摘要
针对Ⅱ类稠油油藏（具有边底水、埋藏较深、黏度大等）蒸汽吞吐开采基本进入中后期，但目前尚未找到其它有效接替技术的难题，本文利用热采物理模拟技术，开展了尿素泡沫辅助蒸汽驱开采机理及技术可行性研究。在驱替实验中，尿素溶液的质量分数为25%，泡沫剂GFPA-4B溶液和降黏剂DVB-107溶液的质量分数均为0.5%，填砂管模型的水测渗透率1.83~2.16 μm2，驱替流速为3.6 mL/min。结果表明：尿素泡沫辅助蒸汽驱可以大幅度提高驱油效率，热水+尿素驱、热水+尿素+泡沫剂驱、热水+尿素+泡沫剂+降黏剂驱的累积采收率比纯热水驱的分别提高了8.13%、16.67%和21.27%；蒸汽带驱油效率也提高了3.49%-9.41%%；蒸汽+尿素驱、蒸汽+尿素+泡沫剂驱、蒸汽+尿素+泡沫剂+降黏剂驱的累积采收率比纯蒸汽驱的分别提高了3.49%、5.31%和9.41%。此外对尿素泡沫辅助蒸汽驱的驱油机理进行了探讨。
Abstract
the Ⅱ reservoir of heavy oil which is a deep buried heavy oil field with active edge and bottom water and high viscosity and so on, almost is in the middle and later stage, however, there are not any effective replacement processes currently. To solve these problems, the mechanism of steam flooding adding urea and foaming agent was studied with the physical simulation. In the experiment, the concentration of urea solution was 25%, the concentration of foam solution GFPA-4B and viscosity reducer DVB-107 was 0.5%, respectively, the permeability measured by water flooding of the sand-pack was 1.83~2.16 μm2, the flooding rate was 3.6 mL/min. The results showed that urea solution could significantly improve the displacement efficiency , the cumulative displacement efficiency of the hot water+urea displacement, hot water+urea+foam solution displacement, hot water+urea+foam solution+viscosity reducer displacement was increased by 8.13%, 16.67% and 21.27%, respectively, compared to that of hot water displacement. The displacement efficiency of steam displacement section was also improved by 3.49%—9.41%, the cumulative displacement efficiency of the steam+urea displacement, steam+urea+foam solution displacement, steam+urea+foam solution+viscosity reducer displacement is increased by 3.49%、5.31% and 9.41%, respectively, compared to that of steam displacement. Besides, that the mechanism of steam displacement adding urea and foam solution was studied.
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