原油分段脱水

大庆油田采用早期内部注水开发方式,在长期高产稳产过程中,随着采出程度的加深,原油含水率不断提高.目前部分地区的原油含水高达60%左右,为适应高含水原油的脱水,采用了热化学沉降脱水与直流电一化学脱水的分段脱水新工艺.在此工艺中改革了脱水器结构,采用了新型破乳剂、管道化学破乳、可控硅自动调压、硅堆整流、差电流自动放水等新工艺、新技术,使脱水后的净化油含水达到了0.3%以下,污水含油达到了0.5%以下,满足了油田原油外输和炼厂加工的质量要求.

NEW TECHNIQUE OF DEHYDRATION OF CRUDE

In the Daqing oil field,the percentage of water content of crude increases steadily with increasing depth of production,reaching as high as 60% in some parts.This paper reviews a new technique of dehydration by section with the application of thermal chemical precipitation and direct currentchemical dehydration.The Daqing crude is paraffin-based,with wax content 28.7%,wax melting point 49℃,freezing point 26℃,viscosity 23.79 cp at 50℃,ashlzaltene content 0.1-0.3%,naphthenic acid 0.02-0.08,gravity 0.86.These proherties constitute the causes of forming water-in-oil emulsion which makes dehydration difficult.Application of thermal-chemical precipitation may reduce the water content of crude,but not to the point of less than 0.5% as required for export.Therefore,it should be sulap lemented by electric-chemical dehydration.Mention is made of the use of new emulsion breaker,chemical pipeline deruulsion,automatic silicon controlled voltage regulation,silicon controiled rectifier,automatic water drain of differential current etc,to reduce the water content of oil to under 0.3%,and the oil content of waste water to under 0.5% to satisfy the re