As interest in hydrogen (H2) grows as an emerging energy resource, research is focused on quantifying the fundamental properties of H2 storage in porous media. Here, we assessed the wetting properties of H2 by measuring the captive contact angle of H2 with brine-saturated subsurface caprock and reservoir rock at reservoir temperatures and pressures. We performed measurements on Upper Fayetteville Shale as a caprock analog and Berea Sandstone to represent a saline reservoir storage rock. We measured contact angle at three temperatures (23 °C, 45 °C, and 70 °C), three pressures (10.3, 34.5, and 51.8 MPa), one salinity (50,000 ppm of NaCl), and several bubble sizes ranging from 400 to 2500 μm. All contact angle values ranged between 7° and 30°, indicating a water-wet system. Our measurements showed that there was no trend or dependency of the contact angle value with sample type (shale and sandstone), temperature, pressure, surface roughness, or salinity. A weak negative linear correlation was observed between bubble size and contact angle; however, H2 remained nonwetting.
Goodman et al. (Tue,) studied this question.