While fluid percolates through porous media in infinitesimal volume generates the noise of the power
in a wide frequency range:
\delta N = A(f) \cdot {\bf u} \cdot \nabla p \cdot \delta V |
where
| flow velocity | |
| fluid pressure | |
normalised noise spectrum, | |
| noise frequency |
While propagating through the rocks the different frequencies will decay at different rate and if noise sensor is located at
then the it will capture:
\delta N_S = \int_V A(f) \cdot {\bf u} \cdot \nabla p \cdot \exp[-r/\lambda(f)] \cdot \delta V |