Fracturing fluid containing gas hydrate inhibitor

摘要

A fracturing fluid comprises water, a hydratable polymer, a crosslinking agent, a crosslinking delay agent, a breaking agent and a gas hydrate inhibitor. The crosslinking delay agent and the gas hydrate inhibitor make it possible to pump the fracturing fluid into deep wells where the temperature may reach 177{C. The gas hydrate inhibitor may be selected from NaCl, KCl, CaCl Þ , MgCl Þ , formates brines, polyols, amine glycols, glycol ethers, alcohols, electrolytes, polymers, vinyl polymers, polysaccharides, amides, lactams, pyrrolidines, acrylates, fatty acid surfactants, alkyl glucosides, alkyl amines, alkyl sulphonates, hydrocarbon based dispersants, polycarbonates, amino acids, proteins and amino carboxylic acids. The hydratable polymer is preferably a polysaccharide, such as guar. The crosslinking agent may comprise a borate, zirconate or titanate ion. The crosslinking agent and the crosslinking delay agent may be a single component, for example slurried borax suspensions, ulexite, colemanite, or complexes of borate ion, zirconate ion and/or titanate ion with a polyol selected from the group of sorbitol, mannitol, sodium gluconate, sodium glucoheptonate, glyceral, alpha D-glucose, fructose, ribose and alkyl glucosides. Preferably, two different gas hydrate inhibitors are used to ensure that gas hydrate inhibitor is present in both the aqueous phase and the polymer accumulation. In addition, the components of the fracturing fluid composition are environmentally benign and/or biodegradable.