Novel hydrophobic associative copolymers for natural gas hydrate fracturing fluids

Natural gas hydrates, which represent a promising future energy resource, present challenges during extraction due to the presence of solid hydrates, limited permeability for diffusion, and a short production cycle. However, despite the effectiveness of fracturing, further investigation is necessary. This study investigates the application of hydrophobic copolymers, specifically poly(acrylic acid-alkyl polyoxyethylene acrylate) (P(AA-AAEOn)), in hydrate fracturing fluids. Experimental tests were conducted to evaluate various properties of P(AA-AAEOn), including hydrodynamic size, molecular weight, radius of gyration, second virial coefficient, temperature resistance, shear resistance, shear recovery, viscoelasticity, salt responsiveness, interfacial tension, and wetting properties. Based on theoretical considerations and practical requirements, P(AA-AAEO10) at a ratio of 1:400 was selected for fracturing testing. The results indicated that the fracturing fluid exhibited exceptional temperature and shear resistance, sand-carrying ability,gel-breaking performance, and compatibility with seawater. The introduction of this novel and flexible molecular structure provides a theoretical assessment of the potential value of the hydrophobic association amphiphilic copolymer fracturing fluid in natural gas hydrate extraction. Furthermore, it presents a potential solution to the industrial challenges encountered in natural gas hydrate extraction.