Slowness of the formation
Input(s)
\(d_{h}\): Borehole Diameter (in.)
\(\Delta t_{m}\): Interval Travel Time \((\mu \mathrm{s} / \mathrm{ft})\)
\(d_{t}\): Tool Diameter (in.)
\(L_{s}\): Spacing of the Tool (ft)
\(l_{c}\): Eccentricity of the Tool (ft)
\(t_{l}\): Time Between Initiation of the Pulse and First Arrival Acoustic Energy at the Receiver ( \(\mu \mathrm{s} / \mathrm{ft}\) )
Output(s)
\(\Delta t\): Slowness of Formation Observed by Sonic Log \((\mu \mathrm{s} / \mathrm{ft})\)
\(t_{m}\): Mud Path Correction Time \((\mu \mathrm{s} / \mathrm{ft})\)
Formula(s)
\[
\begin{gathered}
\Delta t=\frac{t_{l}-t_{m}}{L_{s}} \\
t_{m}=\left(\Delta t_{m}\right) *\left(d_{h}-\left(d_{t}+2 * l_{c}\right)\right) *\left(1-\left(\frac{\Delta t}{\Delta t_{m}}\right)^{2}\right)^{0.5}
\end{gathered}
\]
Reference(s)
Bassiouni, Z., 1994, Theory, Measurement, and Interpretation of Well Logs. SPE Textbook Series Vol. 4. Chapter 10, Page: 189.