Changes

  | part    = Critical elements of the petroleum system

  | part    = Critical elements of the petroleum system

  | chapter = Evaluating source rocks

  | chapter = Evaluating source rocks

  | frompg  = 6-1

  | frompg  = 6-30

  | topg    = 6-41

  | topg    = 6-30

  | 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

==How to use SCI and TAI==

==How to use SCI and TAI==

SCI (spore coloration index) and TAI (thermal alteration index) are maturation indicators that measure the color of palynomorphs. Color changes as a function of maturity.

SCI (spore coloration index) and TAI (thermal alteration index) are maturation indicators that measure the color of [[palynomorph]]s. Color changes as a function of [[Maturation|maturity]].

There are a number of scales for both SCI and TAI within the exploration industry. The SCI and TAI scales have been “standardized” to the vitrinite reflectance maturity scale. Users of SCI and TAI data need to have access to the maturation relationship used by the lab supplying the data, and users should be aware of how the scales compare from one lab to another in order to apply the data correctly. These relationships should be available from the vendor performing the analysis.

There are a number of scales for both SCI and TAI within the exploration industry. The SCI and TAI scales have been standardized to the [[vitrinite reflectance]] (R_o) maturity scale. Users of SCI and TAI data need to have access to the maturation relationship used by the lab supplying the data, and users should be aware of how the scales compare from one lab to another in order to apply the data correctly. These relationships should be available from the vendor performing the analysis.

==Correlation of SCI & TAI with other parameters==

==Correlation of SCI & TAI with other parameters==

The table below shows a very generalized correlation of kerogen maturity parameters with SCI and TAI (after<ref name=ch06r16>Waples, D., 1985, Geochemistry in Petroleum Exploration: Boston, IHRDC, 232 p.</ref>).

The table below shows a very generalized correlation of [[kerogen]] maturity parameters with SCI and TAI (after<ref name=ch06r16>Waples, D., 1985, Geochemistry in Petroleum Exploration: Boston, IHRDC, 232 p.</ref>).

{| class = "wikitable"

{| class = "wikitable"

|-

|-

! Vitrinite reflectance (%Ro)

! [[Vitrinite reflectance]] (%R_o) || Spore coloration index (SCI) || Thermal alteration index (TAI) || Pyrolysis [[Tmax]] (°C) || Generalized hydrocarbon zone

! Spore coloration index (SCI)

! Thermal alteration index (TAI)

! Pyrolysis tmax (°C)

! Generalized hydrocarbon zone

|-

|-

| 0.40

| 0.40 || 4.0 || 2.0 || 420 || Immature

| 4.0

| 2.0

| 420

| Immature

|-

|-

| 0.50

| 0.50 || 5.0 || 2.3 || 430 || Immature

| 5.0

| 2.3

| 430

| Immature

|-

|-

| 0.60

| 0.60 || 6.0 || 2.6 || 440 || Oil

| 6.0

| 2.6

| 440

| Oil

|-

|-

| 0.80

| 0.80 || 7.4 || 2.8 || 450 || Oil

| 7.4

| 2.8

| 450

| Oil

|-

|-

| 1.00

| 1.00 || 8.1 || 3.0 || 460 || Oil

| 8.1

| 3.0

| 460

| Oil

|-

|-

| 1.20

| 1.20 || 8.3 || 3.2 || 465 || Oil & wet gas

| 8.3

| 3.2

| 465

| Oil & wet gas

|-

|-

| 1.35

| 1.35 || 8.5 || 3.4 || 470 || Wet gas

| 8.5

| 3.4

| 470

| Wet gas

|-

|-

| 1.50

| 1.50 || 8.7 || 3.5 || 480 || Wet gas

| 8.7

| 3.5

| 480

| Wet gas

|-

|-

| 2.00

| 2.00 || 9.2 || 3.8 || 500 || Methane

| 9.2

| 3.8

| 500

| Methane

|-

|-

| 3.00

| 3.00 || 10 || 4.0 || 500+ || Methane

| 10

| 4.0

| 500+

| Methane

|-

|-

| 4.00

| 4.00 || 10+ || 4.0 || 500+ || Overmature

| 10+

| 4.0

| 500+

| Overmature

|}

|}

[[Category:Critical elements of the petroleum system]]  

[[Category:Critical elements of the petroleum system]]  

[[Category:Evaluating source rocks]]

[[Category:Evaluating source rocks]]