|
Retention mechanism | Controlling factor | Favorable condition |
|
Surface capillary retention | Wettability, surface roughness | Large roughness, hydrophilic rock, low flow rate |
Surface-bound water film | Surface dryness, liquid surface properties | Dry surface, strong hydrophilicity |
Matrix pore imbibition | Physical properties, liquid type, clay and ion content | Small pores, wetting liquids, high clay/ion content |
Fracture closure “locking” | Contact area, fracture aperture, roughness, stress | Large contact area/stress, high roughness, small aperture |
Gravity retention | Liquid viscosity, fracture aperture, roughness, fracture height | High viscous force, large aperture |
Viscous trapping | Fracture aperture, drive pressure, liquid viscosity | Small aperture and pressure, high viscosity |
|