Mud rheology - Herschel and Buckley law

Input(s)

$\tau_{\mathrm{y}}$: Yield Stress $\left(\mathrm{lb} / 100 \mathrm{ft}^{2}\right)$

$\mathrm{K}$: Consistency Index $\left(\mathrm{lb} / 100 \mathrm{ft}^{2}\right)$

$\gamma$: Shear Rate $(1 / \mathrm{s})$

n: Power Law Index, Slope of Plot Between Log Shear Stress and Log Shear Rate (dimensionless)

Output(s)

$\tau$: Shear Stress $\left(\mathrm{lb} / 100 \mathrm{ft}^{2}\right)$

Formula(s)

$$ \tau=\tau_{\mathrm{y}}+\mathrm{K} *\left(\gamma^{\mathrm{n}}\right) $$

Reference(s)

Samuel. E Robello. 501 Solved Problems and Calculations for Drilling Operations. Sigma Quadrant. 2015. Houston, Texas, Page: 185.