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Per Daling

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Silvia De Bianchi

Università degli Studi di Milano - State University of Milan (Italy)

ISET Nabeul

Ulyanovsk State University

University of Sarajevo

University of East Anglia

Dr. Hariprasad Tarigonda

Sree Vidyanikethan Engineering College

IFEANYICHUKWU U . ONYENANU

Anambra State University, Uli, Anambra state, Nigeria

Reinaldo Imbrozio Barbosa

Instituto Nacional de Pesquisas da Amazônia

Hazara University Mansehra, Dhodial KPK Pakistan

Martin Graziano

Universidad de Buenos Aires

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Papers by Per Daling

Deepwater Response Options - a Modelling Study Comparing Subsea Dispersant Injection and Mechanical Recovery using residual surface oil as a simplified effectiveness indicator

Proceedings, May 1, 2021

The low oil recovery rates reported during Macondo (3-5% of the released oil) have caused discuss... more The low oil recovery rates reported during Macondo (3-5% of the released oil) have caused discussions regarding the efficiency of mechanical recovery compared to other oil spill response options. These low recovery rates have unfortunately been used as reference recovery rates in several later modelling studies and oil spill response analysis. Multiple factors could explain these low rates, such as operational priorities, where dispersants and/or in situ burning are given priority before mechanical recovery; extended safety zones; availability of adequate equipment and storage capacity of collected oil; the number of units available; the level of training and the available remote sensing support to guide operations. This study uses the OSCAR oil spill model to simulate a deep-water oil release to evaluate the effect of different response options both separately and in combination. The evaluated response options are subsea dispersant injection, mechanical recovery, and a combination of these. As expected, Subsea Dispersant Injection (SSDI) was highly effective and resulted in a significant reduction in residual surface oil (8% of released oil volume, versus 28% for the nonresponse option, NR). However, using large offshore oil recovery systems also reduced residual surface oil with a similar amount (9% of released oil volume). These results deviate significantly from the efficiency numbers reported after the Macondo incident and from later modelling studies scaled after the Macondo recovery rates. The

Experiments at Sea with Herders and In Situ Burning (HISB)

Proceedings, May 1, 2017

A series of experiments involving herders and ISB (designated HISB) were conducted at sea on 14 t... more A series of experiments involving herders and ISB (designated HISB) were conducted at sea on 14 th-15 th June 2016, near the Frigg Field in the North Sea. The primary objective of the experiments described in this paper was to demonstrate, at near-full scale, the use of herders followed by in situ burning (ISB) in open water conditions and validate the findings of an earlier field study of herders in conjunction with ISB. Two experimental releases of 6 m 3 (approximately 40 barrels) and one of 4 m 3 of Grane Blend crude oil were undertaken. The released oil spread out differently on the sea surface in each of the slicks due to slight variations in release conditions and prevailing wind conditions. Herder (ThickSlick 6535) was applied around two of the slicks by spraying from a small boat; a third slick was not herded before ignition. In the first test, approximately 80% of the total amount of thick oil was herded to form a coherent slick with an average oil layer thickness of approximately 3 mm to 5 mm. The second herded slick accounted for 40% of the amount of oil released and resulted in an average layer thickness of approximately 2 mm to 3 mm present as several discrete areas of thick oil. The average oil layer thickness in the non-herded slick was 2.5 mm to 3 mm (under very calm weather conditions) and this slick had also been broken up into several discrete areas of thick oil. Ignition with gelled gasoline igniters was carried out approximately one hour after oil release. All three slicks were successfully ignited. Approximately 3.4 m 3 of the available oil in the

Chemical dispersion of oil. Comparison of the effectiveness results obtained in laboratory and small-scale field tests

Oil and Chemical Pollution, 1986

Field tests are of major importance for dispersant product evaluation in addition to laboratory e... more Field tests are of major importance for dispersant product evaluation in addition to laboratory effectiveness studies. To investigate the correlation between laboratory and large-scale field tests, two series of small-scale sea trials were initiated by the Norwegian Oil Pollution Control-Research and Development Program. The field tests comprised the application of seawaterdiluted dispersants as well as neat application from a boat. A total of six dispersants were tested on four oil types. An attempt was made to correlate the field test results with three laboratory test methods. Results showed that there is poor correlation between effectiveness results obtained from three different laboratory test systems, and between results from field and laboratory tests. There was, however, a fairly good correlation between the mean results from the three laboratory tests and the field tests. Efforts should be made to improve the simulation offield conditions in laboratory procedures before it is possible to make a valid mathematical model which is able to predict dispersion effectiveness under given conditions. Furthermore, the methodology and reproducibility of field tests of dispersant effectiveness should be improved.

Dispersant effectiveness testing of crude oils weathered under various ice conditions

In order to get more precise understanding of the potential for use of dispersants in ice covered... more In order to get more precise understanding of the potential for use of dispersants in ice covered areas, an extensive study of the effectiveness and dispersibility of oils weathered under various spill scenarios and ice regimes has been carried out. The chemical dispersibility of five oils representing different categories of crude oils (naphthenic, asphalthenic, waxy and paraffinic) has been investigated as function of weathering up to one week under different ice conditions (0, 30, 50, 70 and 90% ice coverage) using the SINTEF meso-scale flume weathering basin (Brandvik et al., 2010). The dispersibility testing included both ex-situ dispersant testing of oil samples taken during the weathering in the flume, using a standard effectiveness test method (the MNS- test) and in-situ treatment in the flume at the end of each experiment. The results from this systematic series of dispersibility testing, have revealed that several oils can have a longer “operational time window" for use of dispersants in ice covered water compared to open water, because the weathering processes are slowed down in ice. Some oils spilled in high ice coverage conditions remain dispersible for several days / weeks after release. The flume basin experiments for the naphthenic Troll crude oil were verified through a field trial in the Barents Sea. In one of the experiments, 7m 3 of Troll crude was allowed to drift and weather for one week in high ice coverage (70 ‐ 80 % ice) before dispersants were applied from a vessel using a new manoeuvrable spray arm customized for application on oil in ice coverage water. After the dispersant treatment, energy / turbulence using propeller washing and MOB boat water jets to was used to cause the dispersion process of conversion into very small oil droplets. These mixing methods proved to be highly

Dispersant Use in Ice-Affected Waters: Regulatory Status and Opportunities to Advance Decision Making

Proceedings, May 1, 2014

There is increasing interest in, and evolving technological capability to, conduct offshore oil a... more There is increasing interest in, and evolving technological capability to, conduct offshore oil and gas exploration and production operations in sensitive arctic regions. This has focused attention on oil spill preparedness and response for waters which have an ice cover for some part of the year. Given the logistical challenges associated with transporting and deploying mechanical equipment in these remote, ice-prone areas, the application of dispersants below and on the water surface is being considered as one of the ways to mitigate the impact of accidental oil spills from offshore exploration, production and transportation operations.

Investigation of the spreading tendency of emulsified oil slicks on open systems

Marine Pollution Bulletin, Jul 1, 2022

Oil Spill Modeling Toward the Close of the 20TH.CENTURY: Overview of State of the Art

Fate and behavior of Sanchi oil spill transported by the Kuroshio during January–February 2018

Marine Pollution Bulletin, Mar 1, 2020

The fate and behavior of the Sanchi oil spill during January-February 2018 was simulated by coupl... more The fate and behavior of the Sanchi oil spill during January-February 2018 was simulated by coupling an oil spill model and satellite observations with meteo-oceanographic forcing. Extensive validation tests were performed for winds, currents, surface slick, stranded oil and oil fate. A series of hindcast experiments was designed to take into account the uncertainties in oil amount, environmental forcing and model parameters. The simulations confirmed that the stable large-scale Kuroshio acted as the primary driving force. Most oil followed the Kuroshio's large-meander path, rapidly passing through the East China Sea to the waters south of Japan. The wind, appearing as the secondary transport factor, did not change the path of this large-scale current, but did contribute to the drift of surface oil. The different fates for heavy fuel oil and condensate in the accident were also compared quantitatively and discussed in this study.

Droplet size distributions in chemical dispersion of oil spills: Towards a mathematical model

Oil and Chemical Pollution, 1990

The results of a series of chemical dispersion tests are presented, in which three crude oils (Gu... more The results of a series of chemical dispersion tests are presented, in which three crude oils (Gullfaks, Statflord and Arabian heavy), each at 4 states of weathering, have been dispersed at 13 ° C with two dispersants (Finasol OSR-5 and OSR-12) using three laboratory tests (Warren Spring Rotating Flask-WSL test, Institute Frangais du Pbtrole flow test-IFP test and Mackay-Nadeau-Steelman-MNS test). Effectiveness and dispersed oil droplet size distributions in the different test methods have been studied and an attempt has been made to develop correlation or mathematical models of the chemical dispersion phenomena. This mathematical treatment helps to explain the reasons that the tests give different results, but it is concluded that, at present, our understanding of the basic dispersion phenomena is not sufficient to form a basis for a reliable model. Several modelling approaches are discussed in the hope that as further data and insights become available, reliable models may be developed to describe this complex process.

Vurdering av forvitringsegenskapene til ulike Marine Gassoljer. Kriterier for fastsettelse av drivstoff kvalitet ut fra egenskaper ved et eventuelt utslipp

53, Jun 7, 2006

Tabell 2 Kokepunktsdatafor WRG og G0-11. WRG G0-11 Volum% Destillasjons Destillasjons temp. Temp.

Biomonitoring of Benzene and Effect of Wearing Respirators during an Oil Spill Field Trial at Sea

Annals of Work Exposures and Health, Jul 13, 2018

Objectives: The main aim of this study was to assess the biological uptake of benzene and polycyc... more Objectives: The main aim of this study was to assess the biological uptake of benzene and polycyclic aromatic hydrocarbons (PAHs) for subjects exposed to fresh crude oil released at sea. Methods: The study included 22 subjects participating in an «oil on water» field trial in the North Sea. Over two consecutive days there were six releases with two different types of fresh crude oils. Exposed subjects (N=17) were either located in small, open air boats downwind and close to the released oil (<50 m) or on the main deck of two large vessels further from the released oil (100-200 m). Subjects assumed to be unexposed (N=5) were located indoors on the command bridge of either vessel. Full-shift personal benzene exposure was monitored with passive thermal desorption tubes (ATD-tubes) packed with Tenax TA and subsequent gas-chromatographic analysis. Urine samples were collected before and after work-shift on both days and analyzed for urinary markers of benzene (S-Phenyl Mercapturic Acid, SPMA) and PAHs (1-Hydroksypyrene, 1-OH). Information about the use of personal protective equipment, smoking habits, location, work tasks and length of work-shift was recorded by a questionnaire. Results: Subjects located in the small boats downwind and close to the released oil were exposed to relatively high concentrations of benzene (arithmetic mean=0.2 ppm, range 0.002-1.5 ppm) compared to the occupational exposure limits (OELs) for 8 h (1 ppm) and 12 h (0.6 ppm). Although respirators were available to all exposed subjects, SPMA was detected in post-shift urine (0.5-3.3 µmol/mol) of five exposed subjects reporting not wearing respirators, all located in the small boats downwind and close to the released oil. For exposed subjects wearing respirators (N=12) the post-shift urinary SPMA was below the detection limit (0.8 µmol/mol) even when the benzene exposure exceeded the OELs. Urinary levels of PAH were within the reference range of what is considered as background levels (<0.4 µmol/mol). Conclusions: During the initial stages of a bulk oil spill at sea, when the evaporation of benzene is at its highest, it is important to use appropriate respirators to prevent biological uptake of benzene.

Sampling procedures for securing evidence for waterborne oil spill identifications

Abstract Sampling is often the first step in the process of documenting an oil spill. Proper samp... more Abstract Sampling is often the first step in the process of documenting an oil spill. Proper sampling is essential to the quality of the data obtained from the subsequent analysis of the samples. This is particularly critical if any of the data are to be admissible in court. The procedures described in this chapter are based on available guidelines for oil sampling from the water surface, shorelines, and from the suspected polluter, the latter of which is primarily related to sampling for oil spill source identification. Samples must be handled as legal evidence and should be kept within a “chain of custody” until identification and possible legal procedures have been completed. The chapter also describes procedures for taking spill samples during oil spill response operations, as a basis for further characterization of relevant physical and chemical properties of surface oil (w/o emulsion) that are important information, for example, the decision making of response options and fate and transport modeling.

Aerial Application of Dispersants—Comparison of Slick Behavior of Chemically Treated Versus Non-Treated Slicks

Proceedings, Feb 1, 1985

From June 18 to 22, 1984 two series of dispersant tests were carried out off the Norwegian coast.... more From June 18 to 22, 1984 two series of dispersant tests were carried out off the Norwegian coast. The first series comprised 2 parallel slicks: one control and one treated with dispersant 2 hours after discharge. The second series comprised 4 parallel slicks: (1) control; (2) dispersant application after 1 hour; (3) oil and dispersant mixed prior to discharge; and (4) dispersant application 4 hours after discharge. Each slick contained approximately 10 m 3 of fuel oil. The dispersant applied by aircraft was Cor exit 9527. The development of the different slicks was continuously monitored by aerial surveillance using side-looking airborne radar (SLAR), infrared and ultraviolet remote sensing, and vertical color photography as well as video recording for at least 6 hours (first series) and up to 12 hours (second series) after discharge. Dispersion of oil into the water column was investigated by turbidity measurements in the water column and by analyses of oil content in water samples from different depths. Furthermore, emulsion formation and viscosity changes of the surface oil were studied in each slick. Aerial registrations as well as water column measurements show that both the horizontal and vertical spreading of oil was significantly enhanced in dispersant-treated versus non-treated slicks. In the first series, the dispersant-treated slick covered an area 2 to 3 times larger than the control slick a few hours after treatment. Hydrocarbon concentrations in the water column were found to be up to 40 ppm in treated slicks. Viscosity of the surface oil in untreated slicks increased due to emulsion formation, while the viscosity of surface oil in treated slicks decreased, likely due to an emulsion breaking effect of the dispersant.

Improved and Standardized Methodology for Oil Spill Fingerprinting

Environmental Forensics, 2002

The existing Nordtest Methodology for Oil Spill Identification has over the past 10 years formed ... more The existing Nordtest Methodology for Oil Spill Identification has over the past 10 years formed an important "platform" for solving oil spill identification cases both in the Scandinavian countries as well as other countries in Europe, the USA and Canada. '<Revisionof the Nordtest Methodology for Oil Spill Identification" is a cooperative project between the National Oil Spill Identification laboratories in Norway, Sweden, Finland, Denmark and Battelle Memorial Institute (Duxbury) in the USA. The goals of the project are: (1) to refine the existing Nordtest methodology into a technically more robust and defensible oil spill identification methodology with focus on determination of quantitative diagnostic indices (ratios) and (2) to adjust the revised Nordtest methodology into guidelines for the European Committee for Standardization (CEN), This paper presents the recommended methodology for defensible oil spill identification and assessment when a single oil source is involved and there are no confounding effects of pre-spill background hydrocarbons. The sampling techniques and handling of oil samples prior to their arrival at the environmental forensic laboratory is not covered in this paper, The recommended methodology approach is a result of documented analytical improvements and a more quantitative treatment of analytical data from gas chromatographic-flame ionization detector (GC/FID) and gas chromatographicmass spectrometer methods (GCLMS-SIM) and the operational experiences over past few years among the participating forensic laboratories. The

OC2017 A-221 - Summary report - Petromaks 2 Thin Oil Films

55, Nov 3, 2017

Recent improvements in optimizing use of dispersants as a cost-effective oil spill countermeasure technique

All Days, Jun 9, 1996

Recent improvements in optimizing use of dispersants as a cost-effective oil spill countermeasure... more Recent improvements in optimizing use of dispersants as a cost-effective oil spill countermeasure technique. Several oil spill incidents during recent years have demonstrated that the physico-chemical properties of spilled oil and the effectiveness of available combat methods are, in addition to the prevailing environmental and weather conditions, key factors that determine the consequences of an oil spill. Pre-spill analyses of the feasibility and effectiveness of different response strategies, such as mechanical recovery and dispersants, for actual oils under various environmental conditions should therefore be an essential part of any oil spill contingency planning to optimize the overall "Net Environmental Benefit" of a combat operation. During the four-year research program ESCOST ("ESSO-SINTEF Coastal Oil Spill Treatment Program"), significant improvements have been made in oil spill combat methods and in tools for use in contingency planning and decision-making during oil spill operations. This paper will present an overview of the main findings obtained with respect to oil weathering and oil spill dispersant treatment during this research program, including:–New methodology for systematic investigations of the weathering properties of oils at sea–Development of high performance dispersant formulations for weathered and emulsified oils–Improvements in dispersant application techniques and applications procedures /strategies–Development of dynamic oil spill simulation model tools for use in designing more optimal and cost-effective oil spill contingency solutions. The results from the ESCOST program have been obtained through systematic laboratory and meso-scale basin studies, and numerical model developments. In addition, two successful full-scale controlled field trials have been conducted in the North Sea during 1994 and 1995. The results from the full-scale field trials have been used in verifying the laboratory experiments, calibrating the numerical model tools, and to investigate the effectiveness of different oil spill dispersant application techniques under realistic oil spill scenarios. The findings obtained in the ESCOST program have formed a foundation for the present effort among oil companies and authorities in implementing more operational, optimal dimensioned and cost-effective oil spill contingency for offshore platforms, refineries and oil terminals in Norway. Background for the ESCOST Program: Oil spills in recent years have demonstrated the high level of public concern related to the potential effects caused by oil spills. These spills have also reconfirmed the importance of having model tools available both for predicting the different oils behavior and to assess the feasibility and effectiveness of different countermeasure techniques such as mechanical recovery or dispersants. The behavior of spilled crude oils and refined oil products depends on the prevailing conditions (e.g. temperature, sea-state, currents) and on the chemical composition of the oil. Large variations in crude oil properties cause them to behave differently when spilled at sea. The crude spilled at the "Braer" incident in the Shetlands had e.g. a low content of waxes and asphaltenes which are important compounds for stabilizing water-in-oil (w/o) emulsions that usually are formed on the sea surface. This, combined with violent weather conditions, resulted in consequences that were much less severe than might have been expected. Almost all of the 84,000 tons of the spilled crude oil was naturally dispersed. P. 899

Sintef/Iku Oil-Weathering Model: Predicting Oils' Properties at Sea

Proceedings, Apr 1, 1997

ABSTRACT This paper describes the empirical approach used in the development of the IKU oil-weath... more ABSTRACT This paper describes the empirical approach used in the development of the IKU oil-weathering model (IKU-OWM). Weathering data from field trials with experimental oil spills during the past 15 years have provided the basis for the algorithms used in the model. These data, combined with a standardized laboratory study of each specific oil, including a bench-scale (“stepwise”) weathering investigation, a chemical dispersibility investigation, and a meso-scale flume basin weathering investigation, form the basic input to the model. The IKU-OWM has been extensively tested and verified with results from full-scale field trials with experimental oil slicks in the North Sea in 1994 and 1995. This paper presents the correlations between the oil-weathering values predicted by the model and the ground-truth data obtained from the field trials. To obtain reliable weathering predictions, it is essential to have good laboratory weathering data of specific oils. The IKU-OWM is now extensively used in Norway to predict the changes in oil properties due to weathering under user-specified conditions. Predictions provided by the IKU-OWM enable oil spill personnel to estimate the most appropriate “window of opportunity” for using chemical dispersants in various spill situations. Prespill scenario analysis with the IKU's oil spill contingency and response (OSCAR) model system, of which the IKU-OWM is one of several components, has become an important part of contingency plans and of contingency training of oil spill personnel at refineries, oil terminals, and offshore installations in Norway.

Optimisation of oil spill dispersant composition by mixture design and response surface methods

Chemometrics and Intelligent Laboratory Systems, Aug 1, 1998

Oil spill dispersants are used to enhance the rate of natural dispersion of an oil spill at sea. ... more Oil spill dispersants are used to enhance the rate of natural dispersion of an oil spill at sea. Dispersants remove the oil slick from the sea surface and dilute the oil as small droplets in the water column. The large increase in the oil-water interface due to oil droplet formation increases the biodegradation of the oil by natural occurring microorganisms. Mixture de-Ž. w sign simplex-centroid and response surface methods have in an earlier simulation study P.J. Brandvik, Statistical simulation as an effective tool to evaluate and illustrate the advantage of experimental designs and response surface methods, Ž. x Chemometrics and Intelligent Laboratory Systems submitted for publication. proved to be an effective tool to enhance optimisation of oil spill dispersant and to reduce the number of experiments needed for development of new products. This proposed multivariate method is representing a new approach within the development of oil spill dispersants. The main objective for the work presented in this paper was to verify the performance of this new approach within this area on real laboratory data. This combined technique using mixture design and response surface methods has been verified to be a powerful and cost reducing approach in dispersant optimisation. New dispersant formulations for both crude oils and bunker fuels have been formulated and verified by measurements to have high effectiveness.

909 Biological monitoring of benzene after exposure to fresh crude oil spilled at sea in an oil spill field trial

Dispersant effectiveness seminar, Oslo, Norway, May 1985

Oil and Petrochemical Pollution, 1985

Deepwater Response Options - a Modelling Study Comparing Subsea Dispersant Injection and Mechanical Recovery using residual surface oil as a simplified effectiveness indicator

Proceedings, May 1, 2021

The low oil recovery rates reported during Macondo (3-5% of the released oil) have caused discuss... more The low oil recovery rates reported during Macondo (3-5% of the released oil) have caused discussions regarding the efficiency of mechanical recovery compared to other oil spill response options. These low recovery rates have unfortunately been used as reference recovery rates in several later modelling studies and oil spill response analysis. Multiple factors could explain these low rates, such as operational priorities, where dispersants and/or in situ burning are given priority before mechanical recovery; extended safety zones; availability of adequate equipment and storage capacity of collected oil; the number of units available; the level of training and the available remote sensing support to guide operations. This study uses the OSCAR oil spill model to simulate a deep-water oil release to evaluate the effect of different response options both separately and in combination. The evaluated response options are subsea dispersant injection, mechanical recovery, and a combination of these. As expected, Subsea Dispersant Injection (SSDI) was highly effective and resulted in a significant reduction in residual surface oil (8% of released oil volume, versus 28% for the nonresponse option, NR). However, using large offshore oil recovery systems also reduced residual surface oil with a similar amount (9% of released oil volume). These results deviate significantly from the efficiency numbers reported after the Macondo incident and from later modelling studies scaled after the Macondo recovery rates. The

Experiments at Sea with Herders and In Situ Burning (HISB)

Proceedings, May 1, 2017

A series of experiments involving herders and ISB (designated HISB) were conducted at sea on 14 t... more A series of experiments involving herders and ISB (designated HISB) were conducted at sea on 14 th-15 th June 2016, near the Frigg Field in the North Sea. The primary objective of the experiments described in this paper was to demonstrate, at near-full scale, the use of herders followed by in situ burning (ISB) in open water conditions and validate the findings of an earlier field study of herders in conjunction with ISB. Two experimental releases of 6 m 3 (approximately 40 barrels) and one of 4 m 3 of Grane Blend crude oil were undertaken. The released oil spread out differently on the sea surface in each of the slicks due to slight variations in release conditions and prevailing wind conditions. Herder (ThickSlick 6535) was applied around two of the slicks by spraying from a small boat; a third slick was not herded before ignition. In the first test, approximately 80% of the total amount of thick oil was herded to form a coherent slick with an average oil layer thickness of approximately 3 mm to 5 mm. The second herded slick accounted for 40% of the amount of oil released and resulted in an average layer thickness of approximately 2 mm to 3 mm present as several discrete areas of thick oil. The average oil layer thickness in the non-herded slick was 2.5 mm to 3 mm (under very calm weather conditions) and this slick had also been broken up into several discrete areas of thick oil. Ignition with gelled gasoline igniters was carried out approximately one hour after oil release. All three slicks were successfully ignited. Approximately 3.4 m 3 of the available oil in the

Chemical dispersion of oil. Comparison of the effectiveness results obtained in laboratory and small-scale field tests

Oil and Chemical Pollution, 1986

Field tests are of major importance for dispersant product evaluation in addition to laboratory e... more Field tests are of major importance for dispersant product evaluation in addition to laboratory effectiveness studies. To investigate the correlation between laboratory and large-scale field tests, two series of small-scale sea trials were initiated by the Norwegian Oil Pollution Control-Research and Development Program. The field tests comprised the application of seawaterdiluted dispersants as well as neat application from a boat. A total of six dispersants were tested on four oil types. An attempt was made to correlate the field test results with three laboratory test methods. Results showed that there is poor correlation between effectiveness results obtained from three different laboratory test systems, and between results from field and laboratory tests. There was, however, a fairly good correlation between the mean results from the three laboratory tests and the field tests. Efforts should be made to improve the simulation offield conditions in laboratory procedures before it is possible to make a valid mathematical model which is able to predict dispersion effectiveness under given conditions. Furthermore, the methodology and reproducibility of field tests of dispersant effectiveness should be improved.

Dispersant effectiveness testing of crude oils weathered under various ice conditions

In order to get more precise understanding of the potential for use of dispersants in ice covered... more In order to get more precise understanding of the potential for use of dispersants in ice covered areas, an extensive study of the effectiveness and dispersibility of oils weathered under various spill scenarios and ice regimes has been carried out. The chemical dispersibility of five oils representing different categories of crude oils (naphthenic, asphalthenic, waxy and paraffinic) has been investigated as function of weathering up to one week under different ice conditions (0, 30, 50, 70 and 90% ice coverage) using the SINTEF meso-scale flume weathering basin (Brandvik et al., 2010). The dispersibility testing included both ex-situ dispersant testing of oil samples taken during the weathering in the flume, using a standard effectiveness test method (the MNS- test) and in-situ treatment in the flume at the end of each experiment. The results from this systematic series of dispersibility testing, have revealed that several oils can have a longer “operational time window" for use of dispersants in ice covered water compared to open water, because the weathering processes are slowed down in ice. Some oils spilled in high ice coverage conditions remain dispersible for several days / weeks after release. The flume basin experiments for the naphthenic Troll crude oil were verified through a field trial in the Barents Sea. In one of the experiments, 7m 3 of Troll crude was allowed to drift and weather for one week in high ice coverage (70 ‐ 80 % ice) before dispersants were applied from a vessel using a new manoeuvrable spray arm customized for application on oil in ice coverage water. After the dispersant treatment, energy / turbulence using propeller washing and MOB boat water jets to was used to cause the dispersion process of conversion into very small oil droplets. These mixing methods proved to be highly

Dispersant Use in Ice-Affected Waters: Regulatory Status and Opportunities to Advance Decision Making

Proceedings, May 1, 2014

There is increasing interest in, and evolving technological capability to, conduct offshore oil a... more There is increasing interest in, and evolving technological capability to, conduct offshore oil and gas exploration and production operations in sensitive arctic regions. This has focused attention on oil spill preparedness and response for waters which have an ice cover for some part of the year. Given the logistical challenges associated with transporting and deploying mechanical equipment in these remote, ice-prone areas, the application of dispersants below and on the water surface is being considered as one of the ways to mitigate the impact of accidental oil spills from offshore exploration, production and transportation operations.

Investigation of the spreading tendency of emulsified oil slicks on open systems

Marine Pollution Bulletin, Jul 1, 2022

Oil Spill Modeling Toward the Close of the 20TH.CENTURY: Overview of State of the Art

Fate and behavior of Sanchi oil spill transported by the Kuroshio during January–February 2018

Marine Pollution Bulletin, Mar 1, 2020

The fate and behavior of the Sanchi oil spill during January-February 2018 was simulated by coupl... more The fate and behavior of the Sanchi oil spill during January-February 2018 was simulated by coupling an oil spill model and satellite observations with meteo-oceanographic forcing. Extensive validation tests were performed for winds, currents, surface slick, stranded oil and oil fate. A series of hindcast experiments was designed to take into account the uncertainties in oil amount, environmental forcing and model parameters. The simulations confirmed that the stable large-scale Kuroshio acted as the primary driving force. Most oil followed the Kuroshio's large-meander path, rapidly passing through the East China Sea to the waters south of Japan. The wind, appearing as the secondary transport factor, did not change the path of this large-scale current, but did contribute to the drift of surface oil. The different fates for heavy fuel oil and condensate in the accident were also compared quantitatively and discussed in this study.

Droplet size distributions in chemical dispersion of oil spills: Towards a mathematical model

Oil and Chemical Pollution, 1990

The results of a series of chemical dispersion tests are presented, in which three crude oils (Gu... more The results of a series of chemical dispersion tests are presented, in which three crude oils (Gullfaks, Statflord and Arabian heavy), each at 4 states of weathering, have been dispersed at 13 ° C with two dispersants (Finasol OSR-5 and OSR-12) using three laboratory tests (Warren Spring Rotating Flask-WSL test, Institute Frangais du Pbtrole flow test-IFP test and Mackay-Nadeau-Steelman-MNS test). Effectiveness and dispersed oil droplet size distributions in the different test methods have been studied and an attempt has been made to develop correlation or mathematical models of the chemical dispersion phenomena. This mathematical treatment helps to explain the reasons that the tests give different results, but it is concluded that, at present, our understanding of the basic dispersion phenomena is not sufficient to form a basis for a reliable model. Several modelling approaches are discussed in the hope that as further data and insights become available, reliable models may be developed to describe this complex process.

Vurdering av forvitringsegenskapene til ulike Marine Gassoljer. Kriterier for fastsettelse av drivstoff kvalitet ut fra egenskaper ved et eventuelt utslipp

53, Jun 7, 2006

Tabell 2 Kokepunktsdatafor WRG og G0-11. WRG G0-11 Volum% Destillasjons Destillasjons temp. Temp.

Biomonitoring of Benzene and Effect of Wearing Respirators during an Oil Spill Field Trial at Sea

Annals of Work Exposures and Health, Jul 13, 2018

Objectives: The main aim of this study was to assess the biological uptake of benzene and polycyc... more Objectives: The main aim of this study was to assess the biological uptake of benzene and polycyclic aromatic hydrocarbons (PAHs) for subjects exposed to fresh crude oil released at sea. Methods: The study included 22 subjects participating in an «oil on water» field trial in the North Sea. Over two consecutive days there were six releases with two different types of fresh crude oils. Exposed subjects (N=17) were either located in small, open air boats downwind and close to the released oil (<50 m) or on the main deck of two large vessels further from the released oil (100-200 m). Subjects assumed to be unexposed (N=5) were located indoors on the command bridge of either vessel. Full-shift personal benzene exposure was monitored with passive thermal desorption tubes (ATD-tubes) packed with Tenax TA and subsequent gas-chromatographic analysis. Urine samples were collected before and after work-shift on both days and analyzed for urinary markers of benzene (S-Phenyl Mercapturic Acid, SPMA) and PAHs (1-Hydroksypyrene, 1-OH). Information about the use of personal protective equipment, smoking habits, location, work tasks and length of work-shift was recorded by a questionnaire. Results: Subjects located in the small boats downwind and close to the released oil were exposed to relatively high concentrations of benzene (arithmetic mean=0.2 ppm, range 0.002-1.5 ppm) compared to the occupational exposure limits (OELs) for 8 h (1 ppm) and 12 h (0.6 ppm). Although respirators were available to all exposed subjects, SPMA was detected in post-shift urine (0.5-3.3 µmol/mol) of five exposed subjects reporting not wearing respirators, all located in the small boats downwind and close to the released oil. For exposed subjects wearing respirators (N=12) the post-shift urinary SPMA was below the detection limit (0.8 µmol/mol) even when the benzene exposure exceeded the OELs. Urinary levels of PAH were within the reference range of what is considered as background levels (<0.4 µmol/mol). Conclusions: During the initial stages of a bulk oil spill at sea, when the evaporation of benzene is at its highest, it is important to use appropriate respirators to prevent biological uptake of benzene.

Sampling procedures for securing evidence for waterborne oil spill identifications

Abstract Sampling is often the first step in the process of documenting an oil spill. Proper samp... more Abstract Sampling is often the first step in the process of documenting an oil spill. Proper sampling is essential to the quality of the data obtained from the subsequent analysis of the samples. This is particularly critical if any of the data are to be admissible in court. The procedures described in this chapter are based on available guidelines for oil sampling from the water surface, shorelines, and from the suspected polluter, the latter of which is primarily related to sampling for oil spill source identification. Samples must be handled as legal evidence and should be kept within a “chain of custody” until identification and possible legal procedures have been completed. The chapter also describes procedures for taking spill samples during oil spill response operations, as a basis for further characterization of relevant physical and chemical properties of surface oil (w/o emulsion) that are important information, for example, the decision making of response options and fate and transport modeling.

Aerial Application of Dispersants—Comparison of Slick Behavior of Chemically Treated Versus Non-Treated Slicks

Proceedings, Feb 1, 1985

From June 18 to 22, 1984 two series of dispersant tests were carried out off the Norwegian coast.... more From June 18 to 22, 1984 two series of dispersant tests were carried out off the Norwegian coast. The first series comprised 2 parallel slicks: one control and one treated with dispersant 2 hours after discharge. The second series comprised 4 parallel slicks: (1) control; (2) dispersant application after 1 hour; (3) oil and dispersant mixed prior to discharge; and (4) dispersant application 4 hours after discharge. Each slick contained approximately 10 m 3 of fuel oil. The dispersant applied by aircraft was Cor exit 9527. The development of the different slicks was continuously monitored by aerial surveillance using side-looking airborne radar (SLAR), infrared and ultraviolet remote sensing, and vertical color photography as well as video recording for at least 6 hours (first series) and up to 12 hours (second series) after discharge. Dispersion of oil into the water column was investigated by turbidity measurements in the water column and by analyses of oil content in water samples from different depths. Furthermore, emulsion formation and viscosity changes of the surface oil were studied in each slick. Aerial registrations as well as water column measurements show that both the horizontal and vertical spreading of oil was significantly enhanced in dispersant-treated versus non-treated slicks. In the first series, the dispersant-treated slick covered an area 2 to 3 times larger than the control slick a few hours after treatment. Hydrocarbon concentrations in the water column were found to be up to 40 ppm in treated slicks. Viscosity of the surface oil in untreated slicks increased due to emulsion formation, while the viscosity of surface oil in treated slicks decreased, likely due to an emulsion breaking effect of the dispersant.

Improved and Standardized Methodology for Oil Spill Fingerprinting

Environmental Forensics, 2002

The existing Nordtest Methodology for Oil Spill Identification has over the past 10 years formed ... more The existing Nordtest Methodology for Oil Spill Identification has over the past 10 years formed an important "platform" for solving oil spill identification cases both in the Scandinavian countries as well as other countries in Europe, the USA and Canada. '<Revisionof the Nordtest Methodology for Oil Spill Identification" is a cooperative project between the National Oil Spill Identification laboratories in Norway, Sweden, Finland, Denmark and Battelle Memorial Institute (Duxbury) in the USA. The goals of the project are: (1) to refine the existing Nordtest methodology into a technically more robust and defensible oil spill identification methodology with focus on determination of quantitative diagnostic indices (ratios) and (2) to adjust the revised Nordtest methodology into guidelines for the European Committee for Standardization (CEN), This paper presents the recommended methodology for defensible oil spill identification and assessment when a single oil source is involved and there are no confounding effects of pre-spill background hydrocarbons. The sampling techniques and handling of oil samples prior to their arrival at the environmental forensic laboratory is not covered in this paper, The recommended methodology approach is a result of documented analytical improvements and a more quantitative treatment of analytical data from gas chromatographic-flame ionization detector (GC/FID) and gas chromatographicmass spectrometer methods (GCLMS-SIM) and the operational experiences over past few years among the participating forensic laboratories. The

OC2017 A-221 - Summary report - Petromaks 2 Thin Oil Films

55, Nov 3, 2017

Recent improvements in optimizing use of dispersants as a cost-effective oil spill countermeasure technique

All Days, Jun 9, 1996

Recent improvements in optimizing use of dispersants as a cost-effective oil spill countermeasure... more Recent improvements in optimizing use of dispersants as a cost-effective oil spill countermeasure technique. Several oil spill incidents during recent years have demonstrated that the physico-chemical properties of spilled oil and the effectiveness of available combat methods are, in addition to the prevailing environmental and weather conditions, key factors that determine the consequences of an oil spill. Pre-spill analyses of the feasibility and effectiveness of different response strategies, such as mechanical recovery and dispersants, for actual oils under various environmental conditions should therefore be an essential part of any oil spill contingency planning to optimize the overall "Net Environmental Benefit" of a combat operation. During the four-year research program ESCOST ("ESSO-SINTEF Coastal Oil Spill Treatment Program"), significant improvements have been made in oil spill combat methods and in tools for use in contingency planning and decision-making during oil spill operations. This paper will present an overview of the main findings obtained with respect to oil weathering and oil spill dispersant treatment during this research program, including:–New methodology for systematic investigations of the weathering properties of oils at sea–Development of high performance dispersant formulations for weathered and emulsified oils–Improvements in dispersant application techniques and applications procedures /strategies–Development of dynamic oil spill simulation model tools for use in designing more optimal and cost-effective oil spill contingency solutions. The results from the ESCOST program have been obtained through systematic laboratory and meso-scale basin studies, and numerical model developments. In addition, two successful full-scale controlled field trials have been conducted in the North Sea during 1994 and 1995. The results from the full-scale field trials have been used in verifying the laboratory experiments, calibrating the numerical model tools, and to investigate the effectiveness of different oil spill dispersant application techniques under realistic oil spill scenarios. The findings obtained in the ESCOST program have formed a foundation for the present effort among oil companies and authorities in implementing more operational, optimal dimensioned and cost-effective oil spill contingency for offshore platforms, refineries and oil terminals in Norway. Background for the ESCOST Program: Oil spills in recent years have demonstrated the high level of public concern related to the potential effects caused by oil spills. These spills have also reconfirmed the importance of having model tools available both for predicting the different oils behavior and to assess the feasibility and effectiveness of different countermeasure techniques such as mechanical recovery or dispersants. The behavior of spilled crude oils and refined oil products depends on the prevailing conditions (e.g. temperature, sea-state, currents) and on the chemical composition of the oil. Large variations in crude oil properties cause them to behave differently when spilled at sea. The crude spilled at the "Braer" incident in the Shetlands had e.g. a low content of waxes and asphaltenes which are important compounds for stabilizing water-in-oil (w/o) emulsions that usually are formed on the sea surface. This, combined with violent weather conditions, resulted in consequences that were much less severe than might have been expected. Almost all of the 84,000 tons of the spilled crude oil was naturally dispersed. P. 899

Sintef/Iku Oil-Weathering Model: Predicting Oils' Properties at Sea

Proceedings, Apr 1, 1997

ABSTRACT This paper describes the empirical approach used in the development of the IKU oil-weath... more ABSTRACT This paper describes the empirical approach used in the development of the IKU oil-weathering model (IKU-OWM). Weathering data from field trials with experimental oil spills during the past 15 years have provided the basis for the algorithms used in the model. These data, combined with a standardized laboratory study of each specific oil, including a bench-scale (“stepwise”) weathering investigation, a chemical dispersibility investigation, and a meso-scale flume basin weathering investigation, form the basic input to the model. The IKU-OWM has been extensively tested and verified with results from full-scale field trials with experimental oil slicks in the North Sea in 1994 and 1995. This paper presents the correlations between the oil-weathering values predicted by the model and the ground-truth data obtained from the field trials. To obtain reliable weathering predictions, it is essential to have good laboratory weathering data of specific oils. The IKU-OWM is now extensively used in Norway to predict the changes in oil properties due to weathering under user-specified conditions. Predictions provided by the IKU-OWM enable oil spill personnel to estimate the most appropriate “window of opportunity” for using chemical dispersants in various spill situations. Prespill scenario analysis with the IKU's oil spill contingency and response (OSCAR) model system, of which the IKU-OWM is one of several components, has become an important part of contingency plans and of contingency training of oil spill personnel at refineries, oil terminals, and offshore installations in Norway.

Optimisation of oil spill dispersant composition by mixture design and response surface methods

Chemometrics and Intelligent Laboratory Systems, Aug 1, 1998

Oil spill dispersants are used to enhance the rate of natural dispersion of an oil spill at sea. ... more Oil spill dispersants are used to enhance the rate of natural dispersion of an oil spill at sea. Dispersants remove the oil slick from the sea surface and dilute the oil as small droplets in the water column. The large increase in the oil-water interface due to oil droplet formation increases the biodegradation of the oil by natural occurring microorganisms. Mixture de-Ž. w sign simplex-centroid and response surface methods have in an earlier simulation study P.J. Brandvik, Statistical simulation as an effective tool to evaluate and illustrate the advantage of experimental designs and response surface methods, Ž. x Chemometrics and Intelligent Laboratory Systems submitted for publication. proved to be an effective tool to enhance optimisation of oil spill dispersant and to reduce the number of experiments needed for development of new products. This proposed multivariate method is representing a new approach within the development of oil spill dispersants. The main objective for the work presented in this paper was to verify the performance of this new approach within this area on real laboratory data. This combined technique using mixture design and response surface methods has been verified to be a powerful and cost reducing approach in dispersant optimisation. New dispersant formulations for both crude oils and bunker fuels have been formulated and verified by measurements to have high effectiveness.

909 Biological monitoring of benzene after exposure to fresh crude oil spilled at sea in an oil spill field trial

Dispersant effectiveness seminar, Oslo, Norway, May 1985

Oil and Petrochemical Pollution, 1985