Caused by solution.
Pores whose boundaries cross-cut grains, matrices, and/or earlier cement.
Larger than moldic pores.
Common in carbonate rock.
occur in any brittle rock
The crests of anticline
Adjacent to fault plane
Karstic features in carbonates
Porosity of Plutonic and Volcanic Rocks
Cracks form during cooling volcanic rocks vary in porosity but can be very high
Pumicecan have porosity approaching 90%
Basalt hasporosity between 1 and 12%
Porosity of Sedimentary Rocks (Clastic)
depends on grain size, shapes, degree of sorting, and the degree of cementation
Porosity of Plutonic and Metamorphic Rocks
porosity is usually low
Requirements for Reservoir Rock
High Permeability -
What Is Reservoir Rocks
capable of storing large quantities of oil and gas
Low porosity usually results in low permeability
intrinsic permeability of any porous material