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OIL OR GAS RESERVOIR

Medium/coursegrain size

High permeability

Low irreduciblewater saturation

Fine/very fine grain size

Low permeability

High irreducible water saturacion

Kv~RhVertical permeability will be lowHorizontal resistivity will be low

Kh~RvHorizontal permeability will be highVertical resistivity will be high

ACEITE o de gas

Media / cursotamao de grano

alta permeabilidad

irreducible bajasaturacin de agua

Fino / muy fino tamao de grano

baja permeabilidad

Saturacion de agua de alta irreductible

Kv ~ RhPermeabilidad vertical se bajaHorizontal resistividad ser baja

Kh ~ Ap

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Permeabilidad horizontal ser de altaVertical alta resistividad

.

Lithic fragments

With the exception of fragments of polycrystalline quartz, lithic fragments are generally unstable

in the sedimentay environment, yet, if prestn in a sandstone give the best clues to provenance.

Any type of rock fragment can be found in a sandstone, but some kinds are more common due to

the following factors:

Areal extent in the source drainage basin.

Location and relief of the drainage basin . Stability of the rock fragments in the sedimentary

environment.

Size of the crystals in the fragments.

...........................................

Accessory Minerals

Since it is possible that any mineral could be found in a sand or sandstone depending on the

degree of the mineralogical maturity, a variety of the other minerals are possible

.........................................

Glauconite

Glauconite occurs as green or brown sand-sized pellets in some quartz arenites, although

sometimes the glauconite pellets make up a substantial portion of the rock.

.............................

MINERALOGICAL AND TEXTURAL MATURITY

As the percentage of quartz iincreases, the mineralogical maturity of arenites increases.

Also, as the percentage of clay matrix decreased the degree of sorting increases, and thus the

textural maturity increases.

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Textural maturity also increases in the opposite direction as the % clay matrix increases from 50 to

100%.

e rock

As the percentage of quartz increases, the mineralogical maturity of arenites increases.

Also, as the percentage of clay matrix decreased the degree of sorting increases, and thus the

textural maturity increases.

Textural maturity also increases in the opposite direction as the % clay matrix increases from 50 to

100%.

...................................

Clastic Rock

comparison of compositions of clastic and carbonate rocks

Averge Mudrock(shale)

CLAY

MATRIX

illite

kolinite

smectite

CHEMICAL CEMENT

QUARTZ

CALCITEHEMATITE

ALLOCHEMICAL GRAINS

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fossils

pelloidsoolites

MICROCRYSTALINE MATRIX

Calcite

Chemical cement

CALCITE

LIMESTONE

SPARRY

AVERAGE

MUDR

SAND

INTRACTLASTS

BOREHOLE CONDITION

COAL

PRESSURE

SHAPE

SLABBED CONVENTIONAL CORE

ORIENTED CONVENTIONAL CORE

dium/course

grain size

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High permeability

Low irreducible

water saturation

Fine/very fine grain size

Low permeability

High irreducible water saturacion

Kv~Rh

Vertical permeability will be low

Horizontal resistivity will be low

Kh~Rv

Horizontal permeability will be high

Lithic fragments

With the exception of fragments of polycrystalline quartz, lithic fragments are generally unstable

in the sedimentay environment, yet, if prestn in a sandstone give the best clues to provenance.

Any type of rock fragment can be found in a sanstone, but some kinds are more common due to

the following factors:

Areal extent in the source drainage basin.

Location and relief of the drainage basin . Stability of the rock fragments in the sedimentary

environment.

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Size of the crystals in the fragments.

...........................................

Accessory Minerals

Since it is possible that any mineral could be found in a sand or sandstone depending on thedegree of the mineralogical maturity, a variety of the other minerals are possible

.........................................

Glauconite

Glauconite occurs as green or brown sand-sized pellets in some quartz arenites, although

sometimes the glauconite pellets make up a substantial portion of the rock.

.............................

MINERALOGICAL AND TEXTURAL MATURITY

As the percentage of quartz iincreases, the mineralogical maturity of arenites increases.

Also, as the percentage of clay matrix decreased the degree of sorting increases, and thus the

textural maturity increases.