P. Tkalich, K.Y.H. Gin, and E.S. Chan Physical Oceanography Research Laboratory Tropical Marine Science Institute The National University of Singapore TMSI

Oil Demand in Asia-Pacific

Global Movement of Oil in oil refineries in Singapore waters have total capacity over 1 mil. barrels per day. (second largest refinery area in the world, after Houston, Texas) 5 oil refineries in Singapore waters have total capacity over 1 mil. barrels per day. (second largest refinery area in the world, after Houston, Texas) Malacca&Singapore Straits

Major Oil Spills

Money spent by Exxon Corporation subsequentto EVOS (in millions of dollars) Immediate Costs (1989, 19990) Cleanup $2,000 Fisherman 300 Out-of-Court Settlement ( ) Damage assesment 214 Habitat protection 375 Administrative costs 35 Research, monitoring and general restoration 180 Restoration reserve 108 Accumulated interest less Court fees TOTAL $3,224 Civil Trial (1995) Compensation to fishermen $287 Punitive compensation (under appeal) 5000 Money spent by Exxon Corporation subsequentto EVOS (in millions of dollars) Immediate Costs (1989, 19990) Cleanup $2,000 Fisherman 300 Out-of-Court Settlement ( ) Damage assesment 214 Habitat protection 375 Administrative costs 35 Research, monitoring and general restoration 180 Restoration reserve 108 Accumulated interest less Court fees TOTAL $3,224 Civil Trial (1995) Compensation to fishermen $287 Punitive compensation (under appeal) 5000

Evoikos spill

Oil Properties

tarballs evaporation oxidation photolysis emulsification dissolution hydrolysis biodegradation foodweb sedimentation Oil Fate wind gravitation inertia viscous interf.tension

Oil Kinetics

12 I. BOOM APPLICATION top view II. CHEMICAL DISPERSANT APPLICATION

Oil Spill Simulation Models

14

Oil Slick Dynamics Navier-Stokes equations (gravity - viscosity regime)

16 General form of an explicit upstream finite-difference approximation i-2 i-1 l i r i+1

17 HIGH - ORDER ADVECTION APPROXIMATION USING POLYNOMIAL INTERPOLATION space time

18 THIRD -DEGREE POLYNOMIAL: Leonard (1979) QUICKEST (III-order) auxiliary conditions: III Holly-Preissmann (1977) (IV-order)

19 i-2 i-1 l i r i+1 III-order QUICKEST (Leonard, 1979)

20

Oil Transfer at Media Interfaces oil slick  oil-in-water emulsion (due to wind - waves breaking) h zz hh wave breaking oil buoyancy  h=k w (1+S g )H  h=0.2 g -1 k w (1+S g )U 2 S g =  0 /  w U C e = Concentration of oil emulsion in the water column

Oil Kinetics h = Oil slick thickness on the water surface, m C e = Concentration of oil emulsion in the water column, g/m 3 C d = Concentration of dissolved oil in the water column, g/m 3 C p = Particulate oil concentration in the water column, g/kg C db = Concentration of dissolved oil in interstitial water in the bed sediments, g/m 3 C pb = Particulate oil concentration in the bed sediments, g/kg in slick in water column in bed sediments LOSSES: evaporation hydrolysis photolysis oxidation biodegradation

Transport of the oil phases in the water column C e = Concentration of oil emulsion in the water column, C d = Concentration of dissolved oil in the water column, C p = Particulate oil concentration in the water column,

Oil Transfer at Media Interfaces water column - bottom layer b water layer bed sediments zz exchange coefficients

Model Parameters

Comparison with data

27 Comparison with data

Oil Spill at Open Sea Channel 2-D test case 60 m 500 km U=7 m/s oil 28,000 T u=1 m/s L= surface fence

29 2D simulation. Oil slick thickness Dissolved oil concentration in pore water of bed sediments

30 2D simulation. Dissolved oil concentration in water column Emulsified oil concentration in water column

31

32 BOOM-SKIMMER SYSTEM : Boom opening = 100 m Maximum Skimming rate = 150 m 3 / hr Maximum operation at wave height =1 m Maximum effectiveness: (day light) = 80 5 m/s wind speed m/s (night) = 50 % of day light values.

33 DISPERSANT APPLICATION : Dispersant : Arcochem D-609 Oil : Dispersant Ratio = 143 : 1 Maximum dispersant effectiveness = 80 % Lethal concentration (LC 50 ) for Zooplankton (Mysidopsis bahia) = 29 ppm (96 hrs exposure period) Spray width = 50 ft

3-D oil spill simulation at Singapore Straits

Surface currents at one instant of tidal cycle for the south-west monsoon

Day 0 Hypothetical oil spill ~ 28,000 T in Singapore Straits

Day 0.5

Day 1

Day 1.5

Day 2

Day 2.5

Day 3

Conclusions a a The three-dimensional multiphase oil spill model is developed to simulate the consequences of accidental oil releases in the Singapore Straits. a a The model is updated with a high-order numerical scheme for accurate simulation of the oil slick dynamics. a a MOSM is powered with the oil combating techniques evaluation sub-module. Test simulations show a good agreement with empirical data. a a The three-dimensional multiphase oil spill model is developed to simulate the consequences of accidental oil releases in the Singapore Straits. a a The model is updated with a high-order numerical scheme for accurate simulation of the oil slick dynamics. a a MOSM is powered with the oil combating techniques evaluation sub-module. Test simulations show a good agreement with empirical data.