Wide-angle reflection acquisition technology for ultradeep reservoirs based on large-scale low-frequency vibroseis

With the intensification of hydrocarbon exploration in ultradeep reservoirs, conventional seismic exploration methods are no longer applicable to areas with complex surface structures and underground geological structures because they are difficult to acquire effective reflection information with high signal-to-noise ratio, the imaging effects of seismic data are poor, seismic profiles fail to clearly present the geological structures of study areas. Based on the large-scale low-frequency vibroseis excitation technology, the field acquisition requirements, and geological tasks, this study adopted a high-density two-dimensional wide-angle reflection seismic observation system to collect seismic data. This study selected the optimal field acquisition parameters suitable for the study area through numerical simulation of wide-angle seismic waves and field tests. As indicated by the results of this study, the wide-angle reflection acquisition technology for ultradeep reservoirs based on large-scale low-frequency vibroseis can acquire weakly reflected seismic signals at locations with far offset and strong energy, especially the deep low-frequency information, thus effectively improving the signal-to-noise ratio of seismic data. Compared with conventional seismic stacked sections, the wide-angle reflection seismic stacked sections have significantly improved quality, continuous events, clearly visible structural parts, and encouraging seismic imaging effects. The field production practices dominate that the wide-angle reflection seismic exploration technology can be applied to ultradeep hydrocarbon exploration.