From Andy's presentation - Aims

From Andy’s presentation
• Aims
  – high-level techno-economic study
  – Framework for stakeholder engagement
  – Pre-feasibility study
  – May initiate licence applications for coal to
    liquids from brown coal

Project
• 50 Mt per year
• Anglo/Monash open cast coal with
  drying, gasification to make diesel with
  CO2 capture
• Centralised capture/compression
• Transport (40km onshore, 100km
  offshore) to Bass Strait offshore oil
  fields and deeper saline aquifers
• Kingfish field: 15Mt per year for 40
  years

Geology
• Offshore Gippsland basin, Tertiary and Cretaceous
  with oil and gas fields
• Kingfish Paleaocene and Eocene beach sand
  sediments with high permeabilities (up to 10D) and
  high productivities
   – 1 billion bbls
• Reservoir quality is very good
• Seal capacity
   –   Supports 100m CO2 column heights
   –   Intraformational seals 517m height
   –   Top seals 360 column
   –   Regional 395 m column height

Storage concept 1
•   Migration will be west to east, updip
•   Seismically-mapped faults in intra units do not intersect
    migration pathway
     –   3 faults cut top seal
     –   7 intraformational faults
     –   Most have medium to high reactivation potential
     –   System is underpressured due to oil production
•   When CO2 reaches top (100-200yrs) of unconformity it will
    migrate east to west
•   CO2 moves under intraformational seals, leading to lots of
    residual gas trapping and solution trapping (25% after 200 yrs)
•   Some mineral trapping in immature reservoir underneath
    regional seal
•   Pressures always below initial reservoir (pre-production)
    pressures

Storage concept 2
• Hydrogeology
  – Onshore extraction
  – Offshore pressure sink due to depleted
    fields
  – This leads to strong hydrodynamic drive
    which balances east to west CO2
    buoyancy-drive migration at top of Latrobe
• Capacity, >600Mt so enough for storage
  plan
• Injection will start at end of oil
  production but gas production will be
  ongoing at this stage

Modelling
• 1Mt/yr per well, for 15 wells
• Object modelling of shale interlayers
  within reservoir, small or large shales
• Surfaces from 3D seismic
• Permeabilities are averaged within
  formations
• CO2 predicted to reach top seal after
  200 years
• Some potential for CO2 movement ot of
  field but remains trapped.

QRA for Kingfish
• Outcome: total containment risks are
  below the proposed performance
  criteria
• Discussion of terminology
  – Performance assessment or risk
    assessment
  – Consequences of impacts were not
    considered

Key lessons from
 techniques/frameworks used - Andy
• RA aims
   – Transparent process
   – Interface with wider community
   – Allow assessment of safe, measurable, verifiable and
     economically sound
• QRA using URS RISQUE method
   – Using expert panel, of 10 members, to identify risks events,
     likelihood and costs
   – Also includes cost-benefit analyses, impacts on communities
• Fits with Aus/NZ risk standards
• Qualitative descriptions of probability were
  transformed to mathematical probabilities
• No performance indicators when started:
   – Therefore defined by CO2CRC
   – Containment: CO2 retention is 99% after 1000 years
   – Effectiveness: Any CO2 reduction to amount stored should

Latrobe Valley

Evaluation of risk assessment

Strengths and weaknesses of
                      datasets
•   Only publicly available data
     – 3D seismic coverage over field, larger coverage would have been useful
     – Cored wells within Kingfisher field
     – Lack of deep well control
         • Addressed through shale object modelling
         • High uncertainty, lack of pressure data
     – Lack of well density
     – Latest pressure information is unavailable, therefore relied on 15-year
       extrapolation
         • This increases uncertainty in containment and modelling but in terms of public
           concern this is unlikely to be important.
•   Access to commercially-sensitive information could be an issue in
    active oil/gas fields
•   Data that was missing
     – Poroperm data to constrain reservoir simulations
     – Need to drill deep wells to confirm stratigraphy and shale distribution
     – Stress tensors are not well constrained therefore less confidence from
       geomechanical modelling

Strengths and weaknesses of
                  datasets
•   Lack of pressure profile
     – Could provide data on integrity of intraformational seals
•   Modelling highlighted lack of data on seal distribution and
    sensitivity to pathways
•   Well integrity
     – Currently only on classes of wells
     – Not evaluated individually
     – Some are open-hole, it is not known if these have self-sealed
•   Experts could be used to comment on data quality as well as
    identifying risk events
•   Have yet to consider timescales in terms of pressure evolution
     – Risk at highest during injection and have yet to identify pathways
       from wells during injection
     – Due to lack of detailed control of intraformational seal distribution
       and properties

Key lessons from
    techniques/frameworks used
•   Experts only from research organisation but should be extended
    to experts with extensive oil&gas experience
•   Could compare with additional expert panels
•   Plot containment against effectiveness risk indices for a number
    of storage sites, allows interpretation of confidence in risks as
    well as comparison against acceptable risk targets
•   Could perform sensitivity analyses to identify what drives
    confidence (e.g. expert opinion or parameter uncertainty…)
•   RA focussed on long-term issues
     – Containment but little work on near-surface leakage or impacts
     – Well treatments as classes (exploration, production, injection)
     – Development of stand-alone risk screening
•   Performance criteria is leakage from reservoir, this does not
    equate to marine or atmospheric flux

Key lessons from
       techniques/frameworks used
•   Should be clear that this was a research exercise not a RA for seeking a
    licence.
•   Not a formalised FEP approach
     – Due to lack of time and financial resources but might not have been done
       anyway
     – Use approach with which they were familiar
     – Allows rapid assessment, scenario definition and identification of principle
       risks
         • Performance Assessment (instead of RA) component completed by 1 person
           over 2 months and expert panel met twice for review
     – Provides regulators with digestible summary
•   If external stakeholders were involved than a more formal FEP audit
    may be required
•   May not identify all scenarios but key scenarios are probably included
•   Coupling between risk events not included
•   Wells were not evaluated individually
•   Lack of empirical data for leakage rates in faults and wells
•   Modelling has not been peer-reviewed

Inherent assumptions - general
• Performance criteria (

Inherent assumptions - specific
•   Exploration wells, plugged and not re-entered or remediated
     – Assumed that they could leak, leakage rates are generic and are
       fixed
     – 200 t/yr/well for 14 wells over 500 years
•   Production & injection wells will be evaluated and remediated
    prior to abandonment therefore likelihood for leakage is lower,
    no opportunity for remediation after abandonment
•   No expected leakage through seal since a thick seal and
    retained oil for geological timescales
•   Overpressurisation will be avoided by monitoring and could get
    some fluid migration into field due to depletion
•   Seismic activity has been reviewed
     – Assume self-sealing of any reactivated fault with some short-term
       leakage
•   Identification of seismically resolvable faults does not indicate
    potential migration to surface

Confidence in results
•   Publicly available data constrains confidence in some results
     – No access to wells, production data or pressure data etc
     – No operator participation
•   Internal panel experts did not necessarily have wide oil&gas
    expertise
     – estimates of confidence may be different from other experts
•   Could repeat expert panel process with different experts
•   Based on confidence in data, is it right to make assertions to
    non-experts about Gippsland containment?
     – A priori – an oilfield
     – It is recognised that well integrity remains the key issue.
•   The impacts of faster vertical migration could be investigated
•   Uncertainty ranges indicated from this approach for other sites
    possibly too narrow.

Confidence Building
• Explicit statements of known parameters,
  processes and their uncertainty, weaknesses
• This leads to a definition of how to address
  these weaknesses
  – Monitoring programmes could be developed to
    address weaknesses identified.
• The RA was made publicly available with
  strong community engagement
  – Broad support
  – Some issues from agricultural communities
    regarding water supply (storage was good,
    reducing groundwater drawdown)
  – Potential for onshore leakage was raised and then
    adequately addressed