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| | part = Predicting the occurrence of oil and gas traps | | | part = Predicting the occurrence of oil and gas traps |
| | chapter = Predicting reservoir system quality and performance | | | chapter = Predicting reservoir system quality and performance |
− | | frompg = 9-1 | + | | frompg = 9-60 |
− | | topg = 9-156 | + | | topg = 9-63 |
| | author = Dan J. Hartmann, Edward A. Beaumont | | | author = Dan J. Hartmann, Edward A. Beaumont |
| | link = http://archives.datapages.com/data/specpubs/beaumont/ch09/ch09.htm | | | link = http://archives.datapages.com/data/specpubs/beaumont/ch09/ch09.htm |
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| A Pickett plot lets us compare water saturations of different parts of a reservoir in one or many wells. The Pickett plot<ref name=ch09r45>Pickett, G., R., 1973, Pattern recognition as a means of formation evaluation: The Log Analyst, vol. 14, no. 4, p. 3–11.</ref> is a visual representation of the [[Archie equation]]<ref name=Archie_1942>Archie, G. E., 1942, The electrical resistivity log as an aid in determining some reservoir characteristics: Petroleum Transactions of AIME 146: 54–62.</ref> and therefore is a powerful graphic technique for estimating S<sub>w</sub> ranges within a reservoir. All that is needed to make a Pickett plot is a set of porosities and corresponding resistivities taken from well logs and 2×4 cycle log-log paper. The procedure for making a Pickett plot consists of five steps, detailed below. | | A Pickett plot lets us compare water saturations of different parts of a reservoir in one or many wells. The Pickett plot<ref name=ch09r45>Pickett, G., R., 1973, Pattern recognition as a means of formation evaluation: The Log Analyst, vol. 14, no. 4, p. 3–11.</ref> is a visual representation of the [[Archie equation]]<ref name=Archie_1942>Archie, G. E., 1942, The electrical resistivity log as an aid in determining some reservoir characteristics: Petroleum Transactions of AIME 146: 54–62.</ref> and therefore is a powerful graphic technique for estimating S<sub>w</sub> ranges within a reservoir. All that is needed to make a Pickett plot is a set of porosities and corresponding resistivities taken from well logs and 2×4 cycle log-log paper. The procedure for making a Pickett plot consists of five steps, detailed below. |
| | | |
− | {| class = "wikitable"
| + | # Plot points of matching [[porosity]] and true resistivity (R<sub>t</sub> ) on log-log paper. |
− | |-
| + | # Plot R<sub>w</sub> point on the R<sub>t</sub> scale. |
− | ! Step || Action
| + | # Determine ''m'' using the table of values. |
− | |-
| + | # Plot the 100% S<sub>w</sub> line. |
− | | 1 || Plot points of matching [[porosity]] and true resistivity (R<sub>t</sub> ) on log-log paper.
| + | # Plot the lines representing lower values of S<sub>w</sub> . |
− | |-
| |
− | | 2 || Plot R<sub>w</sub> point on the R<sub>t</sub> scale.
| |
− | |-
| |
− | | 3 || Determine ''m'' using the table of values.
| |
− | |-
| |
− | | 4 || Plot the 100% S<sub>w</sub> line.
| |
− | |-
| |
− | | 5 || Plot the lines representing lower values of S<sub>w</sub> .
| |
− | |}
| |
| | | |
| ==Step 1: Plot points== | | ==Step 1: Plot points== |
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| [[file:predicting-reservoir-system-quality-and-performance_fig9-39.png|300px|thumb|{{figure number|4}}An example of plotting the lower percentages of S<sub>w</sub>.]] | | [[file:predicting-reservoir-system-quality-and-performance_fig9-39.png|300px|thumb|{{figure number|4}}An example of plotting the lower percentages of S<sub>w</sub>.]] |
| | | |
− | After plotting the 100% S<sub>w</sub> line, plot the lines representing lower percentages of S<sub>w</sub> using this procedure. | + | After plotting the 100% S<sub>w</sub> line, plot the lines representing lower percentages of S<sub>w</sub> using this procedure: |
| | | |
− | {| class = "wikitable"
| + | # Find the intercept of R<sub>t</sub> = 1 and the 100% S<sub>w</sub> line (made in the last procedure). |
− | |-
| + | # From this intercept, draw a line parallel to the x-axis across the plot. Any point on this line has the same porosity. |
− | ! Step || Action
| + | # Where this line passes through R<sub>t</sub> of 2, 4, 6, 8, 14, and 20, draw a series of lines parallel to the 100% S<sub>w</sub> line. |
− | |-
| + | # Points on these lines correspond to S<sub>w</sub> of 71, 50, 41, 35, 27, and 22%. These percentages are calculated from the Archie equation using ''m'' = 2 and ''n'' = 2 at R<sub>t</sub> of 2, 4, 6, 8, 14, and 20. |
− | | 1 || Find the intercept of R<sub>t</sub> = 1 and the 100% S<sub>w</sub> line (made in the last procedure).
| |
− | |-
| |
− | | 2 || From this intercept, draw a line parallel to the x-axis across the plot. Any point on this line has the same porosity.
| |
− | |-
| |
− | | 3 || Where this line passes through R<sub>t</sub> of 2, 4, 6, 8, 14, and 20, draw a series of lines parallel to the 100% S<sub>w</sub> line.
| |
− | |-
| |
− | | 4 || Points on these lines correspond to S<sub>w</sub> of 71, 50, 41, 35, 27, and 22%. These percentages are calculated from the Archie equation using ''m'' = 2 and ''n'' = 2 at R<sub>t</sub> of 2, 4, 6, 8, 14, and 20.
| |
− | |}
| |
| | | |
| [[:file:predicting-reservoir-system-quality-and-performance_fig9-39.png|Figure 4]] is an example of following this procedure. | | [[:file:predicting-reservoir-system-quality-and-performance_fig9-39.png|Figure 4]] is an example of following this procedure. |
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| [[Category:Predicting the occurrence of oil and gas traps]] | | [[Category:Predicting the occurrence of oil and gas traps]] |
| [[Category:Predicting reservoir system quality and performance]] | | [[Category:Predicting reservoir system quality and performance]] |
| + | [[Category:Treatise Handbook 3]] |