Development and Performance of Water Soluble Salt-Resistant Polymers for Chemical Flooding

Abstract

The basic requirement of polymer for chemical flooding was introduced, development progress and performance evaluation of salt-resistant polymers for chemical flooding were discussed, and development direction of polymers for chemical flooding was indicated in this paper.

Evaluation of Polymeric Materials for Chemical Enhanced Oil Recovery

“…A consideration of polymer microstructures for enhanced oil recovery may include the molecular architecture, the statistical distribution of comonomer units along a linear backbone, or both. The rheology of polymer solutions can change drastically, depending on whether linear or branched polyacrylamides are employed [24,25]. In fact, Zhu et al [25] reported that using nonlinear architectures (comb-shaped, branched, and star-shaped polymers) improved the salt tolerance in terms of viscosity modification and long-term stability.…”

“…The rheology of polymer solutions can change drastically, depending on whether linear or branched polyacrylamides are employed [24,25]. In fact, Zhu et al [25] reported that using nonlinear architectures (comb-shaped, branched, and star-shaped polymers) improved the salt tolerance in terms of viscosity modification and long-term stability. As described earlier (in Figure 2), linear polymer molecules can be significantly affected by charge effects in solutions; high salinity environments can cause polymer coils to shrink, thus reducing the hydrodynamic volume and lowering the viscosity modification ability.…”

“…In terms of biopolymers for EOR, the material with the highest achievable molecular weight (2 × 10 6 g/mol -50 × 10 6 g/mol, as reported by [19]) is xanthan gum; this may be one of the reasons why it is a popular biopolymer for polymer flooding. Similarly, in terms of synthetic materials for EOR, reported molecular weight averages range from 10 4 g/mol [24] to 10 7 g/mol [25,27]. Most researchers studying polymers for EOR agree that a target molecular weight on the order of 10 6 g/mol is appropriate [19,27,61].…”

“…The most experimentally simple approach is to use an Ubbelohde viscometer for viscosity measurements (and subsequent molecular weight determination). This approach has been employed in several EOR studies, including [11,25,29,93]. It can be especially useful for ultra-high molecular weight polymers; Zhu et al [25] reported molecular weights up to 25 × 10 6 g/mol.…”

“…This approach has been employed in several EOR studies, including [11,25,29,93]. It can be especially useful for ultra-high molecular weight polymers; Zhu et al [25] reported molecular weights up to 25 × 10 6 g/mol. The approach is admittedly simple and, hence, popular for relative (quality control) comparisons, if one is careful and consistent with the experimental steps involved.…”