热力泡沫改善稠油油藏蒸汽驱开发效果

Application of Thermal Foam to Improve the Steam-Flooding Performance in Heavy-Oil Reservoir

稠油油藏蒸汽驱开发过程中存在蒸汽窜流及蒸汽超覆等现象,大幅降低了蒸汽的利用率,影响了蒸汽驱开发效果。利用二维可视化物理模拟装置,分析稠油油藏注蒸汽开发过程中的汽窜现象、泡沫封堵性能与改善微观波及体积的效果。研究表明:稠油油藏注蒸汽过程中,注采井间容易形成窜流通道;蒸汽在油层中产生明显的黏性指进现象,降低有效波及系数,窜流通道两侧滞留大量的剩余油;注入的泡沫流体进入并存在于窜流通道内,由于叠加的贾敏效应对窜流通道具有较好的封堵作用,使注入蒸汽及冷凝水进入含油饱和度较高的未波及区域,进一步驱替油藏内的剩余油。蒸汽驱开发的最终采收率为48.48%,热力泡沫辅助蒸汽驱的最终采收率可达到59.95%,最终采收率明显提高。该研究为稠油油藏蒸汽驱开发提供了借鉴。

The steam utilization efficiency during steam-flooding in heavy-oil reservoir is greatly reduced by steam channeling,steam overlaying and other aspects,which will significantly reduce the steam-flooding performance. A 2D visual physical simulation apparatus is used to evaluate the steam channeling,foam plugging performance and the improvement of microscopic swept volume. Research shows that channeling-path is frequently created between injection and production wells during steaming-flooding in heavy-oil reservoir. There is significant steam viscous fingering in reservoir,which will greatly reduce effective swept efficiency and result in a large amount of remaining oil on the both sides of channeling-path. The channeling-paths can be effectively pluggedby the injected foam fluid due to the Jamin superposition in channeling-paths. The injected steam and condensate water will flow into the unswept area with relatively high oil saturation and the remaining oil can be further recovered. The ultimate recovery factor of steam-flooding is 48. 48% and the ultimate recovery factor of thermal foam assisted steam-flooding can be increased to 59. 95%. This research could provide certain reference for the steaming-flooding in heavy-oil reservoir.