygen scavengers, corrosion and scale inhibitors, and pipeline pigging. Interpretation of data and observations for five water injection pipelines, made available by industry, indicate that microbiologically influenced corrosion may play a part in causing channelling corrosion but that the most likely cause is under-deposit corrosion under pipe debris that settles during periods of pipeline shut-downs and low water velocity.
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| 3. |
- Comanescu, Iulian, et al.
(author)
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Data base and corrosion models for MIC in oil & gas
- 2011
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In: European Corrosion Congress 2011, EUROCORR 2011. - 9781618394125 ; , s. 2574-
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Conference paper (peer-reviewed)abstract
- Systems for handling stabilised oil like equipment for top side oil export systems, oil transport and processing plants are subject to high level of bio-corrosion. Bio-corrosion results in extensive and costly damages for the equipment and additional losses due to the shutting down of the transport and production units for several weeks. The objective of this project is to build a database of bio-corrosion case histories on carbon steel in systems containing produced water, to design a statistical model correlating physical and chemical parameters and to create a basis for modelling the prediction of MIC in produced water, as e.g. extracted from the hydrocarbon stream. The intention is to develop the data base to an expertise tool for MIC that can be used for anticipating and preventing bio-corrosion. The work is following the methodology "From the field, through the lab, to the field". The work starts with an extensive literature study for collection of published MIC failures in relevant environments. Additionally, close interactions will be held with field operators within Statoil, M-I SWACO and other oil & gas related companies for collection of MIC failures from the fields. In order to have statistical data existing field and literature data will be complemented with field and laboratory studies both within and outside the Marie Curie BIOCOR ITN. A schematic view of the procedure for the work is given below.
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| 4. |
- Comanescu, Iulian
(author)
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Influence of MIC on corrosion of oil field water injection pipelines
- 2013
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In: Annual Conference of the Australasian Corrosion Association 2013: Corrosion and Prevention 2013. - : Australasian Corrosion Association. - 9781634394369 ; , s. 143-152
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Conference paper (peer-reviewed)abstract
- Water injection or water flooding is widely used as a secondary recovery method to increase the production of oil usually from mature oil wells. It requires the injection of water into the reservoir, typically using carbon steel pipelines. Their corrosion is a major issue for the oil and gas industry, involving high costs of periodic chemical treatment, including biocides, oxygen scavengers, corrosion and scale inhibitors, and pipeline pigging. There is also the high potential cost of premature failure of the pipelines relative to life-time predictions, and the associated potential for unpredicted costs and major environmental implications should the pipeline fail. The present paper presents a review of a pilot study supported by the oil industry and the European Community that aimed to improve understanding of the corrosion behaviour of these pipelines. It draws on data and observations for the long-term corrosion, water quality, intelligent pigging records and microbiological testing to gain a better understanding why some pipelines suffer mild corrosion yet others, apparently similar, are prone to highly aggressive channelling corrosion. Herein the documented experience of several pipelines is reviewed. Observation data taken into consideration include pigging operation information, composition of corrosion products and their amount, corrosion rates and pipe geometry, identified biological consortia, water chemistry and process parameters. Also, the distribution of corrosion along the pipeline as well as the localization of corrosion attack is noted. Preliminary correlations between and conclusions about observed corrosion, operational conditions and service history are made. A Joint Industry research project currently is being arranged by the offshore oil industry to extend this work. Copyright © 2013 by the Australasian Corrosion Association.
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| 5. |
- Comanescu, Iulian, et al.
(author)
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Life time assessment of offshore water injection pipelines as a function of microbiologically influenced corrosion
- 2012
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Conference paper (peer-reviewed)abstract
- Corrosion of water injection pipelines (WIP) in the oil and gas industry is a major issue involving potential premature life time predictions and unpredicted costs like periodic biocide treatment and pipeline pigging. This paper presents a part of a larger project concerned with improving understanding of the influence of bacterial activity on corrosion, as distinct from abiotic corrosion, in oil and gas transport systems for better management of pipeline systems. Observations are made concerning life time as a function of microbiologically influenced corrosion (MIC) risk and relationships between MIC, bacterial numbers and types, and water quality.
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| 6. |
- Comanescu, Iulian, et al.
(author)
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The possible influence of microorganisms on the patterns of corrosion seen in water injection pipelines
- 2013
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Conference paper (peer-reviewed)abstract
- A major problem for the management of oil and gas pipelines is corrosion influenced by microorganisms particularly, bacteria. The present study focuses on the influence particularly of the sulfate reducing bacteria on the internal corrosion of water injection pipelines. The research is based on reports from long-term observations of several water injections pipelines from the North Sea continental shelf. Observation data taken into consideration are pigging operation information, composition of corrosion products and their amount, corrosion rates and pipe geometry, identified biological consortia, water chemistry and process parameters. Observations regarding water quality and mitigation methods are made also. The distribution of corrosion including pitting and 'features' along the pipeline as well as the localization of these in relation to the orientation of the surfaces, is considered. This includes different corrosion patterns along the pipeline and the relative severity of six o'clock corrosion. These observations are used to make correlation estimates between severity and location of corrosion and service history and the local environmental conditions, where this information is available. The correlations are used to develop a clearer view of the proportion of biocorrosion contributing to the total corrosion in water injection pipelines. Additionally, an assessment is made of the efficiency of mitigation procedures such as biocide treatments and pigging operations. The paper provides possible explanations for different rates and spatial patterns of corrosion for water injection pipelines. © 2013 by NACE International.
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