Changes

===Geological reef reservoir model===

===Geological reef reservoir model===

The geological reef model is a composite of the upward-shoaling subtidal-supratidal and karst-collapse reservoir models. The difference is that the facies tracts are compressed onto a carbonate shelf of limited aerial extent with high relief above the seafloor and with steeply sloping sides. The interior shelf or lagoon facies ([[:file:carbonate-reservoir-models-facies-diagenesis-and-flow-characterization_fig2.png|Figure 2]]) located landward of the shelf edge normally contains a high percentage of mud. Grainstones, packstones, and boundstones associated with the reef facies are typically found along the shelf edge.

The geological [[reef]] model is a composite of the [[upward-shoaling]] [[subtidal]]-[[supratidal]] and [[karst]]-collapse reservoir models. The difference is that the [[facies tracts]] are compressed onto a carbonate [[shelf]] of limited areal extent with high relief above the seafloor and with steeply sloping sides. The [[interior shelf]] or [[lagoon]] facies ([[:file:carbonate-reservoir-models-facies-diagenesis-and-flow-characterization_fig2.png|Figure 2]]) located landward of the shelf edge normally contains a high percentage of mud. [[Grainstone]]s, [[packstone]]s, and [[boundstone]]s associated with the reef facies are typically found along the shelf edge.

Compaction and cementation typically destroy the permeability of the lagoonal muds, leaving the grain-dominated sediments and boundstones of the reef edge as reservoir rocks. However, selective leaching, dolomitization, and karsting can significantly alter the permeability patterns, as discussed in previous sections. The reservoir flow units can be very complex due to the numerous possible combinations of depositional and diagenetic events.

[[Reservoir quality#Compaction|]Compaction]] and [[Postaccumulation cementation|cementation]] typically destroy the permeability of the lagoonal muds, leaving the grain-dominated sediments and boundstones of the reef edge as reservoir rocks. However, selective [[leaching]], [[dolomitization]], and [[karst]]ing can significantly alter the [[permeability]] patterns, as discussed in previous sections. The reservoir flow units can be very complex due to the numerous possible combinations of depositional and [[Carbonate reservoir models: facies, diagenesis, and flow characterization#Diagenesis|diagenetic]] events.

==See also==

==See also==