Seismic Sedimentology by Stratal Slicing--A Case History in the Mioceno Norte Area, Lake Maracaibo, Venezuela

Abstract
This report describes a case history in a densely drilled, but spatially restricted, area (47 km2) containing 240 wells in the Mioceno Norte Area of Lake Maracaibo, Venezuela. There, by means of seismic sedimentology, we extended a genetic-stratigraphic-unit-level (15 to 50 m) facies interpretation to a larger, sparsely drilled 3-D survey area (300 km2). Stratal slicing is the basic tool of seismic sedimentology, providing sequential seismic surface displays that tend to follow depositional (time) surfaces, and important distinctions between stratal slices and horizon slices are often useful. We emphasize these distinctions in this report and discuss the implications of their differences. The three basic depositional settings represented in the Mioceno Norte Area that we derived from well-data analysis are shoreface, lacustrine delta, and fluvial. We extrapolated component elements in these systems across the 3-D seismic survey area by analyzing seismic amplitude patterns on stratal slices. We then performed a similar interpretation procedure by using horizon slices to demonstrate that horizon slicing does not provide the depositional details that stratal slicing does. Each depositional setting can be defined by unique seismic amplitude patterns on stratal slices, thus reducing the ambiguity of correlating conventional seismic facies with well log lithofacies distributions. We concluded that seismic sedimentology, because it improved our understanding of reservoir distribution and depositional history, is valuable in basin analysis, hydrocarbon exploration, and reservoir characterization for identifying reservoir sandstones in sparsely drilled or undrilled areas.
Authors
Hongliu Zeng
William Ambrose
Edgar Villita
Roger Tyler
Citation

Zeng, Hongliu, Ambrose, W. A., Villalta, Edgar, and Tyler, Roger, 2002,  Seismic Sedimentology by Stratal Slicing--A Case History in the Mioceno Norte Area, Lake Maracaibo, Venezuela: The University of Texas at Austin, Bureau of Economic Geology, Report of Investigations No. 265, 41 p.

Code
RI265
ISSN
2475-367X
Number
265
Number of figures
25
Number of pages
41
Publisher
The University of Texas at Austin, Bureau of Economic Geology
Series
Report of Investigation
Year
2002