KAZAKHSTAN UPSTREAM OIL AND GAS technology and R&d ...

1.1 Seismic data acquisition and processing
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Solutions commentary
The seismic solutions are grouped into the
natural steps of data acquisition, processing
and interpretation. The seismic data, where
appropriate, are combined with non-seismic
data and utilised in a more sophisticated
manner over time to provide key information,
including fracture orientation and size,
high resolution lithology distribution, fluid
movements and permeability distribution. This
information, which for key fields is expected
to be available on demand via permanent
monitoring, will significantly impact reserves
and production.
In the near term, current global practices
need to be transferred into Kazakhstan, in
some cases they require adapting before
being suitable for use. Some have already
been used, but with mixed results and their
use has not been widespread. Survey design
underpins the seismic capability and source
and sensor coverage, together with spatial
sampling; all of this needs to be optimized
based on the subsurface targets, while
being constrained by cost considerations.
Irrespective of processing or interpretation
capabilities, sub-optimal input field data
cannot be rectified. Optimal design will
improve existing 4D repeatability, it also
will enable broadband, wide-azimuth
and other more sophisticated acquisition
methods – although these are also likely to
require adapting for the shallow waters of the
Caspian.
On the processing side common reflection
point stacking (CRS) for noise removal,
pre-stack depth migration (PSDM) for
improved imaging, and advanced water
bottom multiple attenuation needs to become
standard practice. Significant computer power
is required to enable this. With the newer
acquisition methods and processing capability
growth, full wave-equation-based seismic
processing is the near term goal.
The improved data needs to be interpreted
with the latest 3D visualisation and attribute
analysis packages available. In the mid term,
acquisition design will improve further, land
seismic should move towards mega-channel,
single-sensor, high-fold surveys – providing
step changes in land subsurface images,
while probabilistic inversion for reservoir
properties will become standard.
These developments will be paralleled by
wide coverage with non-seismic methods,
which when combined with seismic further
reduce subsurface uncertainties. All these
steps will be further refined in the long term
with permanent 4D, multi-component sensors
and the ability to determine fractures and infer
permeability; thus providing the support for
increased production and reserves.
Kazakhstan Upstream oil & gas technology and R&D roadmap