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Spotlight

Geotag

Wed, 01/20/2016 - 18:33

The French company Sercel, a global leader in seismic acquisition with 50 years of experience, is continuously developing technologies that help companies in the hydrocarbon exploration industry. One of the company’s leading technologies is GeoTag, an acoustic positioning system for seabed seismic acquisition. In order to conduct a seismic or ocean bottom survey, companies cannot simply send a surveyor equipped with a GPS, as this would not provide any accuracy. GeoTag is the latest generation of positioning devices with the highest degree of accuracy, which is ensured thanks to a twoway communication of time-distance measurements from the GeoTag transponders located on the seabed and the GeoTag transceivers found on a vessel. The AC powered transceiver is connected to the INS via a junction box and can receive up to ten simultaneous replies and absolute positioning is then computed with a precision of 0.2m after processing. One of the challenges faced by similar devices but overcome by GeoTag is saturation. Thanks to its ability to handle up to 10,000 units per crew, the positioning device provides an extremely high quality resolution for large 3D surveys.

The submarine positioning device has an operating range of 1,000m and can function up to a water depth of 500m, making it a suitable option for both shallow water and deepwater surveys. It is an extremely adaptable technology as it can be used with any kind of equipment, be it OBC, transition zones, or ocean bottom nodes, and its size provides customers with considerable advantages. While competitors’ transponders are 442mm long with a diameter of 63mm, Sercel offers the smallest transponder on the market with a length of 370mm and a diameter of 60mm. Maintenance is also simplified by the transponder’s simple design that allows the customer to perform basic repairs independently, including changing the alkaline battery pack that has a typical six-month long life in operation.