oa Fibre Optic Permanent Monitoring System - Towards The Optical Oil Field

Permanent seismic installations at the sea-floor have emerged as a potential tool for oil companies in<br>their work to actively monitor oil/gas flows and injection processes in order to increase hydrocarbon<br>recovery and optimize production. The advantage of fibre optic over electric sensors is that the fibre<br>optic sensor technology is completely passive at the wet-end, i.e. no short circuits will happen, longer<br>life-time of components, high sensitivity, high dynamic range, less intrinsic noise, no corrosion of<br>sensing components, fewer parts and potentially cheaper complete receiver systems. Fibre optic multicomponent<br>ocean-bottom receiver systems for 4D applications can now be produced and installed<br>successfully at locations where the oil companies would like exploit the life-of-field seismic concept.<br>The analysis of the data from the pilot tests confirms the systems high degree of vector fidelity, high<br>signal-to-noise ratio, very good ground-station coupling, reliability and excellent response in general to<br>wave modes in connection with ocean-bottom seismic. Fibre optic based permanent seismic monitoring<br>systems represent a great opportunity for the field engineers to optimize production and increase the<br>hydrocarbon recovery rate from existing fields.<br>We are advocating optical sensing technology to be an important part of the tool box for the oil<br>companies in their work to implement the instrumented oil field in a cost efficient way. The “optical oil<br>field” should represent the next step in technology in connection with reservoir monitoring in order to<br>increase the hydrocarbon recovery rate.