Changes

==Interwell scale heterogeneities==

==Interwell scale heterogeneities==

[[file:geological-heterogeneities_fig3.png|left|thumb|{{figure number|3}}Lateral and vertical bedding and permeability heterogeneity of a typical fluviodeltaic sequence. (From <ref name=pt06r144 />.)]]

[[file:geological-heterogeneities_fig3.png|left|thumb|{{figure number|3}}Lateral and vertical bedding and permeability heterogeneity of a typical fluviodeltaic sequence. (From Van de Graaff & Ealey.<ref name=pt06r144 />)]]

Elements of interwell scale heterogeneity include lateral [[bedding geometry|bedding geometies]], [[bedding style|styles]], and continuity; systematic lateral and vertical textural patterns; and resultant variations in [[reservoir quality]]. This scale of heterogeneity is probably the most difficult to quantify because wellbore data of the type previously described must be extrapolated to the interwell region. In many instances, between-well correlations are difficult because lithofacies may not be continuous at interwell spacings. Thus, interpretation must be guided by an understanding of [[depositional environments]] and facies (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]]), interpreted from core analysis and compared with modern environments or outcrop analogs where actual observations and measurements have been made.

Elements of interwell scale heterogeneity include lateral [[bedding geometry|bedding geometies]], [[bedding style|styles]], and continuity; systematic lateral and vertical textural patterns; and resultant variations in [[reservoir quality]]. This scale of heterogeneity is probably the most difficult to quantify because wellbore data of the type previously described must be extrapolated to the interwell region. In many instances, between-well correlations are difficult because lithofacies may not be continuous at interwell spacings. Thus, interpretation must be guided by an understanding of [[depositional environments]] and facies (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]]), interpreted from core analysis and compared with modern environments or outcrop analogs where actual observations and measurements have been made.