全世界的能源需求逐年增加，非傳統石油及天然氣資源（特別是天然氣）之探勘、開發及生產，已成為石油業者近年來的主要重點。鹽水氣為一種非傳統天然氣資源，其天然氣資源是溶解在鹽水層中。油氣資源潛能評估為油氣資源開發時的重要議題，但目前並無針對溶解型鹽水氣之物質平衡法，因此本研究主要目的為針對溶解型鹽水氣地層進行物質平衡法之研究，並利用所推導的物質平衡法估算鹽水氣地層的天然氣資源量及蘊藏量。
本研究修改Schilthuis的傳統物質平衡法，考慮地層水的體積變化及溶解於水中的天然氣釋出造成的影響，提出了改良型物質平衡方程式。本研究針對鹽水氣地層物質平衡法進行線性歸劃，除了可以直接進行數值計算，利用鹽水氣地層物質平衡法計算不同壓力下的地層採收率及OGIP，亦可以使用作圖法，利用溶解氣對累積氣產量作圖繪出直線後，將直線外推求得OGIP。
在本研究中分別建立了數值計算及數值模擬兩種模型進行討論，第一種模型為直接以方程式計算所得到的簡化數學模型，第二種模型為使用加拿大CMG公司的GEM多成份模擬軟體進行數值模擬。第一種模型所得到的計算結果非常相近，與體積法計算結果相比，誤差均小於0.02%，而第二種模型所得到的結果，由方程式計算得到的OGIP和體積法相比十分接近，其誤差為4.02％，但以繪圖法所得到的計算結果卻有較大的誤差。

本研究蒐集國外礦區資料及文獻建立出鹽水氣地層模型，用以驗證鹽水氣地層物質平衡法之正確性，由數值計算及數值模擬的模型證明鹽水氣物質平衡法在應用上有良好的結果。

The purpose of this study is to apply the traditional material balance equation (MBE) for estimating the original gas in place (OGIP) of Brine-gas reservoirs. The Brine-gas is mainly made up of CH4. The amount of dissolved gas in water is mainly controlled by the solubility of gas, which increases obviously with pressure, decreases slightly with salinity of water, and gets a minimum value at about 80 oC. In this study, the traditional material balance equation is added in solubility of gas in water and expansion of water volume. This equation is derived as a volume balance which equated the cumulative observed production, expressed as an underground withdrawal. There are two case of Brine-gas models to estimate the accuracy of modified MBE. The results show that this derived method is apply on a Brine-gas reservoir, and the accuracy of the estimates from the derived MBE is validated by the case study.

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