Abstract: A method for determining lower radius limit of movable throat of shale is provided, and it includes: performing a low-temperature nitrogen adsorption test on a target shale to obtain first pore radii; performing a high-pressure mercury injection test on the target shale to obtain second pore radii; performing a nuclear magnetic resonance test on the target shale to obtain third pore radii; obtaining a relationship diagram of distribution frequencies and pore radii according to three pore radii; distinguishing, according to the pore radii, relationship diagram data, and performing normalization processing to determining a relationship curve of normalized frequency data and the pore radii; and determining a lower radius limit of movable throat of shale according to relationship curve. A problem of describing characteristics of shale occurrence space with complex pore structures and strong heterogeneity is solved, the method is suitable for determining lower radius limit of movable throat of shale.

Abstract: A method for determining lower radius limit of movable throat of shale is provided, and it includes: performing a low-temperature nitrogen adsorption test on a target shale to obtain first pore radii; performing a high-pressure mercury injection test on the target shale to obtain second pore radii; performing a nuclear magnetic resonance test on the target shale to obtain third pore radii; obtaining a relationship diagram of distribution frequencies and pore radii according to three pore radii; distinguishing, according to the pore radii, relationship diagram data, and performing normalization processing to determining a relationship curve of normalized frequency data and the pore radii; and determining a lower radius limit of movable throat of shale according to relationship curve. A problem of describing characteristics of shale occurrence space with complex pore structures and strong heterogeneity is solved, the method is suitable for determining lower radius limit of movable throat of shale.

Abstract: A core holder and a prediction method for starting pressure gradient of shale oil based on the core hold are provided. The core holder includes an inlet plug, an outlet plug, a core accommodating cavity disposed between the inlet plug and the outlet plug and used for accommodating the shale oil, a rubber gasket disposed between the outlet plug and the core accommodating cavity, and a microinjector including a microinjector needle portion that passes through the outlet plug and the rubber gasket in sequence to be in contact with the shale oil in the core accommodating cavity. The core holder and the method can solve problems that movable oil volume of a low-porosity, low-permeability and small-volume rock sample and a shale rock sample cannot be accurately measured, and that a movable scale and a starting pressure gradient of the shale oil cannot be measured.