FTG Data Imaging Techniques for Geological Interpretation

Summary

Full Tensor Gravity Gradiometry (FTG) has previously been demonstrated to be an effective tool in both the minerals and oil and gas industries and is routinely collected in both airborne and marine platforms. This extra information can be used by tensor imaging techniques to enhance target anomaly definition.

Rotational invariants allow isolated anomalies to be clearly imaged and separated from linear background features. Horizontal invariant lineaments enhance linear features and are used as an efficient edge mapper. Invariant imaging techniques exploit the full tensor in order to enhance features not easily identified in single tensor component data.

Calculating geologic strike angles from FTG data allow us to employ traditional geological analysis tools such as rose diagrams. The tensor components are rendered using arbitrary axes; by recomputing the tensor components with an optimal reference frame we can align the primary axes of the tensor with the underlying geology. This can produce enhanced imaging of target features.

The correct application of these techniques improves the interpretability of the data, providing further insight into the target geology. This paper describes the application of these techniques using recent data examples and shows the value of the FTG in interpretation techniques.

Key words::

• FTG
• Gravity
• Imaging
• Lineaments
• Invariants
• Interpretation