Pre-drill surface seismic in the vicinity of the AIG-10 well and post-drill VSP

Abstract

Pre-drill reflection surface seismic was carried out in the Aigion city area in February 2001. The poor quality of seismic reflections obtained from standard processing did not allow us to refine the location of the vertical well AIG-10 to be drilled. Subsequently, a brief study of refracted seismic arrivals was attempted in order to better define the well location, in conjunction with observations from a shallow well. In 2002, after drilling, an innovative 6-VSP position well seismic survey was successfully run, using a four-component downhole sensor tool, i.e., three orthogonal geophones and a hydrophone. Refracted seismic events and first arrivals from VSP indicated the throw of the Aigion Fault and the fault plane dip; a secondary accident striking about south–north was detected about 100 m west of the well. No P–P seismic reflection was evidenced from standard VSP processing.