3D Migration of 2D Crooked-line Seismic Profiles

Sparse acquisition of 3D seismic data can contribute to cost reduction, which is important especially in geothermal ventures, where profitability often is low and the use of 3D seismic generally is questioned. We reduced a 3D seismic dataset from geothermal exploration in the Upper Rhine Graben, Germany, to one quarter of its traces to simulate a sparse acquisition. The velocity model and the residual static values were newly derived from the reduced dataset. The target of our investigation was a lower Jurassic seismic marker, which is cut by faults of varying size and throw. The smaller ones could best be imaged by horizon based RMS amplitudes of the variance cube. CRS processing significantly improved the imaging of the faults, in both the full and reduced dataset. Whereas the larger faults could be imaged with the simulated sparse acquisition as well, details of the smaller faults are lost, even if processed with the CRS method.