Design of Tailor‐Made Water‐Soluble Copolymers for Enhanced Oil Recovery Polymer Flooding Applications

Abstract

The goal in this study is to shed light on the ambiguous procedure of making AAm/AAc copolymers for polymer flooding applications for enhanced oil recovery (EOR). Despite the extensive use of these copolymers in polymer flooding, a well‐established recipe for the required desirable properties of AAm/AAc copolymers does not exist in the literature. Therefore, the knowledge from copolymerization kinetics and copolymer structure/property relationships is implemented to tailor‐make copolymers for polymer flooding. The detailed knowledge of the copolymerization kinetics enables to design copolymers with desirable properties, such as high molecular weight, high AAm content in the copolymer, and random distribution of anionic charges along the copolymer chain. Moreover, rheological properties show that copolymers with higher AAc content in the copolymer have higher solution viscosity and elasticity, both of which are desirable properties. In general, the main factors that should be considered when designing a polymer for polymer flooding for EOR applications are described.

Evaluation of Polymeric Materials for Chemical Enhanced Oil Recovery

“…Again, employing the widely used HPAM as a benchmark, the degree of hydrolysis (the degree of anionicity) typically ranges from 15% to 35%. The optimal charge density is reservoir-dependent but can be controlled using two different techniques: hydrolysis of polyacrylamide (through co-hydrolysis or post-hydrolysis, see [54,60]) or copolymerization of acrylamide and acrylic acid (sodium acrylate) [26,61,62]. Extensions to other polyacrylamide-based polyelectrolytes would typically involve multicomponent polymerization (see, for example, [26][27][28]53,63]).…”

“…Since the stoichiometric proportions of the individual elements are known, calculating the molar fraction of each comonomer is relatively straightforward. This approach is more widely used in recent EOR literature [29,61,67].…”

“…The "most desirable" polymer microstructure depends largely on the polymer composition and application (reservoir) conditions, which means that each investigation will be targeting a unique polymer microstructure. For example, the microstructure of polyelectrolytes will primarily impact the charge density (and subsequent brine compatibility) [20,61], whereas the microstructure of hydrophobically modified water-soluble polymers will affect the hydrophobic associations within and between coiled polymer chains [19]. Therefore, a "polymer microstructure" relates to several molecular properties that can influence EOR.…”

Water Soluble Polymer Flocculants: Synthesis, Characterization, and Performance Assessment

“…It is worthy to note that the reactivity ratios of water soluble monomers can significantly change with monomer concentration, pH, and ionic strength of the polymerization medium. More information on the optimal design of water soluble flocculants taking these phenomena into consideration can be found elsewhere . Through polymerization kinetics and a surface response methodology, Vajihinejad et al.…”

“…More information on the optimal design of water soluble flocculants taking these phenomena into consideration can be found elsewhere. [150] Through polymerization kinetics and a surface response methodology, Vajihinejad et al studied the impact of copolymer microstructure on the flocculation of oil sands tailings. [151] In another recent study, Gumfekar and Soares showed how polymer reaction engineering tools can help synthesize terpolymer flocculants with predefined and well-controlled compositions.…”