FOR OIL AND GAS EXPLORATION

Sercel’s seismic acquisition systems help oil and gas companies pinpoint the best locations for exploratory drilling.

During seismic exploration, thousands of vibration sensors—10,000 times more sensitive than those inside your average smartphone—are positioned across the area being explored. Acoustic waves created by vibrating trucks are then propagated underground, where they are reflected back to the surface from depths of several kilometers and measured at locations up to ten kilometers away. The waves’ “travel times” are calculated, providing valuable insights into the geological formations underground.

Technology

Seismic acquisition systems generally use analog (a coil and magnet) components. In 1996 Leti and Sercel developed a radically different miniature sensor on silicon. Since then, the system has undergone constant improvements, resulting in performance that remains the best available worldwide.

A suspended mobile structure measuring several square millimeters and integrating a network of intercalated fingers between fixed fingers is subjected to acceleration. The resulting movement—just a few millionths of a millimeter—is measured by capacitive sensing and offset by a feedback mechanism. This structure, so sensitive that the impact of air molecules would be visible, is sealed in a highvacuum enclosure. The resulting device offers a resolution of 15 nano g/√Hz and dynamics of 130 dB.