甜菜碱泡沫稳定性的高盐增效机制

Mechanisms of High-salinity Improvement of the Stability of Betaine Foam

孙琳 董硕 张永昌 辛军 蒲万芬

SUNLin DONGShuo ZHANGYongchang XINJun PUWanfen

油气藏地质及开发工程全国重点实验室·西南石油大学, 四川 成都 610500 中国石油长庆油田分公司第九采油厂, 宁夏 银川 750006 中国石油川庆钻探工程有限公司地质勘探开发研究院, 四川 成都 610051

National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China No.9 Oil Production Plant, Changqing Oilfield Company, PetroChina, Yinchuan, Ningxia 750006, China Research Institute of Geological Exploration and Development, CCDC, Chengdu, Sichuan 610051, China

甜菜碱泡沫耐盐且稳定性可随盐度增加而增强，在提高高盐油藏采收率方面独居优势。以椰油酰胺丙基羟磺甜菜碱和十二烷基羟丙基磺基甜菜碱为研究对象，在剖析其泡沫衰变特征对盐度变化响应的基础上，结合表面扩张流变性质与扩散吸附行为，研究高盐增效甜菜碱泡沫稳定性的作用机制。结果表明，NaCl质量分数从2.3%增至21.1%，甜菜碱泡沫初期排液速度变化不大，但泡沫半衰期最高可延长13倍。盐度增加，甜菜碱饱和吸附量增大、扩散吸附速率减小，导致扩张模量增大、液膜弹性增强，进而明显抑制粗化、聚并，令甜菜碱泡沫稳定性提高。研究成果有助于完善泡沫稳定机理，为高盐油藏泡沫驱体系优化提供技术支持。

Betaine foam, characterized by its salt tolerance and the heightened stability with increasing salinity, holds a unique advantage in improving oil recovery in high-salinity reservoirs. In this paper, cocoamidopropyl hydroxysulfobetaine and dodecyl hydroxypropyl sulfobetaine were taken as the foam system to explore the mechanisms of high-salinity improvement foam stability. Foam performance tests have proceeded under various high-salinities. Particular attention was given to the surface dilatation rheology and diffusion-adsorption behaviors. The results showed that when the concentration of NaCl increased from 2.3% to 21.1%, the drainage velocity of betaine foam at the initial stage had little change, but the half-life of the foam could be extended by 13 times. With increased salinity, the saturated adsorption amount of betaine increased and the diffusion-adsorption rate decreased, which led to the increase of the dilatation modulus and the enhancement of the elasticity of the liquid film. Therefore, the coarsening and coalescence of betaine foam were significantly inhibited, resulting in improved foam stability. This work will generate fresh insight into the mechanisms of foam stability and optimization of foam system in high-salinity reservoirs.

10.11885/j.issn.1674-5086.2021.06.03.02