The alluvial architecture of the Coevorden Field (Upper Carboniferous), the Netherlands

Abstract

A detailed reconstruction of the alluvial architecture of the Coevorden gas Field (Tubbergen Formation, Upper Carboniferous), which is located in the northeastern part of the Netherlands, is presented. This reconstruction is based on well logs, cross-sections and paleogeographic maps. Sedimentological analysis of a 93 m long core allowed to refine the interpretation of the depositional environment. Accurate width determinations are necessary to correctly correlate fluvial sandbodies and reconstruct alluvial architecture. Without using sedimentological information, sandbody width is likely to be overestimated. A method developed by Bridge and Tye (2000) was used to calculate the width of one sandstone body from cross-set thicknesses. On the basis of this calculation and the paleogeographic reconstructions, it may be stated that on average the width of the channel belts we studied in the Coevorden field does not exceed 4 km. Moreover, our paleogeographic reconstructions, which point to a northwestern direction of paleoflow, are in accordance with earlier observations from the study area. The Tubbergen Formation and time-equivalent sediments in Germany are reviewed briefly to put the Coevorden Field in a regional context. The thickness of the Tubbergen Formation is ∼450 m in our study area. In the adjacent German area, time-equivalent sedimentary sequences reach higher thicknesses. This may be attributed to tectonic movements along the Gronau Fault zone and the coming into existence of the Ems Low, of which the Coevorden Field is the westernmost part.

Porosity and Permeability Variations in a Tight Gas Sandstone Reservoir Analogue, Westphalian D, Lower Saxony Basin, Nw Germany: Influence of Depositional Setting and Diagenesis

“…1a). This trend coincides with general NW-ward Westphalian palaeoflow directions in the Dutch and German onshore sector (Jones and Glover, 2005;Kombrink et al, 2007), for example to the NW in the Woitzel quarry (David, 1990) and to the WNW in the Piesberg quarry (Jones and Glover, 2005) (locations in Fig. 1b).…”

“…1b) in the Westphalian D (David, 1987(David, , 1990. The sand percentage decreases NW-wards (Jones and Glover, 2005) towards the Dutch fields (Kombrink et al, 2007) (Fig. 1a).…”

“…Floodplain sediments and coal seams were no longer deposited (David, 1990;Besly et al, 1993). The red beds extend to the onshore Dutch fields (Kombrink et al, 2007) and to the southern North Sea and are known as the "Barren Red Beds" (Besly and Fielding, 1989;Leeder and Hardman, 1990;Besly et al, 1993;Pearce et al, 2005). The red colouration formed either syn-depositionally due to oxidation in a well-drained floodplain environment, or due to later oxidation of originally grey siderite-bearing sandstones during early diagenesis (Besly et al, 1993).…”

“…The NW European Carboniferous Basin hosts degassing hard coal source rocks, seals and siliciclastic reservoir rocks, but major sections remain poorly characterized (Cameron and Ziegler, 1997;Kombrink, 2008). Tight gas reservoir rocks are reported to occur in the southern North Sea (Leeder and Hardman, 1990;Besly et al, 1993;Ritchie and Pratsides, 1993;Moscariello, 2003), in onshore UK and the Netherlands (Kombrink et al, 2007) and in Germany (Hollmann et al, 1997;Henk, 2005;Lüders et al, 2010;Wimmers and Koehrer, 2014) (Fig. 1a).…”

Alluvial architecture of the Holocene Rhine–Meuse delta (the Netherlands)

“…Examples of hydrocarbon reservoirs of fluvio‐deltaic origin are the Oseberg Field, Norwegian North Sea (Middle Jurassic Ness Formation; Ryseth, 2000), the Prudhoe Bay Field, Alaska, USA (Triassic Ivishak Formation; Tye et al. , 1999), and the Coevorden Field, the Netherlands (Upper Carboniferous Tubbergen Formation; Kombrink et al. , 2007).…”