Determining primary static corrections for application to sets of seismic traces comprises performing, for each position of common midpoint, continuous and progressive inversion of first arrival times, from short to longer offsets

摘要

A velocity model enabling the calculation of static corrections is obtained by performing, for each position of the common midpoint, a continuous and progressive inversion of the first arrival times, from short offsets to longer offsets, to enable to go from a sequence of pairs connecting the offsets to the arrival times picked to a sequence of vertical data connecting the depth to the velocity of propagation of the waves. Determining primary static corrections to be applied to sets of seismic traces resulting from seismic prospecting in an underground zone, combined according to the multiple coverage technique and arranged in common midpoint collections (CMP), comprises directly determining a model representative of the velocities of propagation of the seismic waves in a formation zone relatively close to the surface by carrying out, for each position of the common midpoint, a continuous and progressive inversion of the first arrival times, from short offsets to longer offsets, so as to be able to go from a sequence of pairs connecting the offsets to the arrival times picked to a sequence of vertical data connecting the depth to the velocity of propagation of the waves, and applying the obtained velocity model to the sets of seismic traces.