渗透率对致密砂岩储集层渗吸采油的微观影响机制

发布时间：2018-03-03 02:21

本文选题：致密砂岩　切入点：渗吸驱油　出处：《石油勘探与开发》2017年06期 　论文类型：期刊论文

【摘要】：以鄂尔多斯盆地富县地区延长组长8段致密砂岩储集层样品为例,通过自发渗吸模拟实验,结合核磁共振与CT扫描分析,进一步揭示了致密储集层渗透率对渗吸采油效率的微观影响机制。研究结果表明:(1)基质自发渗吸排驱在致密砂岩储集层注水开发中起着至关重要的作用,实验岩心样品自发渗吸采出程度可以达到5.24%~18.23%,且基质的渗透率越大,自发渗吸采出程度越高;(2)受吸附层厚度的影响,亚微米级以上孔隙在致密储集层的渗吸驱油过程中起主导作用,纳米—亚微米级孔隙对渗吸采出程度贡献相对较弱;(3)孔喉的连通性是导致致密储集层基质渗透率与渗吸排驱采油效率呈正相关的主要微观影响机制。不同渗透率样品亚微米—微米级孔隙尺寸分布的差异并不大,但随着渗透率的增加,连通孔喉个数与连通面孔率均呈指数递增,导致渗吸排驱采出程度显著提高。
[Abstract]:Taking the sample of tight sandstone reservoir of Yanchang formation 8 member in Fuxian area, Ordos Basin as an example, the spontaneous infiltration simulation experiment, combined with nuclear magnetic resonance (NMR) and CT scanning analysis, is carried out. The microcosmic influence mechanism of permeability of tight reservoir on oil recovery efficiency is further revealed. The results show that the spontaneous permeability drainage of the matrix plays an important role in the development of water injection in tight sandstone reservoir. The degree of spontaneous osmotic extraction of experimental core samples can reach 5.24% 18.23, and the larger the permeability of matrix, the higher the degree of spontaneous permeability extraction is affected by the thickness of adsorption layer. The porosity above submicron level plays a leading role in the process of oil absorption and displacement in tight reservoir. The connectivity of pore throat is the main microcosmic mechanism that leads to the positive correlation between matrix permeability of tight reservoir and oil recovery efficiency of permeation suction flooding and different permeability. The difference in pore size distribution between submicron and micron size is not significant. However, with the increase of permeability, both the number of connected pores and the connected face rate increase exponentially, resulting in a significant increase in the degree of recovery.
【作者单位】：中国石油大学(华东)石油工程学院;西安石油大学石油工程学院;
【基金】：国家科技重大专项(2009ZX05009,2011ZX05001) 国家自然科学基金(51104173,51274229)
【分类号】：TE31

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