22nd February 2023
Yanna Zhou, Deputy Principal Engineer
Environmental Monitoring and Modelling Division
National Environment Agency
Oil Particle Tracking Model

1. Past Oil Incidents in Singapore
2. NEA’s Continuous Water Quality Monitoring System
3. Strengthening of Oil Particle Tracking Model
Agenda
1
2
3

Past Oil Incidents in Singapore
1

2010
2015
2017
Past Oil Incidents in Singapore
➢ Collision involving
57,017-tonne tanker
MT BUNGA KELANA 3
and 5,272-ton bulk
carrier MV Waily in the
Singapore Strait
➢ Release of
approximately 2,500
tonnes of crude oil
➢ Collision involving Libyan-
registered oil tanker
ALYARMOUK with the
Singapore-registered bulk
carrier Sinar Kapuas about
11 nautical miles north-east
of Pedra Branca
➢ Spilled approximately 4,500
tonnes of crude oil
➢ Collision involving APL
DENVER and another
containership near the
Straits of Johor
➢ Spill of 300 tonnes of
HFO which caused oiling
of shorelines.
May 25
Jan 3
Jan 2

Impact of 2017 Oil Spill Incident
Pasir Ris Beach
Nordin Beach
Changi Beach
Incident Site

NEA’s Continuous Water Quality Monitoring System
2

NEA’s Continuous Water Quality Monitoring System
Buoys
• 8 Monitoring stations along Straits of Johor (SOJ) and Straits of
Singapore (SOS) with sensors, data loggers for automatic
transmission of water quality data to base station
• Operating management system (OMS) that collates/analyses the
data and carries out hindcast/forecast of hydrodynamic data for
various modelling runs.

Overview of Oil Particle Tracking Model
• First developed for OMS in 2014
• Simulate oil spills to predict the movement
and spread of the oil at the coastal waters
and shorelines.
• Ensure efficient and effective deployment
of NEA officers and contractors for clean
up operations.

Oil Particle Tracking Modelling for 2017 Oil Spill Incident
• Model was used to model the spread and landing points of oil spill.
• Modelling result had shown that oil was spreading towards Pulau Ubin, then moving westward
and southward in Straits of Johor

Strengthening of Oil Particle Tracking Model
3

Strengthening of Oil Particle Tracking Model
Capabilities of 2014 oil particle tracking model
Given the model’s usefulness for oil spill incident response, NEA embarked on the project with H2I-
Deltares to enhance the modelling capability of oil particle tracking model in 2022:
➢Model oil spill incidents as instantaneous point sources
➢Hindcast and forecast of oil spills to predict the movement of oil
➢Hindcast simulation up to 12 hours
➢ Expansion on Oil Type Categories
➢ Inclusion of physical processes
➢ Inclusion of Various Spill Types
➢ Simulating over a longer simulation periods (12 days) with reduced calculation time

5 oil types are modelled based on National Oceanic and Atmospheric Administration (NOAA)
ADIOS oil models (Lehr et al., 2002)
Expansion on Oil Type Categories
Type Examples
Density
(kg/L)
Kinematic
Viscosity (cst)
Evaporation (rate)
Other properties and
weathering
information
1. Non-Persistent
Light Oils (API1 >
45°)
Gasoline,
Condensate
<0.8 <3
Very high rate, 100
% within 1 to a few
days
Refer to the received
information for the
specifically spilled oil
or check with the data
library such as NOAA-
ADIOS model
2. Persistent Light
Oils (API 35° – 45°)
Diesel, No. 2 Fuel
Oil, Light Crudes
<0.8 <3
Moderate rate: up
to 1/3 within a few
days
3.Medium Oils (API
25° – 35°)
Most Crude Oils,
IFO 180, No. 4
Fuel Oil, No. 5 Fuel
Oil, Lubricating Oil
0.8-0.95
>4 and <3000 or
semi-solid
Moderate rate: up
to 1/3 within a few
days
4.Heavy Oils (API
15° – 25°)
Heavy Crude Oils,
No. 6 Fuel Oil,
Bunker C,
>0.95
1500 and semi-
solid
Little or no
evaporation
5. Sink Oils (API
<15°)
Slurry Oils,
Residual Oils
>0.95
1500 and semi-
solid
No evaporation,
Sink quickly, no
shorelines
contamination
https://kimray.com/training/types-crude-oil-heavy-vs-light-sweet-vs-
sour-and-tan-count
Selective Extraction of Bio-oil from Hydrothermal Liquefaction of Salix psammophila by Organic
Solvents with Different Polarities through Multistep Extraction Separation (2014)

Inclusion of Physical Processes
1. Evaporation: simulates evaporation of oil
2. Beaching: simulates stickling of oil to land or sea
3. Emulsification: formation of water-in-oil emulsions
4. Dispersion: simulates entrainment of oil into water column
5. Settling: the settling of oil at the sediment layer
* Processes modelled based on the characteristics for the 5
types of oil

Inclusion of Various Spill Types
Point Spill Patch Spill
Instantaneous
Continuous – continuous discharge of oil
Constant Rate
OR
OR
Varied Rate
via User
Defined Time
Series
OR

Longer Simulation Period with Reduced Calculation Time
• Combined hindcast (up to 10 days) and forecast
simulation (up to 2 days) to allow for oil spill
simulation up to 12 days
➢ mimic real oil spill incidents that occur in the near past
and predict its dispersion in the future
➢ Shorten the calculation time by running single
simulation instead of two simulations.
T0 T0+48
T0-12
Previous Model
Separate Hindcast
Separate Forecast
Enhanced Model
T0 T0+48
T0-240
Maximum Simulation Period
D-10 D+2
• Hindcast simulation up to 12 hours
• Forecast simulation up to 48 hours
Enhancement

Demonstration of Simulation – Instantaneous Point Spill
Scenario: Instantaneous Point Spill
• Oil type: Medium oils
• Mass of Oil Discharged: 50000kg
• Number of Particles: 10000
• Date and time of spill: 2023.02.09 23:00
• Simulation period: 2023.02.09 23:00 –
2023.02.21 23:00 (12 days)
Video To Be Shown

Demonstration of Simulation – User Defined Continuous Point Spill
Scenario: User Defined Continuous Point
Spill
• Oil type: Heavy oils
• Number of Particles: 10000
• Date and time of spill: 2023.02.09
23:00
• Simulation period: 2023.02.09 23:00 –
2023.02.21 23:00
Time Period Oil Discharge
Rate (kg/s)
09/02/2023 23:00
– 15/2/2023 00:00
80
15/2/2023 01:00 –
18/2/2023 00:00
40
18/2/2023 01:00 –
20/2/2023 23:00
20
21/2/2023 00:00 –
21/2/2023 23:00
0
Video To Be Shown

Summary
Enhanced version has enabled us to:
✓ Provide better accuracy in predicting spread of oil spills
✓ Strengthen NEA’s awareness of ground situation
✓ Enhance pre-emptive response time for deployment of clean up efforts and resources
✓ Ensure that the public continues to receive timely water quality data and early warnings on
affected areas by oil spill incidents

Safeguard • Nurture • Cherish