The authors regret the following errors:

1. Equation (19) should be
$1R¯∂∂R¯(R¯P¯H¯3∂P¯∂R¯)+1R¯2∂∂θ(P¯H¯3∂P¯∂θ)=Λ∂(P¯H¯)∂θ$
2. Equation (22) should be
$min [f1(x),f2(x),…,fm(x)]$

3. The compressibility number in Table 1 should be 3.68.