Difference between revisions of "Production Index (PI)"
Jump to navigation
Jump to search
FWhitehurst (talk | contribs) |
Cwhitehurst (talk | contribs) m (added Category:Treatise Handbook 3 using HotCat) |
||
| (8 intermediate revisions by 2 users not shown) | |||
| Line 6: | Line 6: | ||
| part = Critical elements of the petroleum system | | part = Critical elements of the petroleum system | ||
| chapter = Evaluating source rocks | | chapter = Evaluating source rocks | ||
| − | | frompg = 6- | + | | frompg = 6-32 |
| − | | topg = 6- | + | | topg = 6-32 |
| author = Carol A. Law | | author = Carol A. Law | ||
| link = http://archives.datapages.com/data/specpubs/beaumont/ch06/ch06.htm | | link = http://archives.datapages.com/data/specpubs/beaumont/ch06/ch06.htm | ||
| Line 16: | Line 16: | ||
[[Maturation|Maturity]] of a homogeneous source section can be accessed from the production index (PI). PI is calculated from [[Rock-Eval]] data: | [[Maturation|Maturity]] of a homogeneous source section can be accessed from the production index (PI). PI is calculated from [[Rock-Eval]] data: | ||
| − | :<math>\mbox{PI} = \mbox{S1} | + | :<math>\mbox{PI} = \frac{\mbox{S1}}{(\mbox{S1} + \mbox{S2})}</math> |
where S1 is the quantity of free hydrocarbons (gas + oil), in mg/g of rock and S2 is the quantity of thermally generated (cracked) hydrocarbons, in mg/g of rock <ref name=NL Oil and Gas Portal>[http://www.nlog.nl/en/activity/analyses.html NL Oil and Gas Portal]</ref>. | where S1 is the quantity of free hydrocarbons (gas + oil), in mg/g of rock and S2 is the quantity of thermally generated (cracked) hydrocarbons, in mg/g of rock <ref name=NL Oil and Gas Portal>[http://www.nlog.nl/en/activity/analyses.html NL Oil and Gas Portal]</ref>. | ||
| Line 24: | Line 24: | ||
{| class = "wikitable" | {| class = "wikitable" | ||
|- | |- | ||
| − | ! Production index | + | ! Production index || [[Petroleum generation|Generation]] zone |
| − | |||
|- | |- | ||
| − | | | + | | < 0.10 || Immature |
| − | |||
| − | | Immature | ||
|- | |- | ||
| − | | 0.10-0.30 | + | | 0.10-0.30 || Oil generation |
| − | | Oil generation | ||
|- | |- | ||
| − | | > 0.30 | + | | > 0.30 || Gas generation/oil [[cracking]] |
| − | | Gas generation/oil cracking | ||
|} | |} | ||
==Caveat== | ==Caveat== | ||
| − | PI data are misleading if the S1 peak includes nonindigenous [[hydrocarbon]]s, such as drilling | + | PI data are misleading if the S1 peak includes nonindigenous [[hydrocarbon]]s, such as [[drilling additive]]s 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 | + | A trend is valid only if developed over a uniform source interval. If the [[depositional environment]] changes significantly, establish a different PI trend for each unique source rock type. |
==See also== | ==See also== | ||
| Line 51: | Line 46: | ||
* [[Spore coloration and thermal alteration indices]] | * [[Spore coloration and thermal alteration indices]] | ||
* [[Hydrogen Index (HI)]] | * [[Hydrogen Index (HI)]] | ||
| + | * [[Rock Eval analysis using hydrogen index (HI) and oxygen index (OI)]] | ||
==References== | ==References== | ||
| Line 62: | Line 58: | ||
[[Category:Critical elements of the petroleum system]] | [[Category:Critical elements of the petroleum system]] | ||
[[Category:Evaluating source rocks]] | [[Category:Evaluating source rocks]] | ||
| + | [[Category:Geochemistry]] | ||
| + | [[Category:Treatise Handbook 3]] | ||
Latest revision as of 16:10, 10 February 2022
| Exploring for Oil and Gas Traps | |
| |
| Series | Treatise in Petroleum Geology |
|---|---|
| Part | Critical elements of the petroleum system |
| Chapter | Evaluating source rocks |
| Author | Carol A. Law |
| Link | Web page |
| Store | AAPG Store |
Maturity of a homogeneous source section can be accessed from the production index (PI). PI is calculated from Rock-Eval data:
where S1 is the quantity of free hydrocarbons (gas + oil), in mg/g of rock and S2 is the quantity of thermally generated (cracked) hydrocarbons, in mg/g of rock Cite error: Invalid <ref> tag; invalid names, e.g. too many.
How to apply PI
PI increases continuously through the oil window up to a value of 0.50. The following cutoffs can generally be applied.
| Production index | Generation zone |
|---|---|
| < 0.10 | Immature |
| 0.10-0.30 | Oil generation |
| > 0.30 | Gas generation/oil cracking |
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.
A trend is valid only if developed over a uniform source interval. If the depositional environment changes significantly, establish a different PI trend for each unique source rock type.
See also
- Evaluating source rock maturity
- Maturation
- Tmax
- Vitrinite reflectance
- Apatite fission track analysis
- Spore coloration and thermal alteration indices
- Hydrogen Index (HI)
- Rock Eval analysis using hydrogen index (HI) and oxygen index (OI)
References
External links
| find literature about Production Index (PI) |
|
|
|
|