辽河油田稠油油藏氮气泡沫驱适应性研究

目前辽河油 田大多数普通稠油油藏都已经历了蒸汽吞吐开采个别原油粘度较低的稠油油藏.在经历了短暂的常规干抽后转入了水驱开发。由 于大多数稠油油藏非均质性较强,经过吞吐开采。其剖面及平面动用矛盾十分突出，加之压力大幅度下降、原油脱气粘度升高.使开发效果明显变差。在这种条件下，开展了氮气泡沫驱提高采收率的机理研究,研究结果认为.采用氮气泡沫驱可以改善上述油藏的开发效果。应用数 值模拟及物理模拟方法首次较为系统地对氮气泡沫驱的适应性进行了研究总结出适合氮气泡沫驱开采的油藏条件.并在此基础上筛选出辽河油田6个适合实施氮气泡沫驱的稠油区块。

Suitability Study of Nitrogen-Foam Flood in Heavy Oil Reservoir --An example of Liaohe oilfield

Up to now,most of heavy oil reservoirs in Liaohe oilfield have undergone steam stimulation development,some of them with lower crude viscosity have undergone processes from transitory conventional recovery into waterflooding.However,most of the heavy oil reservoirs following steam stimulation recovery appear in obvious inconsistency in vertical and horizontal producing performance due to their serious heterogeneities.Moreover,with precipitous pressure decline and degassed crude viscosity decrease,the development effectiveness has been distinctly getting poorer.Therefore,converting available development process of this type of reservoirs is the most urgent situation.This paper presents the studies of the mechanism of nitrogen-foam flood for EOR,and suggests that the mechanism of nitrogen-foam flood used to regulating injection profile is proper to improve the development effectiveness of these reservoirs.In view of few tests of large-scale nitrogen-foam flood at home and abroad,suitability research of such a flood is systematically performed using numerical and physical simulation approaches.Finally,six heavy oil blocks in Liaohe oilfield are selected to be as field operation ones based on the reservoir conditions suitable for nitrogen-foam flood given in this paper.