摘要
针对海上稠油油井乳化堵塞问题,室内分析了胶质、沥青质含量对原油油包水乳状液的影响,通过静态实验,考察了防乳破乳体系对稠油的防乳、破乳性能和油溶性降黏体系的溶沥青质能力、降黏性能;通过动态驱油实验,考察了两种药剂的解堵降压效果和驱油效果。实验结果表明,原油中的胶质、沥青质是稠油形成油包水乳状液的天然乳化剂,且含量越多,乳液越稳定。浓度为0.5%防乳破乳体系的防乳率为83%,破乳率为89%,具有良好的防止和解除乳化堵塞的能力;浓度为5%的油溶性降黏体系的降黏率为90%,溶沥青质速率为3.20 mg/(m L·min),可快速溶解稠油中的沥青质,降低原油黏度。动态驱油实验表明,油溶性降黏体系与防乳破乳体系可降低注入压差0.8 MPa,约为原压差的30%,驱油效果表明,两种体系的加入可使其驱油效率提升5%。化学体系可有效解除稠油乳化堵塞的问题,同时还可进一步提高洗油效率,加快采收速度,提高采收率。
Aiming at the problem of emulsifying blockage in offshore heavy oil wells, the effects of gum and asphaltene content on water-in-oil emulsion were analyzed in laboratory.The anti-emulsifying and demulsifying properties of anti-emulsifying synergistic system for heavy oil and the soluble asphaltene and viscous properties of oil-soluble viscosity-reducing system were investigated through static experiments.Through dynamic oil displacement experiment,the plugging and pressure reducing effect and oil displacement effect of two reagents were investigated.The experimental results show that the colloid and asphaltene in crude oil are the natural emulsifiers for heavy oil to form oil in water emulsion, and the more the content is, the more stable the emulsion is. The anti-emulsification rate and demulsification rate of 0.5 % anti-emulsification synergistic system are 83 % and 89 %,which have good ability to prevent and remove emulsification blockage.The viscosity reduction rate of oil-soluble viscosity reduction system with 5 % concentration is 90 %,and the rate of soluble asphaltene is3.20 mg/(mL·min), which can quickly dissolve asphaltene in heavy oil and reduce crude oil viscosity. Dynamic oil displacement experiment shows that the injection pressure difference can be reduced by 0.8 MPa,about 30 % of the original pressure difference,by adding oil-soluble viscosity reduction system and anti-emulsification synergistic system.The oil displacement effect shows that the oil displacement efficiency can be increased by 5 % by adding the two systems.The chemical system can effectively remove the problem of emulsified blockage of heavy oil,and further improve the efficiency of oil washing, speed up recovery and enhance recovery.
引文
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