Using the Property Calculator to interpolate velocities

The category Property extraction in the Property Calculator contains unique functions for mapping properties from one object type to all others using user-defined interpolation methods and parameters.

Open the Property Calculator (Workspace > Tools > Property Calculator), go to the Functions section and select Property extraction.

Here you find, for instance, the Marker option. Good results in the interpolation of sparse well data can be obtained using kriging with exponential power values between 1.5 and 1.99; and ‘Grid2D’ options, for example:

• 2D grid (with all nodes valid) selected, property name 'V0', property type ‘Velocity’. In the Expression area type Marker (OrdinaryKriging, 1.9, 40, 2000, 2000, 100, "name of the marker", "V0", 0, 0, 1).

For mapping velocities between 2D grids with different dimensions good results can be obtained with simple interpolation methods such as ‘bicubic’, for example:

• Grid2D(Cubic, "name of the marker_Vint", "Vint", 0, 0, 1)

Velocity properties can be mapped from velocity functions (stacking or migration velocities) into regularly sampled (seismic) cubes using expressions such as:

• PolyLineSet(Cubic, "Vstack_2004PSTM", "Vavg", 1, 1, 1)

An expression for extraction of velocity properties (or amplitudes) from seismic volumes onto 2D grids may look like this:

• Seismic(Cubic, "Refl_zPh_2004", "Vavg", 0, 0, 1)