The Development and Application of an On-The-Fly Acidizing Fluid for High-Pressure and Under-Injection Water Well

Water injection is an important method to maintain and restore reservoir pressure and to improve the recovery rate and oil recovery in low permeability oil field. In view of the problems of high injection pressure in water wells, study of an on-the-fly acidification technology is carried out. In order to avoid injection pressure relief, tripping operation and under-pressure operation, an on-the-fly acidizing fluid is developed. The evaluation results show that the on-the-fly acidizing fluid has the advantages of strong chelating capacity, excellent inhibition of precipitation, extremely low corrosion and good retarding performance. With the mounted equipment equipped with acid-proof pump, water and the on-the-fly acidizing fluid can be injected directly after mixing. Eleven field tests prove that it realizes no trip operation, no flowback, non-interference between water injection and acid treatment, which shorten the job execution time and provide an effective stimulation method.