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East Breaks hydrocarbon generation model (view source)
Revision as of 20:04, 30 January 2014
, 20:04, 30 January 2014Initial import
{{publication
| image = exploring-for-oil-and-gas-traps.png
| width = 120px
| series = Treatise in Petroleum Geology
| title = Exploring for Oil and Gas Traps
| part = Critical elements of the petroleum system
| chapter = Sedimentary basin analysis
| frompg = 4-1
| topg = 4-123
| author = John M. Armentrout
| link = http://archives.datapages.com/data/specpubs/beaumont/ch04/ch04.htm
| pdf =
| store = http://store.aapg.org/detail.aspx?id=545
| isbn = 0-89181-602-X
}}
==Method==
A 32-layer, 1-D mathematical model (Figure 4-53) was constructed for the East Breaks 160-161 minibasin. The No. A-29 well in block 160 was used for stratigraphic and thermal control, including borehole temperature surveys and [[vitrinite reflectance]] data. [[Modeling]] was extended [[depth::3,000 ft]] (1000 m) below true vertical drilling depth (12,000 ft, 4000 m) to evaluate the underlying speculated source potential of the middle and lower Miocene section. The figure is a north-south seismic reflection profile across the East Breaks 160-161 intraslope minibasin (see Figures 4-42 and 4-44). The deviated wellbore of the East Breaks well 160 No. A-29 is marked with a white dashed line. Reservoirs for analyzed oils are indicated for the ''Hyal B'' HB-2 reservoir and for the ''Glob alt'' GA-3 reservoir. Rock cutting samples from intervals indicated by A and B were used by Dow et al.<ref name=ch04r29>Dow, W., G., Yukler, M., A., Senftle, J., T., Kennicutt, M., C., IIArmentrout, J., M., 1990, Miocene oil source beds in the East Breaks basin, Flex-Trend, offshore Texas: Proceedings, Gulf Coast Section SEPM 9th Annual Research conference, p. 139–150.</ref> to calibrate kerogen type for kinetic [[modeling]].
[[file:sedimentary-basin-analysis_fig4-53.png|thumb|{{figure number|4-53}}After Dow et al.<ref name=ch04r29 />). Copyright: Gulf Coast SEPM.]]
==Generation and expulsion timing==
Aburial history plot with computed hydrocarbon generation history shows that peak oil generation in the A-29 well began at the inferred base of the lower Miocene when buried below [[depth::11,000 ft]] (3000 m) about 1.2 Ma, at the base of the inferred middle Miocene when it too passed below [[depth::11,000 ft]] (3000 m) burial about 0.2 Ma.
Miocene source beds, if present, would be actively generating and expelling oil and gas at the present time. Dow et al..<ref name=ch04r29 />) interpret this to account for the biodegraded East Breaks 160-161 field oils being recharged with fresh oil during a later [[migration]] phase. The relatively low maturity of the inferred Miocene section should also result in only minor thermogenic gas generation and might explain the absence of evaporative fractionation in the produced crudes of this field in contrast to approximately 75% of Gulf Coast Tertiary crudes<ref name=ch04r96>Thompson, K., F., M., Kennicutt, M., C., IIBrooks, J., M., 1990, Classification of offshore Gulf of Mexico oils and gas condensates: AAPG Bulletin, vol. 74, p. 187–198.</ref>
==Burial history==
The following figure is a 1-D burial history/[[maturation]] plot showing the critical moment (2.0 Ma) and the time of oil generation (2.0 Ma to present) for the East Breaks 160-161 minibasin [[petroleum system]], assuming that lower Miocene rocks have sourced the hydrocarbons. Alternative burial history plots could be constructed using the assumed burial depths for each potential source horizon. For these deeply buried potential source horizons, generation must have been delayed until very recently or secondary migration from older, deeper reservoirs provides the hydrocarbons trapped at the East Breaks 160-161 field. Additionally, basins are 3-D entities, and either 2-D models throughout the basin or a 3-D model of the entire basin is essential to understanding the maturation history of a basin.
==See also==
* [[East breaks petroleum system processes]]
* [[Trap formation]]
* [[Geochemistry of two oils from east breaks]]
* [[Hydrocarbon migration model]]
* [[Hydrocarbon accumulation model]]
* [[Critical moment (or Interval)]]
==References==
{{reflist}}
==External links==
{{search}}
* [http://archives.datapages.com/data/specpubs/beaumont/ch04/ch04.htm Original content in Datapages]
* [http://store.aapg.org/detail.aspx?id=545 Find the book in the AAPG Store]
[[Category:Critical elements of the petroleum system]]
[[Category:Sedimentary basin analysis]]
| image = exploring-for-oil-and-gas-traps.png
| width = 120px
| series = Treatise in Petroleum Geology
| title = Exploring for Oil and Gas Traps
| part = Critical elements of the petroleum system
| chapter = Sedimentary basin analysis
| frompg = 4-1
| topg = 4-123
| author = John M. Armentrout
| link = http://archives.datapages.com/data/specpubs/beaumont/ch04/ch04.htm
| pdf =
| store = http://store.aapg.org/detail.aspx?id=545
| isbn = 0-89181-602-X
}}
==Method==
A 32-layer, 1-D mathematical model (Figure 4-53) was constructed for the East Breaks 160-161 minibasin. The No. A-29 well in block 160 was used for stratigraphic and thermal control, including borehole temperature surveys and [[vitrinite reflectance]] data. [[Modeling]] was extended [[depth::3,000 ft]] (1000 m) below true vertical drilling depth (12,000 ft, 4000 m) to evaluate the underlying speculated source potential of the middle and lower Miocene section. The figure is a north-south seismic reflection profile across the East Breaks 160-161 intraslope minibasin (see Figures 4-42 and 4-44). The deviated wellbore of the East Breaks well 160 No. A-29 is marked with a white dashed line. Reservoirs for analyzed oils are indicated for the ''Hyal B'' HB-2 reservoir and for the ''Glob alt'' GA-3 reservoir. Rock cutting samples from intervals indicated by A and B were used by Dow et al.<ref name=ch04r29>Dow, W., G., Yukler, M., A., Senftle, J., T., Kennicutt, M., C., IIArmentrout, J., M., 1990, Miocene oil source beds in the East Breaks basin, Flex-Trend, offshore Texas: Proceedings, Gulf Coast Section SEPM 9th Annual Research conference, p. 139–150.</ref> to calibrate kerogen type for kinetic [[modeling]].
[[file:sedimentary-basin-analysis_fig4-53.png|thumb|{{figure number|4-53}}After Dow et al.<ref name=ch04r29 />). Copyright: Gulf Coast SEPM.]]
==Generation and expulsion timing==
Aburial history plot with computed hydrocarbon generation history shows that peak oil generation in the A-29 well began at the inferred base of the lower Miocene when buried below [[depth::11,000 ft]] (3000 m) about 1.2 Ma, at the base of the inferred middle Miocene when it too passed below [[depth::11,000 ft]] (3000 m) burial about 0.2 Ma.
Miocene source beds, if present, would be actively generating and expelling oil and gas at the present time. Dow et al..<ref name=ch04r29 />) interpret this to account for the biodegraded East Breaks 160-161 field oils being recharged with fresh oil during a later [[migration]] phase. The relatively low maturity of the inferred Miocene section should also result in only minor thermogenic gas generation and might explain the absence of evaporative fractionation in the produced crudes of this field in contrast to approximately 75% of Gulf Coast Tertiary crudes<ref name=ch04r96>Thompson, K., F., M., Kennicutt, M., C., IIBrooks, J., M., 1990, Classification of offshore Gulf of Mexico oils and gas condensates: AAPG Bulletin, vol. 74, p. 187–198.</ref>
==Burial history==
The following figure is a 1-D burial history/[[maturation]] plot showing the critical moment (2.0 Ma) and the time of oil generation (2.0 Ma to present) for the East Breaks 160-161 minibasin [[petroleum system]], assuming that lower Miocene rocks have sourced the hydrocarbons. Alternative burial history plots could be constructed using the assumed burial depths for each potential source horizon. For these deeply buried potential source horizons, generation must have been delayed until very recently or secondary migration from older, deeper reservoirs provides the hydrocarbons trapped at the East Breaks 160-161 field. Additionally, basins are 3-D entities, and either 2-D models throughout the basin or a 3-D model of the entire basin is essential to understanding the maturation history of a basin.
==See also==
* [[East breaks petroleum system processes]]
* [[Trap formation]]
* [[Geochemistry of two oils from east breaks]]
* [[Hydrocarbon migration model]]
* [[Hydrocarbon accumulation model]]
* [[Critical moment (or Interval)]]
==References==
{{reflist}}
==External links==
{{search}}
* [http://archives.datapages.com/data/specpubs/beaumont/ch04/ch04.htm Original content in Datapages]
* [http://store.aapg.org/detail.aspx?id=545 Find the book in the AAPG Store]
[[Category:Critical elements of the petroleum system]]
[[Category:Sedimentary basin analysis]]