Check shot survey is a method to measure the travel time of seismic signal from source - on the surface - to the receiver in the well bore, from which the velocity of the direct wave can be determined. The sources are located near the well head, and data is recorded from different levels, as pre-determined by the exploration plan. The results of the survey are mainly used for calibrating the seismic stack sections.

The Zero Offset VSP can provide more information than the checkshot survey, because the VSP data are recorded at much smaller spatial sampling intervals. The source point is within 100 m from the wellbore. As result, giving a time-depth relationship and a corridor stack are correlated with surface seismic.

The technology of measuring is almost the same as Zero offset VSP. The difference is that the source points are located along an offset line or some distance from well. The goal of the measurement is to have seismic information from further offsets.  

At the walkaway VSP the sources are on a pre-defined line at the surface, and there are receivers on several levels in the well. The main advantage of this measurement is to provide more accurate seismic information of the reservoir.

This is a special type of seismic survey using VSP methods. The sources are located in the same way as the walkaway VSP. The seismic data is recorded in the borehole and on the surface at same time.
The W-VSP combined with mini 2D seismic results a higher resolution section than surface seismic data and provides more coverage.

This type of measurement is the most cost effective since we can get the most seismic information with one-off cost of equipment,

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