CO2 Sequestration in Deep Saline Aquifers
[Depleted Oil & Gas Reservoirs Vs Deep Saline Aquifers]
[Pore-scale, REV, Core/Laboratory-scale, Pilot-scale, Geostatistical-scale, Aquifer/Reservoir-scale]
If an aquifer is typically extended over several kilometers
in the horizontal directions
(along the flow direction and normal to the flow direction) and
ten to a hundred meters in the vertical direction, then,
how exactly to go about characterizing
the properties of the given aquifer,
given the fact that heterogeneities at different scales
remain to be characterized differently?
Although, CO2 sequestration in depleted oil and gas reservoirs
have the advantage of having an already existing reservoir properties
(while seismic data could provide only limited information about the aquifer properties within the storage reservoir),
would it remain feasible to secure the information
required to characterize the aquifer properties relevant to
CO2-brine flow dynamics, in a deep saline aquifer,
in the absence of well logging measures, rock cuttings and core samples (taken during drilling operation)?
Or
Should we depend heavily on modeling/simulation/statistical-approaches
in order to characterize CO2 sequestration mechanism
in deep saline aquifers?
If so, won’t the reservoir model require
billions or trillions of grid-blocks,
if we opt for the highest possible resolution
(that would include the smallest-scale measurement data)?
Or
Should we convinced with resolution @ geostatistical-scale
(grid-block on the order of 1-10 m)?
If geostatistical-scale is used directly
(where, core-scale data remains insensitive), then,
how exactly upscaling
from geostatistical-scale to an aquifer-scale
would remain to be justified?
In addition, how about the sensitivity of
cross-beddings, inclusions and small-scale laminations
that could significantly
alter the interactions
between viscous, buoyant and capillary forces,
which in turn,
would affect the aquifer-scale CO2-brine plume migration and
CO2 trapping?