New Mexico Geological Society Annual Spring Meeting — Abstracts

Geologists commonly have a problem extrapolating structural and stratigraphic features exposed at the surface into the subsurface. At times, borehole infonnation or geophysical data (e.g., 2-D seismic, gravity, aeromagnetic data) are available to guide the interpretation, but these data may lack resolution or be ambiguous to interpret. Whether the project has an "applied" (e.g., resource extraction) or "academic" (e.g., tectonic reconstruction) focus, the results of the geologist's interpretation can have a significant impact. Even seasoned geologists make mistakes, of various magnitudes, with ambiguous data.

High-quality 3-D seismic data provide the geoscientist with unparalleled opportunities for imaging and (correctly) interpreting subsurface structure, stratigraphy and rock properties. Using data from NW and SE New Mexico, we illustrate how 3-D seismic data can be used on an interactive workstation to image the subsurface. We see features (stratigraphy, structure) that are not visible at the surface. Different structural configurations may be present at different stratigraphic levels, and deep structures may have an influence on deposition at shallower stratigraphic levels. When properly integrated with well data and other sources of infonnation, good quality 3-D seismic data allow the geoscientist to produce maps of subsurface features more accurately and in a fraction of the time that might be spent using well data or 2-D seismic data alone.

The "down-sides" to working with 3-D seismic data are: 1) Availability of data. 3-D seismic data are expensive to collect and therefore tend to be collected only where the project objectives make applying the technology economically feasible (e.g., petroleum industry). 2) Availability of software. 3-D seismic interpretation software can be expensive and takes some training to utilize properly. 3) Over-reliance on seismic data. 3-D seismic data are still seismic data, and various pitfalls (e.g., velocity artifacts) that can haunt the 2-D seismic interpreter can also afflict the 3-D seismic interpreter. Integration of other data types is critical. 4) Over-reliance on technology. Despite the spectacular images that may be obtained from 3-D seismic data volumes, a good geologic background is necessary in order to ask the right questions of the data set and properly interpret the results.