Network modeling of liquid flow in Yanchang shale
Network modeling of liquid flow in Yanchang shale
复制标题
DOI：
10.1190/int-2016-0100.1
复制
发表时间：
2017-05-01
影响因子：
1.2
通讯作者：
Liang, Quansheng
中科院分区：
文献类型：
--
作者：
Afsharpoor, Ali;Javadpour, Farzam;Liang, Quansheng
孔隙几何形状和滑移条件是页岩非圆形纳米孔中液体流动的两个主要特征。我们在中国延长页岩的孔隙网络模型中考虑了孔隙形状和孔隙内壁上的液体滑移。对延长页岩样品的多重扫描电子显微镜 (SEM) 图像进行了分析，以记录和总结各种孔隙形状和尺寸。非圆形孔隙中的流体流动行为明显偏离许多当前模型中使用的圆形孔隙中的流动行为。此外，传统储层系统中的液体流动模拟假设无滑移流动边界条件，这在与延长页岩相关的纳米级孔隙中是不可接受的。我们通过基于氮吸附数据和 SEM 图像分析开发真实的孔隙网络模型来研究延长页岩的液体渗透率。开发的孔隙网络模型的输入数据包括孔径分布、总有机碳、孔隙率、表面积、孔隙几何形状和液体滑移长度。我们发现基于现实多几何模型的有效渗透率明显高于预测的达西渗透率。对于非圆形孔隙数量不断增加的页岩样品，达西定律与实际滑移校正多几何模型之间的表观渗透率差异较大。我们还发现，忽略液体滑移和孔隙的非圆形性会显着低估延长页岩样品的表观渗透率。
The pore geometry and slip conditions are two principal characteristics of liquid flow in shale noncircular nanopores. We have considered the pore shape and liquid slippage on the pore interior wall in pore-network models of the Yanchang shale in China. Multiple scanning electron microscopy (SEM) images of the Yanchang shale samples were analyzed to document and summarize various pore shapes and sizes. Fluid-flow behavior in noncircular pores significantly deviates from the flow behavior in circular pores used in many current models. In addition, liquid flow simulations in conventional reservoir systems assume a no-slip flow boundary condition, which is unacceptable in nanoscale pores associated with the Yanchang shale. We studied liquid permeability in the Yanchang shale by developing realistic pore-network models based on nitrogen sorption data and SEM image analysis. The input data to the developed pore-network models include pore-size distribution, total organic carbon, porosity, surface area, pore geometry, and liquid slip length. We found that the effective permeability based on the realistic multigeometry model is significantly higher than the predicted Darcy permeability. The apparent permeability discrepancy between Darcy's law and the realistic slip-corrected multigeometry model is higher for shale samples with an increasing number of noncircular pores. We also found that neglecting the liquid slip and noncircularity of pores significantly underestimates apparent permeability in Yanchang shale samples.