Seismic geomorphology and high-resolution seismic stratigraphy of inner-shelf fluvial, estuarine, deltaic, and marine sequences, Gulf of Thailand

Abstract

Pleistocene fluvial, estuarine, marine, and deltaic depositional systems were identified in the uppermost 80 m (262 ft) of the central Gulf of Thailand modern continental shelf, situated approximately 70 m (∼230 ft) below sea level. Integration of offshore three-dimensional (3-D) seismic reflection data, highresolution shallow-penetration two-dimensional (2-D) seismic reflection sparker and boomer profiles, and shallow geotechnical borehole measurements enabled the identification of seven depositional sequences. The 3-D plan-view images at successive time slices exhibit single meandering channels (as much as 600 m [1969 ft] wide) and channel belts (as much as 10 km [6.2 mi] wide) deposited in the shelf during times of subaerial exposure. Additional geomorphic features imaged include incised valleys, interfluves, oxbow lakes, neck and chute cutoffs, and point-bar meander scrolls showing evidence of expansion and translation. The high-resolution 2-D profiles, with a tuning thickness of approximately 25 cm (∼9.8 in.), enabled the discrimination of high-frequency stratigraphic discontinuities (sequence boundaries) and allowed a detailed bed-scale seismic facies characterization of fluvial (point bars), deltaic (clinoforms), estuarine, and marine deposits within a sequence-stratigraphic context. The complete succession shows that most fluvial systems lie

Paleohydrology and 3D Facies Architecture of Ancient Point Bars, Ferron Sandstone, Notom Delta, South-Central Utah, U.S.A

“…However, there are very few ancient outcrop examples in which plan-view geometry of channel-belt deposits can be observed directly (Hilton 2013;Ielpi and Ghinassi 2014). Recent 3D seismic examples provide plan-view images of the geomorphology of channels and channel belts, from which channel migration patterns can be inferred (e.g., Zeng and Hentz 2004;Wood 2007;Reijenstein et al 2011) but these seismic examples typically lack data on facies, grain-size variation, paleocurrent variability, and detailed cross-sectional facies architecture.…”

Geometry and compartmentalization of fluvial meander-belt reservoirs at the bar-form scale: Quantitative insight from outcrop, modern and subsurface analogues

“…Where these mud-prone abandoned channel fills border genetically related sand-rich macroforms, they may act as barriers or baffles to hydrocarbon flow, and, as a result, they can compartmentalize meander-belt reservoirs ( Figure 1). The potential importance of the compartmentalization of meander-belt reservoir by mud-prone abandoned channel fills, and its important control on sand connectivity and effectiveness of primary and secondary hydrocarbon recovery, are widely recognized (Berg 1968;Busch 1974;Richardson et al 1987;Ambrose et al 1991;Jordan & Pryor 1992;Galloway & Hobday 1996;Weimer et al 1998;de Rooij et al 2002;Edie & Andrichuk 2003;Jiao et al 2005;Donselaar & Overeem 2008;Shepherd 2009;Reijenstein et al 2011;Alpak & Barton 2014;Shu et al 2015; and references therein). Yet, this problem is typically described and considered at a qualitative level.…”

“…Busch 1974;Berg 1981;Leo 1997;Edie & Andrichuk 2003;Fustic et al 2012). For example, database analysis highlights that many examples from the high-end of the spectrum of bar size (20 to 60 m in thickness; up to 7000 m in width) were deposited in continental-shelf settings, when the shelf was exposed at lowstand (Feng 2000;Posamentier 2001;Miall 2002;Carter 2003;Reijenstein et al 2011 Furthermore, the relationships presented above can be applied for the following purposes:…”

Methods for seismic sedimentology research on continental basins

“…Since it was presented for the first time in the 1990s (Zeng et al 1998a, b), seismic sedimentology has been improved in theory and methodology by many researchers and is playing an increasingly important role in oil and gas exploration and development (Posamentier 2002;Miall 2002;Zeng and Hentz 2004;Zhang et al 2007;Zhu et al 2009;Zeng 2010;Reijenstein et al 2011;Hubbard et al 2011). Early seismic sedimentology research mainly focused on discussions of the cases and workflows of overseas marine basins (Kolla et al 2001;Hentz and Zeng 2003;Zeng and Hentz 2004;Loucks et al 2011) and established two key techniques: 90°phase shifting of seismic traces and strata slicing (Zeng 2011).…”