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) (Leach et al., 1999). 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 (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.

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 />