The relative permeability curve is a key tool for describing the flow characteristics of multiphase fluids in porous media, and is widely used in fields such as oil and gas development and groundwater pollution control. Accurately obtaining and reasonably interpreting the curve through core flow testing requires full process control from experimental design, data collection to result analysis.

Experimental design is the foundation. Representative core samples should be selected to ensure that their pore structure, permeability, and other parameters are consistent with the actual formation. Before the experiment, the rock core should be cleaned, dried, and saturated to eliminate impurity interference. According to the research objectives, select appropriate displacement fluids (such as oil and water) and displacement methods (constant speed or constant pressure), and set reasonable displacement rates and pressure gradients to simulate actual seepage conditions.

Data collection is crucial. During the displacement process, real-time monitoring of parameters such as pressure, flow rate, and fluid production is carried out, and the relative permeability values at different saturation levels are recorded. To improve accuracy, high-precision sensors and automated data acquisition systems need to be used to reduce human errors. At the same time, CT scanning, nuclear magnetic resonance and other technologies are used to obtain images of fluid distribution inside the rock core, assisting in the analysis of seepage laws.

The interpretation of results needs to be combined with theory and practice. According to Darcy's law and the definition of relative permeability, convert experimental data into a relative permeability curve. Analyze the shape of the curve (such as the position of the isotonic point and the size of the endpoint values) to reveal the fluid flow characteristics. Explain the reasons for the differences in curves based on factors such as core pore structure and wettability. For example, if the isotonic point of the high permeability core curve is biased to the right, it indicates that the water phase has strong permeability; However, low-permeability and oleophilic rock cores are the opposite. Ultimately, the relative permeability curve will be applied to numerical simulations to optimize development plans and improve recovery rates.