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important controls. Sediment supply, hydraulic
characteristics and autogenic responses and their
importance for sequence stratigraphic concepts
and models, are studied using experimental mod-
els (Koss et al ., 1994; Wood et al ., 1992; Van Heijst,
2001; Van Heijst et al ., 2002; Muto & Steel, 2004;
Swenson & Muto, 2005) and numerical models
(De Vriend, 2005; Eggenhuisen et  al ., 2005;
Postma, 2014) and through numerous dedicated
studies of outcrop analogues and modern systems
(see references in Schumm, 1993; Bridge, 2003;
Catuneanu, 2006; Rygel & Gibling, 2006). This
combined approach is particularly important for
continental depositional systems and the result-
ing three-dimensional architectural patterns
because of their sensitivity to controlling factors
in both source and sink areas, in particular the
role of sediment supply and water discharge.
Geomorphic models for continental fluvial depo-
sition, erosion and preservation at short to interme-
diate time scales (1 yr to 10 5 yr), outside the direct
control of relative sea-level changes (see overviews
in Schumm, 1977; Knighton, 1998; Bridge, 2003),
are only to a limited extent used in sequence stra-
tigraphy to better understand the mechanisms that
control long-term sediment preservation and the
formation of erosional surfaces in the non-marine
stratigraphic record. A number of non-marine
(sequence) stratigraphic models exist (Legarreta
et  al ., 1993; Wright & Marriott, 1993; Shanley &
McCabe, 1994; Olsen et al ., 1995; Allen et al ., 1996;
Currie, 1997; Dahle et al ., 1997; Dong et al ., 1997;
Fu, 1997; Wang et  al ., 1997; Cai & Zhang, 1999;
Diessel et  al ., 1999; Martinsen et  al ., 1999; Boyd
et  al ., 2000; Yu et  al ., 2000; Plint et  al ., 2001;
Weissmann et  al ., 2002; Holbrook et  al ., 2006) in
which either an attempt is made to apply existing
marine sequence stratigraphic terminology (correl-
ative surfaces, systems tracts) to non-marine set-
tings or to define new concept or correlative
surfaces and non-marine systems tracts. No unity
in non-marine sequence stratigraphy has yet been
achieved and it is argued that the application of
systems tracts as defined for marine environments
to non-marine successions is difficult to justify
(Ethridge et al ., 1998).
The practical application of continental fluvial
sequence stratigraphic concepts and methods to
subsurface datasets as used in hydrocarbon
exploration and particularly in production-related
work tasks is often complex due to a lack of data. In
general, correlation surfaces are commonly not well
developed and difficult to recognise and correlate
across the succession. For example, in combined
wireline and core fluvial datasets it is often difficult
to differentiate between regional unconformities
formed during stratigraphic degradation and local
channel base scours formed during stratigraphic
aggradation. In these instances, correlation of wells
based on erosion surfaces surpasses an acceptable
level of uncertainty and is better done based on
trends. In most published cases, low and high
accommodation zones are recognised. These have
to be of sufficient resolution and an acceptable
uncertainty level to be able to build geologically
realistic 3D reservoir models and to justify the
investments associated with the drilling of infill
production wells particularly in the later phases of
hydrocarbon field development.
AIMS
The aim of this study is to construct an improved
stratigraphic correlation framework for reservoir
property modelling of the fluvial Statfjord Group
(Rhaetian to early Sinemurian; Norwegian North
Sea; Figs  1 to 3; Lervik, 2006) in the Statfjord
Field. This is achieved by integrating two key
additions to existing ideas on continental fluvial
sequence stratigraphy: 1) the notion that the rate
of fluvial aggradation through time, as controlled
by the accommodation versus sediment supply
rate, is dynamic and not static and ii) a modified
definition of base level in fluvial successions to be
able to estimate changes in aggradation rate. The
A/S (in which A is the rate of creation of net
accommodation and S is the rate of sediment
input as a function of sediment liberation and dis-
charge) and autostratigraphy approaches are
applied to a spatially restricted and limited sub-
surface well dataset at reservoir scale (0.1 km to
20 km; Statfjord Field; Fig.  2) that covers a time
scale of several million years. The approach is
used as a tool for organising and mapping changes
in depositional trends as well as reservoir prop-
erty trends from the viewpoint of an integrated
subsurface team while preserving scientific
objectivity.
We do not aim for a generalised approach or
hypothesis to describe fluvial successions by pre-
senting an overarching argument for organisation
of all fluvial systems. However, the study does aim
at contributing to further developing a methodol-
ogy and technique for continental fluvial sequence
stratigraphy that has practical use in subsurface
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