酸岩反应过程模拟实验及残酸离子变化规律——以大庆油田为例  

Simulation experiment of acid rock reaction process and change rules of residual acid ions:a case study of Daqing Oilfield

作　　者：李伟[1] LI Wei(NO.9 Oil Production Plant of Daqing Oilfield Co.,Ltd.,PetroChina,Daqing 163511,Heilongjiang,China)

机构地区：[1]中国石油大庆油田有限责任公司第九采油厂,黑龙江大庆163511

出　　处：《石油地质与工程》2024年第5期100-104,共5页Petroleum Geology and Engineering

摘　　要：酸岩反应复杂,反应过程中会产生大量离子,可能随着pH值升高生成二次沉淀,从而影响酸化效果,因此分析酸岩反应过程中离子变化规律是酸化配方的技术关键。选取盐酸、土酸与大庆油田储层岩屑模拟酸岩反应,通过反应后酸液pH值梯次调控,模拟油层条件下酸岩反应进程及离子浓度变化规律。结果表明,pH值调节过程稀释倍数对残酸中金属离子浓度变化影响小,可不做考虑,放置时间以6 h为最佳;Ca^(2+)、Fe^(3+)、Al^(3+)是盐酸残酸产生二次沉淀的主要离子,Ca^(2+)、Fe^(3+)、Al^(3+)、Si^(4+)是土酸残酸产生二次沉淀的主要离子。在对酸岩反应机理及二次沉淀产生原因分析的基础上,自主研发了能减少酸岩反应二次沉淀的酸液——高络合酸,通过将高络合酸与土酸残酸进行定量对比和评价,验证了高络合酸具有抑制二次沉淀生成的效果,为提高酸化效果提供了新的思路。Due to complex acid rock reaction,a large number of ions are generated in the process.With the increasing of pH value,the secondary precipitation will be formed,which affects the acidification effect.Therefore,simulating the reaction process and analyzing the change rules of ions are the key techniques of acidification formula.Selecting hydrochloric acid,soil acid,and Daqing Oilfield reservoir rock cuttings to simulate acid rock reactions,the acid rock reaction process and ion concentration changes under reservoir conditions are simulated through stepwise regulation of the pH value of the acid solution after the reaction.The results showed that the dilution ratio had little effect on the change of metal ion concentration in residual acid during pH adjustment,and the best place time was 6 hours.Then,the change rules of ion concentration is studied and it is concluded that Ca^(2+),Fe^(3+),Al^(3+)are the main ions for the secondary precipitation of residual acid of hydrochloric acid,and Ca^(2+),Fe^(3+),Al^(3+)and Si^(4+)are the main ions for the secondary precipitation of residual acid of mud acid.Based on the analysis of the reaction mechanism and the cause of secondary precipitation,the acid liquid,high complex acid,which can reduce the secondary precipitation of acid rock reaction,was independently developed.Through quantitative comparison and evaluation of high complex acid and residual acid of soil acid,it is verified that the high complex acid has the effect of inhibiting the formation of secondary precipitation,which provides a new idea for improving the acidification effect.

关 键 词：残酸 离子浓度 二次沉淀 PH值 络合能力 

分 类 号：P585[天文地球—岩石学]