Evolution and Organization of Fundamental Sedimentary Bodies: New Models for Reservoir Characterization

John C. Van Wagoner, T. Sun, N. L. Adair, D. C. J. D. Hoyal, R. W. Wellner, and P. A. Dunn
ExxonMobil Upstream Research Company, Houston, TX

We believe that the siliciclastic sedimentary record deposited from unidirectional, turbulent flows is built from four fundamental types of scale-invariant sedimentary bodies. Each type of sedimentary body has an apex, expands in a down-flow direction, and has a characteristic distribution of relative properties such as grain-size distribution and stratal architecture.

These types of sedimentary bodies and their properties are the products of universal, scale-invariant structures in turbulent flows and the interactions of these flow structures with the substrate. For these reasons, we believe that these types of sedimentary bodies and their relative properties are scale-invariant, independent of environment of deposition, and largely independent of boundary conditions.

Because of scale-invariance, we name these bodies without reference to conventional names like bar and bed, which have scale implications. The names we have selected for these fundamental sedimentary bodies are jet, leaf, leaf complex (or jet complex), and tree deposits. These bodies are also the stages of an evolutionary pathway along which sedimentary bodies form. Each type of fundamental sedimentary body is an archetype and can be represented by an ideal set of property attributes.

These sedimentary bodies provide a new context for the development of geologic models and predicting reservoir properties such as vertical connectivity and permeability.