高压注气条件下地下储气库数值模拟研究

Study on Underground Gas Storage Reservoir under the High Pressure Injection Gas

基于渗流力学理论建立了天然气地下储气库气、水两相渗流数学模型.针对该模型采用全隐式有限差分法在时间和空间上进行离散,将离散后的非线性方程组线性化并采用块系数强隐式预处理正交极小化算法进行求解.利用该模型模拟计算了国内某拟建地下储气库天然气动态运移规律,对比了差分解法与特征线解法的计算精度,研究了储层渗透率、储层厚度、孔隙度和注气速率等参数对地下储气库天然气含气饱和度的影响规律.计算结果表明：差分解法具有较高的计算精度且在数值模拟计算中容易实现等优点.储层压力随着储层厚度和孔隙度的增加而呈非线性降低,随着注气速率和渗透率的增加而呈非线性增加.

According to the percolation mechanics theory, the ground gas storage reservoirs. According to the fully implicit gas--water two--phase flow model IS estaDllsneu ior unaer difference method, time and spatial discretization of the model on gas saturation change laws are studied. The examples show that the calculating results of and correct, and can meet the actual engineering demands. The gas saturation increases with The gas saturation change laws characteristic line method and and porosity and injection rates the difference method is precise injection rates and permeability increasing, whereas it decreases with the increase of reservoir thickness and porosity.