Foam generation in homogeneous porous media

✍ Scribed by P A. Gauglitz; F Friedmann; S I. Kam; W R. Rossen

• Book ID: 108311083
• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 414 KB
• Volume: 57
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/s0009-2509(02)00340-8

✦ Synopsis

In steady gas-liquid ow in homogeneous porous media with surfactant present, there is often observed a critical injection velocity or pressure gradient ∇p min at which "weak" or "coarse" foam is abruptly converted into "strong foam", with a reduction of one to two orders of magnitude in total mobility: i.e., "foam generation". Earlier research on foam generation is extended here with extensive data for a variety of porous media, permeabilities, gases (N2 and CO2), and surfactants. For bead and sandpacks, ∇p min scales like (1=k), where k is permeability, over 2 1 2 orders of magnitude in k; for consolidated media, the relation is more complex. For dense-CO2 foam, ∇p min exists but can be less than 23 KPa=m (1 psi/ft). If pressure drop, rather than ow rates, is ÿxed, one observes an unstable regime between stable "strong" and "coarse" foam regimes; in the unstable regime ∇p is nonuniform in space or variable in time. Results are interpreted in terms of the theory of foam mobilization at a critical pressure gradient.