Oil viscosity below bubblepoint

Oil viscosity below bubblepoint pressure measures the oil’s resistance to flow. Two methods for estimating oil viscosity below bubblepoint pressure are presented.

1. Labedi (1992)
$${\mu }_{\text{l}}=\frac{{\mu }_{\text{ob}}}{1-m(p_b-p)}$$ $$\ln m=a_{\text{1}}+a_{\text{2}}\ln {\gamma }_{API}+a_{\text{3 }}\ln p_{\text{b}}$$ $$\overline{)\begin{array}{}\text{Coefficient}\text{Original}\\ a_1& -8.92482\\ a_2& 1.13020\\ a_3& -0.45577\end{array}}$$