Removing signal distortions due to near surface complexities is the key challenge for land seismic data imaging. In the Middle East, where several major oil fields are located onshore, these complexities require developing new technologies: as extreme shallow velocity variations occur occasionally elsewhere, not enough research and development has been carried out to fully compensate them so far. In addition, the common recording geometry for deep targets produces a near-surface information gap (Vesnaver 2005). In this paper we review recent advances and some ongoing research that address this problem, with applications to real cases in the Arabian Peninsula.
The first technique reviewed is the inversion of the vibrator plate controller data, normally available in the Vibroseis seismic records, but rarely used for improving the Earth imaging. We show that it helps removing high-frequency spatial distortions due to local soil anomalies. As recording this data is part of standard field operations, its use comes almost for free, as the related processing is not heavy in terms of computing power.
A second cost-effective approach is the integration of seismic and satellite imagery. The resolution commercially available for Earth images in various electromagnetic bands is fitting the normal bin size adopted in 3D seismic surveys, e.g., 25×25 m. Thus, correlating the soil properties in terms of back-scattered radiation with physical properties as P-wave velocities or Q factor, allows improving the resolution of the shallowest layer in our Earth model. As this layer – (the so-called weathering) – is normally the most heterogeneous, improving its estimate allows removing better the related distortion for imaging the possible underlying oil and gas reservoirs.