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  = 6-36

  | topg    = 6-41

  | topg    = 6-36

  | 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

  | isbn    = 0-89181-602-X

  | isbn    = 0-89181-602-X

}}

}}

Each kerogen type has its own relationship to maturity parameters. Maturity measurements are made on materials other than kerogen; therefore, they are not a direct measure of the hydrocarbon generation stage of the source intervals. A relationship must be established between maturity of the geologic section and hydrocarbon generation for each kerogen type in a basin. This relationship can be derived using 1-D basin [[modeling]] techniques.

Each [[kerogen]] type has its own relationship to maturity parameters. Maturity measurements are made on materials other than [[kerogen]]; therefore, they are not a direct measure of the [[Petroleum generation|hydrocarbon generation]] stage of the [[Source rock|source]] intervals. A relationship must be established between maturity of the geologic section and hydrocarbon generation for each kerogen type in a basin. This relationship can be derived using 1-D basin [[modeling]] techniques.

==Hydrocarbon generation and maturity==

==Hydrocarbon generation and maturity==

The hydrocarbon generation-depth curve shown below indicates where various phases of hydrocarbons would be generated today in the geologic section if a uniform kerogen existed throughout. We would use the following steps to compare the relationships.

 

 

The hydrocarbon generation-depth curve in [[:file:evaluating-source-rocks_fig6-17.png|Figure 1]] indicates where various phases of hydrocarbons would be generated today in the geologic section if a uniform kerogen existed throughout. We would use the following steps to compare the relationships.

 

 

 

The table below shows examples of the relationships between [[Petroleum generation|hydrocarbon generation]] zones, maturity, and transformation ratio for standard types II and III kerogens, based on a specific burial and thermal history model. The most significant difference is in the depth to the onset of oil generation, where [[depth::1000 m]] separates the top of the oil windows of these two kerogen types.

{| class = "wikitable"

{| class = "wikitable"

|-

|-

! Step

! Hydrocarbon generation zone

! Action

! [[vitrinite reflectance|Vitrinite refl.]], % R_o, Type II

|-

|-

| 1

| Onset oil

| Define the hydrocarbon generation stage for a calibrated well based on the depth vs. hydrocarbon yield plot (left figure). For example, the onset of oil generation occurs at approximately [[length::2.1 km]]. Then transfer to the depth versus maturity plot (in this case vitrinite reflectance, right figure) and follow across at [[length::2.1 km]] until you reach the maturity profile. This vitrinite reflectance value (0.55 %R_o ) would indicate the onset of hydrocarbon generation in this well.

| 0.55

| 0.85

|-

|-

| 2

| Onset peak rate generation

| Apply this relationship to predict the generation zones for this specific kerogen in wells with similar thermal and burial histories in the basin for which maturity data are available.

|-

| 1.35

|}

|}

==See also==

==See also==

* [[Kerogen type and hydrocarbon generation]]

* [[Kerogen type and hydrocarbon generation]]

* [[Kerogen type and transformation ratio]]

* [[Kerogen type and transformation ratio]]

* [[Comparison of kerogen types]]

* [[Kerogen types: comparison of maturity measures]]

* [[Open-vs. Closed-system generation modeling]]

* [[Open- vs closed-system generation modeling]]

==External links==

==External links==

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

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

[[Category:Evaluating source rocks]]

[[Category:Evaluating source rocks]]