分子沉积膜驱剂在原油/水中的分配及油水界面张力

Measurement for distribution coefficient and interfacial tension of molecular deposition filming flooding agent between crude oil and water

考察了pH值、温度和时间对分子沉积膜驱剂在大庆原油和孤岛原油/水中的分配及油水界面张力的影响。结果表明,pH值增加,分子沉积膜驱剂在油水相中的分配系数增加,界面张力降低,但总体上分配系数较低;温度升高,分子沉积膜驱剂在原油/水中的分配系数和界面张力均有所降低;在约196h后,分子沉积膜驱剂在原油/水中的分配达到平衡。分子沉积膜驱剂向界面扩散和吸附的动力学过程缓慢;随着时间的增加,分子沉积膜驱剂溶液与孤岛原油界面张力先迅速降低后缓慢降低,并没有出现象表面活性剂那样的低界面张力;NaCl浓度对油水界面张力的影响不大;分子沉积膜驱剂在孤岛原油中的溶解度大于在大庆原油中的溶解度,且相同条件下的界面张力更低。

The influences of pH, temperature and time on the distribution coefficient and interfacial tension of molecular deposition filming flooding (MDFF) agent dissolved in oil-water were studied. The oil phase includes Daqing crude oil and Gudao crude oil. The water phase consists of MDFF agent and water. The results show that distribution coefficient between crude oil and water increases with the pH increasing while the interfacial tension decreases. But at the range of pH, distribution coefficient is lower than that of oil displacement agent. The distribution coefficients and interfacial tension decrease with temperature increasing. The interfacial diffusion and adsorption is dynamically slow, as is shown about 196 hour needed to reach distribution equilibrium for MDFF agent between crude oil and water. The interfacial tension between crude oil and MDFF agent solution decreases slowly after a rapid decrease in the beginning, and no lowing interfacial tension occurs. Increasing salinity in the water phase can't change interfacial tension between the oil phase and the aqueous phase. The solubility of MDFF agent in Gudao crude oil is greater than that in Daqing crude oil, and the interfacial tension of the former is lower than that of the later at the same condition.