孔隙网络模型法计算水相滞留对气体渗流的影响

The influence of aqueous phase trapping on gas flow by pore scale network model

孔隙结构是影响气藏储集层孔喉中水相滞留的一个重要因素。考虑滞留的水相在孔隙中的微观分布,利用Bethe网络模型模拟,研究水相滞留对不同孔隙结构体系的气体渗流能力的影响规律,主要包括孔喉大小和分布均匀程度等影响因素。初步模拟计算表明,应用孔隙网络模型研究水相滞留对气体渗流的影响规律是可行的,能将水相微观滞留堵塞机理与宏观损害程度相联系。

Aqueous fluid may invade into gas reservoir during drilling, completion and subsequent production operations. A portion of this fluid is still retained in the formatiom in the vicinity of wellbore even after inversing well-flushing. Permeability for gas phase is therefore greatly reduced in these areas. Pore structure is a key factor affecting the trapping of aqueous- phase in gas reservoir. Considering the microscopic distribution of the retained phase, Bethe network is introduced to simulate the trapping process, and predict its effect on gas permeability reduction for different size and uniformity of throat distributions. It is shown that pore scale network model is an efficient tool to relate the microscopic aqueous trapping mechanism to the macroscopic gas permeability reduction.