Journal of Earth Sciences and Geotechnical Engineering

A Hybrid Approach to Near-Surface Imaging and Characterization for an Onshore Niger Delta Prospect Field

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• Abstract

   

  The imaging of the near-surface heterogeneities and its characterization finds useful applications in seismic data processing, geotechnical, civil and mining engineering projects. The conventional approaches to near-surface imaging include inversion of refracted arrivals, uphole techniques and tomography with each approach having its peculiar advantage and limitation. In this study, a hybrid and integrated approach of using both inversion of refracted arrivals and uphole measurements is presented to build a robust, more reliable and near accurate near-surface image for the prospect field being investigated. The layer properties of the near-surface (0–500 meters), was characterized in terms of weathering and sub-weathering thicknesses and seismic velocities. The near-surface model obtained was a 4-layer earth model and the seismic velocity trend observed across the layers was an increasing velocity with increasing depth trend which is commonly expected except in instances where there could be velocity inversions. The output of this study would be used in a subsequent study to derive a refraction statics solution to be used in the processing workflow for the datasets from this prospect field.

   

  Keywords: Near-Surface Heterogeneities, Inversion of Refracted Arrivals, Uphole Techniques, Hybrid Approach, Seismic Velocities, Near-Surface Model