酸化杀菌技术研究及在注水井中应用

从油藏物性着手，结合化验手段分析出地层渗透率下降是由于水质变化和细菌污染所引起，需要对油层进行酸化、杀菌以解堵增注。酸化液体系主要包括预处理液、前置液、氧化杀茵液、主体酸、后置酸，在确定酸化液体系后，开展了酸化液性能评价的室内实验，实验包括4个方面的内容：酸化液的腐蚀性、杀菌性、防二次伤害及穿透性，实验结果表明该酸化液体系能满足文87区块的酸化增注要求。以室内实验为依据开展现场应用，文87—8井在施工前注入压力为36MPa、日注入量为33m3，施工后注入压力为21MPa、日注入量为70m3，酸化液的各组分体积为：预处理液4m3、前置液8m3、氧化杀菌液5m3、主体酸15m3、后置酸4m3、顶替液12m3，矿场实践表明该酸化液体系能满足文87区块的酸化增注要求。

The Research and Application of Acidification and Sterilization Technology in Water Injection Well

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 8 m3,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.