Noise Attenuation on SEAM002 Arid Model data

The SEAM Arid model is a synthetic data set proposed by the SEG Advanced Model (SEAM) that simulates the complexity of seismic wave propagation in a desert environment characterised by surface and near-surface features such as karst, Waadi and sand dunes. The modelled data embodies typical challenges of processing land seismic acquired in the Middle East, characterised by complex near-surface conditions that include sand dunes, karst and rough topography. The complexity of the near-surface due to the strong and rapid velocity variation both vertically and horizontally produce a complex wavefield propagation that generates strong coherent and scattered noise arrivals in the acquired data. The presence of strong velocity contrast in subsurface geological horizons produces strong interbed multiples. Free-surface and interbed multiples constitute a type of coherent noise that needs to be attenuated for accurate imaging. In this work, our main objective is to attenuate the coherent and scattered ground roll, the free surface and interbed multiples. We performed the noise attenuation on a decimated version of the original SEAM Arid model to emulate the orthogonal acquisition geometry of a conventional high-channel-count (HCC) survey often used in the Middle East. We demonstrate, through our processing workflow, how we progressively attenuate these coherent noises while minimising the damage to primary reflection arrivals. We performed isotropic Kirchhoff pre-stack time migration on the processed data using picked velocities for a qualitative assessment of imaging. Given the complexity of the near-surface conditions, an elaborate velocity model building, in depth domain, will be required for a more accurate imaging.