化学破乳/超声协同处理气田废弃油基泥浆

Chemical demulsification/ultrasonic synergistic treatment of waste oil-based mud in gas fields

气田废弃油基泥浆是气田钻井过程中产生的一种成分复杂的乳状液体系,组成复杂且性质稳定、处理难度大,未经处理直接外排对环境危害大。采用化学破乳-超声-离心方法对其进行处理,结果表明:当化学破乳段的体系pH值为5—6,温度为60℃,200 r/min下搅拌时间40 min,AR36型破乳剂的加量8 mg/L;超声强化段的频率25 kHz,功率30 W,超声时间11 min;混凝及离心处理段的阳离子PAM加量60 mg/L,混凝后搅拌时间15 min,离心机转速3000 r/min,离心时间20 min时,油回收率和减量化率均达到94%以上,回收油中含水率降低至0.5%以下,底泥中含油率降低至5%以下。扫描电镜分析表明,在破乳剂/超声的协同作用下,油水固稳定的乳化状态可被打破。

The emulsion system composed of waste oil base mud in gas fields is characterized by its complex composition and stable properties,posing significant challenges in its management.Untreated direct discharge of such mud would inflict substantial environmental damage.The application of a chemical demulsification-ultrasonic-centrifugation method was employed for its treatment.The results show that when the chemical demulsifier pH of 5-6,AR36 demulsifier dosage of 8 mg/L,temperature of 60℃,stirring time of 40 min at 200 r/min,ultrasonic frequency of 25 kHz,power of 30 W,ultrasonic time of 11 min,cationic PAM dosage of 60 mg/L,stirring time of 15 min,centrifuge speed of 3000 r/min,and centrifuge time of 20 min,oil recovery and reduction rate are above 94%.Additionally,the water content in the recovered oil is reduced below 0.5%,and the oil content in the sediment is minimized to less than 5%.The results of SEM analysis demonstrate that the stable emulsification state of oil-water-solid can be disrupted under the synergistic influence of demulsifier and ultrasound.