结合核磁共振技术对不同含水率乳状液稳定性分析

Stability Analysis of Emulsions with Different Water Content Combined with Nuclear Magnetic

蒲万芬 贺 伟 鹿嘉悦 常家靖 李思颖

PU Wanfen，HE Wei，LU Jiayue，CHANG Jiajing，LI Siying

为了研究不同含水率乳状液的稳定性，通过分析不同含水率条件下原油和采出水的自乳化情况，同时与核磁共振技术（NMR）相结合，明确渤海A油藏的不同含水率乳状液稳定性特征。结果表明：在实验条件为 65 ℃（地层温度）、转速为 3000 r/min 的条件下，含水率为 40%和 50%下原油与水完全乳化，形成油包水型乳状液（W/O），乳化效果最好，乳状液平均粒径分别1.905 μm和1.487 μm，界面张力值分别为23.93 mN/m和18.89 mN/m，乳状液最稳定。含水率为40%和50%下所形成乳状液的弛豫时间和自扩散系数最小；含水率为60%的乳状液的弛豫时间和自扩散系数次之；含水率为70%的乳状液的弛豫时间和自扩散系数最大。含水率在40%～50%时乳状液最稳定。结合核磁共振技术，乳状液平均粒径越小，黏度越大，界面张力值越低，水的驰豫时间和扩散系数越小，乳化效果越好。

In order to study the stability of emulsions with different water cut，the self-emulsification of crude oil and produced water with different water cut was analyzed，and combined with nuclear magnetic resonance（NMR），the stability characteristics of emulsions with different water cut in Bohai Sea A reservoir was identified. The results show that under the conditions of 65 ℃（formation temperature）and 3000 r/min rotation speed，the crude oil and water are completely emulsified at water cut of 40% and 50%，and water-in-oil emulsion（W/O）was formed，the average particle size of the emulsion was 1.905 μm and 1.487 μm，and the interfacial tension was 23.93 mN/m and 18.89 mN/m，respectively. The relaxation time and self-diffusion coefficient of the emulsion with 40% and 50% water content were the smallest，the relaxation time and self-diffusion coefficient of the emulsion with 60% water content was the second，while the relaxation time and self-diffusion coefficient of emulsion with 70% water content were the largest. When the moisture content was 40%—50%，the emulsion was the most stable. Combined with NMR technology， the smaller the average particle size of the emulsion，the higher the emulsion viscosity，the lower the interfacial tension，the smaller the relaxation time and self-diffusion coefficient，the better the emulsification effect.

10.19346/j.cnki.1000-4092.2022.03.025