摘要
草舍油田泰州组油藏于1981年发现并投入开发,石油地质储量为142×104t,1990年8月转入注水开发阶段,水驱采收率24%,可采储量34.1×104t。该油藏于2005年7月开始气水交替注CO2驱油试验,至2011年12月,采油井日产CO2气量为12000m3,综合含水率为51%,CO2对井下套管、生产管柱及井下工具的腐蚀十分剧烈,必须加以解决。根据该油藏采油井高含CO2气体防腐的要求,复配出4种HS系列高效CO2缓蚀剂,通过室内实验,评价出HS-20型CO2高效缓蚀剂,并在现场CO2驱试验区采油井中添加,其浓度为50～200μL/L。采用油管内、外监测挂环监测油管腐蚀速率,结果表明,井下油管腐蚀速率仅为0.01～0.001mm/a,具有良好的防腐效果,满足CO2驱采油井的防腐要求,保证了采油井的正常生产。相比于其他防CO2腐蚀措施,本方法简便有效,可供国内其他油田CO2驱油时借鉴。
Taizhou formation oil reservoir in Caoshe oilfield was found in 1981 and put into production with 142×104t of OOIP.It entered water flooding stage in August,1990 with 24% of recovery efficiency and 34.1×104t of recoverable reserves.CO2 flooding by the way of gas-water alternation has been applied in Taizhou formation oil reservoir of Caoshe oilfield since July 2005.By the end of December of 2012,daily CO2 production of production wells was 12000m3 and composite water cut was 51%.The problem of anticorrosion has to be solved for intense corrosion of CO2 on downhole casing,production string and downhole tools.According to the anticorrosion requirements,four high-efficiency CO2 corrosion inhibitors in HS series are prepared.HS-20 CO2 high-efficiency corrosion inhibitor is assessed by laboratory experiments,and was applied in production wells at CO2 flooding pilot site of the field with concentration of 50～200μL/L.Corrosion rate of oil tube inside and outside is monitored.The results show that the corrosion rate of downhole oil tube is only 0.01～0.001mm/a with better anticorrosion effect,which will make sure of normal production of the oil well.Compared with other CO2 anticorrosion technologies,this method is simple and effective,and can provide references for CO2 flooding in other oilfields in China.
出处
《中外能源》
CAS
2012年第6期48-51,共4页
Sino-Global Energy
基金
中石油2004年度油气田开发重大先导项目第五专题"二氧化碳驱注采系统研究"(P03092-5)
国家"863"项目"CO2驱油提高石油采收率与封存关键技术研究"第四专题"CO2驱油注采工程技术研究"(2009AA063404)
关键词
CO2驱油
采油井
缓蚀剂
高效防腐
腐蚀速率
CO2 flooding
production well
corrosion inhibitor
high efficiency anticorrosion
corrosion rate
