Changes

===Predicting from texture and clay content===

===Predicting from texture and clay content===

Predicting sandstone reservoir permeability is possible as long as we realize that potential errors may be large. Any process that decreases pore throat size decreases permeability, so predict accordingly. Use the table below to help predict sandstone reservoir permeability.

Predicting sandstone reservoir permeability is possible as long as we realize that potential errors may be large. Any process that decreases pore throat size decreases permeability, so predict accordingly. Use the procedure below to help predict sandstone reservoir permeability.

# Estimate [[grain size]], [[Core_description#Maturity|sorting]], and [[porosity]] using the [[Depositional environments|depositional environment]]. For example, if a reservoir is a [[beach]] sand, it should be fine to medium grained and well sorted with well-rounded quartz grains

# Apply information from Step 1 to the porosity–permeability–grain size plot ([[:file:predicting-reservoir-system-quality-and-performance_fig9-60.png|Figure 1]]). Use porosity and grain size from sandstone to estimate the permeability on the chart.

# If the sandstone is poorly sorted or is cemented, then discount permeability downward.

# Determine if [ http://dictionary.reference.com/browse/authigenicauthigenic] clay is present. If so, what kind: pore lining, discrete particle, or pore-throat bridging? Adjust permeability downward according to clay type present.

# Determine if [http://www.thefreedictionary.com/Detrital detrital] clay is present using depositional environment (i.e., high energy = low clay content). If detrital clay is likely, then expect permeability  to be low.

| Estimate [[grain size]], [[Core_description#Maturity|sorting]], and [[porosity]] using the [[Depositional environments|depositional environment]]. For example, if a reservoir is a [[beach]] sand, it should be fine to medium grained and well sorted with well-rounded quartz grains

| Apply information from Step 1 to the porosity–permeability–grain size plot ([[:file:predicting-reservoir-system-quality-and-performance_fig9-60.png|Figure 1]]). Use porosity and grain size from sandstone to estimate the permeability on the chart.

| If the sandstone is poorly sorted or is cemented, then discount permeability downward.

| Determine if [ http://dictionary.reference.com/browse/authigenicauthigenic] clay is present. If so, what kind: pore lining, discrete particle, or pore-throat bridging? Adjust permeability downward according to clay type present.

| Determine if [http://www.thefreedictionary.com/Detrital detrital] clay is present using depositional environment (i.e., high energy = low clay content). If detrital clay is likely, then expect permeability  to be low.

==See also==

==See also==