Sea Technology

MAR 2013

The industry's recognized authority for design, engineering and application of equipment and services in the global ocean community

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Page 35 of 71

A map of oil and gas exploration and production blocks in the Gulf of Guinea. companies conduct exploration and production. Measurements in those areas would complement existing ocean and weather observations. Introducing these data in a global system, such as the World Meteorological Organization���s (WMO) Global Telecommunication System (GTS), and providing free access to the scientifc community would improve weather and ocean forecasts to the beneft of civilians as well as the oil and gas industry. Monitoring Network in the Gulf of Guinea The International Centre for Education, Marine and Atmospheric Sciences over Africa (ICEMASA) and Total S.A. (Paris, France) have developed a joint project to provide public, real-time and remote access to the ocean and weather data measured on platforms operated by Total in the Gulf of Guinea. The project started in September 2010 and should be fully operational by 2013. A prototype network of fve existing platforms��� Akpo, Usan, Tchibouela, N���Kossa and Dalia���is sending data to the French meteorological agency M��t��o-France, and fve to 10 more platforms should be added before 2014. The platforms are primarily in Nigeria, Congo and Angola, plus those in the Anguille Marine feld in Gabon. Sensors. Offshore production platforms are often equipped with a helideck, which has to comply with the regulations of the International Civil Aviation Organization and Total���s specifcations. To that extent, platforms are usually equipped with a weather station comprising at least an anemometer, e.g., Vaisala (Vantaa, Finland) WAA151; barometer, e.g., Endress+Hauser Consult AG (Reinach, Switzerland) PMC 731; and hygrometer, e.g., Vaisala PTU200 HMP45D. Some platforms have a more complete weather system, with sensors for temperature, cloud, visibility and precipitation. Most of the sensors directly measure from a helideck height 20 to 35 meters above sea level, but the anemometers are often placed higher, typically on the telecom mast approximately 40 meters above sea level, to limit wind turbulence. Some of the platforms are anchored FPSOs whose drafts change according to their tanks��� fllings. The elevation of the structure can change up to 12 meters. Although most parameters are not sensitive to these variations, the bias in pressure data is corrected using the function: P = 1013.25 [1-{1-(E/44307.69321)}5.253283 E is the elevation of the pressure sensor in meters above sea level, and P is the additional pressure if the sensor were to be repositioned to mean sea level. Some platforms require current and wave monitoring to support marine operations such as oil off-loading, and they could be equipped with a buoy moored a few kilometers from the platform with a current meter, current profler or wave sensor. Examples of current meters being used are the Water column profiling and data collection ��� Moving Vessel Pro��ler (MVP) ��� SeaCycler Moored Pro��ler ��� Free Fall Cone Penetrometer (FFCPT) ��� Laser Optical Particle Counter (LOPC) Rolls-Royce provides a complete line of oceanographic products to collect the data you need. Our rugged, user-oriented systems can measure mid-water characteristics, particulates in the water, and the geophysical characteristics of the seafoor, all in real-time. Our LOPC and FFCPT are designed to work as standalone instruments or as a payload on the Moving Vessel Profler. Contact Rolls-Royce to see how our Environmental Sensing Systems can help you get your work done faster and more cost-efectively. Efciency through automation and innovation 36 st / MARCH 2013

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