废弃钻井泥浆脱水工艺实验研究

Experiental Research on Dewatering of Waste Drilling Mud

对来自新疆某油田的废弃钻井泥浆样品进行稀释、气浮、酸化、混凝处理,通过Zeta电位、毛细吸水时间、粒度分布、扫描电子显微镜对脱水进行表征和分析,获取了实际工程所需的工艺参数。具体条件为废弃钻井泥浆用1.5倍体积水稀释后的混合液气浮20 min,除去上层浮油,混合物离心分离后,泥饼中的含油率在0.7%以下,调pH值为6;加入质量分数为1.0%的自制破胶剂,快速搅拌;加入1.2%无机絮凝剂,慢速搅拌;加入0.5‰有机絮凝剂,缓慢搅拌。该工艺可彻底破坏废弃钻井泥浆的稳定体系,获得较好的脱水效果,抽滤分离后出水率为55%～65%,泥饼无造浆能力。

Waste drilling mud from one oil field of Xinjiang is used as the sample for dilution,floating,acidification,coagulation treatment.Dewatering is characterized and analyzed by Zeta potential,capillary suction time,particle size distribution and scanning electron microscope and the practical parameters for engineering project are obtained.The specific conditions are as follows:waste drilling mud is diluted by the quality of 1.5 times volume of water,floating 20 mins,and removing the upper floating oil;the oil rat of mud cake is under 0.7%,adjusting its pH to 6;mass fraction 1.0% of self-regulating gel breaking agent is added,fast mixing 5mins;adding the inorganic 1.2% flocculant and slowly mixing;adding 0.5‰ of organic polymer flocculant and slowly mixing.This craft can completely destroy the colloidal system of waste drilling mud and the dewatering efficiency is better.The vacuum dewatering rate can be increased to 55%～65% and the mud cake loses mud-producing ability.