Countermeasures and Key Techniques of Integrated Deep Seismic Processing and Interpretation: A Case Study of the Gaoshiti-Moxi Area

Deep seismic data are more prone to noise interference and generally suffer from the problems of low imaging quality, low SNR (signal-to-noise ratio), and high multiplicity of solutions for reservoir prediction. The gas reservoir of the Dengying Formation in the Gaoshiti-Moxi area is buried deeper than 5000 m. After several rounds of processing, the seismic data are still found with low consistency with synthetic seismograms and low reservoir prediction accuracy. In this research, the technical countermeasures and supporting techniques of integrated seismic processing and interpretation for deep layers are put forward and developed. With the seismic forward modeling combing well and seismic, the presence of interference of multiples in deep layers is confirmed and its characteristics are identified. With the techniques such as the well-seismic-combined velocity modeling, layer-controlled multiple suppression, and pre-stack amplitude-preserving quality control, the consistency of well-seismic calibration is improved and the imaging quality of deep weak signals is enhanced. Given the subtle reservoir characteristics and the requirements of different interpretation techniques, the seismic are further processed and optimized. The reservoir prediction is carried out using multiple types of seismic data, which improves the accuracy of fault identification and reservoir distribution. The integration of seismic processing and interpretation combines seismic, geological, drilling, structural, and other information, which is helpful to deeply analyze seismic data, develop targeted processing techniques and workflows, guide and constrain the processing, and review the fidelity of data from the two aspects. With such integration, one is able to produce multi-objective seismic data via optimization, reduce the blind area of seismic data, and improve the accuracy of reservoir prediction, which is of great significance to the future exploration and development of deep reservoirs.