化学—微波—超声复合调质处理气田高乳化含油污泥

气田高乳化含油污泥成分复杂、乳化严重,采用单一的调理方法(微波加热、超声处理、化学调理等)难以实现其有效减量化。为此,以中国石油长庆油田公司米脂天然气处理厂含油污泥作为实验样品,对其进行化学调理并比较各种调理剂的处理效果,确定最佳药剂配方和加药顺序,再将化学调理与物理调理相复合,以降低污泥比阻,获得最佳的调理效果。研究结果表明:(1)以氧化剂MN-S、氧化钙与氢氧化钠的组合配方为化学调理剂,比单一或双药剂复配对高乳化含油污泥的调理效果更佳,其污泥样品脱水速度最快,污泥比阻由130.30×10~(12)m/kg降低至3.81×10~(12)m/kg;(2)对比微波与超声两种物理调理法的处理效果后发现,后者对污泥比阻的降低效果较佳,超声频率40 kHz调理4 min后污泥比阻降至14.01×10~(12)m/kg;(3)将化学调理与物理调理相复合,先化学后超声的调理效果最佳,污泥比阻降低至2.77×10~(12)m/kg,机械脱水后的污泥含水率为68.71%,比原始污泥含水率(90.17%)降低了21.46%。结论认为:所提出的高乳化含油污泥化学—微波—超声复合调理工艺技术,能有效降低污泥比阻和滤饼含水率,进而实现气田高乳化含油污泥的有效减量化。

Chemical-Microwave-Ultrasonic compound conditioning treatment of highly-emulsified oily sludge in gas fields

The highly-emulsified oily sludge in gas fields is complex in components and serious in emulsification, which makes effective reduction extremely difficult only by a single direct mechanical separation method such as microwave heating, ultrasonic treatment, chemical conditioning, etc. In view of this, this paper presented a new chemical–physical compounding conditioning technology for such highly emulsified oily sludge in gas fields. The experimental samples, from the Mizhi Natural Gas Processing Plant of the PetroChina Changqing Oilfield Company, were treated through chemical conditioning, from which the optimal formula, dosages and dosing order were determined. On this basis, the compound technology of chemical–physical conditioning was applied to reduce the specific resistance to filtration (SRF) of the sludge, thus achieving a satisfactory result. The following results were obtained. (1) The chemical conditioning agent with the formula of the oxidant MN-S, calcium oxide and sodium hydroxide was proved to achieve the fastest dewatering speed, and the specific resistance of sludge can be reduced from 130.3 to 3.81 trillion m3 per kg. (2) Comparison between microwave and ultrasonic conditioning methods shows that the latter is better in reducing the SRF (the ultrasonic frequency of 40 kHz was applied to reduce the SRF down to 14.01 trillion m3 per kg after 4 minutes of conditioning treatment). (3) The ultrasonic treatment effect after chemical conditioning is the best; the SRF was reduced to 2.77 trillion m3 per kg, and the moisture content of the sludge after mechanical dewatering was only 68.71%, decreased by 21.46% compared with the original content of 90.17%. In conclusion, this presented chemical–microwave–ultrasonic compound conditioning technology can reduce the sludge's SRF and the moisture content of filter cakes so as to achieve effective reduction of the highly-emulsified sludge in gas fields.