Extend Your Knowledge Base
Gravity and Magnetic interpretations utilize measured rock properties that are directly related to the lithologies, structures, and locations of the underlying basement and stratum for your survey area. While these properties are not exactly the same as those measured by seismic (acoustic impedance), they are closely related and can often be used to interpolate or extrapolate “known” geologic structures.
There are many geological scenarios that can limit the accuracy of seismic, whether it be uncontrolled statics or high velocity layers near the surface. Gravity and Magnetics can look at these areas where there is an uncertain seismic picture and in many cases either clarify or give an independent view of the interpreted geological framework. (see Integrated Interpretations)
Something as simple as running several forward models to test competing seismic scenarios, can eliminate or confirm the geologist’s confidence in his interpreted model. This can often be accomplished at a small percentage of the cost of interpretation, reprocessing, or further acquisition of the seismic data.
Limit Your Risk/Exposure
Seismic and drilling are expensive propositions that comprise the major portion of any exploration budget. It is often the case that to make an informed decision, a geologist wants high resolution seismic data coverage over an area that would be prohibitively expensive to acquire. A preliminary Gravity or Magnetic survey can often help to focus the areas that warrant prospect level evaluation and eliminate unnecessary expenditure. This can be accomplished while providing a regional view in those areas where increased financial exposure is not warranted.