Changes

==Data requirements==

==Data requirements==

Basic data requirements for [[facies analysis]] of subsurface rocks are listed in Table 1. Data associated with wells are most often used, but [[seismic data]], particularly [[3-D seismic: the data cube|three-dimensional data]], are becoming increasingly important in defining sandstone body geometries.<ref name=pt06r17>Brown, A. R., 1986 Interpretation of three-dimensional seismic data: [http://store.aapg.org/detail.aspx?id=1025 AAPG Memoir 42], 194 p.</ref>  Conventional core is perhaps the most diagnostic for sedimentological interpretation of vertical sequences (see [[Core description]]). However, wireline tools such as [[dipmeters]] and [[Borehole imaging devices|formation imaging devices]] can provide electrical images suitable for sedimentological interpretation with the added ability to determine [[paleocurrent]] directions in appropriate cases.

Basic data requirements for [[facies analysis]] of subsurface rocks are listed in Table 1. Data associated with wells are most often used, but [[seismic data]], particularly [[3-D seismic: the data cube|three-dimensional data]], are becoming increasingly important in defining [[sandstone]] body geometries.<ref name=pt06r17>Brown, A. R., 1986 Interpretation of three-dimensional seismic data: [http://store.aapg.org/detail.aspx?id=1025 AAPG Memoir 42], 194 p.</ref>  Conventional core is perhaps the most diagnostic for sedimentological interpretation of vertical sequences (see [[Core description]]). However, wireline tools such as [[dipmeters]] and [[Borehole imaging devices|formation imaging devices]] can provide electrical images suitable for sedimentological interpretation with the added ability to determine [[paleocurrent]] directions in appropriate cases.

{| class = "wikitable"

{| class = "wikitable"

Reservoir quality sand bodies form on both the [http://www.thefreedictionary.com/continental+slope continental slope] and at the base of the slope. Slope environments include sand bodies formed within [[submarine canyons]] and gullies cut into the slope and as [[spillover sheets]].<ref name=pt06r120>Slatt, R. M., 1986, Exploration models for submarine slope sandstones: Transactions of the 36th Annual Meeting of the Gulf Coast Association of Geological Societies, Continental Slope—Frontier of the 80's, p. 295–304.</ref> Sands can also accumulate on [[Tectonics|tectonically]] formed small basins within the slope itself.

Reservoir quality sand bodies form on both the [http://www.thefreedictionary.com/continental+slope continental slope] and at the base of the slope. Slope environments include sand bodies formed within [[submarine canyons]] and gullies cut into the slope and as [[spillover sheets]].<ref name=pt06r120>Slatt, R. M., 1986, Exploration models for submarine slope sandstones: Transactions of the 36th Annual Meeting of the Gulf Coast Association of Geological Societies, Continental Slope—Frontier of the 80's, p. 295–304.</ref> Sands can also accumulate on [[Tectonics|tectonically]] formed small basins within the slope itself.

[[Submarine fans]] may form at the base of slopes that have a [[ Lithofacies and environmental analysis of clastic depositional systems#Deltas|delta]]-like appearance in plan view ([[:file:lithofacies-and-environmental-analysis-of-clastic-depositional-systems_fig3.png|Figure 3i]]). Internal facies vary from channelized sand and gravel bodies to sheet-like, thin, graded beds deposited by [[turbidity flow]]s in distal parts of the fan. Vertical sequences through channelized portions of the fan typically show an upward-fining character accompanied by an upward-fining wireline log motif. Vertical sequences through more distal parts of the fan show an alternation between sandstone and mudstone beds, so that wireline logs are typically interdigitate and irregular. Reservoir quality varys accordingly. Many variations of morphologies and internal facies configurations occur in submarine fans as a function of [[Depocenter#Siliciclastic vs. carbonate supply|sediment supply]], [[Sea level cycle phase|sea level]], type of [[continental margin]], and local [[Tectonics|tectonic]] features.

[[Submarine fans]] may form at the base of slopes that have a [[ Lithofacies and environmental analysis of clastic depositional systems#Deltas|delta]]-like appearance in plan view ([[:file:lithofacies-and-environmental-analysis-of-clastic-depositional-systems_fig3.png|Figure 3i]]). Internal facies vary from channelized sand and gravel bodies to sheet-like, thin, graded beds deposited by [[turbidity flow]]s in distal parts of the fan. Vertical sequences through channelized portions of the fan typically show an upward-fining character accompanied by an upward-fining wireline log motif. Vertical sequences through more distal parts of the fan show an alternation between sandstone and [[mudstone]] beds, so that wireline logs are typically interdigitate and irregular. Reservoir quality varys accordingly. Many variations of morphologies and internal facies configurations occur in submarine fans as a function of [[Depocenter#Siliciclastic vs. carbonate supply|sediment supply]], [[Sea level cycle phase|sea level]], type of [[continental margin]], and local [[Tectonics|tectonic]] features.

==See also==

==See also==