A pH Regulator Used in Low Concentration HPGG Fracturing Fluids

Conventional fracturing fluids formulated with hydroxypropyl guar gum (HPGG) and organoboron crosslinking agent have those problems such as high consumption of guar gum, excessive residue and high operation cost etc. Using a new crosslinking extender, the crosslinking environment can be changed, and the B(OH)₄^- ions necessary for crosslinking reaction are continuously provided by the organoboron in the gel fluid system, ensuring HPGG to do its utmost to gel at the lowest concentration. In this way the consumption of HPGG can be reduced, and formation damage by fracturing fluid residue can be minimized. With this theory, a series of low guar gum fracturing fluids used between 45℃ and 120℃ have been developed. Compared with conventional fracturing fluids, the consumption of HPGG in these low guar gum fracturing fluids was reduced by 20%-35%, and amount of residue reduced by 25%-30%. The temperature resistance, shearing resistance and sand carrying capacity of the low guar gum fracturing fluids are not compromised, and can satisfy the needs of field operations. The new fracturing fluids not only reduce formation damage, they also help reduce time required for fluid mixing and operation cost.