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.