Comparing Modern and Ancient Turbidite Channel and Channel-Like Elements: Insight and Issues for Developing a First Principle Approach to Exploitation of Deep-Water Reservoirs
W. R. Morris
ConocoPhillips, AK, [email protected]
Comparison of modern turbidite channels and ancient turbidite channel deposits and distinguishing channel and channel-like elements is fraught with significant issues and hurdles that must be overcome in order to develop a first principle approach to modeling turbidite channel reservoirs. First, the morphology of modern channels does not necessarily represent the resulting deposits due to channel aggradation, migration, or erosion. Another well documented issue is that few outcrops are of sufficient scale to actually observe the entire channel deposits and its relationship with associated elements. This leads to a bias in data to only part of the channel or smaller channelized systems. Another potential issue is that these smaller channel deposits can have a similar cross-sectional profile and significant overlap of scale with megascour, thalweg, slump scour, and crevasse channel deposits. In addition, features such as mud-drapes and basal clay clast conglomerates that have been used to support channel interpretations, also occur within these other elements.
A second aspect for understanding channel deposits is that there can be significant spatial and temporal variation in channel type and fill within a system and especially between different types of systems (i.e. basin floor fans vs. slope aprons). Thus, while channels can be compared between systems to derive general sedimentologic parameters and processes, outcrop analogs are useful only if like elements are compared, requiring that their type system, physical scales, shape characteristics, sedimentary processes, and time scales (duration of activity) are reasonably similar.
AAPG Search and Discovery Article #90088©2009 Pacific Section Meeting, Ventura, California, May 3-5, 2009