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Marine Construction
We will be rolling out our initial capabilities in support of marine
construction survey services in the offshore oil and gas sector in the
spring of 2007. Please come back for an updated discussion on our Marine
Construction services offered. For now, we offer a basic introduction on the
use of inertial to speed up operations in offshore construction operations:
Why change what is currently working offshore?
Nothing has changed for the past 20 years (apart from colored graphics
at the surface)!
Most current subsea marine construction surveys still use conventional
acoustic positioning techniques. We are beginning to see some inclusion of
inertial instruments within some of the applications discussed below but
most operations use techniques that are basically the same as those used 20
years ago. These conventional acoustic positioning systems provide the
required positioning accuracy, but consume far too much operational time –
they cost too much in Boat and ROV time.
Deepwater marine construction survey methodologies have reached a plateau.
The repeatability of such operations observed in recent years highlights
the mature nature of the technology and procedures. Mistakes are still made
and budgets are still impacted by procedural, equipment and operational
failures. Few can argue about the industries ability to complete deepwater
marine construction survey tasks – the problem is not the quality, or
the capability to complete the task – but the cost to the overall project.
Zupt’s capabilities will significantly reduce vessel and ROV time consumed
to provide precise relative and absolute deepwater positioning for many
marine construction activities.
Some examples of marine construction operational cost saving
Our tools bring major cost savings in many marine construction
applications. A few examples being:
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Metrology – providing
repeatable, reliable positioning data while consuming minimal ROV/spread
time. A local, relative positioning problem well suited to our aided
inertial solution.
Local field development positioning - 300m x 300m subsea infrastructure relative
installation – Zupt significantly reduces the operational time currently
consumed to deploy and calibrate large LBL arrays while we also reduce
the LBL beacon count significantly.
Wide area deepwater absolute positioning – 3,000m x 3,000m field wide
control with significantly reduced acoustic observation sets. For these
operations we reduce Vessel/ROV spread time consumed due to less hardware
deployed on the seabed. Such an application is deepwater permanent
suction mooring installations.
Deepwater pipeline “as built” survey – improving the survey deliverable
from USBL systems by aiding with an inertial observation set – no need
for LBL.
Increases in update rate and quality of positioning and attitude for such
ROV based tasks as bathymetry (multibeam), visualization and automation.
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Significant
cost savings
can be achieved through the use of our technology. If we look at the
example of a single multi-well field development the following are
conservative estimates of costs savings:
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Some very simple
assumptions – Near field/Far field array installations for local subsea
field installations in a large field development program. Multiple frame
set, array installation and calibration at 4 locations:
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Each
location:
5 far field transponders
6 near field transponders
2.8 boat/ROV spread days per location
4 locations
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$65K/day
complete spread rate
4(2.8x65) = $728K
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Using
Zupt’s tools and services:
Each location
3 near field transponders
1.3 boat/ROV spread days per location
4 locations
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$65K/day
complete spread rate
4(1.3x65) = $338K
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A very conservative estimate of savings = $390K on a single job
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High precision and superior quality in deep water
Zupt brings both the operational knowledge and technical expertise to allow
state of the art technical solutions to significantly reduce the
operational time consumed for these tasks.
An example of some subsea positioning tasks and the accuracy required are:
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Metrology
(Jumper and spool piece)
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5-10
cms relative
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Pipeline
Cut to Length
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1-2
meter - absolute
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Batch
Wellhead Positioning
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30
cms-relative
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Seabed
– General Positioning
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1 –
3 meters-absolute
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The water depths for
these operations vary from shallow water shelf operations (200m) to deep
frontier locations (4000m).
Zupt’s capabilities in this market are primarily ROV based and as such
provide the capability to measure distances and angles for many subsea
marine construction tasks.
This subsea aided inertial product provides very precise, high update rate
real time and post processed position, heading and attitude data. These
capabilities have been designed and constructed to survive the offshore
environment and work in the “real world” of daily operations – such as
limited bandwidth ROV communications.
Please come take another look at this page in the near future for a more
detailed discussion of our capabilities.
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