Phase III - Department of Mines and Petroleum

Data Well should also be incorporated into such an integrated report. Further reservoir quality assessment
is strongly recommended using the total core analysis dataset, thin section and quantitative XRD data.
More advanced petrographic analyses could also include stable isotope analysis of carbonate cements, to
confirm the origin for siderite cement.
We strongly recommend that further studies are undertaken to better understand the depositional setting
and the differences between different units (BD, LD, UMS, and UD). Existing sedimentology, ichnology,
FMI and palynology reports, preferably with a new study of benthic foraminifera, should be integrated. It
is recommended that the existing log correlations are reviewed in light of data from the Data Well. A
sequence stratigraphic approach to the correlation is suggested, possibly following the development of logfacies
interpretations, which should be integrated with seismic interpretations. We recommend that
detailed log correlation is attempted as part of an integrated log-correlation-biostratigraphic study. Revised
paleogeographic maps should be generated for each of the major intervals, and we strongly recommend that
variogram parameters be reviewed, and as appropriate modified, following the recommended integrated
study of depositional systems in the Dupuy and suitable analogue data. Models should be run with a range
of variograms to capture uncertainties in facies, and sensitivities in the model documented. The use of
planned sensitivity testing of the static model and construction of a new suite of post-Data Well static and
dynamic models is endorsed. The GJV plan to obtain laboratory measurements of relative permeability and
we strongly recommend that the results from special core analyses, including the assessment of
dehydration, skin factor, and fines release from core-floods, be incorporated in the reservoir simulation
model. We maintain that either a depositional facies scheme or a more detailed petrophysical facies
scheme ought to be developed, which should result in a better understanding of the Dupuy Formation
beneath Barrow Island.
Further interrogation of the flow unit transforms is strongly recommended in association with petrographic
analyses and quantitative XRD results, to better define, flow zones for permeability assessment. While the
GJV have indicated that this interrogation is underway, we recommend it includes further evaluation of
wireline log responses, computed logs and FZI zonation in relation to thin section, SEM and XRD
petrography of sandstones, seals and baffles, reservoir quality and sedimentary facies. Horizontal and
vertical permeability should also be interrogated by formation, lithofacies and facies to better understand
vertical permeability trends, necessary for more accurate reservoir models.
Three dimensional seismic reflection and drill-hole information indicate that faults and fractures are present
in the Dupuy reservoir and the strata that overlie it. We strongly recommend that all seismically resolvable
faults (including lineaments within the seismic volume considered by the Due Diligence Team to probably
be faults) are interpreted to their tip lines. These interpreted faults and predicted sub-seismic faults with
throws of ≥ 5m should be incorporated into the static model. In addition, a detailed analysis of fractures in
all available core and FMI data (include review of differences in two FMI reports) should be undertaken.
To augment existing fracture data multi-azimuth walkaways are recommended to effectively deploy some
of the seismic analytical techniques outlined for fracture detection.
The choice of specific reservoir simulation codes is not considered by the Due Diligence Team to be as
important as the quality of the PVT data used in the models and the quality of the underlying geological
model. However, we do recommend that reservoir simulation models be calibrated by history matching of
monitoring data as such data is obtained. Furthermore, the GJV are urged to consider models which are
able to couple fluid flow, geomechanics and geochemistry.
Geomechanical analysis has been undertaken to determine how the Dupuy reservoir and overlying rocks
will respond to the injection of CO 2 . To calculate critical instantaneous delta pressures, which provide
information on fault stability, we strongly recommend a conservative approach is adopted and that the
minimum reasonable value for fault sliding friction (e.g., 0.7) is used. Fault analysis should also include a
re-examination of the potential for injection induced slip on the Main Barrow fault (including the impact of
dynamic rupture processes) and a review of the impact of slip on hydrocarbon resources adjacent to the
fault. To further improve understanding of how the post-injection reservoir conditions have been
determined, the complete methodology for computing S hmin together with constraints used to compute the
distribution of S hmin should be documented. Estimates of reservoir stress conditions should be augmented
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