废弃钻井液固液分离技术研究

针对江苏油田废弃钻井液处理过程中使用絮凝剂时出现的问题,探讨了废弃钻井液化学固液分离的机理.研究了单独的无机絮凝剂、有机絮凝剂以及无机絮凝剂和有机絮凝剂共同作用下对废弃钻井液和钻井污水的ζ电位的影响,优选确定了5套化学脱稳配方和2套污水二次处理试验方案.对S19-3井废弃钻井液进行了工业化现场试验,结果表明,所选用的化学脱稳配方对废弃钻井液体系有很强的脱稳效果,更易于离心脱水分离.而离心脱出水经混凝沉降和过滤处理,C0D去除率达80.8%,SS去除率达99.2%,混凝沉降、过滤效率高,外排水都符合GB 8978-1996"污水综合排放标准"规定的一级标准要求;絮凝泥渣再造浆率差,泥渣浸出液中主要污染物含量均很低,可以就地掩埋,不会对环境构成危害.

Solid-liquid separation technology of waste drilling fluid

To solve the problems of flocculating setting appeared during the disposal process of waste drilling fluid in Jiangsu oilfield, study on the mechanism of chemical solid liquid separationwas conducted, and based on results of tests which were fixed on effect of single inorganic flocculants, single organic flocculants and combination of both on zeta potential of waste drilling fluid and drilling sewage, two chemical destabilizing compositions and two secondary sewage treating plans were put forward. Industrial trial on waste drilling fluid from well S19 3 shows that the chemical compositions performance perfect destabilizing function on waste drilling fluid, and even more effective for water centrifugal separation. After settingand filtering, removal rate of COD and SS of water separatedis 80.8% and 99.2%respectively, and the discharge water quality meets the requirementsof GB 8978 1996. Yield of the flocculated mud residue was weak, and with little pollutants in the leaching fluid, it could be buried onsite.