Thickening Performance Evaluation and Molecular Dynamics Simulation on Hydrophobic Associated Polymer in Acid Circumstances

Abstract

Acid thickener is of necessity for improving the exploitation capacity for oil and gas resources of carbonate reservoirs. Here a hydrophobic associated polymer (HPA) by introducing a nonionic hydrophobic monomer (AO) was designed as the acid thickener. The experimental results demonstrated that HPA suggests excellent acid resistance, shear resistance, and thermal stability attributing to the gradual exposure of hydrophobic chain to H2O circumstances that enhances the strength of hydrophobic association. The square radius of gyration of HPA raises with the introduction of AO confirming the unfold of HPA by intermolecular hydrophobic association, which strengthens the network structure. The decrease of mean square displacement and diffusion coefficient of H2O and H3O+ molecules suggest the enhancement for network structure by hydrophobic chain owing to HPA hindered the diffusion of H2O and H3O+ molecules. These findings are expected to supply a guidance for the design and research on the acid thickener.