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U.S. Department of Energy
Office of Scientific and Technical Information

Lithologic color-coded sections by AVO crossplots

Conference ·
OSTI ID:89712
;  [1]
  1. Geophysical Development Corp., Houston, TX (United States)

AVO processing and interpretation can yield a lithologic section through a two-step process. First, the well-log curves are analyzed to establish the normal-incidence reflectivity (NI) and the poisson reflectivity (PR). These (NI, PR) pairs are then crossplotted for visual analysis of the grouping of the lithologic boundaries, such as shale over a water-saturated sand or a shale over a gas-saturated sand. The second step uses NI and PR reflectivity sections extracted from seismic data through AVO inversion. The two reflectivity sections are combined into a single color section by assigning each time sample, t, a color based on the spatial position that NI(t) and PR(t) occupy within the crossplot of NI vs PR. The color assignment is based on the separation of the expected lithologic boundaries in the NI vs PR crossplot conducted in the first step. The color on the resulting section then correlates to the lithologic boundaries established in the petrophysical calibration. The entire procedure is performed interactively on a workstation.

OSTI ID:
89712
Report Number(s):
CONF-941015--
Country of Publication:
United States
Language:
English