Reservoir homogeneity​

Reservoir homogeneity​
With regard to a reservoir rock, can be visualised in a formation that consists of ​
1. a single mineralogy with ​
2. all grains of similar shapes and sizes with ​
3. no spatial organization or patterns present; in this example, similar grain shapes and sizes, together with lack of spatial patterns would lead to a uniform distribution of porosity and permeability. ​

Pure homogeneity, with regard to a reservoir rock, can be visualised in a formation that consists of (1) a single mineralogy with (2) all grains of similar shapes and sizes with (3) no spatial organization or patterns present; in this example, similar grain shapes and sizes, together with lack of spatial patterns would lead to a uniform distribution of porosity and permeability. Therefore, ignoring the scalar component of heterogeneity for a moment, there are two contrasting examples of heterogeneity in a reservoir rock.

Homogeneity and heterogeneity can be considered as end members of a continuous spectrum, defining the minimum and maximum heterogeneity, with zero heterogeneity equating to homogeneity. There are a number of characteristics that occur in both end-member examples provided above (for example vertical rhythmicity in terms of bedding or grain size distribution). Neither end-member is obviously more heterogeneous than the other; there may indeed be a relative scale difference between the two examples. Some researchers may perceive a regularly structured system, for example a laminated or bedded reservoir, as homogeneous because these structures are spatially continuous and occur throughout the formation. The presence of structures within a formation is, however, more commonly interpreted as a type of heterogeneity, regardless of how regular their distribution. In this scenario, the structures represent deviation from the homogeneous mono-mineralic ‘norm’