江汉油田孔隙承压水重金属富集特征及成因分析研究

Enrichment Characteristics and Genetic Analysis of Heavy Metals in Pore Confined Water in Jianghan Oilfield

以江汉油田为研究对象,系统采集并测试18组孔隙承压水水样中Fe、Mn、Cu、Zn、Pb、Cd、Cr等7种重金属元素的含量,通过特征值分析、相关性分析,并利用主成分分析法对重金属元素富集模式进行分类,初步分析区域孔隙承压水中两种典型重金属元素富集模式的成因。结果表明,研究区内Fe、Mn超标率较高,超标倍数>4倍,少数点位Pb超标;研究区孔隙承压水中氧化还原电位比pH对于重金属元素的富集与迁移具有更大的影响,且强氧化环境有利于Fe、Mn、Pb、Cr的富集;Fe、Mn、Cr同为Fe族元素,具有相似的水文地球化学性质及富集与迁移特征;研究区内重金属元素具有两种富集模式,分别为原生沉积环境决定的Fe、Mn富集,石油开采及农药化肥影响Cd、Cu的富集。

Taking Jianghan Oilfield as the research object,seven heavy metal elements such as Fe,Mn,Cu,Zn,Pb,Cd and Cr in 18 groups of pore confined water samples were systematically collected and tested.Through eigenvalue analysis and correlation analysis,the enrichment modes of heavy metal elements are classified by principal component analysis,and the causes of two typical enrichment modes of heavy metal elements in regional pore confined water are preliminarily analyzed.The results show that Fe and Mn in the study area exceed the standard rate,exceeding the standard multiple by more than 4 times,and Pb in a few points exceed the standard.The REDOX potential in pore confined water in the study area has a greater influence on the enrichment and migration of heavy metals than pH,and the strong oxidizing environment is conducive to the enrichment of Fe,Mn,Pb and Cr.Fe,Mn and Cr are all Fe group elements with similar hydrogeochemical properties,enrichment and migration characteristics.Research in enrichment of heavy metals has two modes,respectively for the primary sedimentary environment decided to enrichment of Fe,Mn,Cd and Cu enrichment under the influence of petroleum exploitation,pesticides and fertilizers.