Case Study 6 - Solutions

# 25 1 cp 170e 05 psi 1 13 rbstb 051 ft the effective

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Unformatted text preview: effective flowing time is found as follows: This time value will be used as the length of the flow period prior to shut-in. Since this is a buildup test it will be valuable to create a Horner plot. A Horner plot is a semi-log plot of flowing well pressure during a shut-in period versus . In the Horner time ratio t represents the time of shut-in after a flow period, which is a constant and equal to the effective time calculated above. ∆t represents the measured times after the shut-in time, which continuously increases with the test duration. The ratio comes from the derivation of a build-up, which can be found in the course textbook. The pressure readings during the buildup, along with the calculated ratio are shown below: 10 Effective time (t) (t+Delta t)/(delta t) Shut in Time (hrs) Pw (psia) 36.48 730.6 0.05 3284.1 312.7948718 0.117 3310.6 200.3442623 0.183 3321.9 146.92 0.25 3329.1 116.0788644 0.317 3333.6 96.24804178 0.383 3337.1 82.06666667 0.45 3340.3 57.12307692 0.65 3347.5 43.91764706 0.85 3352.8 35.74285714 1.05 3357.1 30.184 1.25 3360.6 25.0474621 1.517 3364.2 18.79512195 2.05 3370 15.49344458 2.517 3374.1 12.96065574 3.05 3377.9 10.00740741 4.05 3383.8 8.223762376 5.05 3388.8 7.029752066 6.05 3392.4 6.174468085 7.05 3395.4 5.531677019 8.05 3398.5 5.030939227 9.05 3401.2 4.629850746 10.05 3403.6 4.301357466 11.05 3405.7 4.027385892 12.05 3408 3.781123733 13.117 3410 3.596441281 14.05 3411.6 3.423920266 15.05 3413.3 3.272897196 16.05 3414.9 3.139589443 17.05 3416.3 3.021052632 18.05 3417.6 2.819451372 20.05 3420.1 2.733016627 21.05 3421.2 2.654421769 22.05 3422.3 2.582646421 23.05 3423.3 2.516839917 24.05 3424.2 2.456287425 25.05 3425.1 2.400383877 26.05 3426 2.348613678 27.05 3426.8 2.300534759 28.05 3427.6 2.257931034 29 3428.3 11 Using this data a Horner plot can be created. As stated, this is a Semi-log plot of flowing well pressure during a shut-in period versus , which are in the second and forth columns of the above table. The Horner plot for this data is shown below: Horner Plot - Case Study 6 3550 3500 pw 3450 3400 3350 3300 3 250 1 10 100 1000 (t+∆t)/∆t Two straight lines have been imposed on the straight line regions of this plot. The first line (with the smaller slope) represents the shift...
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## This note was uploaded on 01/26/2014 for the course ENG 9111 taught by Professor Drjohanssen during the Spring '12 term at Memorial University.

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