onshore spill modelling to inform contingency planning
TRANSCRIPT
Presented by Christopher Kitley, Principal Hydrogeologist.
WorleyParsons
Onshore spill modelling to inform contingency planning
WorleyParsons is a leading provider of project delivery and consulting services to the resources & energy sectors and complex process industries. Our services cover the full asset spectrum both in size and lifecycle – from the creation of new assets to services that sustain and enhance operating assets. Across our comprehensive global network our four customer sector groups use their extensive expertise to deliver small studies through to mega-projects.
With 38,000 people in 157 offices throughout 40 countries, we provide our customers with a unique combination of extensive global resources, world-recognized technical expertise and deep local knowledge.
Onshore spill modelling to inform contingency planning
Contents
§ Introduction & background § Approach § Modelling techniques § Case study § Results § Innovations and development
Track record: q Environmental & Social Impact
Assessment (ESIA). q Contingency planning. q Infrastructure design. q Insurance profiles & liability. q Software development. q Full field ► Refinery ► Tank
WorleyParsons approach Using our multi-disciplinary consulting & engineering teams q Phased & risk based approach for
efficient design q Robust modelling to reduce
uncertainty q Scalable & transferable to all project
lifecycle assets
Phase 1 Screening
Subsurface migration
Surface spreading
Possible significant spills
Low priority
Phase 2 Numerical Modelling
Catalogue results in OSPS matrix
Phased approach to assess Oil Spill Planning Scenarios (OSPS) for contingency planning
Identification
OSPS Matrix
Contingency planning
Case study: Onshore oil spill modelling to inform contingency planning
Location Development Project scope
§ Arid environment § Inland wadi systems § Flat terrain § Fragile ecosystem § Surrounding
groundwater users
Large upstream condensate rich: § >1500 km2
§ >250 gathering wells § >500 km of pipelines § CPF, Waste
treatment, § Reinjection wells § Fluids: Condensate,
diesel, PW, OBM
§ Front End Engineering & Design (FEED)
§ Contingency planning
§ Numerical modelling to assess spill migration with time
§ No applicable guidance
Case study
Oil spill scenario matrix (OSSM)
Identification of oil spill planning scenarios (OSPS)
Identification: causes / scenarios Likelihood: 100% probability
§ Literature review § Oil spill planning scenario workshop § Catalogue of credible oil spill
planning scenarios § Organised by source, mode of
release & product § Each populated with pressures,
flows, mitigation measures & socio - environmental risk
Agreed OSSM included 38 top level scenarios & 1,000+ locations
Environmental Impact Factor (EIF) tool
Phase 1 Screening
Risk prioritisation modelling
§ Developed with Statoil.
§ Multi-scenario on-shore tool.
§ Risk management decisions.
§ Prioritisation of sites.
§ Surface and subsurface impact.
§ Maximum surface spreading plotted on GIS → buffer zones.
§ Maximum subsurface migration compared to groundwater elevations.
§ Update oil spill scenario matrix and categorisation of spill scenarios.
Surface spreading
Phase 2 Numerical Modelling
§ Tank & pipeline leak & failure § Amended flood model and digital elevation model
(DEM)
§ TuFlow 2D surface flow model designed to model shallow flow over complication terrains
§ Amended code for varying fluid properties (density, viscosity, internal eddy friction).
§ Plans and animations of spill migration with time § Pooling depth and area.
§ Can also model transport in surface water
Phase 2 Numerical Modelling
Subsurface flow
Hydrocarbon spill screening model (HSSM), US EPA/RISC beta version)
Three scenarios:
§ No containment (spill area, duration, volume)
§ Containment (depth, duration)
§ Below ground (flux, duration)
Very sensitive to geological conditions and residual saturation
Worst/best/most likely case used to form up and lower bound estimates
Phase 2 Results Example results:
q Geographical spread with time
q Pooling depths
q Assessment of impacts
q Re-assessment of impacts
Pipeline failure case
Tank and containment failure Pipeline leak, oblique view with pooling
Results of subsurface modelling
Sensitivity analysis:
q Variations in pooling depth effects
q Variations in event durations
q Upper & lower band cases
Information for contingency planning
Surface spreading Subsurface
Model outputs
§ Graphics of area vs. time. § Pooling depths. § Shape files for GIS. § Depth profiles. § Upper & lower case envelope. § Updated OSPS Matrix.
Contingency Planning Information
§ Categorization of spill events. § Location of worst credible events. § Response time envelope. § Areas and volumes of impact. § Design implications, including:
§ Leak detection requirements. § Inspection regimes. § Relocation of camps &
infrastructure. § Regulatory compliance
Results summary
Response planning
Summary
Innovation q Project demonstrated that WorleyParsons phased approach worked well. q Combining multidisciplinary teams of hydrocarbon engineers and environmental
scientists.
q Adaptation and application of commercially available software q Robust approach to setting upper and lower bound estimates q First project of its scope and scale.
q Development of software & visualization tools Future developments areas:
q Guidance for standardized approach q Inclusion of air dispersion modelling to simulate well blow out (screening or detailed)
q Inclusion of fire hazards (pool fire effects)
q Inclusion in HAZID workshop q Project engagement window (ESIA, concept design, detailed design).
Innovation & future developments
Thank you
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