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Midale water saturation and pore geometry (view source)
Revision as of 22:19, 31 January 2014
, 22:19, 31 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 = Predicting the occurrence of oil and gas traps
| chapter = Predicting reservoir system quality and performance
| frompg = 9-1
| topg = 9-156
| author = Dan J. Hartmann, Edward A. Beaumont
| link = http://archives.datapages.com/data/specpubs/beaumont/ch09/ch09.htm
| pdf =
| store = http://store.aapg.org/detail.aspx?id=545
| isbn = 0-89181-602-X
}}
==Log response and s<sub>w</sub>==
Variations in pore geometry have the expected effect on log responses and water saturations (S<sub>w</sub>). The Midale Vuggy in a cored field well consists of interbeds of packstone and mudstone. Below is a Pickett plot for the Midale Vuggy from an example well in Weyburn field. Data points cluster around higher resistivities for packstones (group A) and lower resistivities for mudstones (group B), reflecting the higher water saturations of the mudstones.
[[file:predicting-reservoir-system-quality-and-performance_fig9-103.png|thumb|{{figure number|9-103}}. Copyright: Coalson et al., 1994; courtesy RMAG.]]
==Buckles plot==
As shown on Figure 9-102, mudstones (B) are micro- to mesoporous; packstones (A) are meso- to macroporous. The mudstones have more pores with smaller pore throats than the packstones. This means mudstones have greater pore surface area and higher immobile S<sub>w</sub>. As a consequence, S<sub>w</sub> values for mudstones are higher at any given elevation in the oil column.
Following is a Buckles plot for the Weyburn well. The hyperbolic curves represent equal values of S<sub>w</sub> × Φ. Points from the same pore type that fall along a hyperbolic curve are at immobile S<sub>w</sub>. Curves with higher values represent higher immobile S<sub>w</sub>.
On the plot, data for packstones (A), except for point 8, fall on a hyperbolic curve with a value between 100 and 300. This indicates these beds are at immobile water saturations. Point 8 is from a transition zone. Mudstones (B) also are at immobile water saturations but fall on a hyperbolic curve with higher numbers, between 1000 and 1300.
[[file:predicting-reservoir-system-quality-and-performance_fig9-104.png|thumb|{{figure number|9-104}}. Copyright: Coalson et al., 1994; courtesy RMAG.]]
==See also==
* [[Evaluation of trap type]]
* [[Weyburn field location and trap problem]]
* [[Middle lithofacies and distribution]]
* [[Midale porosity, pore geometries, and petrophysics]]
* [[Weyburn seal capacity]]
* [[Seal capacity and trap type]]
==External links==
{{search}}
* [http://archives.datapages.com/data/specpubs/beaumont/ch09/ch09.htm Original content in Datapages]
* [http://store.aapg.org/detail.aspx?id=545 Find the book in the AAPG Store]
[[Category:Predicting the occurrence of oil and gas traps]]
[[Category:Predicting reservoir system quality and performance]]
| image = exploring-for-oil-and-gas-traps.png
| width = 120px
| series = Treatise in Petroleum Geology
| title = Exploring for Oil and Gas Traps
| part = Predicting the occurrence of oil and gas traps
| chapter = Predicting reservoir system quality and performance
| frompg = 9-1
| topg = 9-156
| author = Dan J. Hartmann, Edward A. Beaumont
| link = http://archives.datapages.com/data/specpubs/beaumont/ch09/ch09.htm
| pdf =
| store = http://store.aapg.org/detail.aspx?id=545
| isbn = 0-89181-602-X
}}
==Log response and s<sub>w</sub>==
Variations in pore geometry have the expected effect on log responses and water saturations (S<sub>w</sub>). The Midale Vuggy in a cored field well consists of interbeds of packstone and mudstone. Below is a Pickett plot for the Midale Vuggy from an example well in Weyburn field. Data points cluster around higher resistivities for packstones (group A) and lower resistivities for mudstones (group B), reflecting the higher water saturations of the mudstones.
[[file:predicting-reservoir-system-quality-and-performance_fig9-103.png|thumb|{{figure number|9-103}}. Copyright: Coalson et al., 1994; courtesy RMAG.]]
==Buckles plot==
As shown on Figure 9-102, mudstones (B) are micro- to mesoporous; packstones (A) are meso- to macroporous. The mudstones have more pores with smaller pore throats than the packstones. This means mudstones have greater pore surface area and higher immobile S<sub>w</sub>. As a consequence, S<sub>w</sub> values for mudstones are higher at any given elevation in the oil column.
Following is a Buckles plot for the Weyburn well. The hyperbolic curves represent equal values of S<sub>w</sub> × Φ. Points from the same pore type that fall along a hyperbolic curve are at immobile S<sub>w</sub>. Curves with higher values represent higher immobile S<sub>w</sub>.
On the plot, data for packstones (A), except for point 8, fall on a hyperbolic curve with a value between 100 and 300. This indicates these beds are at immobile water saturations. Point 8 is from a transition zone. Mudstones (B) also are at immobile water saturations but fall on a hyperbolic curve with higher numbers, between 1000 and 1300.
[[file:predicting-reservoir-system-quality-and-performance_fig9-104.png|thumb|{{figure number|9-104}}. Copyright: Coalson et al., 1994; courtesy RMAG.]]
==See also==
* [[Evaluation of trap type]]
* [[Weyburn field location and trap problem]]
* [[Middle lithofacies and distribution]]
* [[Midale porosity, pore geometries, and petrophysics]]
* [[Weyburn seal capacity]]
* [[Seal capacity and trap type]]
==External links==
{{search}}
* [http://archives.datapages.com/data/specpubs/beaumont/ch09/ch09.htm Original content in Datapages]
* [http://store.aapg.org/detail.aspx?id=545 Find the book in the AAPG Store]
[[Category:Predicting the occurrence of oil and gas traps]]
[[Category:Predicting reservoir system quality and performance]]