胜坨油田二区三角洲砂岩油藏剩余油形成的影响因素分析

胜坨油田二区三角洲砂岩油藏剩余油形成的影响因素是多方面的。研究表明，宏观影响因素主要有7种，其中有4种因素影响较大。侧缘微相带由于注水状况差，易于形成剩余油；小鼻状微型构造高部位剩余油相对富集，且向上驱油对油井生产有利；靠近断层的地带封闭性好，剩余油相对富集；注水井网不完善易于形成相对富集的平面剩余油潜力区。微观影响因素主要来自孔隙结构的非均质性、原油性质和注水压差，剩余油主要是在多孔隙网络体系条件下形成，其形态多以油珠、油丝、小油块和孤岛状分布。剩余油形成过程中，宏观因素对微观因素有4个方面的控制作用，它们决定油层孔喉结构及润湿性，提供水驱油动力，控制水驱油过程，影响水驱油的速度。此研究结果有助于研究区的剩余油挖潜。

Analysis of influencing factors on formation of remaining oil in delta sandstone reservoir of the second district in Shengtuo Oilfield

In the second district of Shengtuo Oilfield, the influencing factors on formation of remaining oil in delta sandstone reservoir are comprehensive. The results show that there have seven influencing macrofactors, among which in the river side microfacies remaining oil is easy to form because water injection response is not up to much, at high position of microncse structure remaining oil relatively accumulates and upward oil displacement is good for oil production, in the area near to fault, remaining oil relatively accumulates due to fine sealing, and in the latent areas where flooding network is imperfect, remaining oil tends to get rich on plane comparatively. However, microfactors mainly come from heterogeneity of pore structure, quality of rude oil and injection pressure differential. Remaining oil mainly forms under the condition of multipore network, which distributes primarily as oil droplet, oil silk, detached island. In the course of remaining oil, macrofactors have four controlling function on microfactors, which determine pore structure and wettability of oil stratum, offer dynamic force to water drive oil, control its process and influence its velocity. The results contribute to remaining oil development in the study area.