钻井泥浆膨润土与染料示踪剂的吸附性能及机理研究

Adsorption performance and mechanism of drilling mud bentonite to dye tracers

以新胭脂红(AR)和亚甲基蓝(MB)染料示踪剂作为研究对象,研究其与钻井液中膨润土之间的吸附性能,获得其热力学和动力学作用模型,并探究pH以及矿化度对染料吸附性能的影响。实验结果表明,膨润土对MB具有较强的吸附性能,其吸附量(928 mg/g)远大于膨润土对AR的吸附量(0.73 mg/g);膨润土对示踪剂的吸附过程更加符合伪二级动力学模型和Langmuir等温吸附模型;pH会影响染料示踪剂的紫外吸收,矿化度对染料示踪剂的紫外吸收几乎不产生影响。Zeta电位结果表明,AR主要通过范德华力与膨润土发生作用,因而吸附较弱;MB主要通过静电与膨润土中的Al-O、Si-O键发生作用,因而产生较强吸附。

New cochineal red(AR)and methylene blue(MB)dye tracers are taken as research objects to study the adsorption properties between dye tracers and bentonite in drilling fluid,to obtain the thermodynamic and kinetic models,and to explore the effects of pH and mineralization on the dye uptake properties.Experimental results show that bentonite has strong adsorption performance for MB,delivering an adsorption amount of 928 mg·g^(-1)that is much larger than the 0.73 mg·g^(-1)for AR.The adsorption process of bentonite to dye tracer is more consistent with the pseudo⁃secondary kinetic model and Langmuir isothermal adsorption model.pH affects the UV absorption of dye tracers,and the mineralization has small impact on the UV absorption of dye tracers.Zeta potential results show that AR interacts with the bentonite mainly through Van der Waals forces and thus generates a weak adsorption.MB mainly interacts with Al⁃O and Si⁃O bonds in bentonite through static electricity,which can produce a strong adsorption.