Pre-acid system for improving the hydraulic fracturing effect in low-permeability tight gas reservoir

Abstract Hydraulic fracturing is an important technical means to improve the development effect of low-permeability oil and gas reservoirs. However, for low pressure, low-permeability, tight, high-clay sandstone reservoirs, conventional propped can cause serious damage reservoir restrict effect. The pre-acid technology combines acid treatment with sand-fracturing technology. A system that meets special performance requirements injected before fracturing. reduces formation fracture pressure removes clay damage. During flowback, fluid promoted break gel, dissolve residue polymer filter cake, clean supporting cracks, effectively This study analyzes process principle advantages based on laboratory evaluation mechanism tight To meet reservoirs technology, a set polyhydrogen long-lasting slow reactivity, damage, corrosion was developed used as pre-fracturing acid. mainly composed main agent SA601 auxiliary SA701. Then, basis experiments, this evaluate improvement results show better cake remove