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Advanced Reservoir Engineering Homework #2. 學生:陳逸軒 N46021101 授課教授:謝秉志. Homework #2. Using the p/z plot to estimate cumulative gas production. The initial reservoir pressure was 4200 psia , with a temperature of 180 °F .
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Advanced Reservoir EngineeringHomework #2 學生:陳逸軒 N46021101 授課教授:謝秉志
Homework #2 • Using the p/z plot to estimate cumulative gas production. • The initial reservoir pressure was 4200 psia, with a temperature of 180°F. • The reservoir has been producing for some time. Some pressure surveys have been made at different times: A dry gas reservoir contains gas of the following composition:
Homework #2 • What will be the cumlative gas production when the average reservoir pressure has been dropped to 2000 psia? • Assuming the reservoir rock has a porosity of 12%, the water saturation is 30%, and the reservoir thickness is 15 ft, how many acres does the reservoir cover?
Homework #2 - Solution • 利用已知 p/z 對 Gp之關係作圖。 • 取其趨勢線方程式: Y = -900X + 4600 Y=0 X=5.1111111 • 本構造之OGIP為 5.11 MMM SCF • 接著計算 2000psia 下之Z值。
Homework #2 - Solution Ppc=0.75×673.1+0.20×708.3+0.05×440.1 =668.49 Tpc=0.75×673.1+0.20×708.3+0.05×440.1 =404.07 Ppr= 2000/668.49 = 2.99 Tpr= 640/404.07 = 1.58
Homework #2 - Solution Ppr= 2.99 Tpr= 1.58 查表得 2000 psia 下之Z值為0.815 則 p/z=2000/0.815=2454
Homework #2 - Solution p/z = 2000/0.815 = 2454 由右表可得 Gp = 2.38 MMM SCF
Homework #2 • What will be the cumlative gas production when the average reservoir pressure has been dropped to 2000 psia? • Assuming the reservoir rock has a porosity of 12%, the water saturation is 30%, and the reservoir thickness is 15 ft, how many acres does the reservoir cover?
Homework #2 - Solution • 計算 4200psia 下之Z值。 Ppr= 4200/668.49 = 6.28 Tpr = 1.58 查表取得 4200 psia 下之Z值為0.898