Quantitative Seismic Geomorphology Study in Fluvial Systems – A New Approach

Lorena Moscardelli¹, Denise Woods², and Lesli Wood^1
1 Jackson School of Geosciences The University of Texas at Austin, Austin, TX
² OXY Occidental Oil and Gas Corporation, Houston, TX

The ongoing development and harvesting of shallow marine and terrestrial reservoir systems demand increasingly comprehensive understanding of how to interpret complex reservoir architecture and how to better utilize 3D seismic and dense well databases to improve field development and increase production. This study presents Quantitative Seismic Geomorphology as an alternative methodology that intend to gain a better understanding of productive fluvial depositional systems, to improve reservoir characterization and to generate realistic inputs for stochastic modeling through the use of quantitative data.

Quantitative Seismic Geomorphology (QSG) has been defined as the quantitative analysis of the landforms, imaged in 3-D seismic data, for the purposes of understanding the history, processes and fill architecture of basins. Quantitative data was collected in an U.Paleozoic fluvial stratigraphic succession (USA) and it was compared with data from Mio-Pleistocene fluvial intervals of the Natuna Basin-Indonesia, the coastal plain of the GOM and the modern Brazos River. Several measurements were collected in channels from different locations and stratigraphic intervals, including channel width, meander wavelength, radius of curvature, meander-belt width and meander-arc distance. Sinuosity values were used to classify channels according to their sediment load and to predict sediment type. Morphometric data was also used to evaluate subsurface reservoir dimensions. The data shows a huge variability in terms of dimensions and geometries in the GOM and the Indonesia data bases. However, the U.Paleozoic succession (USA) shows less variability and the predominance of smaller systems (creeks/distributaries), these differences can be associated with changes in extrinsic factors such as clime, paleogeography and tectonism.