陕北地区石油钻井泥浆中污染质分布特征

针对石油勘探开发过程中存在大量废弃钻井泥浆污染土壤、水体的现状,选择长庆油田陕北采区5个 井场的钻井泥浆进行污染特征分析。测定了泥浆中35项理化指标和污染指标,结果表明,废弃钻井泥浆呈粘稠状胶 体,粘度高。钻井泥浆的成分主要为粘土、聚丙烯酰胺(PAM),羧甲基纤维素(CMC)。泥浆中COD、矿物油、NH4+、 Cr、Cd、Pb、As、pH 值和色度等超标,个别井场的Zn超标,除COD、矿物油严重超标之外,其他组分超标倍数不大。 泥浆中COD、矿物油和NH ₄⁺ 等污染组分主要源于地层石油以及PAM,CMC等添加物,pH值升高与加入纯碱或烧 碱有关,而Cr、Cd、Pb、As、Zn等重金属则源于钻井过程中循环泥浆携带上来的井壁物质,与地层组成有关。

Distribution Characteristics of Shanbei Area Pollutant in the Petrolic Drilling Fluids

In view of the present situation that there are a lot of waste drilling fluids pollute soil and water in the process of petroleum exploration and development.The drilling fluids in the 5 well fields which is in the north area of Changqing oilfield was choosed to carry on the pollution characteristic analysis.35 physicochemical indexs and contamination indexes were determined in the drilling fluids.The results show that the waste drilling fluids are ropiness colloid,viscosity high.The drilling fluids' ingredients are clay,polyacrylamide(PAM)and carboxymethylcellulose(CMC).COD,mineral oils,NH+4,Cr,Cd,Pb,As,pH,chromaticity and so on exceed standard in the drilling fluids,Zn exceeds standard in some individual well fields,the other over-standard parameters'multiple is not big except COD,mineral oils which exceed standard siriously.COD,mineral oils,NH+4 and so on are from formation petroleum and the additives such as PAM,CMC etc,high pH is related to calcined soda or caustic soda,Cr、Cd、Pb、As、Zn and so on are from the sidewall material which is cattied by the circulating mud,which are related to formation lithological composition.