Disk Drives Are (Relatively) Cheap.
People’s Time Isn’t.
Changing the way seismic compression technology is adopted by the industry involves balancing compression quality and performance.
Contributed by Hue
he oil and gas industry has long had a keen
interest in seismic compression. Copious quantities of research have been published, but uptake has
lagged. Hue, mostly known for its visualization and
GPU acceleration technologies, aims to change that.
Seismic datasets keep increasing in size and resolution, and it’s not uncommon to see double-digit terabyte size surveys today. The challenges of managing
such large volumes have prompted academia and
industry experts to conduct and publish research on
the topic.
Compression is attractive for several reasons. If
data can be compressed in the field (during acquisition), less data have to be transferred for in-house
processing and analysis, making data available earlier
for decision making. In processing and imaging, it’s
attractive to compress data to increase the throughput of the compute system (cluster) due to band-
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width ceilings in data transfer. In an exploration setting, teams need to condition and interpret these
huge surveys, and although a lot of time can be
wasted on data-copying of uncompressed data, that
implies less time available for real work. People’s
time is not cheap.
Much of the research has focused on the quality
and appropriateness of compression. As a result, there
are now recommendations and standards for data
compression both in oil and gas as well as other
industries. The key reason for the lack of use of data
compression isn’t quality. Rather surprisingly, perhaps, the key reason has been that the compression
(and subsequent decompression) has simply been
too slow to be of great value. For that reason, most
compression used today is for long-term storage, but
this does little to help address the benefits that the
industry wants.
Hue has, over the past eight years, carried out a lot
of R&D on data compression techniques, and the
company believes it has achieved an optimal balance
of compression quality and compression performance. The technology is integral to the company’s
visualization and GPU acceleration product,
HueSpace, but given the excellent results the company has decided to commercialize the data compression and corresponding multidimensional file
format for wider adoption.
Why is this becoming more and more relevant?
The increased acquisition of full-azimuth/wideazimuth (WAZ) and 4-D life-of-field seismic
implies that seismic datasets have become a real
logistical problem. The increasing sizes of the data
pose great challenges to the exploration divisions,
where seismic data account for up to 90% of enterprise storage demands.
Geoscientists working with seismic processing
applications face challenges when trying to access
the data, since large files can cause performance
issues when trying to access such datasets from
semilocal databases or central storage. This
leaves no other choice than to copy the data
to the workstation or workg roup ser ver
instead. Unfortunately, as one senior geophysicist found out, copying 40 terabytes of
WAZ seismic from the high-perfor mance
computing fast storage to the local workgroup
server would take weeks. As a consequence, a
lot of data—especially prestack data—goes
uninterpreted.
As mentioned earlier, geoscientists apply a
large number of algorithms during interpretation and characterization, creating even more
data. For example, it’s not uncommon for users
to export spectral decomposition volumes from
nine different frequency bands. With newer
technologies such as HueSpace, these data could
be computed on the fly and never stored, but in
many legacy packages such attributes need to be
precomputed prior to analysis. Exporting these
introduces a significant and unnecessary strain
on disk and networks.
Cur rent practices in inter pretation and
derisking involve extensive attribute analysis,
reservoir characterization from direct hydrocarbon indicators or amplitude vs. offset, and inversion studies. This implies that input data must be
adequate for quantitative purposes. Not all seismic compression methods guarantee true amplitude, and that is crucial for any quantitative
workflow. Oil companies making use of software that contains seismic compression need to
ensure that any data compression is trustworthy,
as several published papers have indicated possibilities of skewed results deriving from changes
in phase, frequency or amplitude. Data compression isn’t lossless, but the loss should not affect
subsequent use.
Supermajors, nationals and independent software vendors (ISVs) working with Hue have
already conducted rigorous analysis and benchmarking of the compression technique. What
triggered Hue to commercialize its compression technology was additional benchmarks
with key industry software where Hue’s software was found to provide superior results,
resulting in significantly smaller files and
spending far less time on input/output and
compression. Hue’s technique turned out to be
almost 25 times faster than the compression
recently introduced to a prominent software
package. In this particular benchmark, Hue’s
technology compressed the entire 24-gigabyte
North Sea Quad in less than 2 minutes on a
regular laptop PC.
Oil companies and ISVs interested in discussing usage and licensing can visit with Hue
at booth 462. n
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