Amplitude preservation and seismic inversion reliability post spectral shaping

Abstract

Resolution enhancement is often applied to poststack seismic data to obtain higher frequency or wider frequency bandwidth. This enhancement could help seismic interpreters in resolving thinner layers that may not be visible on the original seismic data. The seismic inversion method is the other way to interpret seismic data. The inversion process produces an impedance volume as a layer property that can be used not only for interpretation but also for reservoir characterization. This research aims to study whether vertical resolution enhancement of seismic data preserves the amplitudes and how enhancement affects seismic inversion results. The experiments in this research are performed on synthetic and real data. The modeling is carried out by generating zero-offset synthetic traces using a convolutional model. Meanwhile, real data processing is carried out at the North Sea Volve Data Village at the Ty and Hugin formations. The resolution of the seismic trace is enhanced using a spectral division operator. The inversion techniques used in this research are model-based inversion and sparse spike inversion. The seismic trace after vertical resolution enhancement shows that the separation of events can be improved by this procedure. Inversion of the original and of the enhanced traces shows that the enhancement process still allows obtaining reliable inversion results both from model-based and sparse spike methods; however, there is no significant difference between the inverted impedance using the original trace and enhanced traces. This research concludes that the enhancement process keeps the seismic amplitude preserved for inversion, but it barely improves the inversion result.