Optimized polymer systems for low-temperature stimulation of gas hydrate-bearing sediments

Production from gas hydrate reserves has been limited by the low permeability of hydrate-bearing sediments (HBS). While techniques like multi-well drilling and horizontal wells have improved reservoir access, enhancing reservoir conductivity through hydraulic fracturing is a promising next step. This study evaluates the compatibility of conventional linear and crosslinked gels with polysaccharides and synthetic polymer-based gas hydrate inhibitors for low-temperature stimulation. Established inhibitors like xanthan gum (XG), pectin, and polyvinylpyrrolidone (PVP) were tested in varying concentrations with guar gum (GG) and borate crosslinked gels. XG integrated linear gels exhibited significantly improved rheological performance, with viscosity increases ranging from 30 % to 90 % and viscoelastic enhancements between 90 % and 200 %, particularly under low-temperature conditions. These improvements can be attributed to synergy between XG and GG. Pure pectin gels exhibited a substantial, though disproportionate, increase in viscosity at low temperatures (up to 407 % at 5 °C) compared to ambient conditions. However, the addition of GG was necessary to improve elasticity and ensure stability. The incorporation of GG into the pectin matrix significantly enhanced both the viscous and elastic characteristics of the gel. The work also underscores the limitations of pectin in crosslinked systems, particularly under high pH conditions, where rapid deswelling and phase separation were observed within minutes after the preparation of sample. While PVP-integrated gels exhibit stability in both linear and crosslinked configurations, their rheological properties are compromised at temperatures below 15 °C, leading to a loss of structural integrity. This characteristic renders them more suitable for hydrate inhibition applications than for enhancing the fracturing performance. This novel optimization of polymer blends for stimulation fluids enhances the efficiency and stability of operations in gas hydrate-bearing sediments (GHBS), offering a promising pathway toward energy security and the sustainable, clean production of energy resources.