环境友好型聚合物钻井液抑制剂的室内研究

Laboratory Study on Environmentally Friendly Polymer Shale Inhibitor

随着人们环保理念的增强和新环境保护法的颁布,研发各种新型低毒无害的环境友好型钻井液处理剂替代传统的钻井液处理剂势在必行。川渝地区目前使用较好的KCl-聚合物钻井液体系,其中含有较高浓度的氯离子,氯离子能够与环境中的有机物结合生成具有三致效应的氯代化合物,严重影响生态环境。笔者在室内研发出一种能够取代KCl的聚胺抑制剂,该抑制剂主要是通过胺基特有的吸附而达到抑制泥页岩水化分散的作用。聚胺抑制剂本身具有很好的抑制能力,并能够较好被环境接受,在取代KCl后,还能进一步提高钻井液的抑制能力,很大程度地降低聚合物钻井液中的氯离子,不仅能够改善聚合物钻井液各项性能,还能使其具有很好的环境保护性能。

KCl polymer drilling fluids are currently commonly used in Sichuan and Chongqing areas. The KCl polymer drilling fluids used contain high concentration of chlorines which, when reacted with organic compounds in the surrounding environment, will generate chlorinated chemicals having teratogenesis, carcinogenesis and mutagenesis effects. A polyethylenepolyamine, havingdegree of amination of more than 85%, was synthesized through Hofmann Reaction from polyacrylamide. It has LC50(opossum shrimp) of 18,764 mg/L, actually non-toxic, and BOD5/CODCr of 68.2%, easy to degrade. In laboratory evaluation, the polyethylenepolyaminesolution reduced the linear rate of swelling of cores by 56.79%, and increased the rate of recovery of shale cuttings by 61.84%, while KCl solution reduced the linear rate of swelling of cores by 22.75%, and increased the rate of recovery of shale cuttings by 43.03%.This polyethylenepolyamine is also superior to KCl in reducing the capillary suction time(61.84% against 34.62%). These results show that the polyethylenepolyamine is a better shale inhibitor than KCl.