Hosseini Mirhasan, Fahimpour Jalal, Ali Muhammad, Keshavarz Alireza, Iglauer Stefan
Petroleum Engineering Discipline, School of Engineering, Edith Cowan University, 270 Joondalup Dr, Joondalup 6027, WA, Australia.
Department of Petroleum Engineering, Amirkabir University of Technology, Tehran, Iran.
J Colloid Interface Sci. 2022 May 15;614:256-266. doi: 10.1016/j.jcis.2022.01.068. Epub 2022 Jan 12.
The mitigation of anthropogenic greenhouse gas emissions and increasing global energy demand are two driving forces toward the hydrogen economy. The large-scale hydrogen storage at the surface is not feasible as hydrogen is very volatile and highly compressible. An effective way for solving this problem is to store it in underground geological formations (i.e. carbonate reservoirs). The wettability of the rock/H/brine system is a critical parameter in the assessment of residual and structural storage capacities and containment safety. However, the presence of organic matters in geo-storage formations poses a direct threat to the successful hydrogen geo-storage operation and containment safety.
As there is an intensive lack of literature on hydrogen wettability of calcite-rich formations, advancing (θ) and receding (θ) contact angles of water/H/calcite systems were measured as a function of different parameters, including pressure (0.1-20 MPa), temperature (298-353 K), salinity (0-4.95 mol.kg), stearic acid (as a representative of organic acid) concentration (10 - 10 mol/L), tilting plate angle (0° - 45°) and surface roughness (RMS = 341 nm, 466 nm, and 588 nm).
The results of the study show that at ambient conditions, the system was strongly water-wet, but became intermediate wet at high pressure. The water contact angle strongly increased with stearic acid concentration making the calcite surface H-wet. Moreover, the contact angle increased with salinity and tilting plate angle but decreased with temperature and surface roughness. We conclude that the optimum conditions for de-risking H storage projects in carbonates are low pressures, high temperatures, low salinity, and low organic surface concentration. Therefore, it is essential to measure these effects to avoid overestimation of hydrogen geo-storage capacities and containment security.
人为温室气体排放的缓解和全球能源需求的增长是推动氢经济发展的两大驱动力。由于氢气极易挥发且高度可压缩，在地表进行大规模氢气存储并不可行。解决这一问题的有效方法是将其存储在地下地质构造中（即碳酸盐岩储层）。岩石/氢气/盐水体系的润湿性是评估残余和构造存储能力以及封存安全性的关键参数。然而，地质存储地层中有机物的存在对氢气地质存储作业的成功实施和封存安全性构成了直接威胁。
由于关于富含方解石地层的氢气润湿性的文献极为匮乏，因此测量了水/氢气/方解石体系的前进（θ）和后退（θ）接触角，作为不同参数的函数，这些参数包括压力（0.1 - 20兆帕）、温度（298 - 353开尔文）、盐度（0 - 4.95摩尔/千克）、硬脂酸（作为有机酸的代表）浓度（10 - 10摩尔/升）、倾斜板角度（0° - 45°）和表面粗糙度（均方根粗糙度 = 341纳米、466纳米和588纳米）。
研究结果表明，在环境条件下，该体系表现出强亲水特性，但在高压下变为中性润湿。水接触角随硬脂酸浓度的增加而显著增大，使得方解石表面呈现出亲氢性。此外，接触角随盐度和倾斜板角度的增加而增大，但随温度和表面粗糙度的增加而减小。我们得出结论，降低碳酸盐岩中氢气存储项目风险的最佳条件是低压、高温、低盐度和低有机表面浓度。因此，必须测量这些影响，以避免高估氢气地质存储能力和封存安全性。
