基于苯乙烯焦油的水包油乳状液驱油体系的研制与性能评价

Preparation and Performance Evaluation of Oil-in-water Emulsion Oil Displacement System Based on Styrene Tar

苯乙烯焦油的产量多、价廉,但利用率不高,多用于燃烧,对环境有一定的污染。为了提升苯乙烯焦油的经济附加值,同时给油田开发提供一种低成本的原材料,将苯乙烯焦油制成水包油型乳状液,用于乳状液驱油中。以乳化不稳定系数为乳化剂的指标筛选表面活性剂,将其与苯乙烯焦油混合制得水包油型乳状液,对乳状液的稳定性、流变性和驱油效果进行评价。结果表明,苯乙烯焦油制备的水包油型乳状液的驱油效果较好。当聚氧乙烯醚与醇醚硫酸钠复配质量比为1∶1、总加量为0.3%时,乳状液的稳定性最好。对于黏度为185 mPa·s的普通稠油,苯乙烯焦油制备的水包油乳状液可在水驱基础上提高采出程度16.7百分点。苯乙烯焦油乳状液可用于高含水油田后期开发,提高原油采收率。

The production of styrene tar is high and the price is cheap.However,the utilization ratio of styrene tar is not high and the burning of styrene tar has pollution to environment.In order to enhance the economic value added of styrene tar and provide a kind of low-cost raw material for oilfield development,styrene tar was made into O/W emulsion used in oil displacement process.The emulsification instability coefficient was used as an emulsifier index to select surfactant.The stability,rheology behavior and oil displacement effect of O/W emulsion,that prepared by styrene tar and aqueous surfactant solution,were evaluated.The results showed that O/W emulsion prepared by styrene tar had a good oil displacement effect.The stability of the emulsion was the best when the emulsifier content was 0.3%and the mass ratio of polyoxyethylene ether to alcohol ether sodium sulfate was 1∶1.For the conventional heavy oil with viscosity of 185 mPa·s,O/W emulsion prepared by styrene tar could increase the degree of reserve recovery by 16.7 percentage points on the basis of water flooding.The emulsion prepared by styrene tar could enhance recovery at the later stage of oilfield development with high water cut.