Short Note
Amplitude balancing for 4D seismic monitoring

James Rickett and David Lumley

james@sep.stanford.edu, luml@chevron.com

ABSTRACT

Amplitude balancing is an important part of the cross-equalization process, which aims to remove processing and acquisition differences between surveys. The match-filter approach to cross-equalization estimates an amplitude correction that minimizes the norm of the difference section. However, this correction will be biased by the presence of incoherent noise, and the amplitude of coherent events will not be equalized correctly. Similarly, a scheme that is based on equalizing the energy in the two surveys, implicitly assumes that their random noise levels are equal. We present an approach that correctly scales the amplitudes based on the relative signal-to-noise levels, and discuss where such a process should fit within a larger cross-equalization flow.