油气田聚合物类钻井液添加剂分子结构与环境影响的相关性

Correlation between molecular structure of polymer additives used for drilling fluid and environmental influence

对国内油田24种常用钻井液添加剂进行了红外光谱分析,通过与标准谱图对照及分析,确定了各添加剂分子结构的主要官能团。采用COD测定仪、BOD测定及急性生物毒性测定对添加剂的COD、BOD_5和EC_(50)等环保指标进行检测分析,研究了钻井液添加剂分子结构与环境影响的相关性。结果表明,二者之间具有相关性,特定的官能团会对钻井液添加剂的环保指标产生正面或负面影响。分子结构中含有苯环及苯环上有官能团取代的钻井液添加剂COD较高(>8 000 mg·L^(-1)),BOD_5较低(<389 mg·L^(-1)),生物降解性均为难降解((BOD_5/COD)<5%),急性生物毒性EC_(50)低(<10 000 mg·L^(-1)),有毒性显示。研究结果为钻井废弃物环境污染的源头控制、环保型钻井液添加剂与体系的研制等提供技术依据。

In the study, 24 most used additives were analyzed by infrared spectroscopy. The main functional groups of molecular structure were determined by comparison and analysis with standard spectra. The COD, BOD5 and EC50 of the additives were tested respectively by COD tester, BOD determination and acute biological toxicity. And the correlation between the molecular structure and the environmental impact of the drilling fluid additive were also studied. The results show that there is a correlation between molecular structure and the environmental impact. The specific functional groups can produce either positive or negative impact to the environmental indicators of drilling fluid additives. The drilling fluid additives, whose molecular structure contains benzene ring or characterized benzene ring, have higher COD（above 8 000 mg·L-1）, lower BOD5 （under 389 mg·L-1）, difficult degradation（under 5%） and low EC50 （under 10 000 mg·L-1） respectively. The study provides technical basis for the drilling waste environmental pollution source-control and the development of environment-friendly drilling fluid additives.