タービダイト堆積前進モデリングの動向と探鉱分野における応用

抄録

Sedimentary forward modeling is an effective and economical approach for exploration of sandstone reservoirs, especially in deepwater settings. Computational fluid dynamics brought innovation to modeling and simulating the behaviors of sediment gravity flows (turbidity currents in most cases) along with the prediction of turbidite distribution pattern. Furthermore, establishment of structural and isostatic balancing technique contributed to quantitative reconstruction of paleo-basin structure and paleo-bathymetry. Recent dramatic improvements of computer operating speed and software performance have allowed us to apply such numerical methods to a three-dimensional (3-D), several ten to hundred kilometer wide dataset. The integration of these sedimentary and structural approaches has finally produced an advanced forward sedimentary model that numerically predicts a turbidite distribution on the reconstructed 3-D paleo-bathymetry. Such an integrated model is powerful and useful for better understanding of lobate turbidite distribution and of turbidite deposition in topographically complicated basins, or confined basins, and also for stochastic determination on input parameters of turbidity current (s) based on a limited number of available well-log data. Combination with seismic geomorphology and seismic attribute analysis can improve the quality and accuracy of geological evaluation in deepwater turbidite play.