ROUTAGE AND MONITORING DURING PLATFORM TOWING AND PROVISION OF REAL SEA STATES MEASURED BY THE SAR IN WAVE MODE FOR A CORRELATION WITH MEASUREMENTS OF BARGE MOVEMENTS : THE N'KOSSA PROJECT CASE STUDY
ROUTAGE AND MONITORING DURING PLATFORM TOWING AND PROVISION OF REAL SEA STATES MEASURED BY THE SAR IN WAVE MODE FOR A CORRELATION WITH MEASUREMENTS OF BARGE MOVEMENTS : THE N'KOSSA PROJECT CASE STUDY
Primary Keywords: Forecast, Transport, Oil
Secondary Keywords: Structure design, Sea-state,
Waves, Datawell, Wind
Marine operators, like ELF and Mc DERMOTT-ETPM, need to
minimize the risks of exceeding the transport design criteria when transporting
large structures and platforms towards production sites.
Elaborated by MétéoMer, this procedure make use of
technologies which have been developed within a CLAROM project and a SAAD
project. It use satellite wind and sea-state data and lead to a permanent
control of the meteo analyses and exactness of the model calculations on a
large scale area.
Furthermore, tow movements measurements are implemented in order to make 'a
posteriori' analyses and control of the calculation codes for movement
prediction.
When transporting large structures and platforms towards production sites
across meteorological perturbed areas, risks of exceeding the transport design
criteria must be minimized. Due to the slow progress of the towing, 5 to 8 days
forecasts are unsufficient to guarantee good conditions during the whole route
which can long 40 days or more.
For the optimization of the towing, the operations manager requests that
meteorological events be anticipated, optimized routes proposed when
approaching highly perturbed zones and the prevailing sea states supplied.
The entire technology described in the case study for platform installation, with a systematic calibration of swell calculations through satellite data is also applied here, except that the forecasting area is larger since it is a route instead of a specific site and that local swell and current measurement equipments cannot be implemented.
Here, special emphasis will be put on SAR in wave mode whose data is
compared with results from our ISFS model. Moreover, the platform is equipped
with instruments for continuous data measurements of pitch, roll, yaw, heave,
sway, surge and the corresponding accelerations, transmitted to the tug through
a direct telemetry link.
The archived data enable 'a posteriori' analyses and control of the calculation
codes for movement prediction.
This technology is undertaken in MétéoMer by two marine
meteorologists while the system for measuring tow movements is installed with a
link on the tug, finally supplying us with the necessary information. Satellite
information is also available at MétéoMer by direct link with
ESRIN-Frascati for reception of LBR measurements in a 2-4 hours delay. Data are
processed on a Sun station as well as meteo analyses and ISFS final
calculations.
Moreover, Meteosat pictures are also permanently received.
Final synthesis are continuously available and meteo reports are sent every 12
hours.
Service consists in providing the predicted sea states that the operations manager can analyse and use in two modes:
Such choices are subject to highly accurate predicted parameters, calibrated
with satellite measurements.
This operation has been achieved using a set of method incuding :
These different comparisons enable to check the accuracy of meteorological
analyses and correctness of our calculations and offer an a priori guarantee of
the forecasts on a 24 hours period and more.
This picture shows the equipement used for the monitoring and storage of the
behavior of the transportation barge in waves and wind.
Information is supplied in real time to contol the transportation and stored to
allow the fatigue parameters analysis recorded during transportation.
Systems lies in a self powered movement sensor coupled to a radio link for data
transmittal on the tow. On board, data is received, processed, stored and
display on a PC screen according to the customers' specifications.
For such a study, MeteoMer supply :
With this assistance, ELF and McDERMOTT-ETPM benefited from metocean
reliable information in operational conditions.
In case of structure transport, such procedures offer an increased guarantee on
the metocean conditions and allow the coordination of companies actions, for
the oprimisation of the towing.
Cost for this service is around 450 ecu per day, including data cost. (Cost
for a tow ranges from 45 to 77 Kecu per day).
| Customer1 | Customer2 | |
| Name: | Mr. Perinet | Mr. Pelleau Mr.Lhopitallier |
| Company: | Mc Dermott-ETPM | ELF Congo |
| Address: | 32 Av. Pablo Picasso 92754 Nanterre cedex France |
Tour ELF La Defense 92078 Paris cedex 45 France |
| Name: Mr Lasnier |
| Company: MeteoMer |
| Address: Quartier les Barestes - RN7 - 83480 Puget sur Argens - France |
| Tel: +33 (0)4 94 45 66 11 |
| Fax: +33 (0)4 94 45 68 23 |
| E-mail: 4meteomer@meteomer.fr |
| Web: www.meteomer.fr www.meteomer.com |
| Name: Mr Lasnier |
| Company: MeteoMer |
| Address: Quartier les Barestes - RN7 - 83480 Puget sur Argens - France |
| Tel: +33 (0)4 94 45 66 11 |
| Fax: +33 (0)4 94 45 68 23 |
| E-mail: 4meteomer@meteomer.fr |
| Web: www.meteomer.fr www.meteomer.com |