Changes

Connectivity between individual channels will depend on how much shale is present. The effect of increasing shale content is to reduce vertical connectivity through sand-on-sand contacts and also to increase lateral variability.<ref name=WeimerandSlatt />

Connectivity between individual channels will depend on how much shale is present. The effect of increasing shale content is to reduce vertical connectivity through sand-on-sand contacts and also to increase lateral variability.<ref name=WeimerandSlatt />

Shales may be present either as extensive late-stage channel-fill shales or as shale drapes at the base of the channels. They may be composed of mudstone, siltstone, or heterolithic sediments ([[:File:M91FG194.JPG|Figure 2b]]).<ref name=Beaubouef1999 /> Simulation modeling indicates that shale drapes may be a significant feature reducing connectivity between channel complexes and impairing the recovery efficiency.<ref>Larue, D. K., 2004, [http://archives.datapages.com/data/specpubs/memoir80/CHAPTER16/CHAPTER16.HTM Outcrop and waterflood simulation modeling of the 100-foot channel complex, Texas, and the Ainsa II channel complex, Spain: Analogs to multistory and multilateral channelized slope reservoirs], in G. M. Grammer, P. M. Harris, and G. P. Eberli, eds., Integration of outcrop and modern analogs in reservoir modeling, [http://store.aapg.org/detail.aspx?id=658 AAPG Memoir 80], p. 337–364.</ref> This mechanism has been invoked to explain why channel margins in the Forties field, UK North Sea, appear to act as baffles to fluid flow (Vaughan et al., 2007).

Shales may be present either as extensive late-stage channel-fill shales or as shale drapes at the base of the channels. They may be composed of mudstone, siltstone, or heterolithic sediments ([[:File:M91FG194.JPG|Figure 2b]]).<ref name=Beaubouef1999 /> Simulation modeling indicates that shale drapes may be a significant feature reducing connectivity between channel complexes and impairing the recovery efficiency.<ref>Larue, D. K., 2004, [http://archives.datapages.com/data/specpubs/memoir80/CHAPTER16/CHAPTER16.HTM Outcrop and waterflood simulation modeling of the 100-foot channel complex, Texas, and the Ainsa II channel complex, Spain: Analogs to multistory and multilateral channelized slope reservoirs], in G. M. Grammer, P. M. Harris, and G. P. Eberli, eds., Integration of outcrop and modern analogs in reservoir modeling, [http://store.aapg.org/detail.aspx?id=658 AAPG Memoir 80], p. 337–364.</ref> This mechanism has been invoked to explain why channel margins in the Forties field, UK North Sea, appear to act as baffles to fluid flow.<ref>Vaughan, O., R. Jones, and S. Plahn, 2007, Reservoir management aspects of the rejuvenation of the Forties field, UKCS: Presented at Offshore Europe, Society of Petroleum Engineers, September 4–7, 2007, Aberdeen, SPE Paper 109012, 20 p.</ref>

According to Weimer and Slatt,<ref name=WeimerandSlatt /> the width to thickness ratio of channels typically ranges from 10:1 to 300:1.

According to Weimer and Slatt,<ref name=WeimerandSlatt /> the width to thickness ratio of channels typically ranges from 10:1 to 300:1.