Annual Report 2011 - PGS

Marine Contract
OptoSeis:
Enhancing Reservoir
Production
In appropriate cases, the geophysical and
logistics aspects of a producing reservoir warrant
the use of seismic receivers permanently
installed on the seabed. PGS has developed
the OptoSeis fiber-optic system to meet this
emerging market. The system offers a number of
basic benefits: no in-sea electronics, lightweight,
safe and robust operations over at least two
decades without intervention, deepwater
deployment, adaptable multi-component
configuration and life-of-field cost-effectiveness.
Imaging improvements are also significant:
OptoSeis features a high dynamic range, low
noise and crosstalk and high channel count.
Operational benefits include on-demand periodic
and continuous (passive) 4D acquisition, low
operating costs, superior repeatability and more
frequent updating of the reservoir model. Going
forward, reservoir experts may consider OptoSeis
the ultimate reservoir management solution.
In today’s market there are three potential
providers of permanently installed fiber-optic
monitoring solutions: PGS, TGS and CGGVeritas.
TGS entered the market after acquiring Stingray
in 2011 and CGGVeritas established a market
presence following the merger with Wavefield
Inseis and its subsidiary Optoplan.
Activity in the market for permanent monitoring
systems has been fairly low. In 2008, CGGVeritas
was awarded a contract to supply a seabed
seismic sensor system for reservoir monitoring
at the ConocoPhillips’ operated Ekofisk field
in the North Sea. In 2010, PGS was awarded a
contract by Petrobras to install a permanent
seismic monitoring system at the Jubarte Field
in the North Campos basin, Espiritos Santo
province, offshore Brazil. Installation of the
system is scheduled to be completed in 2012.
This project is a significant step forward in the
use of geophysics for reservoir surveillance,
especially the application of 4D4C seismic to
map the flow of fluids in Brazil’s deepwater
reservoirs. OptoSeis data will improve the
quality and timeliness of information that
Petrobras geophysicists analyze and forward to
their colleagues, the reservoir and production
engineers who operate the offshore fields.
Tendering activity for permanent monitoring
solutions has increased and there is considerable
potential for OptoSeis permanent monitoring
solutions to become an important PGS business
niche.
What is Reservoir Monitoring?
Conducting repeat seismic surveys generates
information vital to optimizing reservoir
production and maximizing resource recovery.
Production and management techniques apply
cell-based model simulations of reservoir
production. History matching is used to reconcile
predicted with actual reservoir state and behavior
observations; the results facilitate modification
of the current reservoir model. New 3D seismic
data is periodically acquired across the reservoir
to further update the reservoir model, particularly
when history matching proves inadequate.
Successive 3D seismic surveys over a field are
referred to as time-lapse 3D or a 4D survey.
Classic applications for 4D seismic include the
identification of bypassed reserves, placement
of injection wells, identification of unknown
permeability conduits, depletion monitoring and
CO2 sequestration.
PGS has dedicated staff with expertise and
technological resources covering the four key
phases of 4D seismic work: planning, acquisition,
processing and interpretation/characterization.
The Company offers 4D services using
acquisition via towed streamer and/or OptoSeis
permanent monitoring solutions.
PGS Annual Report 2011 19