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| | isbn = 0-89181-602-X | | | isbn = 0-89181-602-X |
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− | By studying core and log data from one well (well 11, see Figure 9-86), we see a picture of a clastic reservoir with wide heterogeneity in total porosities, pore-throat sizes, and [[capillary pressure]]s. In addition, the depositional environment of these sandstones (fluvial valley fill and sandstone) indicates they probably have limited lateral continuity within the valley-fill complex. | + | By studying core and log data from one well (well 11; see [[;file:predicting-reservoir-system-quality-and-performance_fig9-86.png|Figure 1]]), we see a picture of a clastic reservoir with wide heterogeneity in total porosities, pore-throat sizes, and [[capillary pressure]]s. In addition, the depositional environment of these sandstones (fluvial valley fill and sandstone) indicates they probably have limited lateral continuity within the valley-fill complex. |
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| + | [[file:predicting-reservoir-system-quality-and-performance_fig9-86.png|thumb|[[figure number|1]]. From Sonnenberg, 1985, courtesy RMAG. |
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| ==Reservoir lithologic description== | | ==Reservoir lithologic description== |
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| ==Reservoir porosity and permeability== | | ==Reservoir porosity and permeability== |
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− | [[file:predicting-reservoir-system-quality-and-performance_fig9-87.png|thumb|{{figure number|1}}. Copyright: Hartmann and ;<ref name=ch09r11>Coalson, E., B., Hartmann, D., J., Thomas, J., B., 1990, Applied Petrophysics in Exploration and Exploitation: Notes from short course sponsored by Univ. of Colo.–Denver, var. pages.</ref> courtesy RMAG.]] | + | [[file:predicting-reservoir-system-quality-and-performance_fig9-87.png|thumb|{{figure number|2}}. Copyright: Hartmann and ;<ref name=ch09r11>Coalson, E., B., Hartmann, D., J., Thomas, J., B., 1990, Applied Petrophysics in Exploration and Exploitation: Notes from short course sponsored by Univ. of Colo.–Denver, var. pages.</ref> courtesy RMAG.]] |
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| Morrow sandstones in Sorrento field have a wide range in porosity and [[permeability]]. Maximum observed porosity (Φ) is 20-22%, but more typical values are 10-15%. Air permeabilities (K<sub>a</sub>) are as great as 1-2 darcies but more commonly are 200-500 md. | | Morrow sandstones in Sorrento field have a wide range in porosity and [[permeability]]. Maximum observed porosity (Φ) is 20-22%, but more typical values are 10-15%. Air permeabilities (K<sub>a</sub>) are as great as 1-2 darcies but more commonly are 200-500 md. |
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− | [[:file:predicting-reservoir-system-quality-and-performance_fig9-87.png|Figure 1]] is a K<sub>a</sub>/Φ crossplot for well 11. Dots and polygons represent measured K<sub>a</sub>/Φ values. Curves are the graphical solution of Winland's r<sub>35</sub> equation<ref name=ch09r46>Pittman, E., D., 1992, [http://archives.datapages.com/data/bulletns/1992-93/data/pg/0076/0002/0000/0191.htm Relationship of porosity to permeability to various parameters derived from mercury injection–capillary pressure curves for sandstone]: AAPG Bulletin, vol. 76, no. 2, p. 191–198.</ref> and represent equal r<sub>35</sub> values (port size). | + | [[:file:predicting-reservoir-system-quality-and-performance_fig9-87.png|Figure 2]] is a K<sub>a</sub>/Φ crossplot for well 11. Dots and polygons represent measured K<sub>a</sub>/Φ values. Curves are the graphical solution of Winland's r<sub>35</sub> equation<ref name=ch09r46>Pittman, E., D., 1992, [http://archives.datapages.com/data/bulletns/1992-93/data/pg/0076/0002/0000/0191.htm Relationship of porosity to permeability to various parameters derived from mercury injection–capillary pressure curves for sandstone]: AAPG Bulletin, vol. 76, no. 2, p. 191–198.</ref> and represent equal r<sub>35</sub> values (port size). |
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| The crossplot shows a large variation in port size for the samples from well 11. Areas between dashed lines group points into beds with similar port size, or flow units. | | The crossplot shows a large variation in port size for the samples from well 11. Areas between dashed lines group points into beds with similar port size, or flow units. |
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| ==Extrapolated capillary pressure curves and pore types== | | ==Extrapolated capillary pressure curves and pore types== |
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− | [[file:predicting-reservoir-system-quality-and-performance_fig9-88.png|thumb|{{figure number|2}}. Copyright: Hartmann and Coalson, 1990; courtesy RMAG.]] | + | [[file:predicting-reservoir-system-quality-and-performance_fig9-88.png|thumb|{{figure number|3}}. Copyright: Hartmann and Coalson, 1990; courtesy RMAG.]] |
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| No capillary pressure measurements were available for this study. They were estimated-by plotting r<sub>35</sub> values on a semilog crossplot of fluid saturation vs. capillary pressure. A capillary pressure curve for each sample passes through its correlative r<sub>35</sub> value. Calculations of r<sub>35</sub> for well 11 indicate a large variety of capillary pressures and pore types. Pore types for the Morrow samples from this well are mega, macro, and micro. | | No capillary pressure measurements were available for this study. They were estimated-by plotting r<sub>35</sub> values on a semilog crossplot of fluid saturation vs. capillary pressure. A capillary pressure curve for each sample passes through its correlative r<sub>35</sub> value. Calculations of r<sub>35</sub> for well 11 indicate a large variety of capillary pressures and pore types. Pore types for the Morrow samples from this well are mega, macro, and micro. |
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− | The numbers on the curves in [[:file:predicting-reservoir-system-quality-and-performance_fig9-88.png|Figure 2]] correspond to the numbers on the K<sub>a</sub>/Φ crossplot on Figure 9-86. Minimum water saturations (“immobile” water) estimated from log calculations let us extrapolate the P<sub>c</sub> curves into low S<sub>w</sub> ranges. | + | The numbers on the curves in [[:file:predicting-reservoir-system-quality-and-performance_fig9-88.png|Figure 3]] correspond to the numbers on the K<sub>a</sub>/Φ crossplot on Figure 9-86. Minimum water saturations (“immobile” water) estimated from log calculations let us extrapolate the P<sub>c</sub> curves into low S<sub>w</sub> ranges. |
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| ==See also== | | ==See also== |