Development of a Heavy Acid for Ultra High Temperature Acidification

Using quinoline, benzyl chloride, and dodecyl bromide as raw materials, first use toluene as a solvent, stir under a water bath at 60 °C for 18 h to obtain an intermediate product. After constant temperature, allow it to settle and separate into layers, with a settling time of 2 h. Then add dodecyl bromide to the intermediate product, use acetone as a solvent, stir under a water bath at 50 °C for 10 h to obtain the final product, which is the main agent of ultra-high temperature acidizing corrosion inhibitor. Mix it with 15% alkynol and 20% amide, use potassium antimony tartrate or antimony trioxide as a synergist, and conduct indoor evaluations at 220 °C. Introduce a solubilizer to solve compatibility issues between heavy inorganic salts and acid solutions, allowing the acid solution density to reach 1.3 g/cm3. Under conditions of 15% hydrochloric acid and 5% formic acid, adding 5% corrosion inhibitor and 0.5% synergist results in an acid corrosion rate below 38 g/m2·h. This can meet the needs of reducing fracturing pressure and increasing liquid injection pressure in ultra-deep, ultra-high-fracture-pressure reservoirs.