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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.

 

[[file:predicting-reservoir-system-quality-and-performance_fig9-86.png|thumb|[[figure number|1]]. From Sonnenberg, 1985, courtesy RMAG.

==Reservoir lithologic description==

==Reservoir lithologic description==

==Reservoir porosity and permeability==

==Reservoir porosity and permeability==

[[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.]]

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_a) 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_a) are as great as 1-2 darcies but more commonly are 200-500 md.

[[:file:predicting-reservoir-system-quality-and-performance_fig9-87.png|Figure 1]] is a K_a/Φ crossplot for well 11. Dots and polygons represent measured K_a/Φ values. Curves are the graphical solution of Winland's r₃₅ 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 r₃₅ values (port size).

[[:file:predicting-reservoir-system-quality-and-performance_fig9-87.png|Figure 2]] is a K_a/Φ crossplot for well 11. Dots and polygons represent measured K_a/Φ values. Curves are the graphical solution of Winland's r₃₅ 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 r₃₅ values (port size).

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.

==Extrapolated capillary pressure curves and pore types==

==Extrapolated capillary pressure curves and pore types==

[[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.]]

No capillary pressure measurements were available for this study. They were estimated-by plotting r₃₅ values on a semilog crossplot of fluid saturation vs. capillary pressure. A capillary pressure curve for each sample passes through its correlative r₃₅ value. Calculations of r₃₅ 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 r₃₅ values on a semilog crossplot of fluid saturation vs. capillary pressure. A capillary pressure curve for each sample passes through its correlative r₃₅ value. Calculations of r₃₅ 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.

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_a/Φ crossplot on Figure 9-86. Minimum water saturations (“immobile” water) estimated from log calculations let us extrapolate the P_c curves into low S_w 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_a/Φ crossplot on Figure 9-86. Minimum water saturations (“immobile” water) estimated from log calculations let us extrapolate the P_c curves into low S_w ranges.

==See also==

==See also==