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| | 2 | | | 2 |
| | Determine the hydrocarbon pressure gradient from one of two ways: | | | Determine the hydrocarbon pressure gradient from one of two ways: |
− | | + | * Measured hydrocarbon density |
− | * Measured hydrocarbon density * Estimates of hydrocarbon density | + | * Estimates of hydrocarbon density |
− | | |
| |- | | |- |
| | 3 | | | 3 |
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| | 4 | | | 4 |
| | Determine a pressure above or below the measured depth point. The table below lists the steps for determining this number. | | | Determine a pressure above or below the measured depth point. The table below lists the steps for determining this number. |
| + | # Pick a depth above or below the measured point. |
| + | # Multiply the difference in depth by the buoyancy pressure gradient. |
| + | # Add the number from step 2 to the measured pressure if the depth is deeper; subtract if shallower. |
| | | |
− | * <table-wrap id="ch05utbl16a" position="float"> <table frame="hsides"> <colgroup> <col align="center"></col> <col align="left"></col> </colgroup> <thead> <tr> <th align="center"> Step </th> <th align="center"> Action </th> </tr> </thead> <tbody> <tr> <td align="center"> 1 Pick a depth above or below the measured point. </td></tr> <tr> 2 Multiply the difference in depth by the buoyancy pressure gradient. </tr> <tr> 3 Add the number from step 2 to the measured pressure if the depth is deeper; subtract if shallower. </tr> </tbody> </table> </table-wrap>
| + | '''Example:''' Measured pressure at [[depth::7607 ft]] is [[pressure::3530 psi]] and buoyancy pressure gradient is 0.076 psi/ft. What is the hydrocarbon pressure at [[depth::7507 ft]]? |
| | | |
| + | '''Solution:''' |
| + | * 7607 ft – 7507 ft = 100 ft |
| + | * 100 ft × 0.076 psi/ft = 7.6 psi |
| + | * Hydrocarbon pressure at [[depth::7507 ft]] = [[pressure::3530 psi]] – [[pressure::7.6 psi]] = [[pressure::3522.4 psi]] |
| |- | | |- |
− | | <th align="center"> Step</th> | + | | 5 |
− | | <th align="center"> Action</th> | + | | Plot the pressure number from step 4 on the pressure–depth plot and draw a line between this point and the measured pressure point. This line is the hydrocarbon pressure gradient. |
− | |-
| |
− | | 1
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− | | Pick a depth above or below the measured point.
| |
− | |-
| |
− | | 2
| |
− | | Multiply the difference in depth by the buoyancy pressure gradient.
| |
− | |-
| |
− | | 3
| |
− | | Add the number from step 2 to the measured pressure if the depth is deeper; subtract if shallower.
| |
| |} | | |} |
− |
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− | '''Example:'''
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− |
| |
− | Measured pressure at [[depth::7607 ft]] is 3530 psi and buoyancy pressure gradient is 0.076 psi/ft. What is the hydrocarbon pressure at 7507 ft?
| |
− |
| |
− | '''Solution:'''
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− |
| |
− | 7607 – 7507 = 100 ft
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− |
| |
− | 100 ft × 0.076 psi/ft = 7.6 psi
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− |
| |
− | Hydrocarbon pressure at [[depth::7507 ft]] = 3530 psi – 7.6 psi = 3522.4 psi
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− |
| |
− | <tr><td align="center">5</td><td align="left">Plot the pressure number from step 4 on the pressure–depth plot and draw a line between this point and the measured pressure point. This line is the hydrocarbon pressure gradient.</td></tr>
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| ==See also== | | ==See also== |