School of Energy Resources, China University of Geosciences(Beijing)
Beijing Key Laboratory for Geological Evaluation and Development of Unconventional Natural Gas
Unconventional Research Center, CNOOC Research Institute

气水相对渗透率是评价煤层气是否具有工业价值的关键参数之一，测量和估算煤层气储层的相对渗透率是推进煤层气产业化亟需解决的基础问题。通过梳理国内外气水相对渗透率的研究进展，重点从煤储层气水相对渗透率的试验方法、理论模型和数值模拟3方面展开论述，主要取得了4项认识：① 非稳态法在煤储层相对渗透率的测试中应用范围更广泛，但较少探究原位温度的影响；微流控试验在可视化和量化多相流体渗流行为方面有很大的应用前景。② 利用核磁共振成像、CT三维扫描试验等新兴技术手段对渗透率试验装置进行改进，可以实时捕获多相流体的驱替过程并使测试结果更为准确。但试验环境较难还原地层的原位条件，且传感器的精度和稳定性仍需要进一步提高。③ 尽管目前针对煤层气储层已建立了多种相对渗透率计算模型，但其之间仍存在不同的假设条件和适用范围，难以统一推广，且未考虑真实孔裂隙结构的几何形态。④ 数值模拟方法破除了物理试验中的样品尺寸限制，在结合煤层气现场开发数据的基础上，可以实现提高采收率过程中相对渗透率变化的动态刻画。最后指出，未来需要将气水相对渗透率的测试环境进一步拓展至原位储层温度条件，探究多类型混合气体与水相流动行为，建立微流控试验的统一测试工序、扩展其应用场景和地质理论联系，并加深数值模拟与物理试验的联动分析与应用。

The gas-water relative permeability is one of the critical parameters that determine the industrial value of coalbed methane (CBM) reservoirs. Measuring and estimating the relative permeability of CBM reservoir is the underlying problem that needs to be solved urgently to promote the industrialization of CBM. Based on the current research on gas-water relative permeability at home and abroad, this paper summarized the research progress from the three aspects including the experimental method, theoretical model, and numerical simulation. And four understandings were obtained: ① the unsteady-state method is more widely used in the measurement of relative permeability of CBM reservoirs, but the effect of in-situ temperature is still less studied. The microfluidic experiments hold great promise in visualizing and quantifying flow behavior of multiphase fluids. ② The improvement of the experimental device combined with emerging technologies such as nuclear magnetic resonance imaging and CT scanning experiments can visualize the fluid displacement process and achieve the test results more accurately. However, the in-situ conditions of the formation is difficult to restore during the experiment. And the accuracy and stability of the sensor still need to be further improved. ③ Although various models for calculating the relative permeability in CBM reservoirs have been established, there are different assumptions and scopes of application, and the universality still needs to be further verified. Besides, the geometry of the real pore-fracture structure is not taken into account in the models. ④ Numerical simulation can break the limited sample size in physical experiments. And the dynamic characterization of the permeability change process can be realized combined with the field development data during enhanced CBM recovery. Finally, this study points out that ① we should further expand the test environment of gas-water relative permeability to in-situ reservoir temperature conditions; ② explore the flow behavior of multi-type mixed gas and water phases; ③ establish a unified test procedire for microfluidic experiments and expand its application scenarios and geological connections; ④ deepen the linkage analysis and application of numerical simulation and physical experiments.

国家自然科学基金资助项目（41922016, 41830427, 42130806）

蔡益栋，杨　超，李　倩，等. 煤层气储层相对渗透率试验及数值模拟技术研究进展[J]. 煤炭科学技术，2023，51（S1）：192−205.

CAI Yidong，YANG Chao，LI Qian，et al. Research progress of relative permeability experiment and numerical simulation technique in coalbed methane reservoir[J]. Coal Science and Technology，2023，51（S1）：192−205.