Evaluation of rheological properties of guar gum-based fracturing fluids enhanced with hydroxyl group bearing thermodynamic hydrate inhibitors

Naturally occurring gas clathrates are a significant methane resource-the primary component of natural gas, regarded as the cleanest hydrocarbon and a key feedstock for producing gray and blue hydrogen. Despite the global abundance of gas hydrate reserves, extraction via depressurization has yet to achieve commercially viable production rates. The primary limitation lies in the low permeability of hydrate-bearing sediments, where solid clathrates obstruct porous pathways, hindering dissociation and slowing gas recovery. Hydraulic fracturing has emerged as a promising technique to enhance conductivity, with initial studies indicating substantial increases in production rates when stimulation is applied. This study investigates the integration of thermodynamic hydrate inhibitors (THIs), such as methanol and polyethylene glycol 200 (PEG-200), into conventional polymer-based linear and crosslinked fracturing gels to improve performance. By targeting both rock and the embedded gas hydrates, these inhibitor integrated fracturing gels aim to facilitate faster fracture propagation and accelerate hydrate dissociation. The rheological performance of THI-integrated gels at varying concentrations is analysed, crucial for fracture formation, propagation, and proppant transport efficiency. Additionally, microscopic observations of additive interactions followed by fluid disintegration according to time are compared to evaluate residue formation and long-term integrity. Results indicate that methanol slightly increased the viscosity of linear gels at low concentrations and improved stability, reducing residue and slowing degradation, while higher concentrations required additional polymerizing agents to maintain performance. PEG-200 enhanced viscosity and stability in guar-based gels at low concentrations but caused shear-thinning at higher levels, limiting its suitability for high-viscosity operations. Crosslinked gels demonstrated superior proppant suspension and stability, generating less sediment-damaging residue compared to linear gels, with methanol further enhancing performance. Optimized integration of PEG-200 during borate crosslinking is critical, as higher concentrations risk premature gel degradation.