The comparison of the response characteristics of the pore space modulus Kρ and the Lamé parameter λρ were examined using two wells that penetrated two different channels. The two offshore West Africa wells penetrated two channels at different depths with different geological ages. These channel sands are of different quality and with various shale percentages and porosities. Three cases of Gassman fluid substitution were analyzed: wet, oil, and gas. Compressional- and shear-wave impedances were calculated for the three fluid cases and Lamé parameters (λρ, μρ) and Kρ.