18 Dec 2002
The world's first permanent fiber-optic seismic-monitoring system is installed in a well in France.
Weatherford International, a US maker of specialized equipment for the oil and gas industries, claims to have installed the world's first permanent fiber-optic seismic monitoring system in a well in France.
The system, which is deployed at Izaute Gas Storage in southwestern France for oil company TotalFinaElf, consists of six sensing stations equipped with Bragg-grating based fiber-optic accelerometers. Five of these stations perform vertical seismic profiling (VSP) for characterizing the reservoir while the sixth continuously records micro-seismic events.
Optoplan - Weatherford's specialist subsidiary in Norway - managed the design and installation of the sensors. According to project manager Hilde Nakstad, fiber-optic sensors offer a number of advantages over their electronic counterparts.
She told OLE that an all-optical approach gives a very reliable permanent solution that eliminates the need for any active electronics in the well. She adds that the sensors are qualified to cope with a temperature of up 175°C and a pressure of up to 1000 bar.
Weatherford has already developed fiber-optic sensors for measuring pressure, temperature and multi-phase flow. Further seismic monitoring installations are now expected to follow.
Oliver Graydon is editor of Optics.org and Opto & Laser Europe magazine.