Question $13$: Time to Reach a Specific Radius of Investigation Using the radius of investigation calculated in Question $11,$ determine the time required to reach a radius of investigation of $200$ feet, given the same formation and fluid properties. Use the inverse of the formula provided in the previous Question $12.$

Hint: use this formula, $t=\frac{c{r}_i^2}{k}$

Question $11$: Calculating Radius of Investigation

Given that the permeability of a formation is $,$ the fluid viscosity is$,$ and the interstitial coefficient $($c$)$ is$,$ calculate the radius of investigation after $10$ hours using the formula.

Hint: use this formula, and Assume porosity is $0\mathrm{.}2.$