Study on the Deployment of Accelerometers in Reflection Seismic Surveys

The RSCS (Real-time Seismic Cable System) is an optical submarine cable system employing a series of 3 axial component velocity type sensors (geophones) mounted in a pressure resistant case capable of withstanding hydraulic pressures up to 800 atmospheres (78.4 MPa). Spreads consisting of several of geophones, spaced at 50 meters interval, have been deployed during actual offshore reflection seismic survey. The resulting data quality with RSCS showed that this system was effective for multi-component reflection seismic survey [1]. In this paper, application of acceleration type sensors (accelerometer) in RSCS was studied. For comparison, a system equipped with 3 component geophones and a 3-axis accelerometer was deployed during reflection seismic survey in an area with a water depth of about 1000 m. The data acquired with both types of sensors have excellent quality and it can be concluded that RSCS equipped with accelerometer is also effective for reflection seismic surveys. This result shows the possibility to reduce the size of RSCS unit, because accelerometer does not need the gimbal mechanism necessary for geophones.