摘要
大牛地气田地层水矿化度较高,随开发时间延长,产层压力下降,在低压高温条件下,地层水大量蒸发以及水中CO_2酸性气体的逸出导致气井结垢严重。通过气田垢样组分分析,结合地层水离子构成及历年气井流温流压测试数据,明确了该气田气井结垢机理,并优化形成了其地层水结垢趋势预测模型。结垢预测显示,D1-2-6井与D52井有较强碳酸钙结垢趋势。针对气田结垢现状,研制GCCG-1除垢剂,并在D1-2-6井进行了除垢试验。GCCG-1除垢剂为无机酸、有机酸、螯合剂、缓蚀剂、防膨剂以及助排剂复配而成,对碳酸盐类垢质有较强的溶解、剥落及分散作用,80℃下溶垢能力达到95%以上,且对管材腐蚀小,80℃下平均腐蚀率为1.80 g/(m^2·h)。D1-2-6井经过除垢作业后,成功复产并稳产,平均增产气量4 000 m^3/d,增产幅度133%。
In Daniudi gasfield,formation-water salinity is high and reservoir pressure decreases along with its development.Under low pressure and high temperature,the formation-water evaporation and the CO2 escaped from water lead to serious scaling.So,scaling mechanism of gas wells,Daniudi gasfield,was clarified by analyzing scale sample composition,formation-water ionic integrant,and some flowing temperature and pressure measured over these years.In addition,a model for predicting formation-water scaling trend was developed.After this prediction,it is found that D1-2-6 and D52 wells have strong trend of carbonate scaling.So,GCCG-1 scale remover was developed and then tested in D1-2-6 well.This remover,which is composed of inorganic acid,organic acid,chelating agent,corrosion inhibitor,anti-swelling agent,and cleanup additive,is featured by strong dissolution,and stripping and dispersion effect on carbonate scale deposit.At 80℃,its scale-solving capacity is over 95%and its corrosion to pipe materials is weak with average corrosion rate of 1.80g/(m^2·h).After descaling,D1-2-6 well achieved a reproduction and kept a stable production,and its average gas production is increased by 133%,i.e.,4 000 m^3/d.
作者
魏凯
何荣华
李国锋
Wei Kai;He Ronghua;Li Guofeng(Engineering Technology Research Institute,Sinopec North China Company,Zhengzhou,Henan 450006,China)
出处
《天然气勘探与开发》
2018年第4期62-68,共7页
Natural Gas Exploration and Development
基金
国家科技重大专项"低丰度致密低渗油气藏开发关键技术"(编号:2016ZX05048)
关键词
大牛地气田
地层水矿化度
结垢机理
饱和指数
除垢技术
Daniudi gasfield
Formation-water salinity
Scaling mechanism
Saturation index
Descaling technique
