Formulation of a Self‐Assembling Polymeric Network System for Enhanced Oil Recovery Applications

Abstract

The chemical formulation and rheological properties of a novel self-assembling polymer (SAP) network system were investigated for potential application in enhanced oil recovery (EOR). The inclusion complexes formed by surfactant (S) and β-cyclodextrin (β-CD) can associate with hydrolyzed polyacrylamides (HPAM) in aqueous solution, and subsequently establish the SAP network, which exhibits advanced viscoelasticity at the optimum molar ratio (S:β-CD = 2:1). Furthermore, this system presents enhanced surface activity and superior mechanical and thermal stability, as well as tolerance to elevated brine salinity and hardness due to the network "interlocking effect". Sandpack flood tests suggest the excellent mobility control ability of this system during polymer flooding, and also a moderate permeability reduction capacity, which makes it more cost effective in oil fields than the currently used HPAM. Regarding EOR performance, this polymeric system (SAP) produced approximately 19% more incremental oil than the baseline HPAM under the same experimental conditions. C

Improved viscoelasticity of xanthan gum through self-association with surfactant: β-cyclodextrin inclusion complexes for applications in enhanced oil recovery

“…The relevance of expressing the association constant in these terms is that the concentration of free surfactant monomer can be determined from the relationship between the surface tension in the pre‐micellar region and surfactant concentration in the absence of β‐CD ; therefore, for the case of 2S:1β‐CD inclusion, is expected to vary linearly with , which we have proved in previous work as presented in Fig. a and b .…”

“…Direct evidence of the formation of the inclusion complex can be obtained from NMR spectroscopic method, because the insertion of guest molecules into the hydrophobic cavity results in the chemical shift of the internal protons of β‐CD . In previous work, we have confirmed the complexation of surfactant: β‐CD in aqueous solution through 1 H NMR spectrometry , as presented in Fig. , which displays the 1 H NMR spectra of β‐CD (Fig.…”

“… 1 H NMR spectra of (a) β‐CD, (b) surfactant, and (c) self‐assembling inclusion (Source: Ref. ). [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.…”

Advanced Polymer-Surfactant Systems via Self-Assembling

“…The formulation of the SAP-AP systems was based on a molar ratio of surfactant to β-CD of 2:1 established from our previous research [17][18][19][20]. In the initial formulation of the SAP-AP system, the concentration of polymer was kept fixed at 0.5 wt% in 2.1 wt% brine.…”

Associating Polymer Networks Based on Cyclodextrin Inclusion Compounds for Heavy Oil Recovery

“…Recent pilot tests conducted by the China National Offshore Oil Corporation illustrate the potential of WSHAP flooding [11]. However, due to the high manufacturing cost, these polymers are still limited in large-scale applications [12]. The major concerns for polymer flooding are the effectiveness and cost of the selected polymer system.…”