渤海油田老化油成因及处理工艺优化研究

Study the cause and treatment process optimization of aging oil in Bohai Oilfield

渤海油田某区块原油脱水处理后普遍存在油水过渡层,经沉积易形成老化油,此现象给生产系统的安全平稳运行带来了严峻挑战。为实现目标区块老化油处理,本文通过对原油、老化油及三氯甲烷不溶物的组成分析开展研究,并进一步明确老化油形成的主要原因。在此基础上,通过对4种不同类型的聚醚型破乳剂进行室内破乳评价实验,并优选最佳的加剂浓度、温度等工艺参数。实验结果表明,原油乳化是形成老化油的主要原因,消除过渡带老化油后再经脱水工艺处理,水含量可下降至0.5%以下;聚醚型BH-41D破乳剂具备最佳破乳效果,采用加剂浓度100×10^(-6)、加剂温度60℃,在现场应用后乳状液处理量可由220m3·d^(-1)增加至250m3·d^(-1),处理效率提升10个百分点。

After dehydration treatment of crude oil in a certain block of Bohai Oilfield,there is generally an oil-water transition layer,which is easy to form aging oil after deposition.This phenomenon brings serious challenges to the safe and stable operation of the production system.In order to realize the treatment of aging oil in the target block,this paper conducts research on the composition analysis of crude oil,aging oil and chloroform insoluble matter,and further clarifies the main reasons for the formation of aging oil.On this basis,the indoor demulsification evaluation experiment was carried out on 4 different types of polyether demulsifiers,and the optimal additive concentration,temperature and other process parameters were optimized.The experimental results showed that the emulsification of crude oil is the main reason for the formation of aging oil.After eliminating the aging oil in the transition zone,the water content can be reduced to less than 0.5%after dehydration process.The polyether type BH-41D demulsifier has the best demulsification effect.When the additive concentration is 100×10^(-6) and the additive temperature is 60℃,the processing capacity of the emulsion can be increased from 220 cubic meters per day to 250 cubic meters per day,and the processing efficiency is increased by 10 percentage points.