--> ABSTRACT: Integration of Well-Log, Seismic, and Outcrop Data for Subsurface Geological Models, by A. Valdisturlo; #91020 (1995).

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Integration of Well-Log, Seismic, and Outcrop Data for Subsurface Geological Models

A. Valdisturlo

Establishing subsurface models requires the integration of geology and geophysics input. However, often subsurface data (seismics, well logs, cores and drill cuttings) do not provide unique solutions for complex structural and depositional settings. The comparison of outcrop and subsurface stratigraphic successions can provide a useful tool to contrain these solutions.

Two case histories in which lithology and vertical setting of outcrop sections were studied to validate subsurface models are presented.

A one-dimensional seismic simulation of a clastic deep-water series based on outcrop geological sections and on impedance data derived from well-logs, was performed to solve a practical problem of seismic interpretation. Several outcrop sections were merged according to the known stratigraphical schemes to obtain a generalized profile of the studied succession. Some wells nearby the outcrop area, penetrating the same stratigraphic interval outcrop sections, provided the impedance model for each lithology (shale, sandstone, conglomerate). A synthetic seismogram was computed and tied to seismic lines, allowing to identify the reflection characters and the true vertical extension of the studied series.

Depositional cyclicity was analyzed in carbonatic and mixed sediments to correlate a well-section with outcrop sections. For this aim, the stacking pattern of parasequences (shale-to-limestone shallowing-upward cycles) was studied on Fischer diagrams. Well-log simulation on outcrop sections and FFT analysis performed both on simulated and actual logs provided adjunctive tools to validate the correlation.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995