Quantitative Seismic Reservoir Architecture Analysis of Tertiary Fluvial System in The Onshore Bohai Bay Basin China

Zhai, Rui; Wu, Shenghe; Fan, Zheng; Zhang, Hua

Meandering river systems are ubiquitous in the tertiary in various basinal depressions of east China, and fluvial sandstones constitute approximately 42% of production reservoirs of china, Often much of the remaining oil remains unrecovered owing to an inability to define boundaries and baffles to flow, map sandbody connectivity, and design effective development plan. So understanding of spatial reservoir geometries and qualities are critical to their proper exploration and exploitation. Traditionally, understanding of reservoirs is enhanced by 3-D seismic facies interpretation, a popular technology is 3-D attribute analysis. In deep zones, however, owing to the limits of seismic resolution, the results are usually only used for qualitative interpretation of reflector geometries, if not impossible to quantity reservoir quality. We attempt to employ a sedimentological characterization of architectural element analysis to the sandstones through 3-D seismic geomorphologic and petrophysical motif delineation. Such a procedure may provide an effective way to interpret reservoir heterogeneity, predict reservoir quality geometries, and if seismic resolution permits, allow the geo-valid dated extrapolation of reservoir qualities stratigraphyically.

Subsurface reservoir architecture characterization dependent primarily on seismic and multi-well information, accordingly, two methods are developed: (1) seismic reservoir architecture analysis, study the distribution of deposit units utilizing seismic imaging feature that acquired by means of 3-D seismic slicing and other seismic attributes ; (2) multi-well pattern forecast, match various order quantitative architecture mode with well information (core, well logging, dynamics, production performance and so on) to infer interwell distribution and communication of architecture units in different geological order. The result of study indicate that meander reservoir has great temporal and spatial variability despite the geological window is small, quantitative seismic geometric analysis from integration of borehole data into 3-D seismic data in sequence frame provide a new strategy for reservoir characterization.

AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013