Scale of Measurements

Typically the borehole size is 6”, 8-1/2” or 12-1/4” diameter, so the information recorded is clearly at a small scale, comparable with other downhole logs.

The large scale structure in the subsurface is commonly defined by interpretation and depth conversion of seismic surveys. The resolution of a modern 3-D survey may be able to resolve dips on a scale down to 50m, but typically noise and other factors reduces this to 100 or 200m. Faults can be resolved down to 25m, slightly less assuming that linear dimmed reflections represent fault.

The photographs below show field examples of the scales of dip information. The white boxes indicate typical borehole size