A GLOBAL-ORIENTED METHOD TO MEASURE THE THRESHOLD PRESSURE GRADIENT IN MICRO-CHANNELS

A global oriented method of measuring of the threshold pressure gradient (TPG) in micro-channels was studied in this paper, in order to more accurately measure the TPG in the low permeability porous media. The method includes the static measurement and the steady flow experiments, and can be defined as the global-oriented method to measure the threshold pressure gradient, which can be used to analyze the pressure responses when the deionized water changes from the static state to the steady flow state in micro-channels. The experiments indicate that the threshold pressure gradient in the steady flow experiments is 14.5 times of that obtained by the static method, which shows that the previously published experimental values are too large, and are difficult to be used in the oil development. The results show that the global-oriented method of measuring the TPG can be applied for low permeability cores to obtain more precise parameters, and the TPG is verified when the liquid flows in micro-channels.