Filtering functions

You can find the filtering functions in the 'Functions and Variables' area of the Property Calculator (for the different areas on the Property Calculator, see The Property Calculator). The filtering functions allow you to smooth properties.

Name Generated expression Description Expression example Ex

smooth

smooth(property,
skip null flag, center, neighbors)

smooth(property,
skip null flag, center, top, base)

smooth(property, skip null flag, center, top, base, north, south, east, west)

Property smoothing.

Skip null flag: 1 – true, 0 – false.

smooth($Kx$, 1, 0.125, 0.125)

12, 13

azimuthSmoothVector2

azimuthSmoothVector2
(azimuth, skip null flag, center, neighbors)

see also smooth function expressions

Azimuth of smoothed direction. Direction is defined by azimuth

azimuthSmoothVector2
($Azimuth$, 1, 1, 1)

14

azimuthSmoothVector3

azimuthSmoothVector3
(azimuth, dip,
skip null flag, center, neighbors)

see also smooth function expressions

Azimuth of smoothed direction. Direction is defined by azimuth and dip.

azimuthSmoothVector3
($Azimuth$, $Dip$,
1, 1, 1)

dipSmoothVector3

dipSmoothVector3
(azimuth, dip,
skip null flag, center, neighbors)

see also smooth function expressions

Dip of smoothed direction. Direction is defined by azimuth and dip.

dipSmoothVector3
($Azimuth$, $Dip$,
1, 1, 1)

VerticalAverage

VerticalAverage
(property,
segment length,
interpolation type,
smoothing window type)

Average property along vertical segment.

Possible interpolation types:

  • linearInterpolation
  • cubicInterpolation


Possible smoothing window types:

  • rescale
  • fix


This function is available only for following objects: seismic volumes, 3D grids, wellbores

VerticalAverage($C$, 100.00, linearInterpolation, fix)

15, 16

filter2D

filter2D (property,
filter type,
north dimension,
east dimension)

This function is meant only for  2D grids. It offers smoothing using various filter types:

  • MeanFilter
  • GaussianFilter
  • MedianFilter
  • IDWFilter

filter2D($Depth$, IDWFilter, 3, 3)

Example 12 Smooth function (property)

Example of smoothing a 3D Grid property.

smooth($P$, 1, 1, 1)    click to enlarge

Example 13 Smooth function (surface)

Example of smoothing a triangulated surface.

smooth($Depth$, 1, 1, 1)    click to enlarge

Example 14 Smoothing of azimuth

Comparison with direct smoothing.

Azimuth    click to enlarge

azimuthSmoothVector2($Azimuth$, 1, 1, 1). Smoothing using a vector    click to enlarge

smooth($Azimuth$, 1, 1, 1). Direct smoothing    click to enlarge

 

Example 15 Vertical average, wellbore

The example on the left shows the rescaling of the smoothing window towards the upper and lower limits of valid data. On the right is the fixed smoothing window.

VerticalAverage($Test$, 50.00)
VerticalAverage($Test$, 100.00)
VerticalAverage($Test$, 500.00)    click to enlarge

VerticalAverage($Test$, 50.00, linearInterpolation, fix)
VerticalAverage($Test$, 100.00, linearInterpolation, fix)
VerticalAverage($Test$, 500.00, linearInterpolation, fix)    click to enlarge

 

Example 16 Vertical average, seismic cube

Input property $P$

VerticalAverage($P$, 500.00, linearInterpolation, fix)

VerticalAverage($P$, 1000.00, linearInterpolation, fix)

VerticalAverage($P$, 1500.00, linearInterpolation, fix)