Wang Lan, Li Zhiping, Mao Gangtao, Zhang Yan, Lai Feng Peng
School of Energy Resources, China University of Geosciences, Beijing 100083, People's Republic of China.
Beijing Key Laboratory of Unconventional Natural Gas Geology Evaluation and Development Engineering, Beijing 100083, People's Republic of China.
ACS Omega. 2022 Feb 10;7(7):6261-6270. doi: 10.1021/acsomega.1c06770. eCollection 2022 Feb 22.
Coalbed methane (CBM) is an important unconventional energy resource, and its micropore structure has a vital impact on its exploitation. Based on the nuclear magnetic resonance (NMR) experiment, the low-temperature liquid nitrogen adsorption experiment, and the contact angle experiment, in this paper, we investigated the influence of nanofluids on the micropore structure of a CBM reservoir from many aspects. The influence of different adsorption mechanisms of TiO nanoparticles on the surface wettability of rock samples was analyzed. The influence of nanoparticle adsorption on the drainage and distribution of liquid in the rock sample was discussed in depth. In addition, the effects of nanofluid treatment on the micropore structure were investigated by comparing the data of low-temperature liquid nitrogen adsorption experiments, including the pore diameter, pore volume, and specific surface area (SSA). The experimental results show that the treatment of nanofluids helps to open the micropores and greatly increases the SSA, pore diameter, and pore volume of the sample. The maximum increase percentages of SSA, pore volume, and pore diameter are 228.12, 80.65, and 18.89%, respectively. It is found that the adsorption of particles is conducive to enhancing the water wettability of the pore throat surface and reducing the damage to water locks.
煤层气（CBM）是一种重要的非常规能源资源，其微孔结构对其开采具有至关重要的影响。基于核磁共振（NMR）实验、低温液氮吸附实验和接触角实验，本文从多个方面研究了纳米流体对煤层气储层微孔结构的影响。分析了TiO纳米颗粒不同吸附机制对岩石样品表面润湿性的影响。深入探讨了纳米颗粒吸附对岩石样品中液体渗流和分布的影响。此外，通过比较低温液氮吸附实验数据，包括孔径、孔体积和比表面积（SSA），研究了纳米流体处理对微孔结构的影响。实验结果表明，纳米流体处理有助于打开微孔，并大大增加样品的比表面积、孔径和孔体积。比表面积、孔体积和孔径的最大增加百分比分别为228.12%、80.65%和18.89%。研究发现，颗粒的吸附有利于增强孔喉表面的水润湿性，并减少水锁损害。
