Assessing the Value of Low Frequencies in Seismic Inversion

We discuss methods to quantify the impact, reliability and value of low frequencies as provided in modern towed streamer broadband acquisitions. Acquisition, processing and inversion all have a role to play in creating reliable low frequency data. In this paper, focusing on marine data, we discuss various aspects of low frequency technology, associated uncertainties and QC methods. We address two key questions: Can broadband deliver the low frequencies? What value do they have? We show that scanning for the crossover frequency at well locations, where the background model is optimally known, is a useful way to visualize the impact of, and quantify the value of the low frequencies. Uncertainties due to unknowns such as wavelet errors at low frequencies and optimal regularization parameters such as sparseness constraints are discussed. Using this method, with a North Sea 3D multi-client data example, we show that broadband data provides valuable information, compared to conventional data that has been broadband processed.