稠油油藏乳化降黏与“宏观和微观”转向联合作业效果实验

Experiment on the combined operation effect between the emulsification viscosity-reduction and “macroscopic and microscopic” diversion for heavy oil reservoirs

针对稠油油藏现场开发的实际需求,以室内评价的方式开展了L油藏稠油乳化降黏与"宏观和微观"转向联合作业效果实验研究。结果表明:冻胶分散体颗粒具有不规则外观形态,可以在多孔介质内发生机械捕集而产生液流转向作用;稠油与乳化剂作用可以形成"O/W"或"W/O/W"型乳状液,进而明显改善稠油流动性;与稠油乳化剂溶液和冻胶分散体颗粒分段塞注入方式相比较,混合形成的非均相体系能够发挥扩大波及体积与提高洗油效率的协同作用;对于存在大孔道或特高渗透条带的厚油层,单独冻胶分散体(或微球)颗粒在多孔介质内的滞留较为困难,难以取得较好液流转向效果,它与稠油乳化降黏剂和强凝胶联合使用才能实现宏观和微观液流转向、改善稠油流动性和提高洗油效率的协同效应,进而提高采收率。

Aiming at the actual requirements of the field development of heavy oil reservoirs, with the indoor evaluation way, the experimental studies on the combined operation effects of the heavy-oil emulsification viscosity-reduction and "macro and micro" turning for Reservoir L were conducted. The results show that the particles of the gel dispersion have irregular appearances and states, and moreover they can be mechanically trapped in the porous media so as to produce the liquid flow diversion;the interaction between the heavy oil and diversion can form "O/W" or "W/O/W" emulsions, which can obviously improve the fluidity of the heavy oil;compared with the slug injection modes of the heavy oil emulsifier solution and gel dispersion particles, the mixed heterogeneous phase system formed by them can perform the synergistic effect on expanding the sweep volume and improving oil washed efficiency;for the thick oil reservoirs with large channels or ultra-high permeability belts, it is difficult for the single gel dispersion(or microsphere)to retain in the porous media and achieve better fluid diversion effect, only combined with the heavy-oil emulsifying viscosity reducer and strong gel, it can realize the macro and micro fluid diversion, improve the viscous oil fluidity and increase the synergy effect of the oil washed efficiency, and furthermore enhanced the oil recovery.