A two-way approach to adapt reduced-scale laboratory experiments and corresponding numerical simulations of offshore seismic surveys in complex marine environments

Abstract

Recently, laboratory experiments have been reintroduced in the ideas-to-applications pipeline for geophysical issues. Benefiting from recent technologic^ advances, we believe that in the coming years, laboratory experiments can play a major role, in support of field experiments and numerical modeling, to explore some of the current challenges of seismic imaging in terms of, for instance, acquisition design or benchmarking of new imaging techniques at a low cost and in an “agile” way. But having confidence in the quality and the accuracy of the experimental data obtained in a complex configuration that mimics at a reduced scale a real geological environment is an essential prerequisite. This requires a robust framework regardless of the configuration studied. The goal of this work is to provide a global reflection on this framework in the context of offshore seismics. To illustrate this framework, we rely on a reduced-scale model representing a 3D complex-shaped salt body buried in sedimentary layers with curved surfaces. Zero-offset and offset reflection data are collected on this model in a water tank, using a conventional pulse-echo technique. We follow a cross-validation approach that allows, through the comparison between the experimental data and the numerical simulation of wave propagation, to point out both the improvements of the experimental setup that must still be made to increase the accuracy (and decrease the uncertainties) of the experiments, and the limitations of the numerical tools that must be tackled. This framework can be used with confidence to extensively investigate cutting-edge seismic imaging and acquisition issues in complex environments.