落地油泥土壤性质对超声除油效果的影响

落地油泥是油田产生的一类危险固体废弃物，其无害化处理是目前各大油田所面临的重大挑战之一。为了深入认识超声处理过程中油泥土壤性质与超声处理除油效果之间的关系，以不同油田典型落地油泥为研究对象，超声处理后对其土壤残留含油量、土壤颗粒级配、土壤化学组成等进行分析。结果表明：油泥中土壤颗粒粒径较大的大庆、大港落地油泥经超声处理后的除油效果均在60%以上，而土壤颗粒粒径较小的冀东落地油泥超声除油率仅为11%；同时，超声除油效果较好的大庆、大港落地油泥中的钙氧化物含量较低(分别为4.84%和5.94%)，而超声除油效果差的冀东落地油泥中的钙氧化物含量较高(11.57%)。进一步的模拟实验结果表明，钙氧化物含量高的土壤对原油的吸附量大、吸附强度高、超声除油效果差，而钙氧化物含量低的土壤吸附量小、吸附强度低、超声除油效果好。以上结果可为油田落地油泥超声处理技术的开发及规模化应用提供指导。

Influence of oil sludge soil properties on oil removal efficiency by ultrasonic treatment

Oil sludge from oilfield is one kind of hazardous wastes, and its harmless treatment is one of the major challenges faced by the oil field in our country. In order to get better understanding on the relationship between oil sludge soil properties and crude oil removal efficiency by ultrasonic irradiation, typical oil sludge samples from different oilfield were investigated. After the treatment, the residual crude oil content, solid particles diameter distribution and chemical composition of the soil were analyzed, and the results showed that the oil removal efficiency was higher than 60% for Daqing and Dagang oil sludge with the large soil particles diameter treated by ultrasonic, while the oil removal efficiency was only 11% for Jidong oil sludge with the smaller soil particles. Daqing and Dagang oil sludge had low calcium oxides contents of 4.84% and 5.94%, respectively, while Jidong oil sludge had high calcium oxides contents of 11.57%. Further simulation experiments also showed that the soil with high calcium oxides content had large adsorption capacity toward crude oil, high adsorption affinity and low oil removal efficiency by ultrasonic irradiation, while the soil with low calcium oxides content had small crude oil adsorption capacity, low adsorption affinity and good oil removal efficiency. The results from this study could provide supports for the development and large-scale application of the ultrasonic technology treating the oil sludge in the oil fields.