Seismic tomography, seismic reflection and 3D seismic surveying is the geophysical exploration technique most commonly used in the onshore and offshore petrochemical exploration industries. Seismic reflection techniques are used to map the subsurface distribution of stratigraphy and its structure, which can be used to map out hydrocarbon plays; seismic refraction parameters are used to calculate the density of the subsurface layers to determine such parameters as density, porosity and rock type.
Downhole geophysics tools are used within oil and gas exploration for several purposes;
density tools measure rock density and porosity
caliper tools measure hole diameter
gamma-logging tools measure the radioactivity of the wall rocks in the bore hole
EM tools measure wall-rock conductivity - to inform on porosity, sulphide content, lithology, etc.
