水驱油过程的核磁共振二维谱研究

岩心水驱油过程中油水分布状况是岩心多孔介质的重要性质. 水驱油过程的研究是进一步进行提高采收率研究的基础. 核磁共振扩散-弛豫二维谱提供了岩心中流体性质的多方面信息，与核磁共振一维弛豫谱相比极大地提高了区分油水的能力. 该文通过2组岩心水驱油实验，从不同含油饱和度的扩散-弛豫二维谱中提取出水的一维弛豫谱，在原油粘度比较高的情况下获得了驱替过程中油水在不同孔隙中的分布状况以及润湿性等信息， 解决了单独用一维弛豫谱方法难以区分油水的问题. 该文的研究方法对油田提高采收率的研究有比较大的参考价值.

Water Flooding Studied by Measuring NMR Two-Dimensional Distribution Function

The distribution of water and oil is a very important property of porous media such as rock cores. The study on water flooding is an essential part in the research of enhanced oil recovery (EOR). Nuclear magnetic resonance (NMR) diffusion-relaxation two-dimensional (2D) distribution function (spectrum) provides a large variety of information of fluids in porous media. Compared with NMR 1D relaxation spectrum, the 2D spectrum greatly improves the ability to separate water from oil. In this article, two sets of core flooding experiments were conducted. The relaxation spectra of water were extracted from the 2D spectra acquired with different oil saturations,and used to calculate wettability and distribution of water and oil in different pores under the condition of higher oil viscosity. It was shown that the difficulty of oil and water separation by traditional 1D NMR relaxation spectrum can be overcome by using the 2D method.