坨五站中间乳化层快速增长原因及治理方案

胜利采油厂坨五站高含水(95％)原油化学预脱水中，二级沉降罐内油水相之间的中间乳化层增长迅速，引起了一系列问题。现场调查和大量室内测试结果表明，产生这一现象的原因有：油溶性破乳剂WD-1加入点不合理。有2／3的含水原油在通过油水分离器之后才与破乳剂混合；二级沉降罐进油口伸入油相内，油流的冲击达不到中间层；WD-1对坨五站混合原油中的稠油破乳脱水性能欠佳，不能适应坨五站混合原油组成和含水的变化。针对上述各种原因筛选出了性能更好的一种破乳剂1916。根据确定的几种原因采取了相应的措施：将破乳剂加入点改在3个并联油水分离器之前；将二级沉降罐的进油口移到水相内；改用筛选出的破乳剂1916，结果使中间乳化层的增长受到了抑制。图2表4参2。

Origins of and Preventative Measures against Quick Growth of Middle Emulsion Layer in Secondary Sedimentation Tank at Oil Treatment Plant T5

At oil gathering/treating plant T5 of Shengli oil production factory, Shengli oilfield company, Sinopec, where coarse dehydration of high water cut (95%) mixed crude oil is conducted, a quick growth of middle emulsion layer between the separated oil and water phases in the secondary sidimentation tank was observed and led to some trouble consequence. A field investigation and comprehensive laboratory studies showed following origins of this phenomenon: the location of the demulsifier inlet was unproper and resulted in delayed mixing of 2/3 of the crude with the demulsifier introduced only after the oil/water separators; the crude was fed into the oil layer in the secondary sedimelation tank and the inlet oil stream did not disturb the middle emulsion layer formed; the oil-soluble demulsifier used, WD-1, had poor demusifying/dehydrating capacity for the heavy oils comprising the gathered mixed crude of T5 and did not fit the mixed crude of varying composition and water cut well. A demulsifier, 1961, effective to the above mentioned crudes is selected out in a series of dehydration experiments. Starting from the origins ascertained, following measures were taken: to introduce the demulsifier into the crudes before all the 3 parallel oil/water separators; to feed the crude into the water layer in the sedimentation tank and to use the selected demulsifier, 1996, instead of WD-1 and the growth of middle emulsion layer was depressed.