An Integrated
Approach for Delineating Structural Trends Using Regional Gravity Enhancements
and Borehole Imaging in the
Egorov, Vsevolod1, Pedram
Zarian2 (1) Fugro Robertson Inc,
Regional gravity data is often used in
petroleum exploration to map large-scale tectonic elements within a basin.
However, small-scale structural features are difficult to delineate mainly due
to low-density contrasts within the sedimentary strata, dominance of basement
signature in the gravity field, and data resolution limitations. Directional
gravity enhancement is one of the methodologies that can be used for mapping
fine tectonic trends. However, the pitfall is that arbitrary selection of
enhancement direction while amplifying real features creates artifacts.
High-resolution borehole image data, if available, as an independent source of
subsurface information, provides the attitude of small-scale faults and
fractures from direct borehole measurements.
A statistical approach is demonstrated
here to analyze lineaments picked from a generated set of the directional
horizontal gravity gradients. Utilizing acoustic borehole imaging techniques,
the natural fractures and faults are identified, picked and statistically
presented from a number of wells in the
The results show a significant
improvement in imaging geological features, the locations of which are also
supported by other available geological information. The application of this
approach can be potentially expanded to areas with no or limited surface
structural information.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California