(jSINTEF 

SINTEF Applied Chemistry 

Address: 

Location: 

Telephone: 

Fax: 

N-7465 Trondheim, 

NORWAY 

S.P. Andersens vei 15A 

+47 73 59 20 80 / 12 12 

+47 73 59 70 51 

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REPORT NO. CLASSIFICATION 

STF66 A04025 Unrestricted 

CLASS. THIS PAGE ISBN 

Unrestricted 82-14-03047-1 

ELECTRONIC FILE CODE 

Final report.doc 

FILE CODE DATE 

2004-03-29 

ABSTRACT 

SINTEF REPORT 

TITLE 

!Development of Data Sets from Experimental Oil Spills for 

OWM Algorithm and Model Testing and Validation 

AUTHOR($) 

Merete 0verli Moldestad, Per Johan Brandvik and Per S. Daling 

CLIENT(S) 

U.S. Minerals Management Service, Alaska Region 

CLIENTS REF. 

Dr. Richard Prentki 

PROJECT NO. 

661189 

PROJECT MANAGER (NAME, SIGNiA? 

Mark Reed //~~ 

APPROVED BY (NAME, POSITION, SIGN.) 

Tore Aunaas, Research Director 

NO. OF PAGES/APPENDICES 

63 A 

CHECKED BY (ti~• SIGY,-

Janne L.M R€ s~.j/ U1. ei~ 

field data and weathering data from the following field trials are presented in this report: 

• Haltenbanken 1989 

• MIZ-experiment (in ice) 1993 

• NOFO-trial 1994 

• NOFO-trial 1995 

• NOFO-trial 1996 (limited data) 

• UK trials 1997 (AEA-trials) 

Additionally, the surface oil data from the Deep Spill 2000 experiment is presented. 

A short overview over each field trial is given together with the data sets, and weathering predictions 

made by the SINTEF Oil Weathering Model. The data sets has been developed and collated as a basis for 

validation testing of various oil weathering models, and we hope that these data will be valuable for 

other insitutes/organisations for this purpose. 

KEYWORDS ENGLISH NORWEGIAN 

GROUP 1 Chemistry Kjemi 

GROUP 2 Environment Milj0 

SELECTED BY AUTHOR Fie Id data Feltdata 

Weathering data F orvitringsdata 

Oil spills Olje utslipp 
~SINTEF 2 

TABLE OF CONTENTS 

1 Introduction ........................................................................................................................... 3 

I . I Background and objectives .............................................................................................. 3 

1.2 Conclusions and recommendations from the Phase I report ........................................... 3 

1.3 Datasets collected presented in this report ....................................................................... 4 

2 The Haltenbanken experiment 1989 .................................................................................... 6 

2. I The field experiments ....................................................................................................... 6 

2.2 Objectives ......................................................................................................................... 6 

2.3 Conclusions ...................................................................................................................... 6 

2.4 Field data Haltenbanken 1989 .......................................................................................... 9 

3 MIZ-1993 ......................................................................................................................... 14 

3.1 The field experiments ..................................................................................................... 14 

3.2 Field and input data MIZ 1993 ....................................................................................... 16 

4 NOFO exercise 1994 ............................................................................................................ 19 

4.1 The field experiments ..................................................................................................... 19 

4.2 Field and input data 1994 ............................................................................................... 22 

5 NOFO exercise 1995 ............................................................................................................ 27 

5.1 The field experiments ..................................................................................................... 27 

5.2 Field and input data 1995 ............................................................................................... 30 

6 NOFO exercise 1996 ............................................................................................................ 36 

6. 1 The fie ld experiments ..................................................................................................... 36 

6.2 Field and input data 1996 .............................................................................................. .40 

7 AEA field experiments UK 1997 ......................................................................................... 47 

7. 1 The field experiments ..................................................................................................... 47 

7.2 Field and input data 1997 ............................................................................................... 50 

8 Deep Spill JIP 2000 .............................................................................................................. 56 

8. 1 Field data 2000 ............................................................................................................... 58 

9 References ......................................................................................................................... 63 

1:ICll6611 89 MMS OWM Phases II and 111\Task 7\Final report.doc 
~SINTEF 3 

1 Introduction 

1.1 Background and objectives 

In 1998 SINTEF Applied Chemistry completed the Phase I review "Revision of MMS Offshore 

Continental Shelf Oil-Weathering Model: Evaluation," OCS Study MMS 98-0031 for MMS. This 

review recommended: 

• upgrading to an existing state-of-the-art OWM 

• additional improvements needed to maintain state-of-the-art and to meet needs of MMS 

users 

• spill data sets that would be suitable for model testing and validation. 

The recommendations described in the Phase 1 report, lead to a follow-up study" Revision of the 

OCS Oil-Weathering Model: Phases II and III". The objectives ofthis study are: 

1) to obtain and adapt the SINTEF Oil Weathering Model (OWM) to MMS needs, 

2) to expand the OWM oil library to include oils of interest to MMS, and 

3) to develop and collate data sets identified in Phase I from experimental oil spills for 

validation testing of various OWModels. 

This report is connected to the last objective in this study: Task 7: "Development of Data Sets 

from Experimental Oil Spills for OWM Algorithm and Model Testing and Validation" 

A framework for this task 7 was described in the MMS OWM Phase I Technical Meeting held in 

Anchorage, in March, 1998 with two alternative approaches: 

One approach at that time was that SINTEF, in collaboration with organizations like Alun Lewis 

Oil Spill Consultant in UK, CEDRE in France, and NOOA in US should try to develop a JIC 

program to address: 

• model sensitivity testing 

• preparation and archival of specified data sets 

• testing of model algorithms. 

Many data sets of potential interest were identified in the Phase I Report (OCS Study MMS 98-

0058), and MMS would like to see an eventual such JIC program developed in a manner which 

could facilitate use of the data in OWM testing, for use with models, such as the NOAA ADIOS 

model, in addition to with the SINTEF OWM. During the project period, it appeared, however, to 

be difficult to develop such an extended JIC program. We therefore agreed with MMS that 

SINTEF proceeded alone in this task with the limited budget from MMS allocated for task 7 to 

address the two last scopes/goals: i.e. preparation of available oil spill data sets, and in testing/ 

validating these ground-truth data with the new version of the SINTEF OWM only. The data sets 

presented in this report can however, be used by any organizations /model operators in model 

algorithm testing / validation. 

1.2 Conclusions and recommendations from the Phase 1 report 

In the Phase I Report (OCS Study MMS 98-0058, chap. 5.1.), criteria for an "ideal data set" from 

experimental oil releases at sea was specified with respect to: 

• Environmental background data 

• Oil characterization ( original oil properties and changes as function of weathering) 

• Documentation - Standardized methods for sampling and analysis 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
~SINTEF 4 

• Sampling frequency 

• Replicate samples 

An overview of experimental oil releases were identified and preliminary evaluated. None of the 

field trials satisfied the strict criteria for an "ideal data set", both with respect to methodology and 

data-documentation. However, this lack of the "ideal data set" should not prevent us from using 

the best series of these data sets for calibration/validation of oil weathering models. However, it 

also became very obviously during this review that many of the older data sets from experimental 

trials had a very limited potential for model calibration-/validation. This caused by varying quality 

of the data due to lack of consistent procedures for sampling and analytical methodology. 

Some recent field trials had, however, more well-documented and suitable procedures for field 

sampling and further analysis. The preliminary conclusion from this preliminary review was that 

data from recent field trials in UK and Norway (se below) had a potential for 

calibration/verification of oil weathering models, and an effort in collecting all relevant data from 

these series should be given priority in task 7: 

UK: Field trials in the North Sea from the period 1992-97: These experiments have been 

conducted on a yearly basis with different objectives. The more recent experiments have well 

documented and suitable procedures for sampling and further analysis. These field trials cover 

several crude oil (Forties, Alaska North slope) and different bunker fuels. The weathering time 

ranges from only hours to several days and the weathering parameters include ( emulsification, 

evaporation, natural dispersion, water soluble components, emulsion viscosity, emulsion stability, 

water droplets distribution in emulsion and others). Some of these UK sea trials also include 

extensive monitoring of dispersed oil concentrations versus time and also measurements of 

droplet sizes of the dispersed oil droplets. Some relevant data seemed to be available from e.g. 

AMOP-publications by AEA Technology, however, e.g. More extensive environmental data from 

the field test is needed in order to make then appropriate as validation data-sets. 

Norway: Field trials in the North Sea and in the marginal ice zone of the Barents Sea from the 

period ( 1989-96): In Norway, field experiments have been conducted on an almost yearly basis 

since late 70's, but only some of the trials were considered to be relevant for our purpose. The 

SINTEF-89 and MIZ-93 trials give data sets which can be used to compare weathering of the 

same crude oil type at a North Sea and an Arctic environment. These trials and the later NOFO 

trials (1994/95/96) have used well-documented and suitable procedures for sampling and further 

analysis. The weathering time ranges from one day up to seven days, and the weathering 

parameters include emulsification, evaporation, natural dispersion, water-soluble components, 

emulsion viscosity, and emulsion stability, among others. Data are available from SINTEF as 

reports and publications. 

1.3 Datasets collected presented in this report 

In the period from December 2002 to July 2003, an effort was made to collect all relevant data 

from the recommended series of field trials. As a result, data-set from the following trials are 

presented in this report: 

• Haltenbanken 1989 

• MIZ-experiment (in ice) 1993 

• NOFO-trial 1994 

• NOFO-trial 1995 

• NOFO-trial 1996 (limited data) 

l:\CH66 I I 89 MMS OWM Phases II and 111\Task 7\Final report.doc 
~SINTEF 

• UK trials 1997 (AEA-trials) 

• Surface oil data from the Deep spill 2000 experiment 

The data-sets from the earlier field tests in UK are not included in this report. This is due to lack 

of available documentation of environmental data during the field tests. Lewis Oil Spill 

Consultant in UK did an extensively search for obtaining data reports from field various field 

trials in UK at the library at MCA (Maritime and Coastal Agency in Southampton) without any 

success. 

5 

Weathering data, wind speed, temperature and film thickness are presented from the trials. For the 

trials including dispersant treatment, only the weathering data before dispersant treatment is 

presented in this report. 

The film thicknesses parameters used as input to the model for the predictions of the different 

trials, are based on the film thickness data measured in the individual trials. 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
~SINTEF 6 

2 The Haltenbanken experiment 1989 

2.1 The field experiments 

This experiment was organized by the oceanographic research company OCEANOR with 

SINTEF (IKU) and NINA as partners. The oil was released at Haltenbanken (65° 00 N, 08° 00 E) 

10.05 am July 1

st• The oil was released from a small tanker by a hose hanging above the sea 

surface. The release of total 30 tons took 16 minutes, forming a small and concentrated oil slick in 

the beginning. 

The first samples were collected 5 minutes after the oil was released and a comprehensive 

sampling program was carried out during the next four days. The results of the physico-chemical 

properties of the surface samples are given in the following tables. The results are average values 

of2-3 replicate samples. 

2.2 Objectives 

This full-scale experimental oil spill was carried out to study several objectives: 

1. Evaluation of different types of oil spill drifters (Argos positioned buoys) versus oil drift 

2. Intercalibration of different aerial surveillance systems 

3. Study of weathering processes of the Sture Blend crude (also here called Oseberg Blend) 

4. Study interactions between a drifting oil slick and sea birds 

2.3 Conclusions 

Generally, the measured changes in the oil properties with time gave a good agreement with 

predicted data of Sture based on small-scale laboratory experiments and using the SINTEF Oil 

Weathering model. 

Due to relatively rough weather conditions during the release, the oil was discharged vertically 

into the sea from a hose (1-3 meter above sea surface). This release arrangement resulted in a 

temporary mixing of the oil into the seawater, leading to a relative high starting film thickness. An 

initial filmthickness of20 mm has therefore been used in the model predictions. Additionally, the 

tanker had to use its thrusters (side propellers) during the discharge to keep distance to the oil 

slick. It is therefore reason to believe that this could cause additional mixing of oil and water and 

lead to higher water uptake for the samples from the first 5 - 30 minutes. 

Weathering data for Sture blend is included in the report. Sture blend is the present name of the 

Oseberg Blend used in 1989. Sture is the name of an Oil Terminal on the west coast of Norway. 

Crude oil from the various wells at the Oseberg field is the main contributor to this terminal. 

There may be some minor variation in the chemical composition to the Sture blend due to the 

daily variation in the daily production at the various field. 

Predicted evaporation, water uptake and emulsion viscosity together with field data is shown in 

Figure 2.1, Figure 2.2 and Figure 2.3, respectively. 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
SINTEF 

Property: Evaporation 

Temperature 1•q · 10 

Wind Speed (mis)· Wind file 

lmbal film thtclmess (mm) : 20 

Terrmnal film thlcl<ness (mm) 2 

100 

90 

80 

C 

70 

C: 60 

.2 

'§ 50 

0 

C. 40 "' > 

w 30 

20 

10 

----

• 

0 

0,25 0,5 

• 

SINTEF 

20 0 2002 

Pred Dato Apnl 30. 2003 

- .. -----• • .. • .. -. 

2 3 6 9 12 2 3 4 5 

Hours Days 

Figure 2.1 : Predicted evaporation and field data Haltenbanken 1989. 

Property: Water uptake 

Temperature (•C) 10 

Wind Speed (m/s). Wind file 

tn1bal film th1cl<ness (mm) . 20 

Terminal film thickness (mm) 2 

100 

90 

80 

70 

Cl) 60 "" "' .. • / a. 50 :, 

Cl) 40 / 

30 

20 

/ 

/ 

10 

0 

0,25 0,5 

• 

/ -----

2 3 

Hours 

SINTEF 

20 0 2002 

Pred Dato Apnt 30. 2003 

& - . -• • • 

6 9 12 2 3 4 5 

Days 

Figure 2.2 : Predicted water uptake and field data Haltenbanken 1989. 

l:\C!-1661189 MMS OWM Phases II and 111\Task 7\Final rcpon.doc 

7 

- Sture blend 

... F,eld data 

- Sture blend 

... Field data_] 
SINTEF 

Property: Emulsion viscosity 

Temperature {'C) · 10 

Wind Speed (mis) Wind file 

lmt1a1 film thickness {mm) 20 

Terminal film thickness (mm) 2 

100000 

10000 -

'iii 

0 

u 

Ill 

·;. 1000 

C 

0 

'iii 

:i 

E 

w 100 -

10 

0,25 0,5 

Hours 

SINTEF 

20Q 2002 

Pred. Dato: April 30, 2003 

6 9 12 2 3 4 5 

Days 

Figure 2.3 : Predicted emulsion viscosity and field data Haltenbanken 1989. 

l:ICll661189 MMS OWM Phases II and 11 1\Task 7\Final rcpon.doc 

8 

- Sture blend 

... Field data 
((jSINTEF 

2.4 Field data Haltenbanken 1989 

Table 2.1 

Table 2.2 

Table 2.3 

Table 2.4 

:Physico-chemical properties on waterfree residues ofSture Blend (1989 

crude)and their water-in-oil emulsions. 

:Water content and stability of the wlo-emulsions. 

: Wind conditions at Haltenbanken July 1989. 

: Input data for weathering predictions Sture blend. 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 

9 
(riSINTEF 10 

Table 2. 1 :Physico-chemical properties on waterfree residues of Sture Blend (1989 crude)and their water-in-oil emulsions. 

Station Time Evap. Water Viscosity1 Density Density Flash- Pour- lnt.f. Chemical Film 

(weathering loss cont. (10°C, cP) emulsion oil point point tension disp.- Thickness 2 

at sea) (wt.%) (vol.%, (kg/I) (kg/I coq {°C) (mN/m) ability (mm) 

total) 

0 (crude) 0 0 0 12.4 0.855 0.855 - -22 21 Good - 1 5min. 1 42 39.0 0.900- - <5°C - - Good - 2 l0min. 5 50 - - 5.1 - - Good 3.2 (1.3)2 

3 15 min. 2 53 6 0.944 0.872 13 -13 - Good 7.7 (4.3) 

4 30min. 7 58 100 0.955 0.867 20 - - Good 6.5 (-) 

5 1 hour 6 64 120 0.971 0.882 33 - - Good 2.4 (1.7) 

6 2 hours 15 70 225 0.975 0.888 102 -6 - Good 4.3 (2.1) 

7 4 hours 18 83 1000 1.003 0.892 >100 - - Reduced? 4.4 (-) 

8 6 hours 21 60 1300 0.965 0.895 >100 -2 12 Good 4.0 (-) 

9 8 hours 23 56 1600 0.970 0.895 >100 - - Good 1.8 (0.1) 

10 10 hours 18 69 2300 0.978 0.893 >100 - - Good 6.1 (2.8) 

11 12 hours 21 64 1800 0.974 0.902 >100 +7 10 Good - 12 1 day 30 77 6100 - 0.910 >100 +14 9 Reduced 2.4 (0.5) 

13 2 days 26 78 11500 - 0.917 >100 +18 3 Bad - 14 3.5 days 39 71 17500 - 0.935 >100 +32 - Bad - l)The viscosity measurements were performed at shear rates JOO s- 1 for the samples taken at stations Oto 6, and shear rate JO s-' for the samples taken at 

stations 7 to 14. 

2) The number in brackets gives the standard deviation based on three parallel film thickness measurement samples. 

I:\CH66l 189 MMS OWM Phases II and 111\Task ?\Final report.doc 
((j SINTEF I I 

Table 2.2 : Water content and stability of the wlo-emulsions. 

Station Age Total water Expelled water Expelled water Total expel. Water residue Stabilityrr of Efficiency2> of 

content after24 h after by 24 h water (Vol.%) in emulsion emulsion chemical 

(vol.%) settling (Vol.%) settling of 

chemically treated 

emulsions (Vol.%) 

0 (crude) 0 - - - - - - - I 5min. 42 - 42 42 - - 1.0 

2 I0min. 50 - 50 50 - - 1.0 

3 l5min. 53 22 30 52 I .58 .98 

4 30min. 58 13 40 53 5 .78 .91 

5 I hour 64 45 17 62 2 .30 .97 

6 2 hours 70 15 50 65 5 .79 .93 

7 4 hours 83 6 74 80 3 .93 .96 

8 6 hours 60 3 50 53 7 .95 .88 

9 8 hours 56 0 50 50 6 1.00 .89 

10 10 hours 69 0 66 66 3 1.00 .96 

11 12 hours 64 0 59 59 5 1.00 .92 

12 1 day 77 0 67 67 10 1.00 .87 

13 2 days 78 0 73 75 5 1.00 .94 

14 3.5 days 71 0 54 54 17 1.00 .76 

1) Fraction of total water content left in w/o-emu/sion after 24 h settling, (0-> emulsion is totally broken, 1.0-> emulsion not broken). 

2) Fraction of total water content expelled after chemical treatment with Alcopol 0 60% and 24 h settling (0 -> no water expelled, low efficiency, 1.0-> all 

water expelled, high chemical efficiency). 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
~SINTEF 12 

Table 2.3 : Wind conditions at Haltenbanken July 1989. 

Start date: 01.07.1989 

Cum. time Sea temp. Wind speed Direction 

(h) (OC) (mis) (0) 

0 9.6 11.3 287 

3 9.8 10.1 337 

6 9.8 8.4 350 

9 9.8 7.5 164 

12 9.8 6.9 262 

15 9.8 3.9 1 

18 9.6 7.8 273 

21 9.6 6.3 96 

24 9.9 7.5 230 

27 10.1 5.4 263 

30 10.2 6.9 14 

33 10.2 7.5 26 

36 10.2 7.5 157 

39 10.1 14.3 214 

42 10.1 16.1 231 

45 9.8 24.2 279 

48 9.6 25.1 256 

51 9.6 22.1 247 

54 9.8 17.0 312 

57 9.8 16.1 266 

60 9.8 11.0 233 

63 9.8 8.7 255 

66 9.8 4.8 325 

69 9.9 3.6 30 

72 9.9 4.2 86 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
{(iSINTEF 13 

Table 2.4 : Input data for weathering predictions Sture blend. 

Fresh oil properties 

Specific Gravity (60 F/60 F) 0.85 

Pour Point (

0

C) -9 

Reference temperature # I (0C) 13 

Viscosity at ref. temp.# I (cP) 11 

Vanadium (ppm wt.) -

Nickel (ppm wt.) -

Asphaltenes (wt.%) -

n-Pentane Insolubles (wt.%) -

Flash Point (

0

C) -

Wax Content ( wt. %) - Dispersable for vise. < 2000 

Poorly dispersable for vise. > 7000 

Maximum water uptake(%) at 5°C/13°C 80 

Data missing 

True boiling point curve Film thickness {mm) 

Temperature Cumulative 

(OC) volume 

Initial I 20 

Terminal I 2 

(%) 

90 10.62 

120 16.74 

145 21.48 

160 24.23 

205 32.29 

250 40.62 

295 50.27 

350 61.09 

420 70.84 

565 89.12 

Weathering properties (laboratory data) 

Fresh 150°C+ 200°C+ 250°C+ 

Boiling temperature (°C) - 185 250 303 

Volume topped(%) 0 16 28 39 

Residue (wt%) l00 86 76 65 

Specific gravity (g/1) 0.847 0.877 0.892 0.907 

Pour point (

0C) -3 6 15 18 

Flash point (

0C) - 38 80 119 

Viscosity at 13°C (cP)* 10 25 65 350 

Viscosity of 50% emulsion ( cP)* - 190 480 2800 

Viscosity of75% emulsion (cP)* - 1400 2600 6300 

Viscosity of max water ( cP)* - 950 10000 14000 

Maximum water content (%) - 80 80 78 

Halftime for water uptake (hrs) - 0.13 0.1 0.18 

Stability ratio - 0,79 0.705 1 

Not measured .. Viscosity measured at shear rate 10s·1 

• 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
~SINTEF 14 

3 MIZ-1993 

3.1 The field experiments 

An experimental oil spill in the Barents Sea marginal ice zone (MIZ) was performed in the last 

part of April 1993. 26 m

3 of Sture blend was released approximately 45 km inside the ice edge at 

an ice concentration of approximately 90%. During a 7 day period of sampling and analysis of the 

surface oil/emulsion, the slick drifted to a position approximately 6 km from the ice edge, and the 

ice concentration varied from 70-90%. The dominant wind direction was from the ice towards 

open water, and the wave energy conditions were relatively low most of the time. The wind speed 

was 6-10 mis and the temperature - l 6-0°C. 

Objectives 

The intention of the experimental oil spill in the marginal ice zone was to contribute further to 

existing knowledge about the behaviour of oil under Arctic conditions and to acquire knowledge 

about the specific conditions (wind, waves, ice conditions, drift and spreading) in the marginal ice 

zone. 

Conclusions 

Measurements performed during the MIZ experimental oil spill showed that oil spilled in ice will 

have a relatively high oil film thickness (often in cm-range) compared to oil spills in open waters 

(maximum I to 4 mm). The measured film thickness in the MIZ experiment ranged from 5-120 

mm of emulsion. This is caused by a reduced spreading due to the presence of ice. The ice acted 

as a barrier and prevented spreading, especially at high ice concentrations. As a result of the high 

oil film thickness combined with low temperatures, the evaporation of the light components in the 

oil was low compared to experimental oil spills in open waters. The emulsification was low. 

Prediction of evaporation, water uptake and emulsion viscosity for oil in ice (90% ice coverage), 

oil in open waters and field data from the MIZ-experiment is shown in Figure 3.1 , Figure 3.2 and 

Figure 3.3 respectively. 

Property: Evaporation 

Temperalure . o•c 

Wind Speed (m/s): 8 

lmlia1 film thickness (mm) 8 (1n 1cc) and 20 {open waters) 

Terminal oil film thickness (mm) : 8 (1n ice) and 1 (open walers) 

100 

90 I 

80 

70 

C: 60 

I 

I 0 

:, 

E 50 I 

0 

C. 

<'O 40 > I ' UJ 30 

20 

10 

---==::::::: 

---A 

-

I 

I 

I 

• 0 

0,25 0,5 2 3 

Hours 

6 9 12 

~SINTEF 

2.0 C 2002 

Pred. Dato November 25, 2003 

- & 

A • • 

2 3 4 5 

Days 

Figure 3.1 Predicted evaporation and field data Sture blend MIZ 1993. 

l:\Cll661 I 89 MMS OWM Phases II and 111\Task 7\Final report.doc 

• Field data 

- 90% Ice coverage 

- Slure in open waters 
~SINTEF 

Property: Water uptake 

Temperature o•c 

Wind Speed (mis): 8 

Initial film thickness (mm) : 8 (in ice) and 20 (open waters) 

Terminal oil film thickness (mm) 8 (in ice) and 1 (open waters) 

100 

90 

80 

70 

c 60 ., 

E 

0 50 

/ 

/ u 

40 .. 

;: 30 

20 

10 

/ 

/ 

0 - 0,25 0,5 3 6 

Hours 

SINTEF 

20 0 2002 

Pred Dato November 25, 2003 

4 4 

- - - - 9 12 2 3 4 5 

Days 

Figure 3.2 : Predicted water uptake and field data Sture blend MIZ 1993. 

Property: Emulsion viscosity 

Temperature o•c 

Wind Speed (mis) 8 

lnibal film tl11ckness (mm) 8 (in ice) and 20 (open waters) 

Terminal ocl film thickness (mm) 8 (1n ice) and 1 (open waters) 

100000 

a:-

Ill 

0 

u 

1/1 

·;; 

C: 

.2 

Ill 

"5 

E 

w 100 

10 

0,25 0,5 3 

Hours 

SINTEF 

20 0 2002 

Pred Dato November 25, 2003 

6 9 12 2 3 4 5 

Days 

Figure 3.3 : Predicted emulsion viscosity and field data Sture blend MIZ I 993. 

l·ICH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 

15 

... Field data 

- 90% ice coverage 

- Sture 1n open waters 

... Field data 

- 90% ,ce coverage 

- Sture in open wa1ers 
~SINTEF 16 

3.2 Field and input data MIZ 1993 

The data from samples taken of the oil slick is given in the tables described here. 

Table 3.1 : Field data Sture blend MIZ 1993. 

Table 3.2: Input data for weathering predictions ofSture blends behaviour at sea. 

l:ICH661189 MMS OWM Phases II and 111\Task 7\Final rcportdoc 
G)SINTEF 17 

Table 3.1 : Field data Sture blend MIZ 1993. 

Viscosity 

Water (cP) at Interfacial 

Time content 100s"1 Density Density Evaporation Evaporation Pour tension 

(Days) (%) 0-6°C (kg/L) (kg/L) (Vol%) (Vol%) point (mN/m) Dispersibility 

(based on (based on 

emulsion emulsion Oil/residue density)) GC) 

Crude oil 0 0 32 0,847 0 0 -3 27,5 Good 

Crude oil 0 0 33 0,847 0 7 Good 

Thick oil 0,17 0 62 0,872 8 12 6 18,4 Good 

Oilfilm 0,33 0 150 0,872 13 17 0 19,2 Good 

Emulsion 0,71 0 97 0,928 0,88 17 18 Good 

Thick oil 3 0 105 0,89 24 19 12 11,2 Good 

Thick oil 4 7 68 0,908 0,882 19 14 12 6,7 Good 

Thick oil 5 12 255 0,903 0,887 21 21 12 5,3 Good 

Thick oil 5,2 1 240 0,895 0,885 20 22 Good 

Thin oil 6 6 300 0,895 0,89 24 23 Good 

Thick oil 7 20 680 0,912 0,893 25 24 12 3,3 Good/reduced 

l:\Cl-1661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
~SINTEF 18 

Table 3.2: Input data for weathering predictions of Sture blends behaviour at sea. 

Fresh oil properties 

Specific Gravity (60 F/60 F) 0.847 

Pour Point (

0C) -3 

Reference temperature # 1 (0C) 13 

Viscosity at ref. temp.# 1 (cP) 10 

Vanadium (ppm wt.) -

Nickel (ppm wt.) -

Asphaltenes (wt.%) - n-Pentane Insolubles (wt.%) -

Flash Point (

0

C) - Wax Content (wt. %) - Dispersable for vise. < 2000 

Poorly dispersable for vise. > 9000 

Maximum water uptake(%) at 5°C/13°C 80 

Data missing 

True boiling point curve Film thickness (mm) 

Temperature Cumulative Initial I 8 

(OC) volume Tenninal I 8 

(%) 

90 10.62 

120 16.74 

145 21.48 

160 24.23 

205 32.29 

250 40.62 

295 50.27 

350 61.09 

420 70.84 

565 89.12 

Weathering properties (laboratory data) 

Fresh 150°C+ 200°C+ 250°C+ 

Boiling temperature (°C) - 185 250 303 

Volume topped(%) 0 16 28 39 

Residue (wt%) 100 86 76 65 

Specific gravity (g/1) 0.847 0.877 0.892 0.907 

Pour point (

0C) -3 6 15 18 

Flash point (

0C) - 38 80 119 

Viscosity at 13 °C ( cP)* 10 25 65 350 

Viscosity of50% emulsion (cP)* - 190 480 2800 

Viscosity of75% emulsion (cP)* - 1400 2600 6300 

Viscosity of max water ( cP)* - 950 10000 14000 

Maximum water content (%) - 80 80 78 

Halftime for water uptake (hrs) - 0.13 0.1 0.18 

Stability ratio - 0,79 0.705 1 

Not measured 

* · Viscosity measured at shear rate Jos-1

• 

l:\CH66 l l 89 MMS OWM Phases II and 111\Task 7\Final report.doc 
~SINTEF 19 

4 NOFO exercise 1994 

4.1 The field experiments 

The NOFO oil-on-water exercise 1994 was Phase 1 of a series of 3 field trials. Phase 1 included 

two surface releases and treatment with dispersant. The experiments were performed at the Frigg 

field in June 1994. 

Objectives 

The main objectives of the field trials were: 

To verify laboratory studies on the rate of weathering ( evaporation, natural dispersion and 

emulsification) of Sture Blend crude oil and determine the extent of changes in these 

processes caused by the application of dispersant. 

To assess quantitatively the effectiveness of aerially applied dispersant by following the fate 

and weathering properties of two slicks of partially weathered North Sea crude oil (one treated 

and one control slick). 

To define the operational parameters required for practical dispersant treatment strategies. 

To provide a realistic training scenario for oil spill combat personnel. 

Releases 

Two slicks, each of20 m3 fresh, stabilized Sture Blend crude were released about 1 nautic mile 

(nm) apart. The oil were pumped gently on the sea surface by using the Transrec system (leading 

to a generally lower starting film thickness compared to the e.g. 1989-Haltenbanken experiment). 

One slick, called Tango, was treated with the dispersant Corexit 9500 from a S6 l-N helicopter 

with a Rotor tech TC-3 underslung bucket after 3 hours weathering of the oil at sea. A reapplication of dispersant on the same slick was performed after totally 7 hours weathering of the 

oil. The Tango slick disappeared totally from the sea surface and dispersed into the water column 

within 12 hours at sea. 

The other slick, Charlie, was used as control slick the first day. The second day, about 29 hours 

after the oil had been released, and after the Tango slick had disappeared, the Charlie slick was 

treated with Corexit 9500. Soon after this treatment, the slick dispersed into the water column. 

Conclusions 

The main conclusions from the field experiments were: 

The Sture Blend lost about 45 vol.% of its volume due to evaporation and reached a 

viscosity of approximately 9000 cP (at shear rate 10 s·1) within 28 hours at sea. The water 

content in the emulsions was 75-80%. 

The weathering predictions (evaporation and emulsification) of the Sture Blend crude (from 

1993) proceeded similarly to what was observed in the Haltenbanken trial in 1989 with the 

Sture Blend (from 1989). 

The dispersant applications resulted in decreased emulsion water content and decreased 

emulsion viscosity. The oil/emulsion disappeared totally into the water column. 

The quality of the data are good and gave valuable input to the IKU Oil Weathering Model and 

formed basis for further refinements and verifications of the algorithms in the model. 

Further details from the field experiments are described in Lewis et al., 1995 and Str0mKristiansen and Daling, 1994. 

I:\CH661189 MMS OWM Phases II and 111\Task 7\Final repon.doc 
~SINTEF 20 

Data from the Charlie slick and from Tango slick before dispersant treatment is presented in this 

report. Predicted evaporation, water uptake and emulsion viscosity from SINTEF OWM is 

presented together with field data in Figure 4.1 , Figure 4.2 and Figure 4.3, respectively. 

Property: Evaporation 

Temperature ("C) : 10 

Wind Speed (mis) 7,5 - 10 

Initial film thickness (mm) · 10 

Termianl film thickness (mm) 1 

100 

90 

80 

70 

0 

60 C: 

50 

I! 

0 40 Q. 

"' > 

w 30 

20 

10 L---"A 

0 

0,25 0,5 

I 

I 

------ • 

2 3 

Hours 

~SINTEF 

20 0 2002 

Pred Dato Apnl 30, 2003 

I I 

I I 

I 

I 

I 

I 

; 

I ... 

. "' 

I t i 

I 

6 9 12 2 3 4 5 

Days 

Figure 4.1 : Predicted evaporation and field data, Stu re blend 1994. 

Property: Water content 

Temperature ("C) : 10 

Wind Speed (mis): 7,5 - 10 

ln1uaI film thickness (mm) 10 

Terrmnal film thickness (mm) · 1 

100 

90 

80 

-C: 60 

.! 

C: 

0 50 u 

a, 40 

iu 

;: 30 

10 

0 

0,25 0,5 2 

Hours 

SINTEF 

200 2002 

Pred Dato: Aptil 30, 2003 

3 6 9 12 2 3 4 5 

Days 

Figure 4.2 : Predicted water uptake and field dala, Sture blend 1994. 

l:\Cll66 I 189 MMS O WM Phases II and 111\Task 7\Final report.doc 

- Sture 1994 

... Field data ChM1e 

• Field data Tango 

- Sture 1994 

... Field data Charlie 

• Field data Tango 
SINTEF 

Property: Emulsion viscosity Temperature ("C) · 10 

Wind Speed (mis): 7,5. 10 

Initial film thickness (mm) . 10 

Terminal film th1clmess (mm) 1 

100000 

10000 

"' 0 

.., 

·; "' 1000 

C: 

0 

.; 

:i 

E 

w 100 

10 

0,25 0,5 2 

Hours 

SINTEF 

2.0 Q 2002 

Pred Dato Apnl 30, 2003 

3 6 9 12 2 3 4 5 

Days 

Figure 4.3 : Predicted emulsion viscosity and field data Sture blend /994. 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final rcpon.doc 

- Sture 1994 

.I. Field data Charlie 

• Field data Tango 

21 
(j SINTEF 22 

4.2 Field and input data 1994 

The data from samples taken of the oil slick are given in the tables described here. 

Table 4.1: Physico-chemical properties on waterfree residues o/Sture Blend and their water-inoil emulsions from the control slick (Charlie) in the North Sea field trial in June 1994 (-: not 

performed, GC: gas chromatography, WOR is water-to-oil ratio, IFT is interfacial tension, Dis 

fractional dehydration of emulsion). 

Table 4.2: Physico-chemica/ properties on water-free residues o/Sture Blend and their water-inoil emulsions from the treated slick (Tango) in the North Sea field trial in June 1994 (-: not 

performed, GC: gas chromatography, WOR is water-to-oil ratio, IFT is interfacial tension, D is 

fractional dehydration of emulsion). 

Table 4.3: Wind conditions at June 1994 Friggfield trial. 

Table 4.4: Input data/or weathering predictions o/Sture blends behaviour at sea. 

l:\CH661189 MMS OWM Phases II and III\Task 7\Final report.doc 
(j SINTEF 23 

Table 4. 1 : Physico-chemical properties on waterfree residues of Sture Blend and their water-in-oil emulsions from the control slick (Charlie) in the North Sea 

field trial in June 1994 (-: not performed, GC: gas chromatography, WOR is water-to-oil ratio, /FT is interfacial tension, D is fractional 

dehydration of emulsion). 

Charlie Weathering Pour point Flash point IFT 

sampling time Evaporation (wt.%) water-free water-free water-free Emulsion water content Emulsion 

station residue residue residue dispersibility 

(Hours) Density• GC (OC) (OC) (mN/m) (vol.%) (WOR) 

Fresh 0 0 0 0 - 24 0 

Cl 0.2 4.6 - - 22 - 55 1.2 - C2 0.7 14.7 - - 36 - 71 2.5 - CJ I.I 20.3 19.8 15 58 19 69 2.2 Good 

cs 3.1 24.6 - 18 90 - 75 3.0 Good 

C6 6.5 30.3 - 21 - - 78 3.5 - cs 13.3 33.1 32.7 24 - 7 81 4.3 Reduced/bad 

Cll 27.7 47.9 43.2 - - 3** 66 1.9 Bad 

Charlie Viscosity (cP) Density (e/mL) Effect of Emulsion 

sampling Haake Rotovisco RV20 Bohlin 888V Emulsion stability Alcopol 060% film 

station Water-free Emulsion Emulsion Emulsion Water-free on emulsion thickness 

residue residue 

Dth D3h Dz4h Dt0d (DAie) (mm)• 

(IOOs-1) (lOs-1) (tos-1) 

Fresh 10 0.846 

CI 21 ± I - 75 0.949 0.857 1.0 1.0 1.0 1.0 - 12.9 

C2 82± 5 123 271 ± 162 0.981 0.875 0.9 1.0 1.0 1.0 1.0 3.5 ± 1.4 

CJ 113 297±4 845 0.981 0.884 0.3 1.0 1.0 1.0 1.0 1.8 ± 0.2 

cs 190 638 ± 171 1410 ± 85 0.991 0.892 0.0 0.3 0.3 - 1.0 1.9 ± 0.7 

C6 356± 27 3333 ± 197 4130 0.996 0.901 0.0 0.0 0.0 - 0.7 I.I± 0.2 

cs 554 ± 78 4159 ± 199 5010 ± 255 1.002 0.906 0.0 0.0 0.0 0.5 0.8 - Cll - 9023 12400 0.993 0.931 0.0 0.0 0.0 0.0 - 0.1 ± 0.02 

* · Based on predictions of oil density assuming zero water uptake. ** : Very difficult to measure. •: Based on pad extraction. 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
(iSINTEF 24 

Table 4.2 : Physico-chemical properties on water-free residues of Sture Blend and their water-in-oil emulsions from the treated slick (Tango) in the North Sea 

field trial in June 1994 (-: not performed, GC: gas chromatography, WOR is water-to-oil ratio, /FT is interfacial tension, D is fractional 

dehydration of emulsion). 

Tan20 Weathering Pour point Flash point IFT 

sampling time Evaporation (wt.%) water-free water-free water-free Emulsion water content 

station residue residue residue 

(Hours) Density* GC (OC) (OC) (mN/m) (vol.%) (WOR) 

Fresh 0 0 0 - - 24 0 

T2 1.0 17.6 - - - - 57 1.4 

T3 1.9 23.8 23.6 - - - 76 3.2 

T4 3.3 22.0 - - - 16 75 2.9 

TS •• 3.8 24.2 - - - 11 63 1.7 

T7 5.3 25.4 - - - - 71 2.5 

TS 7.5 28.6 - - - 4 73 2.7 

T9 ••• 7.9 28.9 26.7 - - •••• 49 1.0 

Tane:o Viscosity (cP) Density (e/mL) Effect of 

sampling Haake Rotovisco RV20 Bohlin 888V Emulsion stability Alcopol 060% 

station Water-free Emulsion Emulsion Emulsion Water-free on emulsion 

residue residue 

Dth D3hD24h (DAie) 

(t0os-1) (tos-1) (tOs-1) 

Fresh 10 0.846 

T2 64±7 - 602 ± 187 0.963 0.880 1.01.0 1.0 - T3 142±4 840± 57 1415 ± 148 0.992 0.890 0.20.7 0.8 1.0 

T4 181 ± 11 1207 ± 164 1960 0.989 0.887 0.00.0 0.1 1.0 

TS •• 273 ± 68 1177 ± 324 1975 ± 148 0.975 0.891 0.00.0 0.0 0.9 

T7 277± 77 1838 ± 190 2500 ± 127 0.986 0.893 0.00.0 0.0 0.7 

TS 342± 85 2813 ± 149 3595 ± 318 0.990 0.899 0.00.0 0.0 0.4 

T9 *** 374±64 892 ± 15 744± 119 0.961 0.899 0.01.0 1.0 0.8 

*· 

•••• 

Based on predictions of oil density assuming zero water uptake. ••: After Isl treatment•••: After 2nd treatment 

Impossible to measure •: Based on pad extraction. 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 

Emulsion 

dispersibility 

Good 

-

Good 

Good 

- Good/reduced 

Good 

Emulsion 

film 

thickness 

(mm)• 

1.4± 0.7 

2.7 ± 1.4 

1.9 ± 0.2 

1.8 ± 0.9 

2.4 

1.9 

-
{j SINTEF 25 

Table 4.3: Wind conditions at June 1994 Friggfield trial. 

Start date: 07.06.1994 

Cum. time Wind speed Direction 

(h) (mis) (0) 

0 8,2 245 

4 9,8 255 

8 8 243 

12 8,2 230 

16 8,2 250 

20 8 260 

24 7,5 270 

28 8 290 

32 8 290 

120 8 290 

I:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
(iSINTEF 26 

Table 4.4 : Input data for weathering predictions of Sture blends behaviour at sea. 

Fresh oil properties 

Specific Gravity (60 F/60 F) 0.847 

Pour Point (

0

C) -3 

Reference temperature # 1 {0C) 13 

Viscosity at ref. temp.#1 (cP) 10 

Vanadium (ppm wt.) -

Nickel (ppm wt.) -

Asphaltenes (wt.%) - n-Pentane Insolubles (wt.%) -

Flash Point {

0

C) - Wax Content ( wt. %) - Dispersable for vise. < 2000 

Poorly dispersable for vise. > 9000 

Maximum water uptake(%) at 5°C/13°C - Data missing 

True boiling point curve Film thickness (mm) 

Temperature Cumulative Initial I 10 

(OC) volume Terminal I 1 

(%) 

90 10.62 

120 16.74 

145 21.48 

160 24.23 

205 32.29 

250 40.62 

295 50.27 

350 61.09 

420 70.84 

565 89.12 

Weathering properties (laboratory data) 

Fresh 150°C+ 200°C+ 250°C+ 

Boiling temperature (°C) - 185 250 303 

Volume topped(%) 0 16 28 39 

Residue (wt%) 100 86 76 65 

Specific gravity {g/1) 0.847 0.877 0.892 0.907 

Pour point {

0

C) 0 9 18 21 

Flash point (

0

C) - 38 80 119 

Viscosity at l 3°C ( cP)* 10 25 65 350 

Viscosity of50% emulsion (cP)* - 190 480 2800 

Viscosity of75% emulsion (cP)* - - 2600 6300 

Viscosity of max water ( cP)* - - - - Maximum water content (%) - 80 80 78 

Halftime for water uptake (hrs) - 0.13 0.1 0.18 

Stability ratio - 0.2 0.705 1 

Not measured 

• · Viscosity measured at shear rate /Os·'. 

l:\CH66l 189 MMS OWM Phases II and 111\Task 7\Final report.doc 
{(j SINTEF 27 

5 NOFO exercise 1995 

5.1 The field experiments 

The NOFO oil-water exercise 1995 included totally four surface releases and one sub-surface 

releases of stabilized Troll crude oil. The experiments were performed at the Frigg field in August 

1995. The slicks were followed for about 0.5 - 2 days. 

Objectives 

The main objectives of the dispersant and underwater release activities at the Frigg field during 

the NOFO 1995 oil on water exercise were: 

To study the behavior, rate of spreading and weathering (evaporation, emulsification, natural 

dispersion etc.) of crude oil slicks released both from surface and sub-surface (107 meters 

depth simulating sub-sea pipeline leakage). 

To support valuable input data to the IKU Oil Weathering Model. These data will form basis 

for further refinements of the algorithms in the model. 

To assess the effectiveness of different methods of applying dispersant concentrates on oil 

slicks (from boat and helicopter). 

To study the capability of satellite-tracked drifting buoys to simulate the drift of surface and 

dispersed oil under various environmental conditions. 

To calibrate aerial remote sensing sensors (in aircraft, helicopter, and satellites) with ground 

truth data of the surface oil slicks. 

Surface releases (day 1) 

Three surface release slicks, each of 15 m3 (Release rate: 1 m3 / min) of stabilized Troll crude oil, 

were released about 1 nm apart: 

One slick (designated Hotel), was treated with Corexit 9500 from a S61-N helicopter using 

a SOKAF 3000 underslung bucket after 2 hours weathering of the oil at sea. The thick 

emulsion of the Hotel slick totally disappeared from the sea surface and was dispersed into the 

water column just after the dispersant application, and only sheen was left behind. 

The other slick, ( designated Bravo), was treated with Corexit 9500 from the response vessel 

Gullbas using the Clearspray system, after 2 hours weathering. The treatment caused the 

Bravo emulsion initially to lose water before the thick part of it gradually dispersed into the 

water column. 

The third slick, (Charlie), was used as a control slick. 

Results from the Charlie slick are presented in this report. 

Sub-surface release (day 2) 

Two slicks, each of 25 m3 of stabilized Troll crude oil, were released about 1 nm apart: 

One slick, designated Uniform, was released by pumping the oil from 106 m depth. The oil 

was released without any gas present and resulted in a 2 to 5 mm thick surface slick of 

emulsion. No data are reported from this experiment due to very limited sampling. 

The other slick, Sierra, was a surface release and was used as a control for the Uniform 

slick. 

Conclusions 

The main conclusions from the 1995 NOFO sea trial were: 

I:\CH661189 MMS OWM Phases II and III\Task 7\Final report.doc 
~SINTEF 28 

A modern dispersant, correctly applied with a helicopter bucket or with spray arms from a 

ship, within the oils "window of opportunity" for dispersant use, is capable of dispersing the 

th ick oil completely, within 10-30 minutes. 

No significant w/o-emulsification, of the oil in the underwater plume was observed, 

probably due to the low release pressure and that no gas was released with the oil (this was 

simulating a pipeline leakage). 

The weather conditions were rougher during the Phase I trial with 8 to 10 m/s wind compared to 

Phase 2, where the wind speed varied between 7 and 4 m/s wind on Day 1 and 6 and 2 m/s on Day 

2. 

A more entire overview of the total field trial is given in The Operation Plan (Brandvik et al., 

1995-a), the Cruise Report (Jensen et al., 1995) and the main technical report (Brandvik et al., 

1995-b ). The analyses data are presented in Str0m-Kristiansen et al., 1995. 

Predicted evaporation, water uptake and emulsion viscosity from SINTEF OWM is presented 

together with field data for the Charlie and Sierra slicks in Figure 5.1, Figure 5.2 and Figure 5.3, 

respectively. The observed water content and emulsion viscosity of the Sierra slick was lower 

than for the Charlie slick. The Sierra emu lsions taken during the first hour were very unstable, and 

both the water content and viscosity was probably under-estimated. The weather conditions were 

calmer during the Sierra release (2-6 m/s wind). The deviation in the viscosity from the OWM 

may be explained by that the majority ofoffshore field experiments which the development of the 

empirical algorithms are based on, have been performed under moderate to rough weather 

conditions (typical 6-15 m/s wind). Another explanation may also be due to that the input to the 

model are based on emulsion prepared in the laboratory (using the rotating flasks) that are 

simulating a more higher energy level. 

Property: Evaporation 

TemperaIure ('C) : 15 

Wind Speed (m/s): Wind file 

Initial film lh1ckness (mm) . 10 

Terminal film lhickness (mm) 1 

100 

90 

80 

70 

I 

I 

0 

60 

C: 

0 50 

0 40 a. 

I 

I .. 

> 

w 30 

20 I 

10 

0 ' - • A -

0,25 0,5 

I 

I 

I 

• 

I 

I 

I . 

2 3 

Hours 

I 

I 

I 

I 

I 

I 

& 

6 9 12 

SINTEF 2.o c 2002 

Pred DaI0· Apnl 30, 2003 

I 

I 

I 

I 

I I 

I 

_;--

2 3 4 5 

Days 

Troll Charlie 1995 

- Troll Sierra 1995 

4 Field dala Charlie 

4 F 1eld daIa Sierra 

Figure 5.1 : Predicted evaporation and field data Troll crude oil, Charlie and Sierra I 995. 

l:\Cll66 I I 89 MMS OWM Phases II and II !\Task 7\Final rcpon.doc 
SINTEF 

Property: Water content 

Temperature ("C) · 15 

Wind Speed (mis): Wind file 

lnioal film thickness (mm) 10 

Tennmal film thickness (mm) 1 

100 

90 

80 

l 70 

"E 60 ., 

"E 50 0 

u 

., 40 iii 

30 

20 

10 

A 

0 

0,25 0,5 2 

Hours 

3 

29 

SINTEF 200 2002 

Pred Dato Apnl 30, 2003 

- Troll Chartie 1995 

- Troll Sierra 1995 

• Field data Charlie 

• Field data Sierra 

6 9 12 2 3 4 5 

Days 

Figure 5.2 : Predicted water content and field data Troll crude oil, Charlie and Sierra 1995. 

Property: Emulsion viscosity 

Temperature ("C) 15 

Wind Speed (mis): Wind file 

Initial film thickness (mm) · 10 

Tenmnal film thickness (mm) 1 

a:-

; 1000 !-----------.~ 

'iii 

0 

u 

·;; "' 

C: 

.!2 

3 "' 100 

E 

w 

SINTEF 2.0 0 2002 

Pred Dato April 30, 2003 

10 _._ ___________ ____ ____________ _, 

0,25 0,5 3 6 9 12 3 4 5 

Hours Days 

- Troll Chart1e 1995 

- Troll Sierra 1995 

• Field data Chart1e 

• Field data Sierra 

Figure 5. 3 : Predicted water content and field data Troll crude oil, Charlie and Sierra 1995. 

l:ICH66I 189 MMS OWM Phases II and 111\Task 7\Final rcpon.doc 
G) SINTEF 30 

5.2 Field and input data 1995 

The data from samples taken of the oil slick is given in the tables described here. 

Table 5.1: Physico-chemical properties on waterfree residues of Troll crude and their water-inoil emulsions from the control slick Day 1 (Charlie) in the North Sea field trial in August 1995. 

Table 5.2 : Physico-chemical properties on waterfree residues of Troll crude and their water-inoil emulsions from the control slick Day 2 (Sierra) in the North Seafield trial in August 1995. 

Table 5.3: Wind conditions at August 1995 Friggjield trial. Charlie slick. 

Table 5.4 : Wind conditions at August 1995 Friggfield trial. Sierra slick. 

Table 5.5: Input data/or weathering predictions o/Troll crude oil behaviour at sea. 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
~SINTEF 31 

Table 5.1: Physico-chemical properties on waterfree residues of Troll crude and their water-in-oil emulsions from the control slick Day 1 (Charlie) in the 

North Seafield trial in August 1995. 

W lo emulsion properties 

Stability **Emul brea. en: 

Sampling Weath. time Water cont. Density Viscosity Shear rate Dispers- *D,h *D24h *D,h 

station (hours) (vol.%) (2'mL) (cP) cs·') ibility 

co 0 0 0.886 - - Good - - - Cl 0.25 5 0.903 56± 14 20 - - - - C2 0.5 29 0.935 •40±6 20 - 0.35 0.59 0.40 

CJ 1.0 66 0.983 405 ± 92 20 - 0.15 0.79 0.87 

C4 2.2 57 0.974 699± I 8 Good 0.24 0.51 1.00 

C5 3.8 59 0.977 805 ± 76 8 Good 0.01 0.14 0.89 

C6 7.3 74 0.996 3435 ± 64 8 Red. disp. 0.01 0.16 0.73 

C7 11.6 78 1.000 3280 ± 127 8 Red. diso. 0.00 0.01 - C9 25.0 73 0.995 5430 ± 339 8 Bad diso. 0.00 - 0.57 

ClO 33.5 77 1.001 5320 8 - 0.00 0.Ql 0.83 

Waterfree residue properties 

Sampling Weath. time Evap. loss Density Viscosity Pour point Flash point Interf. tension 

station (hours) (wt.%) (21ml) (cP, 100 s·1

) (OC) (OC) (mN/m) 

co 0 0 0.886 21 -39 - 10.4 

Cl 0.25 3.0 0.897 42 - 34 - C2 0.5 3.7 0.898 40 - 42 - C3 l.0 7.4 0.902 64 -21 64 - C4 2.2 12.4 0.908 83 -14 116 0.8 

C5 3.8 13.3 0.909 99 - 125 - C6 7.3 17.2 0.914 168 -6 - 0.6 

C7 11.6 17.7 0.914 193 - - - C9 25.0 19.4 0.916 217 -3 - 0.4 

ClO 33.5 24.7 0.923 200 - - 0.3 

Nol performed 

*· 

**· 

•: 

Dis fractional dehydration of emulsion. D1h is effect after I hour, Duh is effect after 24 hours. D=0: no waler sellled D=: I all waler seuled 

Effect of 500 ppm concentration of the emulsion breaker Alcopol 060%, relative to the oil volume. 

••: 

·••: 

··••: 

Unstable emulsion that was broken during measurement. 

Pad sample gave 38 μm emulsion film thickness (in JR "black" area,flnish aircraft, lewis, J995). 

Pad sample and cylinder measurement are not comparable values; taken in different parts of the slick. 

Pos. B 26 μm (JR "black" area, German aircraft, lewis, 1995), pos. C 9 μm (UV area, German aircraft, lewis, J995). 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 

*D24h 

-

-

0.77 

0.88 

1.00 

0.96 

0.93 

0.41 

0.76 

0.89 

Film thickness (mm) 

Pad In-situ 

- - - 10.3 ±4.2 

- 6.0 ± l.4 

2.2 ± 0.2 3.5 ±0.7 

--1.2 ± 0.1 5.0 ± 1.7 

... 1.0 ± 1.3 8.5 ± 2.1 

- 10.0 ± 2.8 

.... 2.1 ± 0.4 7.5 + 2.4 

- 10.0 

- 6.3 ± 3.1 
G)SINTEF 32 

Table 5.2 : Physico-chemical properties on water.free residues of Troll crude and their water-in-oil emulsions from the control slick Day 2 (Sierra) in the North 

Sea field trial in August 1995. 

W/o emulsion properties 

Stability **Emul brea. etT. Film thickness (mm) 

Sampling Weath. time Water cont. Density Viscosity Shear rate Dispers- *D1h *D24h *D1h *D24h Pad In-situ 

station (hours) (vol.%) (wmL) (cP) (s-•) ibility 

so 0 0 0.886 - - Good - - - - - - SI 0.4 0 0.898 •15 ±2 20 - - - - - - 5.8 ± 1.8 

S2 0.7 4 0.904 •21 ±2 20 - 0.00 1.00 1.00 1.00 - 6.8±2.8 

SJ 0.9 2 0.903 •29 20 - 0.00 0.63 - - - 4.8 ± 1.6 

S4 3.1 26 0.938 123 ±9 8 - 0.00 0.62 1.00 1.00 4.5 ± 1.4 6.3 ± 3.2 

S6 7.2 37 0.951 126±4 8 - 0.00 1.00 0.91 1.00 1.9 ± 0.4 3.4 ± 1.7 

Waterfree residue properties 

Sampling Weath. time Evap. loss Density Viscosity Pour point Flash point 

station (hours) (wt.%) (1!/ml) (cP, 100 s"1

) (OC) (OC) 

so 0 0 0.886 21 -39 - SI 0.4 3.6 0.898 41 - - S2 0.7 4.1 0.899 42 - 38 

SJ 0.9 6.0 0.901 55 -27 52 

S4 3.1 11.9 0.908 80 -18 110 

S6 7.2 12.5 0.908 105 -12 119 

Not performed. 

•: Unstable emulsion that was broken during measurement. 

*· 

**· 

Dis fractional dehydration of emulsion. D1h is effect after 1 hour, D2-1h is effect after 24 hours. D=0: no water settled. D=: 1 all water settled. 

Effect of500 ppm concentration of the emulsion breaker Alcopol 060%, relative to the oil volume. 

I:\CH661 t 89 MMS OWM Phases II and 111\Task 7\Final report.doc 
(j SINTEF 33 

Table 5.3: Wind conditions at August 1995 Friggfield trial. Charlie slick. 

Cum. time Wind Direction Cum. time Wind Direction 

(houn) (mis) (0) (houn) (mis) (0) 

•o.o 6.5 274 22.0 6.1 222 

0.5 5.9 281 22.5 6.1 248 

1.0 6.4 267 23.0 7.0 248 

1.5 6.5 314 23.5 7.0 267 

2.0 7.0 268 24.0 7.0 290 

2.5 6.8 274 24.5 6.6 259 

3.0 6.2 263 25.0 7.5 267 

3.5 7.2 270 25.5 7.0 281 

4.0 7.0 270 26.0 7.5 284 

4.5 7.5 253 26.5 7.5 321 

5.0 7.5 143 27.0 5.6 276 

5.5 7.0 262 27.5 5.6 281 

6.0 7.5 278 28.0 5.2 278 

6.5 6.6 276 28.5 5.6 270 

7.0 6.6 253 29.0 6.1 284 

7.5 5.6 287 29.5 5.6 262 

8.0 5.2 250 30.0 5.6 298 

8.5 4.7 262 30.5 5.6 278 

9.0 6.1 250 31.0 5.2 276 

9.5 5.6 284 31.5 4.7 270 

10.0 5.6 259 32.0 4.7 290 

10.5 5.6 245 32.5 4.2 270 

11.0 5.6 242 33.0 3.8 287 

11.5 5.6 262 33.5 3.3 278 

12.0 5.2 250 34.0 2.3 264 

12.5 5.2 264 34.5 1.4 256 

13.0 4.7 253 35.0 2.3 256 

13.5 4.7 245 35.5 2.3 222 

14.0 4.7 253 36.0 2.8 236 

14.5 4.2 231 36.5 2.8 219 

15.0 4.7 233 37.0 3.3 203 

15.5 5.2 233 37.5 3.3 200 

16.0 5.2 208 38.0 3.3 208 

16.5 6.1 208 38.5 3.8 228 

17.0 6.1 222 39.0 2.8 208 

17.5 6.6 233 39.5 3.3 222 

18.0 7.0 200 40.0 2.8 203 

18.5 7.5 208 40.5 3.3 191 

19.0 8.0 312 41.0 3.3 197 

19.5 7.5 214 41.5 2.8 214 

20.0 7.0 236 42.0 2.3 217 

20.5 7.5 225 42.5 1.9 219 

21.0 7.0 270 43.0 2.3 211 

21.5 6.1 239 43.5 2.3 200 

120.0 2.3 200 

*· Start time is 0630 15th August 1995. 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
~SINTEF 34 

Table 5.4 : Wind conditions at August 1995 Friggfield trial. Sierra slick 

Cum. time Wind Direction Cum. time Wind Direction 

(hours) (mis) (0) (hours) (mis) (0) 

*0.0 5.6 270 8.0 2.8 219 

0.5 6.1 284 8.5 3.3 203 

1.0 5.6 262 9.0 3.3 200 

1.5 5.6 298 9.5 3.3 208 

2.0 5.6 278 10.0 3.8 228 

2.5 5.2 276 10.5 2.8 208 

3.0 4.7 270 11.0 3.3 222 

3.5 4.7 290 11.5 2.8 203 

4.0 4.2 270 12.0 3.3 191 

4.5 3.8 287 12.5 3.3 197 

5.0 3.3 278 13.0 2.8 214 

5.5 2.3 264 13.5 2.3 217 

6.0 1.4 256 14.0 1.9 219 

6.5 2.3 256 14.5 2.3 211 

7.0 2.3 222 15.0 2.3 200 

7.5 2.8 236 120.0 2.3 200 

*· Start time is J 1°0 16h August 1995. 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
~SINTEF 35 

Table 5.5: Input data for weathering predictions of Troll crude oil behaviour at sea. 

Fresh oil properties 

Specific Gravity (60 F/60 F) 0.893 

Pour Point (°C) -12 

Reference temperature # I (0C) 13 

Viscosity at ref. temp.# I ( cP) 27 

Vanadium (ppm wt.) -

Nickel (ppm wt.) -

Asphaltenes (wt.%) -

n-Pentane Insolubles (wt.%) -

Flash Point (

0C) 3 

Wax Content (wt. %) - Dispersable for vise. < 3000 

Poorly/not dispersable for vise.> 7000 

Maximum water uptake(%) at 5°C/13°C - Data missing 

True boiling point curve Film thickness (mm) 

Temperature Cumulative 

(OC) volume 

Initial I 10 

Terminal I 1 

(%) 

65 1.43 

90 3.04 

150 9.57 

180 13.83 

240 24.49 

320 45.71 

375 57.21 

420 63.49 

525 83.78 

565 87.99 

Weathering properties (laboratory data) 

Fresh 150°C+ 200°C+ 250°C+ 

Boiling temperature (°C) - 210 255 300 

Volume topped(%) 0 8 15 24 

Residue (wt%) 100 93 87 78 

Specific gravity (g/1) 0.893 0.903 0.909 0.919 

Pour point (0C) -39 -15 -9 3 

Flash point (

0

C) 3 50 80 119 

Viscosity at 13°C (eP)* 27 49 83 200 

Viscosity of 50% emulsion ( cP)* - 343 593 1300 

Viscosity of75% emulsion (eP)* - 1815 2673 4790 

Viscosity of max water ( cP)* - - - - Maximum water content (%) - 75 75 75 

Halftime for water uptake (hrs) - 0.09 0.07 0.13 

Stability ratio - 0.78 I I 

Not measured 

* · Viscosity measured at shear rate Jos· 1

. 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
~SINTEF 36 

6 NOFO exercise 1996 

6.1 The field experiments 

The NOFO oil-water exercise 1996 included two surface releases and one sub-surface release of 

stabilized Troll crude oil with gas present. The experiments were performed at the Frigg field in 

June 1996. 

Objectives 

The objectives ofthe 1996 exercise were: 

To determine how the weathering processes (evaporation, water-in-oil emulsification and 

natural dispersion) of Troll crude oil proceeded in the control (Charlie) and the treated slick 

(Hotel, treated by helicopter with the new "Response 3000" bucket) after dispersant 

application. 

To determine how the surface slick resulting from the underwater release ( designated 

Uniform) of Troll crude oil combined with gas (GOR of 1 :67), behaved. 

The field trials in both 1995 and 1996 were performed in order to form basis for building up an 

operational and cost-effective dispersant response in Norway (for terminals, refineries, offshore 

oil fields etc.). 

Surface releases 

Two surface released slicks of fresh, stabilized Troll crude oil were released about 1 nm apart: 

One slick, ( designated Hotel), was treated with the dispersant Corexit 9500 from a S6 l-N 

helicopter using the newly developed underslung bucket "Response 3000" ( described in 

Brandvik 1996b) after 4 hours weathering of the oil at sea. The treated part of the Hotel slick 

totally disappeared from the sea surface and dispersed into the water column just after the 

dispersant application. 

The other slick, Charlie, was used as a control slick. 

Sub-surface releases 

In 1995 field trial the oil was released without any gas present, in the 1996 field trials compressed 

air was used to simulate an oil-gas blow-out. 

One release of fresh, stabilized Troll crude oil, together with compressed air simulating gas, 

was released from l 06 m depth (not discussed in this report, due to too low film thickness for 

surface oil sampling). 

Conclusions 

The main conclusions from the experiments were: 

Troll crude oil emulsified slowly and reached a maximum water content of approximately 60 

vol.% and a viscosity of2000 cP (shear rate 10 s·

1

) after 10 hours weathering at the sea 

surface. These measured values were lower than the predicted values due to unstable 

emulsions. The weather conditions were rather calm, with an average wind speed of about 4 to 

5 mis, and too low to cause breaking waves. The same situation occurred during the August 

1995 trials when the Sierra slick was monitored on Day 2 (5 to 6 mis wind). 

The physico-chemical properties of surface oil from the field experiment in 1996 are further 

described by Str0m-Kristiansen et al., 1996. 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
(jSINTEF 37 

Weathering data from the Charlie slick and the Hotel slick before dispersant treatment is 

presented in this report. Predicted evaporation, water uptake and emulsion viscosity from SINTEF 

OWM is presented together with field data in Figure 6.1, Figure 6.2 and Figure 6.3 respectively. 

l:\CH66l 189 MMS OWM Phases II and 111\Task 7\Final report.doc 
~SINTEF 

Property: Evaporation 

Temperature ('C) 10 

Wind Speed . Wind files 

ln1uaI film 1h1ckness (mm) 10 

Terminal film lhlckness (mm) · 1 

100 

90 

80 I 

70 I 

0 60 

C: I :8 50 I 

0 40 I 

C. 

"' > I w 30 

20 I 

I I 10 - • - 0 

0,25 0,5 1 2 3 

Hours 

I 

I .. 

---- I 

I 

6 9 12 

SINTEF 2.0 0 2002 

Pred Dalo Apnl 30, 2003 

I 

I 

I 

-----

1 2 3 4 5 

Days 

- Troll Cha~ie 1996 

- Troll Holel 1996 

... Field dala Charlie 

• Field dala Holel 

Figure 6.1 : Predicted evaporation and field data Troll crude oil Charlie and Hotel I 996. 

Property: Water uptake 

Temperature ('C) 10 

Wmd Speed Wind files 

lniual film lh1ckness (mm) 10 

Terminal film 1h1ckness (mm) 1 

100 

90 

80 

l 70 

- 60 C: 

111 

c 50 0 

0 

.. 

111 40 

.; 

;: 30 

20 

10 

0 

0,25 0,5 2 3 

Hours 

SINTEF 200 2002 

Pred. Da10· Apnl 30, 2003 

6 9 12 3 4 5 

Days 

- Troll Cha~,e 1996 

- Troll Holel 1996 

... Field dala Charlie 

• Field dala Holel 

Figure 6.2 Predicted water uptake and field data Troll crude oil Charlie and Hotel 1996. 

l:\Cll66 I 189 MMS OWM Phases II and 11 1\Task 7\Final report.d oc 

38 
SINTEF 

Property: Emulsion viscosity 

Temperature c•C) 10 

Wind Speed . Wind files 

Initial film thickness (mm) · 10 

Terminal film thickness (mm) 1 

SINTEF 2 o Cl 2002 

Pred Dato· Apnl 30. 2003 

100000 r----,----------------------------

0:- 10000 

2:- .iii 

0 

u 

., 

·;; 

C 

0 

'iii 

"3 

E 

w 

1000 

10 '-------------------- - ---------' 

0,25 0,5 2 3 6 9 12 2 3 4 5 

Hours Days 

- Troll Cha~1e 1996 

- Troll Hotel 1996 

A Field data Charlie 

• Field data Hotel 

Figure 6.3 : Predicted emulsion viscosity and field data Troll crude oil Charlie and Hotel. 

l:ICll661 189 MMS OWM Phases II and 111\Task 7\Final rcpon.doc 

39 
(j SINTEF 40 

6.2 Field and input data 1996 

The data from samples taken of the oil slick are given in the tables described here. 

Table 6.1: Overview surface oil sampling in Charlie slick (control) 11 - 12 June 1996. 

Table 6.2 : Physico-chemical properties on water-free residues of Troll crude and their water-inoil emulsions from the control slick Day 1 (Charlie) in the North Sea field trial in June 1996. 

Table 6.3 Physico-chemical properties on water-free residues of Troll crude and their waterin-oil emulsions from the helicopter treated slick released on Day 1 (Hotel slick) in the North Sea 

field trial in June 1996. 

Table 6.4: Wind conditions at June 1996 Friggfield trial. Charlie slick. 

Table 6.5: Wind conditions at June 1996 Friggfield trial. Hotel slick. 

Table 6.6: Input data for predictions ofTroll crude oil behaviour at sea. 

l:\CH661189 MMS OWM Phases II and 111\Task 7\Final report.doc 
((j SINTEF 41 

Table 6.1: Overview surface oil sampling in Charlie slick (control) 11 - 12 June 1996. 

ID Date Time (local) Weathering Latitude / Longitude Film Thickness Pad Comments 

time GPS (Global Pos. System) (cylinder, in-situ) sample 

Charlie 11.06. 08.00 - 08.15 O• Release of Charlie slick. 

Cl .. 08.23 0.13 60.00.255 I 002.24.888 Full set of samples collected in thick part of the slick). Slick front 

just before sampling (08.19): 60.00.305 / 002.24.857. 

C2-A .. 08.45 0.5 60.00.322 I 002.25.032 Full set of samples collected in thick part of the slick. 

C2-B .. 08.50 0.6 60.00.322 I 002.25.032 3mm 

C3 .. 09.15 1.0 60.00.392 I 002.25.268 Full set of samples collected in thick part of the slick (at buoy 

9810). Slick front just before sampling: 60.00.413 / 002.25.269. 

C4 .. 09.33 1.3 60.00425 I 002.25.432 Full set of samples collected in thick part of the slick (at buoy 

9810). Slick frontjust before sampling: 60.00.472 / 002.25.498. 

C7-A .. 13.53 5.6 60.00.135 I 002.25.595 5mm 

60.00.318 I 002.25.097 10mm GPS positions were logged during the 3 thickness measurements. 

10mm 

C7-B .. 13.55 5.7 60.00.135 I 002.25.595 Full set of samples collected in thick part of the slick (at buoy 

9810). 

CS-A .. 16.51 8.6 60.01.361 / 002.23. 752 Full set of samples collected in thick part of the slick. Lots of thick 

emulsion. 

C8-B .. 16.55 8.7 60.01.353 I 002.23.742 15mm 

C9 .. 18.45 10.5 

Cl0-A 12.06 14.25 30.2 60.01.398 I 002.29.092 1 

CIO-B .. .. 30.2 60.01.367 I 002.29.081 1 

•: Time 0 is 08.15. 
G) SINTEF 42 

Table 6.2: Physico-chemical properties on water-ji-ee residues a/Troll crude and their water-in-oil emulsions ji-om the control slick Day I (Charlie) in the 

North Sea field trial in June 1996. 

Sampling 

station 

co 

C l 

C2-A 

C2-B 

C3 

C4 

C7-A 

C7-B 

C8-A 

C8-B 

C9 

C I0-A 

C I0-B 

•: 

*· 

**· 

W/o emulsion properties 

Weath. time Water cont. Density Viscosity Shear rate 

(hours) (vol.%) (!!/mL) 

0• 0 0.887 

0.1 0 0.89 1 

0.5 6 0.904 

0.6 - -

1.0 5 -

1.3 7 0.912 

5.6 -

5.7 56 0.975 

8.6 61 0.98 1 

8.7 - -

10.5 64 0.983 

30.2 - -

30.2 - -

Time 0 is 08. I 5, I I June (oil release finished). 

Not performed. 

(cP) (s-•) 

44 10 

4 1 10 

- -

37 10 

67 10 

1080 10 

1930 10 

- -

1740 10 

- -

- -

Stability **Emul brea. eff. Em. film thickness 

* D1h * D2~h * D1h *DHh Pad In-situ 

(mm) (mm) 

- - - - -

0.0 0.0 0.0 0.0 - -

1.0 1.0 1.0 1.0 - -

- - - - - 3 

1.0 1.0 1.0 1.0 - -

0.7 0.7 0.7 0.7 - -

- 5 

10 

10 

0.0 0.0 0.9 0.9 - -

0.0 0.0 0.0 1.0 - -

- - - - - 15 

0.0 0.2 0.0 0.9 - -

- - - - 0.002 -

- - - - 0.001 -

Dis fractional dehydration of emulsion. D 11, is effect afler I hour, D2~1, is effect afler 24 hours. D=0: no water sell led. D=: I all water sell led. 

Ejfec/ of 500 ppm concentration of the emulsion breaker Alcopol O 60 %, relative to the emulsion volume. 

Water-free residue 

properties 

Evap. loss Density 

(wt%) (2/mL) 

0.0 0.887 

- 0.892 

2.6 0.897 

- -

- -

8.9 0.904 

- -

16.2 0.913 

17.7 0.914 

- -

16.4 0.913 

- -

-
(jSINTEF 43 

Table 6.3 Physico-chemical properties on water-free residues ofTro/1 crude and their water-in-oil emulsions from the helicopter treated slick released on 

Day 1 (Hotel slick) in the North Sea field trial in June 1996. 

Sampling 

station 

HO 

HI-A 

Hl-B 

1-11-C 

1-11-01 

Hl-D2 

1-11-E 

1-12-A 

1-12-B 

Disp.appl. 

HJ-A 

H3-B 

1-13-C 

H4 .. 

H5-A 

H5-B 

1-15-C 

•: 

••: 

.. 

••• 

W/o emulsion properties 

Weath. time Water cont. Density Viscosity Shear rate 

(hours) (vol.%) (f!/mL) (cP) (s-•) 

0• 0 0.889 

1.03 36 0.948 188 10 

1.5 

1.6 - - - - 1.67 - - - - 1.67 - - - - 1.7 - - - - 1.9 25 0.938 157 10 

3.7 27 - 241 10 

-

4.00 25 0.940 130 10 

4.07 - - - - 4.13 - - - -

8.3 60 0.981 2480 10 

9.5 - - - - 9.5 - - - - 9.5 - - - -

Time 0 is 09. 15 ( oil release finished). 

Sample collected in a minor area of the Hotel slick not hit by dispersant. 

Not performed. 

Stability 

*D1h *D24h 

- -

1.0 1.0 

- -

- -

- - - -

0.8 0.8 

- -

- -

0.2 0.6 

- -

- -

0.1 0.1 

- -

- -

- -

**Emul brea. eff. Em. film thickness 

*D1h *D24h Pad In-situ 

(mm) (mm) 

- - - 0.9 0.9 - -

- 13 

15 

- - - 2 

- - 1.70 4 

- - 0.75 5 

- - - 1.0 1.0 - - - - - - - 0.3 0.8 0.13 - - - 0.05 - - - 0.04 - 0.1 0.2 - - - - - 4 

- - - 15 

- - - 10- 15 

D is fractional dehydration of emulsion. D Jh is effect after 1 hour, Duh is effect after 24 hours. D=0: no water settled D=: 1 all water sell led 

Effect of 500 ppm concentration of the emulsion breaker A/copol 060%, relative to the oil volume. 

Water-free residue 

properties 

Evap. loss Density 

(wt%) (f!/mL) 

0.0 0.889 

10.1 0.906 

- -

- -

- - - -

- - 12.5 0.908 

- - - -

14.8 0.911 

- - - -

20.3 0.917 

- - - - - -
~SINTEF 44 

Table 6.4: Wind conditions at June 1996 Friggfield trial. Charlie slick. 

Cum. time Wind Direction Cum. time Wind Direction 

(hours) (mis) (0) (hours) (mis) (0) 

*0.0 4.7 174.4 17.0 4.2 174.4 

0.5 4.7 149.1 17.5 4.7 143.4 

1.0 4.2 177.2 18.0 4.7 120.9 

1.5 4.7 160.3 18.5 2.3 154.7 

2.0 4.7 168.8 19.0 2.3 154.7 

2.5 4.7 180.0 19.5 3.3 208.1 

3.0 4.2 160.3 20.0 2.3 230.6 

3.5 3.8 157.5 20.5 2.8 278.4 

4.0 4.2 149.1 21.0 4.2 275.6 

4.5 5.2 137.8 21.5 6.1 298.1 

5.0 5.6 146.3 22.0 8.0 289.7 

5.5 5.6 168.8 22.5 10.3 309.4 

6.0 3.3 174.4 23.0 10.8 309.4 

6.5 6.1 157.5 23.5 11.3 292.5 

7.0 6.6 135.0 24.0 11.3 300.9 

7.5 7.0 149.1 24.5 10.3 295.3 

8.0 7.0 160.3 25.0 10.3 303.8 

8.5 7.5 174.4 25.5 8.9 295.3 

9.0 7.0 146.3 26.0 8.9 292.5 

9.5 6.6 157.5 26.5 8.9 281.3 

10.0 6.6 163.1 27.0 9.4 286.9 

10.5 7.0 188.4 27.5 9.4 331.9 

11.0 6.6 157.5 28.0 9.4 264.4 

11.5 6.1 180.0 28.5 8.4 289.7 

12.0 6.1 177.2 29.0 8.4 275.6 

12.5 6.1 163.1 29.5 8.9 292.5 

13.0 5.6 171.6 30.0 8.9 261.6 

13.5 6.1 154.7 30.5 8.4 222.2 

14.0 5.6 168.8 31.0 8.9 275.6 

14.5 5.6 168.8 31.5 8.4 264.4 

15.0 5.6 160.3 32.0 8.4 267.2 

15.5 5.6 168.8 

16.0 5.2 165.9 

16.5 5.2 168.8 

* · Start time is 08°0 1 J

thJune 1996 (start oil release). 
~SINTEF 45 

Table 6.5: Wind conditions at June 1996 Friggfield trial. Hotel slick. 

Cum. time Wind Direction Cum. time Wind Direction 

(hours) (m/s) (0) (hours) (m/s) (0) 

•o.o 4.2 177.2 16.0 4.2 174.4 

0.5 4.7 160.3 16.5 4.7 143.4 

1.0 4.7 168.8 17.0 4.7 120.9 

1.5 4.7 180.0 17.5 2.3 154.7 

2.0 4.2 160.3 18.0 2.3 154.7 

2.5 3.8 157.5 18.5 3.3 208.1 

3.0 4.2 149.1 19.0 2.3 230.6 

3.5 5.2 137.8 19.5 2.8 278.4 

4.0 5.6 146.3 20.0 4.2 275.6 

4.5 5.6 168.8 20.5 6.1 298.1 

5.0 3.3 174.4 21.0 8.0 289.7 

5.5 6.1 157.5 21.5 10.3 309.4 

6.0 6.6 135.0 22.0 10.8 309.4 

6.5 7.0 149.1 22.5 11.3 292.5 

7.0 7.0 160.3 23.0 11.3 300.9 

7.5 7.5 174.4 23.5 10.3 295.3 

8.0 7.0 146.3 24.0 10.3 303.8 

8.5 6.6 157.5 24.5 8.9 295.3 

9.0 6.6 163.1 25.0 8.9 292.5 

9.5 7.0 188.4 25.5 8.9 281.3 

10.0 6.6 157.5 26.0 9.4 286.9 

10.5 6.1 180.0 26.5 9.4 331.9 

11.0 6.1 177.2 27.0 9.4 264.4 

11.5 6.1 163.1 27.5 8.4 289.7 

12.0 5.6 171.6 28.0 8.4 275.6 

12.5 6.1 154.7 28.5 8.9 292.5 

13.0 5.6 168.8 29.0 8.9 261.6 

13.5 5.6 168.8 29.5 8.4 222.2 

14.0 5.6 160.3 30.0 8.9 275.6 

14.5 5.6 168.8 30.5 8.4 264.4 

15.0 5.2 165.9 31.0 8.4 267.2 

15.5 5.2 168.8 

* · Start time is o</1° 11th June 1996 (start oil release). 
~SINTEF 46 

Table 6.6: Input data for predictions of Troll crude oil behaviour at sea. 

Fresh oil properties 

Specific Gravity (60 F/60 F) 0.893 

Pour Point (

0C) -12 

Reference temperature # 1 (0C) 13 

Viscosity at ref. temp.# 1 ( cP) 27 

Vanadium (ppm wt.) -

Nickel (ppm wt.) -

Asphaltenes (wt.%) -

n-Pentane Insolubles (wt.%) -

Flash Point (

0

C) 3 

Wax Content (wt. %) - Dispersable for vise. < 3000 

Poorly/not dispersable for vise. > 7000 

Maximum water uptake(%) at 5°C/13°C - Data missing 

True boiling point curve Film thickness (mm) 

Temperature Cumulative Initial I 10 

(OC) volume Terminal I 1 

(%) 

65 1,43 

90 3,04 

150 9,57 

180 13,83 

240 24,49 

320 45,71 

375 57,21 

420 63,59 

525 83,78 

565 87,99 

Weathering properties (laboratory data) 

Fresh 150°C+ 200°C+ 250°C+ 

Boilin~ temperature (°C) - 210 255 300 

Volume topped(%) 0 8 156 24 

Residue (wt%) 100 93 87 78 

Specific gravity (g/1) 0.893 0.903 0.909 0.919 

Pour point (0C) -39 -15 -9 3 

Flash point (

0C) 3 so 80 119 

Viscosity at 13 °C ( cP)* 27 49 83 200 

Viscosity of50% emulsion (cP)* - 343 593 1300 

Viscosity of75% emulsion (cP)* - 1815 2673 4790 

Viscosity of max water ( cP)* - - - - Maximum water content (%) - 75 75 75 

Halftime for water uptake (hrs) - 0.09 0.07 0.13 

Stability ratio - 0.78 1 1 

Not measured 

* · Viscosity measured at shear rate /Os'. 
(j SINTEF 

7 AEA field experiments UK 1997 

7.1 The field experiments 

During the AEA '97 Experimental Sea Trial outside UK, September 1 J1h - 241

\ the target was 

therefore to let the oils weather at sea to a stage where the weathered and emulsified oils were 

considered to be more difficult to disperse. During these experimental field trials the following 

three oils were released and weathered at sea prior dispersant application with Corexit 9500: 

• 50m3 Forties weathered for 2 days at sea prior to treatment of2.5m3 Corexit 9500 

• 20m3 IFO-180 Heavy bunker fuel weathered for 4.5 hours at sea prior to treatment of 0.9m3 

Corexit 9500 followed by a 2nd treatment 23-25 hours at sea (2.0 m

3 Corexit 9500) 

• 31 m3 Alaska North Slope (ANS) crude (designated "Alpha") weathered for 2.5 days at sea 

prior to treatment of 

1.0 m

3 Corexit 9500 

Due to lack of ground truth sampling of oil weathering data of the Forties and the HFO slicks, 

only weathering data and predictions of the Alpha slick is presented in this report. 

The primary purpose of the experiments was to measure the changes in oil properties during 

weathering at sea, and to determine the period of time during which Corexit 9500 can be 

considered as a viable response option for these oils. 

47 

In order to have a better understanding and documentation of the likely weathering properties and 

chemical dispersibility with Corexit 9500 on the oils planned to be used in the field, it was 

decided to perform some laboratory experiments prior the field trial. 

Summary 

During a laboratory study prior the field trials, the weathering properties and the "dispersibility 

properties" for weathered ANS crude and IFO-180 heavy fuel oil were defined. The 

experimental data from this laboratory study were used as input to the SINTEF Oil Weathering 

Model to improve the validity of the predictions of the weathering properties and in estimating 

the ''time window" for effective use of Corexit 9500 on the oils to be used in the field trial. 

Compared to earlier studies carried out with Corexit 9527 at SINTEF, Corexit 9500 shows an 

improvement in the dispersibility up to a viscosity of20.000 cP on the ANS emulsions. This 

gives a significant increase in the "time window" for effective use of dispersant on the ANS 

crude. 

In addition to the ANS testing, some limited chemical dispersibility testing with Corexit 9500 on 

two different batches of IFO-180 HFOs was carried out in SINTEFs laboratories. Also for the 

bunker fuels, the dispersant dosage seem to be very critical to the effectiveness results ( dosages up 

to I: 10 is required). More systematic investigation is also needed in order to better establish the 

"viscosity areas" for dispersibility for different bunker oil qualities and their w/o-emulsions. 

The viscosity data obtained in the laboratory and by the model predictions generated prior the 

trials corresponded well with the weathering and dispersant performance that took place in the 

field. These field trials therefore confirmed laboratory studies carried out at SINTEF indicating 
~SINTEF 48 

that it is possible to disperse ANS crude oil emulsions up to a viscosity of20,000cP and IFO-180 

emulsions to viscosities of 20,000 to 30,000 cP. Emulsions weathered to viscosities above these 

values seem to disperse slowly/ poorly when treated with dispersant. Such available data of the 

"viscosity area" the dispersibility are crucial information for the OSC during spraying operations. 

The ground truth data of the water content in the surface emulsion gave fairly good correlations to 

the model predictions for the first half day after release. However, over the next days, a reduction in 

the water content was obtained in the field. This may be explained by an evaporation of the 

emulsified water in the surface emulsion probably took place, due to high sea-temperature and 

extremely sunny conditions during the experiment period. Temperature in the oil was measured up 

to 5°C higher than sea temperature. This needs further investigation because this process in not 

reflected in present weathering models. Algorithms for evaporation of water in surface emulsions 

should therefore be developed. This is particularly relevant when predicting more long-term 

weathering (several days at sea) and under more temperate / tropical conditions. 

The results from the field experiment in 1997 are further described by Daling, 1998 and also 

discussed by Daling and Strnm, 1999 and Lewis et al., 1998. 

Predicted water uptake and emulsion viscosity from SINTEF OWM is presented together with 

field data in Figure 7. 1 and Figure 7.1 , respectively. 
~SINTEF 

Property: Water content 

Temperature (

0

C) 15 

Wind Speed (mis) Wind file 

Initial film thickness (mm) . 20 

Terminal film thickness (mm) 1 

100 

90 

80 

l 70 

-

C: 60 .. 

C: 

0 50 u 

:;; 40 .; 30 

20 

10 . 0 - 0,25 0,5 

A __1/ 

- • 

Hours 

SINTEF 

2 0 0 2002 

Pred. Dato Apnl 30, 2003 

--Dispersant 

/ l1cat:men I 

/• • I 

• .. / - • .. 

6 9 12 2 3 4 5 

Days 

Figure 7. 1 Predicted water uptake and field data Alaska North Slope 1997. 

Property: Emulsion viscosity Temperature (

0

C) 15 

Wind Speed (mis). Wind file 

Initial film thickness (mm) 20 

Terminal film thickness (mm) 1 

100000 

ii:" 10000 

z. 

·;;; 

0 

u 

II) 

·;; 1000 

C: 

0 

·;;; 

"3 

E 

w 100 • 

10 

0,25 0,5 2 

Hours 

3 

SINTEF 

2.0 0 2002 

Pred Dato April 30. 2003 

6 9 12 2 3 4 5 

Days 

- Alaska North Slope 

A Field data 

- Alaska No<1h Slope 

• Field data 

Figure 7. 2 : Predicted emulsion viscosity and field data Alaska North Slope 1997 

49 
~SINTEF 50 

7.2 Field and input data 1997 

The data from samples taken of the oil slick is given in the tables described here. 

Table 7.1 Physico-chemical properties and "field check" of dispersant and demulsifier 

effectiveness of Alaska North Slope crude ("Alpha slick") at sea. UK Trials, 20. - 23. September, 

1997." 

Table 7.2 Wind conditions (average wind in mis) during the AEA '97 field trial used as input 

to the SJNTEF Oil Weathering Model. 

Table 7.3 Input data for predictions of Alaska North Slope crude oil behaviour at sea. 
(j)SINTEF 51 

Table 7. 1 Physico-chemical properties and ''field check" of dispersant and demulsifier effectiveness of Alaska North Slope crude ("Alpha slick") at sea. UK 

Trials, 20. - 23. September, 1997. " 

Sample/ Date/ AEA Water Viscosity Dispersibility Emulsion stability and 

Time at Sea Time ID-no (vol.%) (cP, at 15°C, at (DER= 1: 25) Demulsijier effectiveness 

AEA) (fraction deh 11drated at 15° CJ 

(Alcopol- (at shear rate= los-1

) Field test Dosage: D2nun D1h Duh 

method) (Concawe, 1988) DER=500oom 

Saturday, 20. Sept 

Release 0837-0900 31 Tons of Alaska North Slope released - - - · AO l(rresb·crude, analyzed at SINTEF (0.883 kwL1 20 (100 s-:1 ) !! - - - Al/ 20 min. 0920 AA00167 <l 135 (I 00 s- 1

) AEA Good - - -

A2 / 40 min. 0920 AA00l 71 <5 157 (I 00 s- 1

) Good - - - A3 Pos A/ l h. 1000 AA00175 <5 165 (I 00 s- 1

) Good - - - A3 Pos B / 1.5 h. 1030 AA00185 18 266 (100 s- 1

) Good Stability 0 0.2 0.8 

Alcopol O 60 0 0.4 1.0 

Corexit 9500 0 0.3 1.0 

A4 Pos A /2 h. I 100 AA00189 <5 266 (100 s- 1

) Good - - - A4 Pos B /2 h. 1100 AA00193 <5 182 (I 00 s- 1

) Good - - - AS /2.5 h. 1230 AA00197 20 469 (10 s- 1

) Good Stability 0 0.3 0.8 

Alcopol O 60 0 0.7 0.8 

Corexit 9500 0 0.5 1.0 

A6 Pos A I 5 h. 1350 AA00206 33 1010 Good Stability 0.1 0.2 0.4 

Alcopol O 60 0.3 0.6 0.6 

Corexit 9500 0.2 0.3 0.6 

A6 Pos B / 6 h. 1500 AA00212 25 818 Good Stability 0 0.2 0.5 

Alcopol O 60 0 0.6 0.6 

Corexit 9500 0 0.6 0.8 

A7 Pos A I 8.5 h. 1720 AA00214 48 2491 Good Stability 0 0 0.1 

Alcopol O 60 0 0.2 0.5 

Corexit 9500 0 0.1 0.4 
~SINTEF 52 

Sample/ Date / AEA Water Viscosity Dispersibility Emulsion stability and 

Time at Sea Time ID-110 (vol. %) (cP, at 15°C, at (DER= I : 25) Demulsifier effectiveness 

AEA) (fraction de/, vdrated at 15° C) 

(Alcopol- (at shear rate= 10s-') Field test Dosage: D2,,,;,, Du, Du1, 

method) (Concmve, 1988) DER = 500 /}/}Ill 

A 7 Pos B I 9.5 h. 1820 AA00220 45 1849 Good Stability 0 0 0.4 

Alcopol O 60 0 0. 1 0.8 

Corexit 9500 0 0. 1 0.7 

Sum/av, 21. Sevt. 

A8 Pos A I 22.5 h. 0730 AA00225 45 2703 Good Stability 0 0 0.2 

Alcopol O 60 0 0.2 0.5 

Corexit 9500 0 0.2 0.4 

A8 Pos B I 22.5 h. 0739 AA0023 I 43 2812 Good Stability 0 0 0.2 

Alcopol O 60 0 0.1 0.3 

Corexit 9500 0 0.1 0.4 

A9 I 32.5 h. 1720 AA00320 35 4948 (AEA) Good I Reduced Stability 0 0 0 

(36% KF) 5300 (SINTEF) Alcopol O 60 0 0 0.1 

Corexit 9500 0 0 0.1 

Mondav, 22. Sevt. 

Al O / 54.5 h. 1525 AA00363 30 15076 Reduced Stability 0 0 0 

Al I / 54.8 h. 1540 AA00367 30 19700 (AEA) Slowly/ Stability 0 0 0 

(35% KF) 22000 (SINTEF) Reduced Alcopol O 60 0 0 0.1 

Corexit 9500 0 0 0.2 

Treatment 1552-1600 400 liters of Corexit 9500, spray runs 1-3 

A 12 / 55 h. 1555 AA00371 25 14200 Reduced Stability 0 0 0 

Non-treated area(?) 

A 13 I 55 h. 1610 AA00375 25 10839 (AEA) Reduced / Good Stability 0 0. 1 0.22 

Treated area (22% KF) 11 800 (SINTEF) Alcopol O 60 0 0.1 0.7 

Corexit 9500 0 0.1 0.4 

A 14 I 55 h. 1625 AA00379 35 8863 ?? (AEA) Reduced Stability 0 0 0 

Non-treated area(?) (37% KF) 15000 (SINTEF) Alcopol O 60 0 0 0.2 

Corexit 9500 0 0 0.1 
G) SINTEF 

Sample/ 

Time at Sea 

Treatment 

A15 / 55.5 h. 

Non-treated area (? 

Date/ 

Time 

1628-1638 

1645 

AEA 

ID-no 

AA00383 

Water 

(vol.%) 

(Alcopolmethod 

600 liter. s 

25 

Viscosity 

(cP, at 15°C, at 

AEA 

53 

Dispersibility 

(DER= 1: 25) 

Emulsion stability and 

Demulsijier effectiveness 

·,action dehvdrated at 15°C 

(at shear rate = 10s·1

) I Field test I Dosage: D2m1nl D1h I Duh 

'Concawe,_ 1988) DER= 500 

runs 4-9. 1000 liters of Corexit 9S00. now a 

15027 I Reduced I Stability 0 0 

*· D is fractional dehydration of emulsion. After 2 min, 1 hour and 24 hours settling after demulsifier addition in the vials 
(jSINTEF 54 

Table 7.2 Wind conditions (average wind in mis) during the AEA '97 field trial used as input to 

the SINTEF Oil Weathering Model 

Time after Wind speed (mis) 

release ANS-slick 

(hours) Release: Sept 20. 

0840-0900 

0 4 

2 4 

4 5 

6 6 

8 6 

10 6 

12 6 

16 5 

20 3 

24 4 

28 5 

32 6 

36 5 

40 4 

48 5 

56 6 

72 6 

120 6 
((j SINTEF 55 

Table 7.3 Input data for predictions of Alaska North Slope crude oil behaviour at sea. 

Fresh oil properties 

Specific Gravity (60 F/60 F) 0.908 

Pour Point {

0

C} -31.666 

Reference temperature # I (0

C) 13 

Viscosity at ref. temp.# I ( cP) 76 

Vanadium (ppm wt.) -

Nickel (ppm wt.) -

Asphaltenes (wt.%) -

n-Pentane Insolubles (wt.%) -

Flash Point {

0

C} - Wax Content (wt.%) - Dispersable for vise. < 4000 

Poorly/not dispersable for vise.> >20000 

Maximum water uptake(%) at 5°C/13°C 75 

Data missing 

True boiling point curve Film thickness (mm) 

Temperature Cumulative 

(OC) volume 

Initial I 20 

Terminal I I 

(%) 

30 3 

82 7 

166 19 

193 23 

288 38 

343 49 

510 74 

Weathering properties (laboratory data) 

Fresh IS0°C+ 200°C+ 2S0°C+ 

Boiling temperature (°C) - 197 255 320 

Volume topped(%) 0 20 26 32 

Residue (wt%) 100 84 78 67 

Specific gravity {g/1) 0.908 0.919 0.93 0.947 

Pour point (

0 C} -30 0 3 9 

Flash point {

0

C} - 43 78 127 

Viscosity at 13°C (cP)* 76 109 287 853 

Viscosity of 50% emulsion ( cP)* - 676 1776 4991 

Viscosity of 75% emulsion ( cP)* - 1819 10000 22000 

Viscosity of max water ( cP)* - 3059 10000 22000 

Maximum water content (%) - 75 75 75 

Halftime for water uptake (hrs) - 0.28 0.22 0.43 

Stability ratio - I 1 I 

Not measured 

* · Viscosity measured at shear rate /Os·'. 
(j SINTEF 

8 Deep Spill JIP 2000 

In order to increase the understanding of how oil and gas from subsea leaks or blowouts will 

behave in deep water. The DeepSpill Joint Industry Project was established with the aim of 

detennining the fate of oil and gas released in deepwater by perfonning full-scale field 

experimental releases. 

Objectives 

The main purposes of these experiments were: 

• to obtain data for verification and testing of numerical models for simulating accidental 

releases in deep waters; 

• to test equipment for monitoring and surveillance of accidental releases in deep waters; 

• to evaluate the safety aspect of accidental releases of gas and oil in deep waters. 

56 

Verified numerical models combined with improved surveillance of the releases should then 

provide a better basis for oil spill contingency planning and environmental impact assessments in 

conjunction with future deep water exploration, development and production. 

Releases 

The experiments were conducted at 844 m depth in the Helland Hansen region in the Norwegian 

Sea. 60 m3 marine diesel and 60 m3 Sture blend together with 18 m3 liquefied natural gas (LNG) 

equivalent to IO 000 m3 of gas at atmospheric pressure were released from a discharge platfonn 

lowered down to the seabed. 

The results from the DeepSpill JIP 2000 are presented in Johansen et al., 2000. 

Figure 8.1- Figure 8.3 predictions of evaporation, water content and viscosity of emulsion of Sture 

Blend compared to sample data from the deep spill experiment. The data from the deep spill 

experiment is in good accordance to the predictions made by the SINTEF OWM (Johansen et al., 

2001). 

- Wind Speed (mlw): 15 lnltllllr11rmlnal Oil film thlc:lcnou: O.S mm/0.5 mm • Measured Data 

---· Wind Speed (mlw): 10 Rlllllaao ratcr.1.00 metric tonllmlnut11 

•••••• Wind Speed (mlw): 5 

Sea surface temperature: 1 O ·c 

0.25 0.5 6 9 12 2 3 4 5 

Hours Days 

Figure 8.1 Evaporative loss of crude oil after resurfacing. Measured values compared with 

predictions based on laboratory data obtained from Sture Blend (2000). Note that this 

is essentially the same blend of crude oils as the Sture blend used in the experiment, 

but previously marketed with another name. 
~SINTEF 

--Wind Speed (m/s): 15 

- - - - Wind Speed (m/s): 10 

------ Wind Speed (m/s): 5 

lnitiaVTcrminal Oil film thickness: 0.5 mm/0.5 mm 

Release rate: 1.00 metric tons/minute 

Sea surface temperature: 1 O ·c 

• Measured Data 

1010-.-------------------------------------. 

80-

l 60- 'E 

C: 

0 

u 

... 

s 

"" 40-

;: 

20· 

0.25 0.5 2 

Hours 

• 

12 3 • 5 

Days 

Figure 8.2 Water uptake of Sture Blend crude oil after reswfacing. Predicted and measured 

values. 

--Wind Speed (mis): 15 

---- Wind Speed (mis): 10 

D Chemically dispersible (<2000 cP) lnltlal/Termlnal OIi film thickness: 0.5 mm/0.5 mm 

[::::J Reduced chemical dlspersibility Release rate: 1.00 metric tons/minute 

•····· Wind Speed (mis): 5 CJ Poorly / slowly chemically dispersible (>9000 cP) • Measured Dala 

Sea surface temperature: 1 o ·c 100000-~--------- ------- - -----------------, 

10000-

i:L 

.::- 1000- "iii 

0 

Ii! 

> 

100-

tn->------------------------------------- 0.25 0.5 2 

Hours 

9 12 

Based on viscosity measurements carried ou1 at a shear rale of 1 O reciprocal seconds. 

Chemical dispersabilily informa1ion based on exper,mcnts under slanda,d laboratory cond111ons. 

2 3 4 5 

Days 

Figure 8.3 : Viscosity of emulsion, Sture Blend crude oil after resurfacing. Predicted and 

measured values 

57 
~SINTEF 58 

8.1 Field data 2000 

The data from samples taken of the oil slick are given in the tables described here. 

Table 8.1: Emulsionfilm thickness (μm)-Sture Blend crude oil 

Table 8.2 : W/o emulsion properties 

Table 8.3 : Wind data 2000 

Table 8.4: Model input-weathering data Sture blend 
(<iSINTEF 59 

Table 8.1 : Emulsion/Um thickness (μm) - Sture Blend crude oil 

Emulsion 

Film Position 1

) Comments 

Sampling time Water thickness (sampling technique / Visual 

{local time) content.•> (μm) Lat Long observations) 

0902 29 19 65 00.037 4 50.775 PP-Pad, spot sampling/ metallic 

0904 29 171 65 00.034 4 50.775 PP-Pad, spot sampling / Thick oil 

(Discontinuous/ continuous true) 

0908 29 38 65 00.009 4 50.772 PP-Pad, spot sampling/ thick oil 

(Discontinuous) 

0909 29 7 65 00.001 4 50.719 PP-Pad, S(!Ot sam(!ling / metallic 

1035 29 15 65 00.150 4 51.517 PP-Pad, spot sampling/ 4 samples 

1036 29 101 65 00.146 4 51.500 in thick (discontinuous) oil and 

1037 29 27 65 00.139 4 51.496 metallic. In an area with relatively 

1038 29 36 65 00.130 4 51.487 fresh oil 

1100 66 676 64 59.635 4 51.091 PP-pad, spot sampling from 

emulsi fled patches 

1105 66 1983 64 59.588 4 51.156 PP-pad, spot sampling from thick 

emulsion 

1110 63 1187 64 59.433 4 50.971 Thick emulsion, estimated > 1-3 

mm 

1116 63 1008 64 59.398 4 50.989 PP-Pad, spot sampling from thick 

emulsion 

1116 63 1902 64 59.398 4 50.989 PP-pad, spot sampling from thick 

emulsion 

1617 69 1264 2) PP-pad in thick emulsion, 3 

1617 69 1204 parallel samples 

1617 69 777 

1

) Position given in geographical degrees followed by decimal minutes 2

) Samples taken in the southern front of the slick (Position not recorded) 
~SINTEF 60 

Table 8.2 : W/o emulsion properties 

2

>Emulsion breaker Stability 

efficiency 

Viscosity 

Sampling Tentative Density at 10(s·1

) Water cont 

station Weath. time (~ml} (mPas} (vol%} I) D4b •>D •>D •>D -,t'b fb -af'h 906 0.5 0.9259 4) 29.2 4) 4 

920 0.75 0.9550 706 51.5 1.00 1.00 0.50 0.78 

1010 1 0.9810 1935 65.8 0.53 0.53 0.16 0.61 

1055 1.5 0.9841 3400 67.6 0.82 0.82 0.00 0.27 

1116 2 0.9822 3100 66.7 0.83 0.83 0.08 0.41 

1427 5 0.9910 7600 75.1 0.61 0.61 0.00 0.00 

1506 6 0.9928 5000 72.1 0.69 0.69 0.00 0.24 

1620 7 0.9840 6700 68.5 0.73 0.73 0.00 0.00 

Fresh crude - 0.8423 84 

200°C+ 0.8903 477 

1) Dis.fractional dehydration of emulsion. D4h is effect after 4 hours, D2-1h is the effect after 24 hours. D=0: no 

water settled. D = 1: all water settled. 

2) Effect of500 ppm concentration of the emulsion breaker Alcopol 060%, relative to the oil volume 

3) Properties of the oil residue after the water has been drained off by 0.5% emulsion breaker Alcopol at 6(/1C 

4) The sample volume was too small to perform the analysis. 

Evaporative loss quantified by GC - SINTEF Evap-program) 

Water free residue 

properties 3

> 

Density Evap loss 

(~ml} (wt%} 5) 

0.8852 28.2 

0.8806 31.7 

0.8962 32.3 

0.8987 33.5 

0.8967 36.2 

0.8885 35.6 

0.9096 39.3 

0.8950 39.3 

0.8423 

0.8903 
SINTEF 

18 180 

-o-Wind speed 

15 7 --Wind direction 120 

VI 12 e 60 

"O 

GI 

GI 

Q. 9 0 VI 

,, 

C: 

6 -60 

3 -120 

0'---- ------'-------------------' -180 

26. Jun 00:00 27. Jun 00:00 28. Jun 00:00 

Time UTC 

29. Jun 00:00 30. Jun 00:00 

61 

GI 

Cl 

GI 

,, 

c 

0 

.... 

u 

GI 

... 

,, 

,, 

C: 

Figure 8.4 Plot of wind speed and direction al the Helland Hansen site during !he DeepSpill sea 

/rial. Based on smoothed data as shown in Figure 6.1. 

Table 8.3 : Wind data 2000 

Start date: 25.06.2000 00 UTC 

Time from start Wind speed Direction 

(h) (m/s) (0) 

0 10,4 15 

6 9,3 10 

12 4,9 6 

18 2,8 337 

24 2,9 316 

30 2,1 33 1 

36 2,1 0 

42 3,2 0 

48 6,3 347 

54 9,3 336 

60 11 ,7 335 

66 13,5 334 

72 14,2 336 

78 14,0 339 

84 12,8 34 1 

90 10,7 346 

96 9,1 356 

102 8,2 8 

108 8,8 19 

11 4 10,7 26 

120 13,6 30 
((jSINTEF 62 

Table 8.4: Model input - weathering data Sture blend (2000) 

Fresh oil properties 

Specific Gravity (60 F/60 F) 0.847 

Pour Point (

0

C) -3 

Reference temperature # I (0C) 13 

Viscosity at ref. temp.# I ( cP) 10 

Vanadium {ppm wt.) - Nickel {ppm wt.) - Asphaltenes (wt. %) - n-Pentane Insolubles (wt.%) -

Flash Point (

0C) - Wax Content ( wt. %) - Dispersable for vise. < 2000 

Poorly dispersable for vise. > 9000 

Maximum water uptake(%) at 5°C/13°C 75 

Data missing 

True boiling point curve Film thickness (mm) 

Temperature Cumulative Initial I 0,5 

coq volume Terminal I 0,5 

(%) 

90 10.62 

120 16.74 

145 21.48 

160 24.23 

205 32.29 

250 40.62 

295 50.27 

350 61.09 

420 70.84 

565 89.12 

Weathering properties (laboratory data) 

Fresh l50°C+ 200°C+ 250°C+ 

Boiling temperature (°C) - 185 250 303 

Volume topped(%) 0 16 28 39 

Residue (wt%) 100 86 76 65 

Specific gravity (g/1) 0.847 0.877 0.892 0.907 

Pour point (

0 C) 0 9 18 21 

Flash point {

0

C) - 38 80 119 

Viscosity at 13°C (cP)* 10 25 65 350 

Viscosity of50% emulsion (cP)* - 190 480 2800 

Viscosity of75% emulsion (cP)* - - 2600 6300 

Viscosity of max water ( cP)* - - - - Maximum water content (%) - 80 80 78 

Halftime for water uptake (hrs) - 0.130 0.100 0.180 

Stability ratio - 0.200 0.705 1 

Not measured 

* · Viscosity measured at shear rate /Os1

• 
(j SINTEF 63 

9 References 

Brandvik, P.J., Jensen, H., Dating, P.S., Lewis, A., 1995-a: NOFO exercise 1995, Dispersant and 

underwater release experiments- Operational plan. 

Brandvik, P.J., T.Str0m-Kristiansen, A.Lewis, P.S.Daling, M.Reed, H.Rye, H.Jensen, 1995-b: 

Summary report from the NOFO 1995 oil-on-water exercise. 

CONCA WE, 1988: A field guide to the application of dispersants to oil spill, 64 p. Concawe 

report no. 2/88. 

Dating, P.S., 1998: Performance testing of Corexit 9500 on oils weathered in laboratory and in 

experimental field trials. SINTEF Report no. STF66 F98023. 

Daling, P .S., 1998: Performance testing of Corexit 9500 on oils weathered in laboratory and in 

experimental field trials. SINTEF Report no. STF66 F98023. Restricted. 

Dating, P.S., Aamo, O.M., Lewis, A., Str0m-Kristiansen, T., 1997: IKU Oil Weathering Model -

predicting oil's properties at sea. 1997 International Oil Spill Conference, Fort Lauderdale, 

Florida, 2-10 April, pp.297-307. 

Dating, P.S., T.Str0m, 1999: Weathering of Oils at Sea: Model/Field Data Comparisons. In: Spill 

Science and Technology Bulletin, Vol.5, No. 1, pp.63-74. 

Jensen, H., Brandvik, P.J., Reed, M., 1995: Dispersant trials - NOFO exercise 14-17 August 1995 

- Cruise report. SINTEF NHL report no. STF60 F95092. 

Johansen, 0., H.Rye, A.G.Melbye, H.V.Jensen, B.Serigstad, T.Knutsen, 2000: Deep Spill JIPExperimental discharges of gas and oil at Helland Hansen - June 2000, Technical report. 

Lewis, A., T.Str0m-Kristiansen, P.J.Brandvik, P.S.Daling, H.Jensen, G.Durell, 1995: Dispersant 

trials - NOFO Exercise, June 6th-9th 1994 - Main report. ESCOST report no. 14. 

Lewis, A., A.Crosbie, L.Davies, T.Lunel, 1998: Large Scale Field Experiments into Oil 

Weathering at Sea and Aerial Application of Dispersants. In: Proceedings of the 21st Arctic and 

Marine Oilspill Program (AMOP) Technical SEminar, June I 0-12, 1998, Edmonton, Canada. 

Str0m-Kristiansen, T., J.N.Hokstad, A.Lewis, P.J.Brandvik, 1996: Oil on water exercise -

Analysis of sample material. Data report. 

Str0m-Kristiansen, T., P.S.Daling, 1994: Dispersant trials - NOFO exercise June 1994. Surface 

oil sampling and analysis. ESCOST report no. 15 

Str0m-Kristiansen, T., P.S.Daling, P.J.Brandvik, 1995: NOFO exercise 1995; Dispersant and 

underwater release experiments. Surface oil sampling and analysis - Data report. ESCOST report 

no. 25. 
•;: .. 

·- • ....'. ·i I; 

'::1. 

I . ,