Changes

Reservoirs are inherently heterogeneous assemblages of depositional facies and subfacies (for more information, see [[Lithofacies and environmental analysis of clastic depositional systems#Clastic depositional lithofacies and environments|Clastic lithofacies]] and [[Carbonate reservoir models: facies, diagenesis, and flow characterization#Carbonate sediments and environments|Carbonate lithofacies]]), each with characteristic and commonly differing [[sediment texture]]s, [[stratification type]]s, and [[bedding architecture]]s. Variability is compounded by postdepositional alterations of the strata, such as through [[Reservoir quality#compaction|compaction]], [[Reservoir quality#cementation|cementation]], and tectonic [[deformation]]. Geological heterogeneities have been classified in a variety of ways according to their size or scale; the common categories, used here, are ''wellbore, interwell'', and ''fieldwide'' scales of heterogeneity ([[:file:geological-heterogeneities_fig1.png|Figure 1]]).

Reservoirs are inherently heterogeneous assemblages of depositional facies and subfacies (for more information, see [[Lithofacies and environmental analysis of clastic depositional systems#Clastic depositional lithofacies and environments|Clastic lithofacies]] and [[Carbonate reservoir models: facies, diagenesis, and flow characterization#Carbonate sediments and environments|Carbonate lithofacies]]), each with characteristic and commonly differing [[sediment texture]]s, [[stratification type]]s, and [[bedding architecture]]s. Variability is compounded by postdepositional alterations of the strata, such as through [[Reservoir quality#compaction|compaction]], [[Reservoir quality#cementation|cementation]], and tectonic [[deformation]]. Geological heterogeneities have been classified in a variety of ways according to their size or scale; the common categories, used here, are ''wellbore, interwell'', and ''fieldwide'' scales of heterogeneity ([[:file:geological-heterogeneities_fig1.png|Figure 1]]).

Heterogeneities at the wellbore scale affect matrix [[permeability]], distribution of [[Interpreting hydrocarbon shows#Residual shows|residual oil]], directional flow of fluids, potential [[Rock-water reaction|fluid-rock interactions]], and [[Rock-water reaction: formation damage|formation damage]]. Heterogeneities at the interwell scale affect [[Fundamentals of fluid flow|fluid flow]] patterns, [[drainage efficiency]] of the reservoir, and vertical and lateral [[Enhanced oil recovery|sweep efficiency]] of [[Waterflooding|secondary and tertiary recovery projects]]. Heterogeneities at the fieldwide scale determine the in-place hydrocarbon volume, areal distribution, and trend of hydrocarbon production.

Heterogeneities at the wellbore scale affect matrix [[permeability]], distribution of [[Interpreting hydrocarbon shows#Residual shows|residual oil]], directional flow of fluids, potential [[Rock-water reaction|fluid-rock interactions]], and [[Rock-water reaction: formation damage|formation damage]]. Heterogeneities at the interwell scale affect [[Fundamentals of fluid flow|fluid flow]] patterns, [[drainage efficiency]] of the reservoir, and vertical and [[lateral]] [[Enhanced oil recovery|sweep efficiency]] of [[Waterflooding|secondary and tertiary recovery projects]]. Heterogeneities at the fieldwide scale determine the in-place hydrocarbon volume, areal distribution, and trend of hydrocarbon production.

==Wellbore scale heterogeneities==

==Wellbore scale heterogeneities==