水驅型氣田轉為儲氣窖之評估研究

Evaluation on The Conversion of A Water-Drive Gas Reservoir to Gas Storage

陳永隆(Yeong-Long Chen) ； 陳大麟(Ta-Lin Chen) ； 吳沂全(I-Chang Wu) ； 吳健一(Chien-I Wu) ； 王勝雄(Sheng-Hsiung Wang)

《鑛冶：中國鑛冶工程學會會刊》 38卷1期 (1994/03) Pp. 49-62

摘要

A氣田屬於水驅型氣田，本研究根據van Everdingen-Hurst水侵模式，配合最佳化（Optimization）理論，自行建立一套最佳化電腦模式。利用這套模式可以迅速地自動調整地層參數，並得到A氣田之原始蘊藏量。應用節點分析及水侵模式，可估算未來進行地下儲氣時，須注入墊底氣0.5億立方公尺以確保每口井之產能為每天70萬立方公尺。而要維持A氣田水侵量不再繼續增加（亦即氣層面積不再繼續縮小），則氣層平均靜壓須維持2250 psia以上。本研究並假設三種注／供氣方案，探討在不同的注／供氣量時，水驅型氣田氣層靜壓及氣層面積之變化情形。由於本研究結果認為A氣田轉為地下儲氣窖之可行性高，且在未來『擴大進口LNG計劃案』中，地下儲氣窖之興建將使整體計劃節省新台幣二百四十餘億元之投資費用，並具有容易調節供氣、貯存安全及降低對環境之衝擊等無形效益。

並列摘要

＂A＂ reservoir is a moderate water-drive gas reservoir and is almost depleted. It is considered to be converted into an underground gas storage for the purpose of peak shaving. An optimization model based on van Everdingen-Hurst water influx method and optimization theory is developed with the computer programming to estimate the original gas in place (OGIP) of ＂A＂ reservoir rapidly and to determine the optimum parameters automatically. The future production performance of this storage reservoir is predicted by the Nodal Analysis and water influx model. The volume of cushion gas is about 50 MMCM in order to have the daily production rate for each well to be 700 MCMD and the future average static pressure of gas reservoir should be larger than 2250 psia to prevent further water influx into the gas reservoir (this means the area of gas bubble will be no more shrunk). Three cases with different working gas volume were performed to predict the variation of storage pressure and area of gas bubble in this reservoir. This study has concluded that the conversion of ＂A＂ reservoir to an underground storage is highly feasible. In addition, the development of underground storage in the project of scaling up the imported LNG has several significant advantages, such as saving NT$24 billion in the investment, having the high efficiency to cope with the variable demand of market, providing the safest way for storing natural gas and reducing the environment impact.