关键词: 酸化 , 杀菌 , 缓速 , 二次伤害

Abstract: On the base of reservoir properties, and combined with chemical analysis, this paper revealed that formation permeability reduction was due to changes in injection water quality and the pollution of formation caused by bacteria. It was necessary to take acidification, sterilization on the reservoir to increase the injection water volume. The system of acidification fluid mainly included pretreating solution system, preflush, oxidation sterilization liquid, body acid, rear acid, in the setting of acidizing fluid system, the evaluation of acidizing fluid performance was carried out by laboratory experiments. The experiment included four aspects of acidizing fluid: corrosivity, bactericidal properties, preventing the secondary damage and penetrability. The experimental results show that the acidizing fluid system can meet the requirement of Wen 87 block acid stimulation. The field application was carried out, based on laboratory experiments. Injection pressure of W87-8 well was 36 MPa and injection volume was 33 m³ before the construction. And after the construction, injection pressure was 21 MPa and injection volume was 70 m³. The dosage of each component in acidification fluid as follow: pretreatment liquid was 4 m³, pad fluid was 8m³, oxidation and disinfection liquid was 5 m³, subject acid was 15 m³, after-pad acid was 4 m³, displacement fluid was 12 m³. The results of practice indicated that the acid has a very good stimulation effect.

Key words: Acidification, Sterilization, Retardation, The secondary damage