Sonic logging

Sonic logging is a well logging tool that provides a formation’s interval transit time, designated as ${\displaystyle {\Delta }t}$, which is a measure of a formation’s capacity to transmit seismic waves. Geologically, this capacity varies with lithology and rock textures, most notably decreasing with an increasing effective porosity. This means that a sonic log can be used to calculate the porosity of a formation if the seismic velocity of the rock matrix, ${\displaystyle V_{mat}}$, and pore fluid, ${\displaystyle V_{l}}$, are known, which is very useful for hydrocarbon exploration.

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