镇北油田致密储层注水井复合酸化技术
Complex Acidizing Technique for Water-Injecting Wells in Zhenbei Oilfield
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- 引用格式:
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高,翔,蒋建方,赵,珊.镇北油田致密储层注水井复合酸化技术[J].天然气与石油,2016,34(6):0.doi:
Complex Acidizing Technique for Water-Injecting Wells in Zhenbei Oilfield.Complex Acidizing Technique for Water-Injecting Wells in Zhenbei Oilfield[J].Natural Gas and Oil,2016,34(6):0.doi:
- DOI:
- 作者:
- 高 翔 蒋建方 赵 珊
Complex Acidizing Technique for Water-Injecting Wells in Zhenbei Oilfield
- 作者单位:
- 中国石油大学(北京)提高采收率研究院
China University of Petroleum (Beijing). Institute of Enhanced Oil Recovery
- 关键词:
- 注水井;二次沉淀;复合酸化;模拟实验;矿场应用
Water-injecting wells; Secondary precipitation; Complex acidification; Simulation experiment; Field application
- 摘要:
- 镇北油田存在常规酸化注水井注入压力高,二次沉淀严重问题。针对长庆镇北油田复杂岩性地层的特征和以往注水井酸化效果,进行解堵方案分析,拓展复合酸化技术在注水井中的应用,研究适应长3、长8储层的酸化液配方,并通过模拟程序“顶替液→油田回注水→前置酸→主体酸→后置酸→顶替液”进行评价。结果表明,注入水和前置液都会对岩心渗透性造成伤害,主体酸可以对岩心中的部分可溶矿物进行溶蚀,与注入水中的微粒等发生反应,使得岩心的渗透性得到较好的恢复和提高,后置酸液通过维持体系pH值防止二次沉淀发生。矿场应用表明,酸化解除了储层伤害,3口试验井酸化过程中施工压力明显降低,降压幅度明显高于以往酸化井,取得较好的酸化效果。
Zhenbei oilfield has the problems of high injection pressure and serious secondary precipitation. According to the characteristic of complex lithologic strata and previous acidizing performance at Zhenbei oilfield, plug removal analysis were conducted and then proposed a complex acidizing formula aiming at damage removal for layer Chang 3 and Chang 8. To evaluate the character of this complex formula, three groups of experimental were conducted to study on fluids ability to remove damage resulted from water injection and performance of improving cores permeability. These experiments are: displacing fluid → oilfield reinjection water → pre-flush → main fluid → after-pad → displacing fluid. The results showed that both of the oilfield reinjection water and pre-flush can take toll on cores permeability, and the smaller the cores initial permeability is, severer the damage will be. However, pre-flush and main fluid are able to dissolve the solvable mineral particles in cores and react chemically with micro-particulates in water so as to recover and improve permeability of cores highly. Applications from oilfield showed the treatments applied to three test wells removed well-bore damage. The pressure of water injection obviously reduced and the step-down was highly stronger than former treatments. Better acidizing performance were obtained.