Reservoir Hetrogenity

[rashidalishaikh]

salam,
can anybody tel what is hetrogenity..itx types?
how can we determine them?
and why it is so important in the oil industry?

[vinomarky]

Think of a reservoir as behaving like a network of roads

If you wanted to predict how quickly, and the best way to evacuate a city, you would need to understand where the roads are, where they connect, where the choke points are, where the highways are and where the dead ends are. This variability of the interconnected road system is analogous to heterogeneity of a reservoir, and just as important to understand if you want to predict how quickly and the best way to get hydrocarbons out of the ground - especially in the presence of a second phase of significantly different mobility and/or density

[DAH7542]

The following explanation is extracted from Schlumberger's paper: "Measuring Permeability Anisotropy: The Latest Approach"; it will make it clear:

Permeability—the ease with which fluids flow through rock—has long been identified as one of the most important parameters controlling reservoir performance. Yet it is one of the most difficult to measure. If permeability were the same at all places and in all directions—homogeneous and isotropic —then measuring the flow through a sample of rock would reveal its value. However, rock type and grain size may vary through a reservoir leading to variation in permeability. To complicate matters further, measuring permeability parallel to layers of sedimentary rocks may give a different value to a perpendicular measurement. Therefore permeability measured at the same point in the horizontal direction, kh, may be different from permeability measured in the vertical direction, kv. This directional dependency on any type of measurement is called anisotropy. A measurement, such as vertical permeability, in the same direction at two distinct points may also be different. Positional dependency is called heterogeneity. Needless to say, in the horizontal plane, horizontal permeability may have a maximum value, KH and a minimum value, kh. Although anisotropy strictly refers to the directional dependency of a measurement, the ratio kv /kh is often used
to quantify permeability anisotropy.

[sami22]

thanks