| 摘要: |
| 目的 胜利油田CNL联合站采出液以高黏度稠油为主，经化学强化采油工艺处理后，液相中残留稠油降黏剂、有机缓速酸、油层清洗剂等增产处理剂；在气驱、泡沫驱开采模式下，稠油乳状液内形成高分散性微气泡群，消泡破乳困难。针对上述技术瓶颈，系统解析泡沫稠油乳状液多尺度稳定机制，对开发靶向破乳技术具有关键指导意义。方法 基于多相界面作用机制，系统探究原油特征组分、起泡剂界面活性以及增产处理剂吸附特性，从分子水平揭示影响泡沫稠油乳状液稳定性的主控因素；基于界面扩张流变学、Zeta电位谱图以及动态光散射实验，多维度阐释界面膜强度、静电排斥效应及空间位阻效应在乳状液稳定性中的协同作用机制。结果 原油中胶质-沥青质质量比为1.45：1，胶质协同沥青质吸附到油水界面膜，通过空间位阻效应强化界面膜稳定性；QP2（起泡剂Ⅱ型）、CL3（水溶性降黏剂）对泡沫稠油乳状液稳定性影响因素最强；二者复配时，界面扩张黏弹模量提升至83.9mN/m, Zeta电位绝对值达到32.6mV, 且稳定性参数TSI值降至23.6，较单一体系下降14.2%。结论 本研究首次阐明气驱/化学驱复合开采模式下，化学剂-微气泡-界面膜多尺度协同稳定机制，可指导联合站基于反作用原理研究靶向破乳体系，提高联合站工作效率，降低生产成本。 |
| 关键词: 泡沫稠油 乳状液 Zeta电位 界面黏弹性 稳定性 |
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| Study on the factors affecting the stability of N2 foam heavy oil emulsion |
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Sun Yuhai, zhang yang
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Petroleum Engineering Technology Research Institute of Shengli Oilfield Branch
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| Abstract: |
| Objective The produced fluid from the Shengli Oilfield CNL joint station is predominantly composed of high-viscosity heavy oil. After chemical enhanced oil recovery (EOR) treatment, residual heavy oil viscosity reducers, organic retarding acid, reservoir cleaning agents and other production enhancing treatment agents in the liquid phase are remained. Under the mode of gas flooding and foam flooding, highly dispersed microbubble groups are formed in the heavy oil emulsion, which makes defoaming and demulsification difficult. In view of the above technical bottlenecks, the systematic analysis of the multi-scale stability mechanism of foam heavy oil emulsion has key guiding significance for the development of targeted demulsification technology. Methods Based on the mechanism of multiphase interface interaction, the characteristic components of crude oil, the interfacial activity of foaming agent and the adsorption characteristics of stimulation treatment agent were systematically explored, and the main controlling factors affecting the stability of foam heavy oil emulsion were revealed at the molecular level. Based on interfacial dilational rheology, Zeta potential spectra and dynamic light scattering experiments, the synergistic mechanism of interfacial film strength, electrostatic repulsion effect and steric hindrance effect in emulsion stability was explained in multiple dimensions. Results The mass ratio of resin to asphaltene in crude oil was 1.45:1. The resin and asphaltene were adsorbed to the oil-water interfacial film, and the stability of the interfacial film was enhanced by the steric hindrance effect. QP2 ( foaming agent type II ) and CL3 ( water-soluble viscosity reducer ) had the strongest influence factors on the stability of foam heavy oil emulsion. When the two were compounded, the interfacial dilational viscoelastic modulus increased to 83.9 mN / m, the absolute value of Zeta potential reached 32.6 mV, and the stability parameter TSI value decreased to 23.6, which was 14.2 % lower than that of the single system. Conclusion This study first elucidates the multi-scale synergistic stabilization mechanism of chemical agent-microbubble-interface film under the combined exploitation mode of gas flooding and chemical flooding. It provides guidance for the joint station to study the targeted demulsification system based on the reaction principle, improve the work efficiency of the joint station and reduce the production cost. |
| Key words: foam heavy oil emulsion Zeta potential interfacial viscoelasticity stability |
