Combining Full-Volume 3-D Seismic Interpretation With Quantitative Seismic Geomorphology and Modern Process-Based Analogue Databases: The Next Generation Tools for Stratigraphic Analysis and Reservoir Characterization

Abstract

Following three decades of technological innovation, both industry and academic geologists have access to 3D seismic datasets imaging extensive areas at very-high resolution. How seismic stratigraphers will efficiently use this considerable amount of data to improve their understanding of the subsurface in a cost-effective timeframe will mainly rely on: -using global (“full-volume”) horizon extraction and attribute mapping tools -an understanding of their limitations and an awareness of the stratigraphic significance of the attribute maps interpreted -a solid knowledge of sedimentology and geomorphology of ancient and modern systems -the integration of queryable, analogue geospatial databases Once stratigraphically-significant attribute maps have been generated the best approach for depositional interpretation is to use modern analogues with similar geomorphology. Quantitative seismic geomorphology has been mainly applied to fluvial channels to predict their reservoir properties. However comparing the geometries of individual subsurface elements to their modern counterparts can also help predicting the characteristics of their parent depositional system (process regime, neighbouring depositional elements and range of lithologies). Here we apply quantitative seismic geomorphology to a broader range of fluvial to shallow marine depositional elements using a number of subsurface case studies. This approach is illustrated through the use of channels and channel belts. Measurements of channel parameters (distance between inflection point, along channel length, curvature amplitude, channel width) are used to find similar modern channel stretches based on query of an extensive modern channel database. It enables the determination of likely reservoir facies as well as the prediction of ranges of applicable depositional environments. In areas of higher quality seismic, shallow marine depositional elements (beach ridges, mouth bars, barrier islands…) can sometimes also be mapped. Combining surface mapping and process-based, hierarchical classification allows further constraining the overall process regime of the parent “shoreline”. Query of a modern geospatial database then permits identification of a suite of suitable analogues and interrogation of reservoir characterization data below seismic resolution. This database-assisted, quantitative seismic geomorphologic approach allows placing a particular set of seismic observations in an uncertainty depositional framework.

AAPG Datapages/Search and Discovery Article #90291 ©2017 AAPG Annual Convention and Exhibition, Houston, Texas, April 2-5, 2017