Difference between revisions of "Maps of hydrocarbon types: Gulf of Mexico example"
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==Discussion== | ==Discussion== | ||
− | Hydrocarbon types reflect the composition of the kerogens from which they were generated. Kerogens are the insoluble organic matter in sedimentary rocks. Maps of hydrocarbon types estimate the number and distribution of mature generating | + | Hydrocarbon types reflect the composition of the kerogens from which they were generated. Kerogens are the insoluble organic matter in sedimentary rocks. Maps of hydrocarbon types estimate the number and distribution of mature generating [[source rock]]s. The following map of hydrocarbon types is based on analyses of more than 2000 oil, 600 gas, and 1200 seep samples correlated to specific source rocks. Nine oil-source-rock families have been identified (labeled 1-9; see table on following page), each having a specific geographic distribution related to mature source-rock location and [[migration]] paths. We will focus on the High Island-East Breaks area, where families 1 and 6 overlap (bold arrow). |
==Source table== | ==Source table== | ||
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|- | |- | ||
| Lower Tertiary (centered on Eocene, ~50-40 Ma) | | Lower Tertiary (centered on Eocene, ~50-40 Ma) | ||
− | | Tertiary marine <ref group="t" name="ch04tblfn1"></ref> | + | | |
− | + | * Tertiary marine <ref group="t" name="ch04tblfn1">Tertiary marine and Tertiary intermediate are mapped together.</ref> | |
− | + | * Tertiary intermediate <ref group="t" name="ch04tblfn1"></ref> | |
+ | * Tertiary terrestrial | ||
+ | | ①<br />①<br />② | ||
|- | |- | ||
| Upper Cretaceous (centered on Turonian, ~85-95 Ma) | | Upper Cretaceous (centered on Turonian, ~85-95 Ma) | ||
− | |||
| | | | ||
− | + | * Marine; low sulfur; no Tertiary influence | |
+ | * Calcareous; moderate sulfur; no Tertiary influence <ref group="t" name="ch04tblfn2"></ref> | ||
+ | | ③<br />④ | ||
|- | |- | ||
| Lower Cretaceous (centered on Aptian, ~115-105 Ma) | | Lower Cretaceous (centered on Aptian, ~115-105 Ma) | ||
− | | Carbonate; elevated salinity; Lower Cretaceous | + | | |
− | + | * Carbonate; elevated salinity; Lower Cretaceous | |
− | + | * Calcareous; moderate sulfur; Lower Cretaceous <ref group="t" name="ch04tblfn2">Calcareous–Moderate Sulfur–No Tertiary Influence and Calcareous–Moderate Sulfur–Lower Cretaceous are mapped as an undifferentiated unit.</ref> | |
+ | | ⑤<br />④ | ||
|- | |- | ||
| Uppermost Jurassic (centered on Tithonian, ~140-130 Ma) | | Uppermost Jurassic (centered on Tithonian, ~140-130 Ma) | ||
− | |||
| | | | ||
− | + | * Marine; high sulfur; Jurassic <ref group="t" name="ch04tblfn3">Oil subtypes related to variations in sulfur content and associated geochemical parameters have not been subdivided on Figure 4–5.</ref> | |
+ | * Marine; moderately high sulfur; Jurassic <ref group="t" name="ch04tblfn3"></ref> | ||
+ | * Marine; moderate sulfur; Jurassic <ref group="t" name="ch04tblfn3"></ref> | ||
+ | * Calcareous; Upper Jurassic or Lower Cretaceous? | ||
+ | | ⑥<br />⑥<br />⑥<br />⑦ | ||
|- | |- | ||
| Upper Jurassic (Oxfordian, ~ 152-145 Ma) | | Upper Jurassic (Oxfordian, ~ 152-145 Ma) | ||
− | | Carbonate; elevated salinity; Jurassic <ref group="t" name="ch04tblfn4"></ref | + | | |
− | | | + | * Carbonate; elevated salinity; |
− | + | * Jurassic <ref group="t" name="ch04tblfn4">Oil subtypes reflecting differences in salinity and clastic input to source facies are known but are not delineated on Figure 4–5.</ref> | |
+ | | ⑧ | ||
|- | |- | ||
| Triassic (Eagle Mills, > 210 Ma) | | Triassic (Eagle Mills, > 210 Ma) | ||
− | |||
| | | | ||
− | + | * Triassic; lacustrine | |
+ | | ⑨ | ||
|} | |} | ||
+ | {{reflist|group="t"}}<!-- This reflist is just for the table footnotes --> | ||
[[file:sedimentary-basin-analysis_fig4-5.png|thumb|{{figure number|4-5}}Modified from Gross et al.<ref name=ch04r40 />).]] | [[file:sedimentary-basin-analysis_fig4-5.png|thumb|{{figure number|4-5}}Modified from Gross et al.<ref name=ch04r40 />).]] |
Revision as of 19:15, 30 January 2014
Exploring for Oil and Gas Traps | |
Series | Treatise in Petroleum Geology |
---|---|
Part | Critical elements of the petroleum system |
Chapter | Sedimentary basin analysis |
Author | John M. Armentrout |
Link | Web page |
Store | AAPG Store |
Discussion
Hydrocarbon types reflect the composition of the kerogens from which they were generated. Kerogens are the insoluble organic matter in sedimentary rocks. Maps of hydrocarbon types estimate the number and distribution of mature generating source rocks. The following map of hydrocarbon types is based on analyses of more than 2000 oil, 600 gas, and 1200 seep samples correlated to specific source rocks. Nine oil-source-rock families have been identified (labeled 1-9; see table on following page), each having a specific geographic distribution related to mature source-rock location and migration paths. We will focus on the High Island-East Breaks area, where families 1 and 6 overlap (bold arrow).
Source table
The table below, modified from Gross et al.[1] lists source-rock ages, oil types, and map numbers for Figure 4-5.
Source-rock age | Oil type | Map # |
---|---|---|
Lower Tertiary (centered on Eocene, ~50-40 Ma) | ① ① ② | |
Upper Cretaceous (centered on Turonian, ~85-95 Ma) |
|
③ ④ |
Lower Cretaceous (centered on Aptian, ~115-105 Ma) |
|
⑤ ④ |
Uppermost Jurassic (centered on Tithonian, ~140-130 Ma) | ⑥ ⑥ ⑥ ⑦ | |
Upper Jurassic (Oxfordian, ~ 152-145 Ma) |
|
⑧ |
Triassic (Eagle Mills, > 210 Ma) |
|
⑨ |
- ↑ 1.0 1.1 Tertiary marine and Tertiary intermediate are mapped together.
- ↑ 2.0 2.1 Calcareous–Moderate Sulfur–No Tertiary Influence and Calcareous–Moderate Sulfur–Lower Cretaceous are mapped as an undifferentiated unit.
- ↑ 3.0 3.1 3.2 Oil subtypes related to variations in sulfur content and associated geochemical parameters have not been subdivided on Figure 4–5.
- ↑ Oil subtypes reflecting differences in salinity and clastic input to source facies are known but are not delineated on Figure 4–5.
Summary
By overlaying maps of total overburden thickness above major source-rock intervals, thermally mature source-rock distribution, hydrocarbon occurrences, and major structural features, the regional elements of the petroleum system(s) begin to emerge.
See also
- Defining the basin framework
- How to define the framework of a basin
- Example: defining a basin outline
- Example: mapping sediment thickness and field location