Blackfoot 3C/3D test makes the point for VectorSeis

Input/Output has been promoting its three-component VectorSeis sensor for land seismic surveys over the last two or three years. Here Jon Tessman of Input/Output and Bill Goodway of PanCanadian Energy Corp describe the key field test carried out in Canada on the way to commercialization. The Blackfoot field represents a style of stratigraphic trap common in the Western Canadian Basin. In many cases the acoustic impedance of the regional formations is similar enough to the reservoir to make detection through conventional P-wave seismic difficult at best. Observations based on log and core analysis suggested that the application of Vp/Vs techniques could provide a seismic method for identifying channel location and evaluating reservoir quality. These considerations led to the Consortium for Research in Elastic Wave Exploration Seismology (CREWES) acquiring a 3C/3D survey over the Blackfoot field in 1995. In 1999, PanCanadian volunteered the site for the first precommercial test of the VectorSeis sensor, a three-component, MEMS based, digital accelerometer fabricated using bulk micromachining of commercial 6 in silicon wafers (for more details on the manufacturing, see references). A Mega- Bin 3D survey was carried out over a large portion of the legacy CREWES survey. While four years of hydrocarbon production, acquisition, processing, and sensor differences prevented quantitative analysis of VectorSeis performance, this paper evaluates several qualitative aspects. Processing of the compressional and converted wave datasets showed the VectorSeis data to be comparable with the legacy geophone data. Further amplitude and Vp/Vs analysis confirmed these conclusions as well as the viability of Vp/Vs techniques as a tool for the identification and evaluation of compound incised valley fill systems in western Canada.