油田钻井废液预处理技术研究

Study of the pretreatment technology of the waste liquid from the well drilling in oilfield

新型复合高效废液处理剂ZF-Ⅰ和ZF-Ⅱ应用于废液破稳分离处理,结果永66-29#钻井废水悬浮物去除率达83.6%,油含量去除率达到86.2%;史3-12-13#酸化废液悬浮物去除率达80.7%,油含量去除率达到85.3%;史3-12-X9#洗井废水悬浮物去除率达87.8%,油含量去除率达到90.5%;王家岗废液混合样悬浮物去除率达92.2%,油含量去除率达到93.6%;处理过程中形成的絮团大且密实,沉降速度快。在室内研究以及现场中间试验的基础上,进一步开发了集一级强化破胶、两级破稳分离工艺于一体的钻井作业废液预处理装置,该装置应用于废液处理后悬浮物含量由原水中的985.8 mg/L降至处理后的30.2 mg/L,油含量由原水中的91.0 mg/L降至2.8 mg/L,处理成本降至10.7元/m3,且处理后的废液与油田采出水配伍性良好,实现了处理后废液与油田采出水配伍混合回注地层的预处理工艺目的。

The new and efficient complex treatment agent ZF- Ⅰ and ZF-Ⅱ were used to destabilize and separate the waste liquid. The results indicated that 83.6% suspensions and 86.2% oil in the waste liquid from the Yong-66-29^# well drilling, 80.7% suspensions and 85.3% oil in the acidic waste liquid from Shi-3-12-13^#, 87.8% suspensions and 90.5% oil in the waste liquid from Shi-3-12-X9^# well washing, 92.2% suspensions and 93.6% oil in the mixture of the waste liquid from Wangjiagang were removed. Moreover the formed floc was large and dense during the process of the treatment and the settling velocity of the floe was fast. And then the pretreatment equipment which integrated the gel-breaking and two stage destabilization of the separation process for the waste liquid of the well drilling was designed and manufactured on the base of the study in laboratory. The suspensions in the produced liquid decreased from 985.8 mg/L to 30.3 mg/L, the oil decreased from 91.0 mg/L to 2.8 mg/L, and the expense decreased to 10.7 yuan/m^3 after the uselful of the equipment. Moreover the experiment data of water compatibility showed that the treated waste liquid was in good compatibileness with the produced water from the oil field, then the objective for the injection of mixture of the treated waste liquid and the produced water from oilfield was realized.