摘要
在油气开采与生产过程中,稠化酸中常见问题是稠化剂自身的耐温性能和耐酸性能不佳,导致不能达到高温下深度酸化的目的;此外,当前酸化用高温缓蚀剂与酸液体系配伍性差,防腐蚀能力不足.因此,导致目前高温深井的碳酸盐岩储层酸化难度增加.为解决上述问题,设计并制备了一系列聚丙烯酰胺基阳离子型耐温耐酸的稠化剂,并研究了其基本性能.同时,筛选出适合高温酸液用缓蚀剂,结合其余助剂形成耐高温稠化酸,进一步研究稠化酸的性能.结果 表明,自制的SH4稠化剂耐酸性能和增黏性能极佳,20％的盐酸中,0.6％的稠化剂黏度可达到59.88 mPa·s.加入缓蚀剂1后形成的稠化酸体系配伍性良好,经180℃高温高压动态腐蚀测试,N80钢片腐蚀速率仅为41.614 g/(m2·h).在180℃,170 s-1下稠化酸体系黏度保持在33.258 mPa·s,证明其耐温耐剪切能力强,可用于高温酸化.
Abstract
In the process of oil and gas exploitation and production,thickened acid is a commonly used working fluid in acid fracturing.The main performance supporters of thickening acid are thickening agent and corrosion inhibitor.The role of thickening agent is to increase viscosity and reduce acid rock reaction rate,and the role of corrosion inhibitor is to protect equipment.The common problem in the thickening acid is that the thickener's own temperature resistance and acid resistance are poor,resulting in the failure to achieve the purpose of deep acidification at high temperature.In addition,the current high temperature corrosion inhibitor for acidification has poor compatibility with the acid system and insufficient anti-corrosion ability.Therefore,the acidification of carbonate reservoirs in high temperature deep wells is more difficult.A series of polyacrylamide cationic thickeners with temperature and acid resistance were designed and prepared,and their basic properties were studied.At the same time,the corrosion inhibitor suitable for high temperature acid solution was screened out,and the high temperature resistant thickening acid was formed in combination with other additives to further study the performance of thickening acid.The results show that the self-made SH4 thickener has excellent acid resistance and viscosity increasing performance.In 20％hydrochloric acid,the viscosity of 0.6％thickener can reach 59.88 mPa·s.The corrosion rate of N80 steel sheet is only 41.614 g/(m2·h)after high temperature and high pressure dynamic corrosion test at 180 ℃.The viscosity of the thickened acid system remained at 33.258 mPa·s at 180℃and 170 s-1,which prove that it had strong temperature and shear resistance and could be used for high temperature acidification.
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