PROCESSING OF 3D SPARSE AND IRREGULAR SEISMIC REFLECTION DATA

• Main Author: Faizi Pratama, Difo
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/86276
• Institution: Institut Teknologi Bandung

Processing of 3D seismic reflection data with a sparse and irregular layout presents significant challenges in improving the quality of subsurface images. Ideal seismic surveys are typically conducted with symmetrical and dense layouts, resulting in data with uniform fold counts and high-quality images. However, such surveys often require high costs and may not always be feasible under all field conditions. As an alternative, 3D seismic surveys with a sparse and irregular layout are conducted with fewer shots and receivers, leading to irregular fold, offset, and azimuth distributions, which degrade seismic image quality. This study aims to analyze the characteristics of seismic data obtained from 3D seismic surveys with a sparse and irregular layout, evaluate effective data processing methods, and produce a seismic stack cube from the processed data. The data processing workflow includes time break correction, geometry assignment, denoising, amplitude recovery, deconvolution, velocity analysis, NMO correction, residual static correction, stacking, and enhance. The results of this study show that signal and noise components overlap at low frequencies, necessitating additional denoising techniques beyond bandpass filtering. Denoising and residual static correction proved to be crucial stages, as they both significantly improved the S/N ratio. However, good S/N ratio results were only achieved along certain inline directions, making the outcome more accurately described as pseudo-3D. To achieve uniformly high quality across the entire survey area, techniques such as regularization and interpolation may be applied.