页岩储层两相流体润湿滞后对流动阻力的影响

Effect of Wetting Hysteresis on Flow Resistance for Two-phase Fluid System in Shale Reservoirs

高艳玲 吴克柳 陈掌星 田伟兵 李靖

GAOYanling WUKeliu CHENZhangxing TIANWeibing LIJing

中国石油大学(北京)油气资源与探测国家重点实验室, 北京 昌平 102249 中国石油大学(北京)石油工程学院, 北京 昌平 102249 卡尔加里大学化学与石油工程系, 加拿大 艾伯塔 T2N1N4

State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum, Changping, Beijing 102249, China College of Petroleum Engineering, China University of Petroleum, Changping, Beijing 102249, China Department of Chemistry and Petroleum Engineering, University of Calgary, Alberta T2N1N4, Canada

通过揭示两相流体润湿滞后对启动压力和流动阻力的影响机理，基于静态润湿滞后方程及动态接触角方程，分别建立了两相流动中气泡/液滴欲移动时的启动压力模型和运动后的流动阻力模型。基于前人实验数据，应用建立的模型，分别计算得到由润湿滞后引起的不同温度和压力下的启动压力，以及不同孔隙尺度、黏度和表面张力下的流动阻力。结果表明，在页岩纳米级孔隙中，由于孔喉细小，静态润湿滞后和动态润湿滞后引起的启动压力和流动阻力较大，均不可忽略；动态润湿滞后引起的流动阻力大于静态润湿滞后引起的启动压力，且随着流速增大，这种流动阻力也持续增大，但增速幅度逐渐降低。该研究为页岩储层两相流体启动压力和流动阻力的精确表征提供了数学模型，将为页岩气开发及页岩储层中CO地质埋存的准确数值模拟提供部分理论基础。

The mechanism of the wetting hysteresis effect on threshold pressure and flow resistance was revealed, and the threshold pressure model and the flow resistance model after the movement of the bubble/droplet were established for a twophase fluid system based on the static wetting hysteresis equation and the dynamic contact angle equation, respectively. Based on the experimental data in the literature, the threshold pressure at different temperature and pressure, and the flow resistance at different pore size, viscosity and surface tension were calculated, by using the established models. The results show that the threshold pressure and the flow resistance caused by static wetting hysteresis and dynamic contact angle hysteresis cannot be ignored in nano-scale pores of shale. The flow resistance caused by dynamic wetting hysteresis is greater than the threshold pressure caused by static wetting hysteresis, and with the increase of flow velocity, the flow resistance continues to increase, but the degree of the growth rate gradually decreases. This study provides a mathematical model for the accurate characterization of the threshold pressure and flow resistance of two-phase fluid in shale reservoirs, which will provide some theoretical basis for accurate numerical simulation of shale gas development and geological storage of CO in shale reservoirs.

10.11885/j.issn.1674-5086.2021.03.15.05