American Oil and Gas Reporter - November 2015 - 57

SpecialReport: Oil & Gas Computing

Advances Opening New Possibilities
By Kari Johnson
Special Correspondent

Permanent sensors both on land and
on the seafloor are collecting a new
stream of seismic data that can be used
for repeated active seismic, microseismic
analysis, and continuous passive monitoring. Distributed acoustic sensors (DAS)
record continuous seismic data very cheaply, taking another quantum step in the
amount of data coming from the reservoir
during exploration, development and production.
These are just two examples of how
dramatically the volume of technical data
is rising, says Biondo Biondi, professor
of geophysics at Stanford University.
"The big change taking place is in the
breadth of data we can get with different
kinds of sensors," he states. "Beyond seismic, there are streams of data from sensors
measuring temperature, pressure, flow,
and other physical information. This is
putting a strain on computational capability,
but it does open the possibility of a lot of
integration of geophysical and other data."
Data sources are evolving rapidly, becoming less expensive and providing
denser data. "One Stanford student is experimenting with rotational sensors that
record six or seven components," says
Biondi. "Others are working with both
active and passive DAS data."
When and how to process those data
are also subjects of study. "A simple
DAS fiber creates terabytes of data every
day," he explains. "It is unlikely that all
of the data can move in bulk across the
network. Instead, some amount of realtime processing will be needed near the
source."
In addition, while DAS arrays offer a
low-cost way to collect dense acoustic
data passively or actively, data quality is
lower than from conventional geophones,
Biondi says. "The challenge in this case
is to get high-quality insight from lowquality data."
While cloud computing certainly is
proving useful in meeting some industry
needs, Biondi says it may be more appropriate to keep the data "closer to the
ground" because of its volume and proprietary nature. "Fog computing is the
term for this mixed model," he relates.
Data collected from DAS acquisition
may be preprocessed local to the acqui-

sition center, for example, then sent to
the cloud for analysis, and then into the
hands of the interpreter, he speculates.
"The more channels and better data collected, the more accurate the wave field
capture," he comments. "This will speed
the transition from seismic processing to
waveform imaging. The interpreter and
processor can interact in a feedback loop.
Many types of geological and geophysical
information could be part of the fog computing process."
Reservoir-Centered Geology
Another ongoing trend in geophysics
is a push to place more emphasis on
reservoir-centered geology, according to
Biondi. "The goal is tighter integration
of reservoir properties, geomechanics,
seismic, petrophysics, etc. One student
constrained anisotropic parameter estimation using petrophysical data and well
logs and models. Some students are constraining attenuation and connecting seismic with geomechanics, including reservoir compaction and overburden stretching. Others are working with reservoir
engineers to model fluid flows that include
geomechanical effects," he notes.
"As we move toward waveform inversion, we no longer are dealing with

'magic' processing parameters, but with
more description of the geology," says
Biondi. "That allows us to bring quantitative information into seismic imaging."
That includes unconventional plays,
where Biondi says integrated reservoir
analysis soon could be performed in real
time to guide well planning, drilling,
completion and fracturing design decisions.
An important step in data analysis is
merging statistical data analytics with
physics-based analysis. "Traditional seismic imaging is based on the physics of
waveform propagation, fluid flow modeling is based on physics, and geomechanical analysis is based on mechanical
modeling," Biondi remarks. "By adding
details about the physics and geology,
we can point researchers in the direction
of physical phenomenon or geological
settings where a different understanding
of the geology and physics is needed."

Integrating Data And Processes
The industry is finding tremendous
value in integrating data and multidisciplinary processes, says Kamal Al-Yahya,
senior vice president at CGG GeoSoftware.
Traditional tools for reservoir characterization and petrophysical analysis were
essentially siloed by data type and disci-

A new geostatistical inversion tool in CGG GeoSoftware's Hampson-Russell 10.0 software helps deliver lithology and other rock property volumes to give interpreters a better
understanding of the reservoir. Pre- and post-stack stochastic inversions generate an
unlimited number of detailed realizations to allow for uncertainty analysis.

NOVEMBER 2015 57

American Oil and Gas Reporter - November 2015

Table of Contents for the Digital Edition of American Oil and Gas Reporter - November 2015