Fibre-Optic Vsps: Borehole Seismic Revolution in Australia

Abstract

The borehole seismic industry is undergoing a quantum leap in the acquisition technology. The standard borehole seismic imaging tools such as accelerometers and geophones are now being replaced by the fibre-optic (FO) acquisition for basic surveys such as zero-offset vertical seismic profiles (ZVSPs) and checkshots. This saves significant time, and associated rig cost, whilst providing sufficient data quality for basic interpretation. Schlumberger’s heterodyne distributed vibration sensing (hDVS) technology, deployed within a wireline heptacable, was recently used in Australia to acquire a zero-offset VSP dataset, whilst simultaneously taking downhole core measurements. The hDVS technology is based on the distributed acoustic sensing (DAS). This presentation shows the acquired dataset and the basic processing results. A comparison between the FO and conventional dataset, in the nearby wellbore, as well as surface seismic and synthetics is made showing remarkable similarity between all datasets, validating the FO data.