Direct measurement of frequency-dependent phase velocities from Snowflake data

Chioma Chineke, Kristopher A. Innanen

CCS is an effective technique for reducing or eradicating the CO₂ imprint in the atmosphere. However, continuous monitoring of the sequestrated CO₂ is important to make sure it remains contained within the geological storage. The data analyzed in this research is from the Newell County facility. Newell County facility is a shallow CO₂ injection project which continuously encourages the development of modern technologies for measurement, monitoring and verification related to CCS. The seismic method is useful for estimating the frequency-dependent phase velocities of seismic waves. The velocity of a wave in a medium is determined by the properties of that medium and the frequency of the wave. From dispersion, we understand that seismic waves of varying frequency travel with different velocities, largely due to the non-uniform elastic properties in the subsurface. In this research, we are interested in estimating the phase velocities of the frequencies of the seismic waves as it varies along different direction of seismic propagation.The method used in this study is concerned with the analysis of uncorrelated vibroseis data, with a focus on the frequency dependence of seismic velocities. We are concerned with the estimation of frequency-dependent phase velocities, which is largely based on exploiting the difference in the arrival and departure times of each frequency present in the data.