摘要
稠油火驱开发能否实现高温氧化将会直接影响开发效果,火驱燃烧状态的判识已成为火驱开发的技术难点之一。为攻克这一难题,采用天然岩心开展火驱实验,利用气相色谱技术对采集的原油开展饱和烃、烯烃和芳香烃指纹特征对比分析。实验结果表明:受高温氧化作用影响,火驱后稠油中的饱和烃含量明显上升,色谱指纹图呈前峰单峰型分布,正构烷烃含量增加、轻重比(∑nC_(21)-/∑nC_(22)+)变大、无奇偶优势;裂解生成的烯烃在色谱指纹图中表现为同碳数烯烃与正构烷烃含量比值始终小于1,并且随着碳数的增加该比值降低;芳香烃色谱指纹图呈前峰型分布,萘系列化合物中甲基萘含量明显低于萘,更容易在裂解生成的萘系列化合物的α位发生加甲基反应,菲系列化合物与萘系列化合物特征相似。气相色谱技术可以有效指示稠油火驱前后的微观变化特征,为火驱燃烧状态的判识奠定基础。
In fire flooding development of heavy oil,oxidation at high temperature directly affects the evaluation on the development effi⁃ciency,and how to identify the combustion state is a technical difficulty.Physical simulation experiments on fire flooding were performed on natural cores,and fingerprint characteristics of saturated hydrocarbon,olefin and aromatic hydrocarbon in heavy oil were analyzed through gas chromatography.The results show that after fire flooding,influenced by oxidation at high temperature,(1)the content of saturat⁃ed hydrocarbon in the heavy oil increases significantly,the chromatographic fingerprint is a pre⁃peak unimodal type,both the content of N⁃alkane and light⁃heavy ratio(∑nC_(21)-/∑nC_(22)+)increase,and no odd⁃even predominance appears;(2)on the chromatographic fingerprint,the olefins generated from cracking shows that the ratio of olefins to N⁃alkanes with the same carbon numbers is always less than 1,and the ra⁃tio decreases with the increase of the carbon number;(3)the chromatographic fingerprint of aromatic hydrocarbon is a pre⁃peak type,the content of methylnaphthalene is significantly lower than that of naphthalene in the naphthalenes,so it is easier to have methylation at theαplace of the cracked naphthalenes,and the characteristics of the phenanthrenes are similar to those of the naphthalenes.Chromatographic fingerprint can effectively indicate microscopic changes of the heavy oil before and after fire flooding,which lays a foundation for identify⁃ing the combustion state of fire flooding.
作者
闫红星
YAN Hongxing(Research Institute of Exploration and Development,Liaohe Oilfield Company,PetroChina,Panjin,Liaoning 124010,China)
出处
《新疆石油地质》
CAS
CSCD
北大核心
2021年第5期592-597,共6页
Xinjiang Petroleum Geology
基金
国家科技重大专项(2016ZX05055)。
关键词
稠油油藏
火驱开发
燃烧状态
高温氧化作用
色谱指纹特征
饱和烃
烯烃
芳香烃
heavy oil reservoir
fire flooding
combustion state
oxidation at high temperature
chromatographic fingerprint characteristic
saturated hydrocarbon
olefin
aromatic hydrocarbon
