论文标题
气体传感流的组成孔网建模
Compositional Pore-Network Modeling of Gas-Condensate Flow
论文作者
论文摘要
液体辍学和在气体传感器储层中的保留率，特别是在近孔区域，阻塞气体流动路径，并对产生的液体体积和成分产生负面影响。然而，由于实验很少再现储层极端条件和复杂的液体组成，而大多数孔尺度模型过多地简化了气体和凝结物之间的相位过渡物理学，因此冷凝物储备预测通常是不准确的。为了解决这一差距，提出了完全隐式的等温组成孔网模型，用于气体和冷凝水流量。所提出的孔网由连接的圆形毛细管连接的孔的3D结构组成。计算毛细管的液压电导率，该毛细管可以根据局部气体和液体饱和度表现出单相流量或两相环状流量，或者当毛细管克服粘性力时，可以根据局部气体和液体饱和度进行阻塞。基于Peng-Robinson EOS的PT-FLASH以每个时间步骤定义的对照量执行，以更新阶段属性。基于文献中报道的核心流血实验以及匹配的流体组成和流动条件以及近似的孔隙空间几何形状进行流动分析。预测和测量的相对渗透率曲线显示出良好的定量一致性，其中两个界面张力值和三个气流速度值的值。
Liquid dropout and retention in gas-condensate reservoirs, specially in the near wellbore region, obstruct gas flowing paths and impact negatively the produced fluid volume and composition. Yet, condensate banking forecasting is commonly inaccurate, as experiments seldom reproduce reservoir extreme conditions and complex fluid composition, while most pore-scale models oversimplify the physics of phase transitions between gas and condensate. To address this gap, a fully implicit isothermal compositional pore-network model for gas and condensate flow is presented. The proposed pore-networks consist of 3D structures of pores connected by constricted circular capillaries. Hydraulic conductances are calculated for the capillaries, which can exhibit single-phase flow or two-phase annular flow, according to local gas and liquid saturations, or be blocked by a liquid bridge, when capillary forces overcome viscous forces. A PT-flash based on the Peng-Robinson EoS is performed at control volumes defined for the pores at each time step, updating the phases properties. Flow analyses were carried based on coreflooding experiments reported in the literature, with matching fluid composition and flow conditions, and approximated pore-space geometry. Predicted and measured relative permeability curves showed good quantitative agreement, for two values of interfacial tension and three values of gas flow velocity.
