Fluoroboric acid blocking remover and acidification de-blocking method

The invention discloses a fluoroboric acid blocking remover and an acidification de-blocking method. The blocking remover is composed of prepad acid, subject acid and afterpad acid. The prepad acid and the afterpad acid are prepared from the same constituents which include, by mass, 10% of hydrochloric acid, 0.8-1.5% of clay stabilizer, 0.2-1.0% of ferrous stabilizer, 0.25-1.0% of corrosion inhibitor, 0.4-1.0% of water block removal agent, 0.2-1.0% of mutual solvent and the balance water. The subject acid is prepared from, by mass, 6% of acetic acid, 2% of fluoroboric acid, 0.8-1.5% of clay stabilizer, 0.2-1.0% of ferrous stabilizer, 0.25-1.0% of corrosion inhibitor, 0.4-1.0% of water block removal agent, 0.2-1.0% of mutual solvent and the balance water. By the adoption of the fluoroboric acid blocking remover, de-blocking of a low-yield unconventional tight sandstone oil and gas reservoir caused by water blocking reaction, inorganic scale and inflow fluid emulsification can be achieved effectively.