Analysis of the internal architectural elements of tidal-influenced meandering fluvial deposits using well logging and seismic data: The study of the Athabasca Oil Sands, Alberta, Canada

Abstract

A reservoir was dominated by inclined heterolithic stratification (IHS) formed in large point bars of the McMurray Formation. We have used high-resolution seismic data and logging data to identify the internal architectural elements of the reservoir. From the core data, we defined four lithofacies and recognized the architectural element boundary. Then, we used stratum dip data across wells, combined with seismic reflectivity, isopach, and amplitude attributes, to understand the lateral continuity of the boundaries. Later, we established the sedimentary model and found the differences between tidal-influenced meandering fluvial channels and conventional meandering fluvial channels. Research showed that tidal bedding was especially well-developed, and breccia deposition and muddy IHS were also frequent. The development of the lateral accretion packages was more frequent than that in the conventional meandering fluvial channels. The characteristics of the interbedded layers in sandy IHS were very thin, mainly approximately 20 to 40 cm. The dip of the lateral accretion packages was smaller and distributed from 4° to 8°. The studies were expected to have a major impact on the understanding of reservoir formation, distribution, and heterogeneity for improved hydrocarbon recovery purpose in the area.