Visualization study on fluid distribution and end effects in core flow experiments with low-field mri method

Core flow experiment is an important means of simulation experiments to evaluate the effect of displacing agent, but conventionally the internal characteristics in the core cannot be intuitively observed, and then some important information can not be directly acquired by experiments. In this paper, a visualization method was used to detect the water-flooding process by using an improved low field nuclear magnetic resonance imaging (MRI) device, and the images describing the distribution of oil and water were collected. The experimental results show that the distribution of oil and water can be visually detected in an appropriate range of core porosity, and the end effect in many mechanics experiments is found to exist also in natural core flow test, and the influence range is about 0.004 m from the end of a 0.05752 m length natural core. The results also indicate that MRI is an effective tool to study the real time fluid distribution in natural core.