Changes

[[File:M91FG194.JPG|thumb|300px|{{Figure number|2}}Features influencing fluid flow in deep-marine sandstones.]]

[[File:M91FG194.JPG|thumb|300px|{{Figure number|2}}Features influencing fluid flow in deep-marine sandstones.]]

Channel fills can show differing degrees of amalgamation laterally and vertically ([[:File:M91FG193.JPG|Figure 1]]). The degree of sandstone continuity is influenced by the stacking patterns. In channelized systems, this can be a critical parameter in assessing economic feasibility for reservoir appraisal, e.g., as in the appraisal of the Schiehallion field, offshore United Kingdom (see Chapter 3, this publication).<ref>Leach, H. M., N. Herbert, A. Los, and R. L. Smith, 1999, The Schiehallion development in A. J. Fleet and S. A. R. Boldy, eds., Petroleum geology of northwest Europe: Proceedings of the 5th Conference, Geological Society (London), p. 683–692.</ref> Eubanks (1987) described channelized turbidites from the Oligocene lower Hackberry sands of the North Sabine Lake field, Louisiana. Stacking of individual channels resulted in a large amalgamated reservoir interval with pressure communication throughout. Isolated channels also occur, but these have shown rapid depletion within 2 months following production start-up.

Channel fills can show differing degrees of amalgamation laterally and vertically ([[:File:M91FG193.JPG|Figure 1]]). The degree of sandstone continuity is influenced by the stacking patterns. In channelized systems, this can be a critical parameter in assessing economic feasibility for reservoir appraisal, e.g., as in the appraisal of the Schiehallion field, offshore United Kingdom (see Chapter 3, this publication).<ref>Leach, H. M., N. Herbert, A. Los, and R. L. Smith, 1999, The Schiehallion development in A. J. Fleet and S. A. R. Boldy, eds., Petroleum geology of northwest Europe: Proceedings of the 5th Conference, Geological Society (London), p. 683–692.</ref> Eubanks<ref>Eubanks, L. G., 1987, [http://archives.datapages.com/data/bulletns/1986-87/data/pg/0071/0010/1150/1162.htm North Sabine Lake field: Complex deposition and reservoir morphology of lower Hackberry (Oligocene), southwest Louisiana]: AAPG Bulletin, v. 71, no. 10, p. 1162–1170.</ref> described channelized turbidites from the Oligocene lower Hackberry sands of the North Sabine Lake field, Louisiana. Stacking of individual channels resulted in a large amalgamated reservoir interval with pressure communication throughout. Isolated channels also occur, but these have shown rapid depletion within 2 months following production start-up.

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 />