Foam Performance in Low Permeability Laminated Sandstones

• Published in: Energy & fuels 2014-02, Vol.28 (2), p.803-815
• Main Authors: Solbakken, Jonas S, Skauge, Arne, Aarra, Morten Gunnar
• Format: Article
• Language: English
• Subjects: Applied sciences; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Foams; Foundry sands; Fuels; Heterogeneity; Laminates; Permeability; Reservoirs; Rock; Sandstones
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/ef402020x

Most studies on foam are related to homogeneous and highly permeable porous media. As the reservoir situation is rather heterogeneous with respect to permeability and layering, foam properties in layered porous media with lower permeabilities are also important to understand. This study investigates foam behavior and performance in naturally laminated sandstone cores. Laminations are common constituents in sandstone petroleum reservoirs where they usually occur as thin deformed layers in the host formation. Evidences of rock heterogeneity were confirmed by several different analyses on laminated material. From image processing of thin sections and 2D X-ray experiments, the laminas present were found to exhibit both lower porosity and permeability than the host rock, and also shown to form barriers to fluid flow. Foam experiments were performed in three low permeability sandstone cores with relative similar permeability but with a different degree of laminated stratifications parallel to flow direction. Foam was generated in all the low permeability laminated cores. However, the degree of lamina in each core influenced foam performance significantly, reflected by large variations in mobility reduction factors (MRF ∼ 20–500) and foam breakthrough times. Increased lamination resulted in weaker foams and earlier foam breakthroughs. One explanation to this could be that the low permeability laminas introduce different degrees of discontinuities and compartmentalization to foam flow. Findings in our study indicate that foam properties and performance can be strongly influenced by local heterogeneities, such as laminations naturally found in many sandstone reservoirs.