基于砂岩岩心模型的微观水驱油渗流规律和剩余油赋存状态实验

Experiment of microscopic water flooding seepage law and remaining oil occurrence state based on sandstone core model

为了深入认识真实砂岩岩心微观驱替过程中流体的流动规律和驱替完成后剩余油赋存状态,通过自主研制的一套微观可视化驱替观测装置,研究了3种不同岩心薄片模型的水驱油过程,并利用尼康高倍金相显微镜和拟三维数值图像分析技术,对3种岩心模型微观驱油剩余油赋存状态进行观测和分析。实验结果表明真实模型驱替实验中油水间无清晰界面;微观模型从入口到出口剩余油分布增多,饱和度增大;驱替完成后,剩余油主要以孤立点珠状、膜状、不规则珠串状、渠道状以及段塞状赋存于岩石孔隙中。以上成果对认识微观驱替过程中流体的流动规律具有重要参考价值。

In order to understand the fluid seepage law and remaining oil distribution characteristics of real sandstone cores,this paper studied the water flooding process of three different core thin film models through a self-developed set of microscopic visualization displacement observation devices.The Nikon high-power metallographic microscope and quasi-three-dimensional numerical image analysis technology were used to observe and analyze the microscopic flooding remaining oil occurrence status of the three core models.The experimental results show that there is no clear interface between oil and water in the real sandstone micro-displacement experiment;the remaining oil saturation and displacement efficiency are related to the location of the micromodel;after the displacement is completed,the remaining oil is mainly bead-like,membrane-like,irregular beads,channels,and slugs occur in rock pores.The recognition of the above results has important reference value for understanding the fluid flow law during the micro-displacement process.