Select the sonic curve (Vp) that will be used in the equation. The sonic curve should have the units m/s.

This equation will take the sonic curve input and compute the shear velocity component using the following equation:

Select the resistivity curve that will be used in the equation. You can also override the constant, used in the equation.

Using a resistivity curve, and the depth at the sample point, a sonic curve is calculated using the following equation:

Sonic = Faust's Constant x (Resistivity x Depth)^⅙

The output sonic is in usec/m.

Select the sonic curve that will be used in the equation. You can also override the constant, used in the equation.

Using the sonic curve, a density curve is calculated using the following equation:

Density = Gardner's Constant x sonic^¼

The Density curve output is in g/cc.

Select the sonic and density curves that will be used in the equation.  A shear curve can also be selected, which if it doesn't exist, it will calculate the shear using  Castagna's equation.

Using the sonic and density curves and the shear (either from a curve or calculated from the sonic curve using Castagna's equation), the lambda rho output is calculated as shown in the equation:

Lambda-rho=

(Sonic x Density)2

- 2

(Shear x Density)2

The output Lambda-Rho is in GPa*g/cc

Select the density curves that will be used in the equation. A shear curve can be selected, which if it doesn't exist, it will calculate the shear from the selected sonic curve using Castagna's equation.

The Mu-Rho curve is calculated using the shear (either from a curve or calculated from the sonic curve using Castagna's equation) and density curve as shown in the equation:

Mu-Rho= (Shear x Density) 2

The output mu-rho curve is in GPa*g/cc

Select the sonic curve that will be used in the equation. A shear curve can also be selected, which if it doesn't exist, it will calculate the shear using  Castagna's equation.

Poisson's ration is calculated using the Sonic curve and a shear curve (either from a curve or calculated from the sonic curve using Castagna's equation) in the equation below.

Poisson's Ratio= 0.5 x
	Sonic2	- 2	(Shear2)
	Sonic2	-	Shear2

 

Select the sonic curve that will be used in the equation. A shear curve can also be selected, which if it doesn't exist, it will calculate the shear using  Castagna's equation.

The ratio is calculated using the Sonic curve and a shear curve (either from a curve or calculated from the sonic curve using Castagna's equation) in the equation below. 

Vp	=	Shear
Vs		Sonic

 

 

Select the sonic curve that will be used in the equation. A shear curve can also be selected, which if it doesn't exist, it will calculate the shear using  Castagna's equation.

The ratio is calculated using the Sonic curve and a shear curve (either from a curve or calculated from the sonic curve using Castagna's equation) in the equation below. 

Select the sonic and density curves that will be used in the equation below.

Impedance = Velocity x Density

The velocity curve is created using the inverse of the selected sonic curve. The impedance result is in m/s*g/cc or ft/s*g/cc depending on the sonic log input units.

Select the bulk density curve that will be used in the equation. You can also specify values for the matrix and fluid density.

The porosity is calculated with using the bulk density curve with the values for Matrix and Fluid densities specified in the equation below:

Porosity =	(Bulk Density - Matrix Density)
	(Fluid Density - Matrix Density) x 100

The Matrix Density is a constant which default to 2.648 for sandstone, 2.71 for limestone, 2.876 for dolomite, but can be set to a user value using other.

The Fluid Density is a constant which default to 1.0 for fresh water and 1.1 for salt water, but can be set to a user value using other.

The output curve values for Porosity are in percent (%).