Processing of 3D Marine Seismic Data in Deep-Water Exploration: Challenges and Solutions

The definition of reliable processing flow of seismic data is a complex and challenging task in most cases. In this study, additional complexity related to deep-water acquisition environment and the necessity to preserve the recorded amplitudes arises since the Amplitude Variation with Offset (AVO) analysis is key tool for interpreters to identify prospects. Here, an efficient workflow based on a pre-stack time migration (Pre-STM) sequence is presented. After quality control (QC) of the data and the identification of the different noises contaminating the data, a tailored and cascaded pre-processing sequence is defined that effectively attenuated noise, corrected the wavelet and filled the acquisition gaps. Compared to shallow marine environments, the additional complexity is related to water column statics that exhibits an accentuated impact. The migration of the data is done through a PreSTM using a reliable velocity model updated using a fast and effective non linear tomographic approach. The data quality is further ameliorated using migration post-processing sequence. The workflow presented in this study proved its efficiency by rapidly achieving interpretative and high quality seismic volumes.