Permeability is a measure of how easily fluids can flow through the pore spaces in a rock. It depends on properties like pore size, shape, and connectivity. Porosity refers to the total pore space in a rock, while permeability reflects how readily fluids can move through that space. Factors like grain size, clay content, and compaction influence a rock's permeability. Larger, well-sorted grains generally yield higher permeability, as do rocks with fewer obstructions to fluid flow in their pore networks. Permeability is quantified using units like square meters or millidarcies.

1. topic:
Permeability
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sultan e room

2. Topic overview
What is
Permeability?

3. 1: What is Permeability
 Definition:
 The permeability of a rock is a measure of how easily a fluids may flow
through the pore channels in a rock. It depends on the size, shape, tortuosity
and number of the pore channels in the porous medium.
Absolute permeability is the permeability of the porous medium if a single
fluid is flowing. Effective permeability is the permeability of a fluid if another
fluid is present. Relative permeability is the effective permeability divided by
the absolute permeability.
What is the difference between
permeability and porosity ?

4. Distinct between porosity and permeability
 Porous: a rock that hold much fluid
Permeable: a rock that allow fluid to flow is described as permeable
Most sand and conglomerate are both porous and permeable
 Impermeable: a rock that doesn’t allow fluid to flow through it is called
impermeable,
 E.g; unfractured granite and schist are impermeable
 Shale can have substantial porosity, but it has low permeability because its
pores are to small are too small to permit easy passage of water.

5. Factors affecting permeability the magnitude
and/or direction of permeability.
 Factors affecting permeability Numerous factors affect the magnitude and/or
direction of permeability.
 1. Textural properties
 a. Pore size/ grain size b. Grain size
distribution
 c. Shape of grains d. Packing of grains
 2. Amount, distribution, and type of clays
 3. Overburden pressure
 4. Impurities in water
 5. High velocity flow effects

6. There is a general increase in permeability as grain size increases from very fine to coarse
Both porosity and permeability increase as sorting progresses from very poor to well sorted

7. Unit:
 The SI unit for permeability is m2
 A practicle unit for permeability is darcy (d) or more commonly the millidarcy
(md) (1 darcy = 10^12m2)