3D Seismic Geometries

Fully Sampled 3D Geometry

A full sampled 3D is where the sources and receivers are evenly spread on a grid where the receiver and source interval is equal to the receiver and source line intervals.  It is the ideal 3D geometry we would all use if cost were not a consideration.

Orthogonal 3D Geometry

An Orthogonal geometry is where the source and receiver lines are placed orthogonal to one another with the line intervals being larger than the station intervals.

Megabin 3D Geometry (Parallel)

A Megabin geometry has the source and receiver points on the same line with all lines running parallel. The source interval is typically a factor of the receiver interval.

Slant 3D Geometry (26.565 degrees)

A Slant geometry has receivers lines at an acute angle (<90 degrees) to the source lines. Two of the most angles used in Slant surveys are 26.565-degrees and 45-degrees.  The angle represents the azimuthal difference between source and receiver lines.

A 26.565-degree angle between source and receiver lines will result in the sources being shifted ½ the source interval crossline from the previous source.

Slant 3D Geometry (45 degrees)

The second common 3D Slant geometry involves a 45-degree angle between source and receiver lines.  The 45-degree angle results in a crossline shift of 1 SI from the previous source point.

Brick 3D Geometry (standard)

The standard Brick geometry has the source line between alternating receiver lines shifted by half the SLI to produce a standard brick pattern. 

Brick 3D Geometry (triple)

The triple brick is a variation on the standard brick where the source line is split into 3 alternating offsets between receiver lines with each offset being 1/3 of the SLI.