CO_2驱过程中碳酸盐溶蚀和地层水结垢趋势实验研究  

Experimental Study on Dissolution of Carbonate and Scaling Tendency of Formation Water in CO_2 Flooding

作　　者：马丽萍[1,2] 黎晓茸[1,2] 谭俊领[1,2] 贾玉琴[1,2] 马云[3] 

机构地区：[1]长庆油田分公司油气工艺研究院,陕西西安710021 [2]低渗透油气田勘探开发国家工程实验室,陕西西安710021 [3]西安石油大学化学化工学院,陕西西安710065

出　　处：《西安石油大学学报（自然科学版）》2016年第5期68-72,共5页Journal of Xi’an Shiyou University（Natural Science Edition）

摘　　要：为研究长庆油田某长6储层CO_2驱过程中高压CO_2注入造成的碳酸盐溶解以及降压后碳酸盐的析出规律,用自行构建的实验装置研究高CO_2注入压力下相同矿化度模拟地层水中Ca^(2+)质量浓度对模拟地层水溶解CaCO_3能力的影响,压力下降方式以及泄压后CO_2饱和度降低对CaCO_3析出量的影响。结果表明,在矿化度为100 000 mg/L的模拟地层水中,随着模拟地层水中Ca^(2+)含量的增加,其溶解CaCO_3能力下降;快速泄压会使CaCO_3快速析出,泄压后CaCO_3析出量也会增加。因此,CO_2驱过程中需关注地层水矿化度与Ca^(2+)含量,为防止采出水在地面管网或后续工艺设备中结垢,建议CO_2驱后的采出水在地面构筑物内集中快速泄压然后再集输至污水处理站。In order to understand the carbonate dissolution caused by high pressure CO_2 injection and the carbonate precipitation law after depressurization in CO_2 flooding process of a Chang 6 reservoir of Changqing oilfield,the influence of Ca^（2＋） mass concentration in the simulation formation water of the same salinity on the CaCO_3 dissolution ability of the simulation formation water and the influences of depressurization way and CO_2 saturation drop after depressurization on CaCO_3 precipitation are studied using self-developed experimental device. The results show that,with Ca2 ＋mass concentration in the simulation formation water with the salinity of 100 000 mg / L increasing,the CaCO_3 dissolution ability of the simulation formation water decreases,quick depressurization will make CaCO_3 rapid precipitation,and the precipitation amount of CaCO_3 will increase after depressurization. Therefore,the salinity and Ca2 ＋content of formation water need to be taken care of in CO_2 flooding. In order to prevent the produced water scaling in the ground pipe network or subsequent process equipment,it is suggested that the produced water after CO_2 flooding should rapidly depressurize in the ground structures and then be transported to sewage treatment station.

关 键 词：二氧化碳驱 碳酸钙溶蚀 结垢 

分 类 号：TE357.45[石油与天然气工程—油气田开发工程]