Abstract: Extension of Object-based Modeling to Deep-Water Depositional Systems

JONES, T. A., and D. K. LARUE

Object-based facies models (OBMs) are constructed by stochastically distributing idealized facies elements (objects) that have well-defined geometries. The resulting 3-D models contain geological features and shapes that are distributed according to sequence-stratigraphic and other geological rules and are conditioned with available data. Benefits of using OBM include: 1) the model shows connectivity between objects and continuity within objects; 2) the resulting 3-D model visually resembles "natural" geology, making it easier to incorporate or demonstrate geologic concepts or features; and 3) because the model attempts to capture true geological relationships, the resulting OBM can be validated stratigraphically after construction. The model then can be queried for adherence to geological observation and for estimating flow properties.

Typical OBM programs are designed to simulate fluvial channels and splays, but other geological objects may be modeled through special methods or manipulations. We have developed techniques to incorporate key stratigraphic and sedimentologic features into deep-water depositional models, including: 1) Gross internal stratigraphy: fan stratigraphy using various layering assumptions; 2) Sequence-stratigraphic architecture: multiple, high-frequency sequences, each characterized by an abrupt erosional base and overlain by a retrograding succession of channel deposits; 3) Channel distribution: channels radiating from a canyon area; 4) Channel types and forms; 5) Down-fan trends: channel deposits widen and thin in a down-fan direction until attaining a stochastically determined zero edge; 6) Other facies: within-channel heterogeneities, and levee and splay deposits. We illustrate the benefits of object-based modeling with several deep-water depositional system reservoirs.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria