Liang Chong, Qi Ning, Zhao Liqiang, Li Xuesong, Li Zhenliang
School of Petroleum and Natural Gas Engineering, South West Petroleum University, Chengdu 610500, China.
Research Institute of Petroleum Exploration & Development, CNPC, Beijing 100007, China.
Polymers (Basel). 2025 Jun 1;17(11):1543. doi: 10.3390/polym17111543.
In oil and gas production, reservoir heterogeneity causes plugging removal fluids to preferentially enter high-permeability zones, hindering effective production enhancement in low-permeability reservoirs. Traditional chemical diverting agents exhibit insufficient stability in high-temperature, high-salinity environments, risking secondary damage. To address these challenges, this study developed a water-sensitive self-thickening emulsion, targeting improved high-temperature stability, selective plugging, and easy flowback performance. Formulation optimization was achieved via orthogonal experiments and oil-water ratio adjustment, combined with particle size regulation and viscosity characterization. Core plugging experiments demonstrated the new emulsion system's applicability and diverting effects. Results showed that under 150 °C and 15 × 10 mg/L NaCl, the emulsion maintained a stable viscosity of above 302.7 mPa·s, with particle size increasing from 31.1 μm to 71.2 μm, exceeding API RP 13A's 100 mPa·s threshold for acidizing diverters, providing an efficient plugging solution for high-temperature, high-salinity reservoirs. The injection pressure difference in high-permeability cores stabilized at 2.1 MPa, significantly enhancing waterflood sweep efficiency. The self-thickening mechanism, driven by salt-induced droplet coalescence, enables selective plugging in heterogeneous formations, as validated by core flooding tests showing a 40% higher pressure differential in high-permeability zones compared to conventional systems.
在油气生产中，储层非均质性导致解堵液优先进入高渗透区，阻碍了低渗透油藏有效增产。传统化学转向剂在高温、高盐环境下稳定性不足，存在二次损害风险。为应对这些挑战，本研究开发了一种水敏性自增稠乳液，旨在提高高温稳定性、选择性封堵和易返排性能。通过正交试验和油水比调整，结合粒径调控和粘度表征实现了配方优化。岩心封堵实验证明了新型乳液体系的适用性和转向效果。结果表明，在150℃和15×10mg/L NaCl条件下，乳液保持稳定粘度高于302.7mPa·s，粒径从31.1μm增大到71.2μm，超过美国石油学会（API）RP 13A酸化转向剂100mPa·s的阈值，为高温、高盐油藏提供了一种高效封堵解决方案。高渗透岩心中的注入压差稳定在2.1MPa，显著提高了水驱波及效率。由盐诱导液滴聚并驱动的自增稠机理能够在非均质地层中实现选择性封堵，岩心驱替试验验证了这一点，结果表明与传统体系相比，高渗透区的压差高40%。
