碳酸盐岩缝洞型油藏注氮气驱后剩余油可视化研究

发布时间：2018-08-19 16:15

【摘要】：塔河油田碳酸盐岩缝洞型油藏水驱开采后,仍残留有大量阁楼油、绕流油。利用氮气密度小,重力分异作用显著等特点将部分剩余油驱出,充分认识气驱之后剩余油的分布,对优化气驱设计方案具有借鉴意义。通过设计、制作物理可视化模型进行气驱模拟实验,直观展示缝洞型油藏气驱后剩余油的分布情况,并探讨相关影响因素。实验结果发现:氮气驱能有效地提高缝洞型油藏水驱后剩余油的采收率,但仍有部分残留油,如因气体气窜、底水能量不足而残留溶洞中部的窜流油,因气体洗油效率低而残留在裂缝中的油膜和小油段塞等;同时,注入方式、注入井别和注入速度等人为因素对气驱效果也有影响。研究成果为注气提高水驱后剩余油开采以及气驱后再次提高采收率提供了实验依据,认为采用水气交替等不稳定注气方式、复杂区域注气以及适中的注入速度可提高气驱效果,也认识到了溶洞形状、缝洞分布等客观因素应作为后续深化研究的重点。
[Abstract]:After being exploited by water drive in carbonate fracture-cavern reservoir in Tahe Oilfield, there is still a large amount of loft oil and circulating oil. By using the characteristics of low nitrogen density and remarkable gravity differentiation, some remaining oil can be driven out, and the distribution of remaining oil after gas flooding can be fully understood, which is useful for optimizing the design scheme of gas drive. Through the design of physical visualization model for gas drive simulation experiments, the distribution of remaining oil after gas flooding in fractured and cavernous reservoirs is displayed intuitively, and the related influencing factors are discussed. The experimental results show that nitrogen flooding can effectively improve the oil recovery of residual oil after water flooding, but there are still some residual oil, such as channeling oil in the middle of the cave due to gas channeling and insufficient bottom water energy. The oil film and small oil slug remaining in the fracture due to the low efficiency of gas washing, meanwhile, the artificial factors such as injection mode, injection well type and injection rate also affect the gas drive effect. The research results provide experimental basis for gas injection to increase residual oil recovery after water flooding and oil recovery after gas flooding. It is considered that using unstable gas injection methods such as alternating water and gas, gas injection in complex areas and moderate injection rate can improve the gas drive effect. It is also recognized that the objective factors, such as cave shape and distribution of cracks and caverns, should be regarded as the emphasis of further study.
【作者单位】：中国石油大学(北京)提高采收率研究院;中国石化海相油气藏开发重点实验室;石油工程教育部重点实验室;
【基金】：国家科技重大专项“缝洞型碳酸盐岩油藏提高开发效果技术——补充能量注入体系优选实验研究”(2011ZX05014-003) 国家“973”项目“碳酸盐岩缝洞型油藏提高采收率基础研究——提高采收率方法研究及优化”(2011CB201006) 国家自然科学基金项目“缝洞型碳酸盐岩油藏多相流体流动规律与剩余油形成机理研究”(51504268) 中国石油大学(北京)科研基金“缝洞型碳酸盐岩油藏提高采收率技术研究”(2462014YJRC053)
【分类号】：TE357.45

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