废弃油基钻井液是钻井作业完成后产生的固体废物,因含有矿物油和柴油等,属于国家危险废物,成为制约油田清洁生产的一个技术难题.针对废弃油基钻井液的特点,经大量室内试验和多种处理方案的筛选,开发出了废弃油基钻井液资源回收与无害化处置技术.在废弃油基钻井液中加入收油剂,回收有用的油类.在收油后的剩余泥渣和产生的废水中分别加入无害化处理剂和絮凝剂,进行回用和无害化处理.油回收率可达90%以上,回收的油品质量达到《车用柴油》(GB T19147—2003)规定的-10#车用柴油技术要求;无害化处理后的泥渣浸出液中石油类,CODCr和重金属等污染物指标均低于《污水综合排放标准》(GB 8978—1996)二级标准限值;处理后的废水达到《污水综合排放标准》(GB 8978—1996)要求.
Waste oil-based drilling fluid is the solid waste generated by drilling.It is a national hazardous waste in China because it contains mineral oil and diesel,so it is a restricting factor for the development of cleaner production technology in oilfields.According to the characteristics of waste oil-based drilling fluid,this paper develops a resource recycling and harmless treatment technology for waste oil-based drilling fluid after laboratory experiments and screening of several treatment schemes.The useful oil was recycled by adding a recycling oil agent in the oil-based drilling fluid.The harmless treatment agents and flocculants were added in the mud slag and wastewater respectively after the recycling oil.The mud slag and wastewater were reused or treated.The oil recovery rate was as high as 90%,and the quality of recycled oil met the standard of-10# motor diesel as required in GB T19147-2003.The oil,CODCr and heavy metals contained in the lixivium of the harmless treated sludge were all under the secondary standards of GB 8978-1996,"Integrated Wastewater Discharge Standard".The treated wastewater met the requirement of GB 8978-1996,"Integrated Wastewater Discharge Standard".