Changes

==Caveat==

==Caveat==

PI data are misleading if the S1 peak includes nonindigenous hydrocarbons, such as drilling additives or migrated hydrocarbons. Expulsion characteristics of a source rock are not considered when looking at PI numbers. If the expulsion saturation threshold of the source rock is high, the PI data will be overestimated. If the expulsion saturation threshold is low, the data will be underestimated.

PI data are misleading if the S1 peak includes nonindigenous [[hydrocarbon]]s, such as drilling additives or [[Migration|migrated]] hydrocarbons. Expulsion characteristics of a [[source rock]] are not considered when looking at PI numbers. If the [[expulsion saturation threshold]] of the source rock is high, the PI data will be overestimated. If the expulsion saturation threshold is low, the data will be underestimated.

A trend is valid only if developed over a uniform source internal. If the depositional environment changes significantly, establish a different PI trend for each unique source rock type.

A trend is valid only if developed over a uniform source internal. If the [[depositional environment]] changes significantly, establish a different PI trend for each unique source rock type.

==See also==

==See also==