Three-dimensional facies architecture and three-dimensional calcite concretion distributions in a tide-influenced delta front, Wall Creek Member, Frontier Formation, Wyoming

Abstract

Cluster analysis of the GPR attributes (instantaneous amplitudes and wave numbers) calibrated with the cores and the outcrop was used to predict the distribution of near-zero permeability concretions throughout the 3-D GPR volume; clusters of predictive attributes were defined and applied separately in the bars and channels. The predicted concretions in the bars and the channels are 14.7 and 10.2% by volume, respectively, which is consistent with those observed in the cores (14.7 and 10.5%, respectively), and their shape and thickness are also generally in consonance with those in the outcrop and cores. The estimated concretions are distributed in an aggregate pattern with irregularly shaped branches within the 3-D GPR volume, indicating that the cementation does not follow a traditional center-to-margin pattern. The concretions and 3-D geological solid model provide cemented flow baffles and a 3-D structural framework for 3-D reservoir modeling, respectively.

Basic Building Blocks and Process Variability of a Cretaceous Delta: Internal Facies Architecture Reveals a More Dynamic Interaction of River, Wave, and Tidal Processes Than Is Indicated by External Shape

“…A companion study (Lee et al 2007, this issue) used 2D and 3D ground penetrating radar to investigate the 3D geometry of the bar and channel elements described in greater sedimentological detail in this paper.…”

Three-dimensional modeling of clinoforms in shallow-marine reservoirs: Part 1. Concepts and application

“…For example, in Pleistocene fluvial-dominated delta deposits imaged in shallow-seismic data, Roberts et al (2004, p. 185) comment that "each clinoform set represents rather continuous deposition from a distributary or related set of distributaries, resulting in the formation of a delta lobe." Shale drapes and cemented concretionary layers occur along depositional surfaces at each hierarchical level but generally have greater continuity and extent at larger lengthscales of the hierarchy (e.g., Gani and Bhattacharya, 2007;Lee et al, 2007;Ahmed et al, 2014). Thus, delta lobes tend to be overlain across flooding surfaces by prodelta shales and distal-delta-front heteroliths, which may cause them to behave as distinct reservoir zones that can be correlated between wells, whereas clinoforms are associated with heterogeneity between wells and within reservoir zones (e.g., Ainsworth et al, 1999;Hampson et al, 2008).…”

Three-dimensional modeling of clinoforms in shallow-marine reservoirs: Part 2. Impact on fluid flow and hydrocarbon recovery in fluvial-dominated deltaic reservoirs

“…There are few outcrop data sets that quantify the extent or geometry of such barriers along clinoforms (e.g., White and Willis, 2000;Lee et al, 2007;Eide et al, 2014;Hampson et al, 2014). Sensitivity tests indicate that ellipses are suitable objects to represent these barriers for modeling and flow simulation purposes, because they can be described using simple mathematical functions and their abundance and overlap control barrier coverage along clinoforms, provided ellipse dimensions are small relative to the area of the clinoform .…”