Detailed mapping of marine erosional surfaces and the geometry of clinoforms on seismic data: a tool to identify the thickest reservoir sand

Abstract

Deltaic sediments of the Billund and Bastrup sands were deposited in a ramp setting in the storm‐dominated North Sea during the early Miocene. A marked relief in the hinterland and the relatively high precipitation resulted in a high sediment supply to the sea and progradation of major delta‐coastal plains south of the present‐day Norway. The focus of this study is on the forced regressive wedge system tracts of the two delta complexes, which show remarkably well‐developed marine erosional surfaces associated with sand‐rich packages characterised by steeply dipping clinoforms (up to 10°). The well‐developed clinoformal packages indicate that deposition occurred in water depths of 60–100 m even under a sea‐level fall. The sand‐rich delta lobes also demonstrate that it was a high‐energy environment and that wave‐generated re‐suspension at the delta front effectively re‐sorted the sediments and sand‐rich systems became separated from mud‐dominated portions of the delta complexes. The evolution of the above occurred in a basin that has been exposed by inversion tectonism. The sediment supply was consequently high. During deposition, eustatic sea‐level changes strongly controlled the evolution of sequences. The results found in this study may be applicable for mapping reservoir sands in ramp settings and in rift basins especially when looking for reservoir rocks in the basinal setting or when carrying out detailed reservoir mapping in already existing hydrocarbon fields.

Clinoforms and clinoform systems: Review and dynamic classification scheme for shorelines, subaqueous deltas, shelf edges and continental margins

“…However, they are often well-imaged by GPR data (Jol et al, 1996(Jol et al, , 2002Smith and Jol, 1997;Hampson et al, 2008) (Fig. 11a) or high-resolution shallow seismic (Tesson et al, 2000;Hansen and Rasmussen, 2008;Rasmussen, 2009). They are also demonstrated in outcrops (Gani and Bhattacharya, 2005;Hampson et al, 2008; (Fig.…”

“…In wave-or tide-dominated settings, sediments are reworked and redistributed by basinal processes away from the river mouth, both alongshore and across-shelf (e.g., Yang and Nio, 1989). Wave-dominated coastal environments, in particular, consists of alternations of erosional stretches and accretive shore-parallel clinothems in plan-view (e.g., wave-dominated deltas, shorelines/beaches, strandplains, spits, barrier islands and cheniers) (Augustinus, 1978;Morales, 1997;Heward, 1981;Jiménez et al, 1997;Jol et al, 1996Jol et al, , 2002Bhattacharya and Giosan, 2003;Rasmussen, 2009). More generally, all shoreline clinoforms can be subject to a variable degree of wave, tide and riverine influence, with processes that may vary systematically in space and time during cross-shelf transits (e.g., increasing wave dominance as deltas prograde outwards on the shelf - Porębski and Steel, 2006;Steel et al, 2008;Patruno et al, 2015bPatruno et al, , 2015c.…”

Substratum control on tunnel-valley formation in Denmark

“…The Miocene sediments in the central and southern parts of Jutland have been intensively studied in recent years (e.g. Rasmussen 2004Rasmussen , 2009). The Miocene succession consists of sequences of deposits ranging from deep marine to terrestrial environments.…”

The Scandinavian mountains have not persisted since the Caledonian orogeny. A comment on Nielsen et al. (2009a)

“…Rasmussen, 2009a,b, fig. 7), in contrast to later systems where meandering was common (Rasmussen, 2009b). The braided character of the Billund sand is found in all boreholes and outcrops drilled or exposed in Denmark.…”