Abstract: A method, article of manufacture, and data set for simulating seismic prestack depth migrated images on the basis of a model of a selected GF-node, without the use of real or synthetic recorded data, provides a very efficient and flexible way to calculate a simulated depth migrated image as a function of parameters such as survey, overburden model, pulse, elastic wavefield, and local reflectivity structure. Important information needed for the method is the scattering wavenumber, calculated for example, by ray methods and other equivalent methods. Complex model geometry can be done in 2-D and 3-D.

Abstract: Method simulating local prestack depth seismic migrated images from target models, without using either real or synthetic recorded data. The input is a background model and some surveys, with the possibility of defining some acquisition surfaces to describe any acquisition geometry of potential surveys. In addition, detailed target models are given, generated from different type of input, such as parameter grids, interpreted time- or depth-horizons with attributes reservoir models, and other models. In the most efficient application of the invention, a point in the background model is chosen by the user and will act as a node for Green's functions calculation between the surveys/acquisition surfaces and that point. Green's functions can be calculated in many ways (classic ray tracing, Wavefront Construction, and Eikonal solvers are possible methods), the mandatory information being slowness vectors to form a sum vector called the scattering wavenumber.

Abstract: Method for solving the classical inversion problem of finding the angle dependent reflection coefficients along selected reflectors in the subsurface. The input data to the method include seismic constant offset or constant angle data cubes from Pre-Stack Depth Migration of Kirchhoff type and the corresponding reflectors and velocities from the interpretation and velocity analysis of the data. One or more of the reflectors are chosen and ray modeling is done to create synthetic seismics for all shot/receiver pairs in the seismic survey. Based on these modeling results, amplitude correction maps are made for the various reflection angles. These correction maps are applied to the amplitudes from the seismic data. The corrected amplitudes are approximations to the angle-dependent reflection coefficients in all points on each selected reflector. For each point, a weight function is computed, giving the quantitative resolution of the estimate of the reflection coefficient.