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Heavy oil recovery using ASP flooding: A pore‐level experimental study in fractured five‐spot micromodels
Author(s) -
Sedaghat Mohammad,
Mohammadzadeh Omid,
Kord Shahin,
Chatzis Ioannis
Publication year - 2016
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.22445
Subject(s) - residual oil , coalescence (physics) , wetting , enhanced oil recovery , polyacrylamide , petroleum engineering , materials science , porous medium , pulmonary surfactant , polymer , chemical engineering , imbibition , composite material , displacement (psychology) , chemistry , porosity , geology , polymer chemistry , engineering , psychology , physics , astrobiology , psychotherapist , germination , botany , biology
Although alkaline‐surfactant‐polymer (ASP) flooding has proven efficient for heavy oil recovery, the displacement mechanisms and efficiency of this process should be discussed further in fractured porous media. In this study, several ASP flooding tests were conducted in fractured glass‐etched micromodels with a typical waterflood geometrical configuration, i.e. five‐spot injection‐production pattern. The ASP flooding tests were conducted at constant injection flow rates but different fracture geometrical characteristics. The ASP solutions consisted of five polymers, two surfactants, and three alkaline types. It was found that using synthetic polymers, especially hydrolyzed polyacrylamide with high molecular mass, as well as cationic surfactant increases the ultimate recovery. The location of the injection well with respect to the fracture system plays a significant role in the ASP flooding performance, i.e. an increase in the angle associated with the longitudinal extension of fractures with respect to the main flow direction resulted in enhanced oil recovery and also postponed the wetting phase breakthrough time. Mechanistic study of this displacement process revealed that dispersive and diffusive behaviour of the ASP front enhanced the fluid transport from fracture to matrix and increased the microscopic displacement efficiency. Emulsification and coalescence mechanisms were responsible for ASP frontal advancement. Residual oil in the invaded region, which was observed in the form of discontinuous oil ganglia dispersed in the invaded pore bodies or in the form of pendular bridges formed around some of the solid particles, was mobilized in the form of oil wads through the droplets of the displacing phase.