Process and device for measuring physical characteristics of a porous sample by centrifugal displacement of fluids

A process for measuring physical characteristics of a porous solid sample by performing drainage operations, in a presence of a first electrically-conductive fluid and of a second fluid of lower density than the first electrically-conductive fluid using a centrifugation assembly including at least one vessel each provided with a chamber, each vessel being fastened to an arm secured to a hub, a rotational drive which drives each arm in rotation which creates centrifugal force exerted in a radial direction along each vessel, a sonde for detecting, in each vessel, an interface between the first electrically-conductive fluid and the second fluid of a lesser density and a system, responsive to each sonde, which determines a volume of fluid channel drained from the sample, comprising:

• a) placing in each chamber filled with a volume of the second fluid of a lesser density a sample previously saturated with the first electrically-conductive fluid and a spacer made of a nonporous material with the spacer positioned so as to be at a different distance from the hub than the sample;
• b) injecting a known amount of the first electrically-conductive fluid into each chamber on the side thereof occupied by the spacer;
• c) centrifugating each vessel at a centrifugation speed which increases by steps until a capillary equilibrium is reached for each step;
• d) acquiring, during centrifuging, signals from each sonde representative of level variations of an interface between the first electrically-conductive fluid and the second fluid of lower density;
• and
• e) determining with the system a volume of the first fluid drained from the sample.

A process for measuring physical characteristics of a porous solid sample in a presence of a non-electrically-conducting fluid and a non-electrically-conducting gas, by using a centrifugation assembly including at least one vessel provided with a chamber, each vessel being fastened to the end of an arm secured to a hub, a rotational drive which drives each arm in rotation which creates centrifugal force exerted in a radial direction along each vessel, a sonde which detects, in each vessel, an interface between the non-electrically-conducting fluid and the non-electrically-conducting gas and a system, responsive to each sonde, which determines a position of the interface in each vessel, comprising:

• placing the sample saturated with the non-electrically-conductive fluid in the at least one vessel filled with the non-electrically-conductive gas;
• placing a spacer made of a nonporous material in a container, made of an insulating material positioned in the at least one vessel with the spacer positioned at a farther distance from the hub than the sample, to collect the non-electrically-conductive fluid drained from the sample;
• injecting a volume of the non-electrically-conductive fluid in each container;
• centrifugating the at least one vessel at a centrifugation speed which increased by steps until a capillary equilibrium is reached for each step;
• and
• measuring with the system a displacement of an interface between the non-electrically-conductive fluid and the non-electrically-conductive gas.

A device for measuring physical characteristics of a porous solid sample by performing drainage phases, in a presence of a first electrically-conductive fluid and of a second fluid of lower density than the first fluid comprising:

• a centrifugation assembly including at least one vessel provided with a main chamber, each vessel being fastened to an end of an arm secured to a hub, a rotational drive which drives each arm in rotation to produce centrifugal force exerted in a radial direction along each vessel, a detector which detects a position, in a side chamber of each vessel, of an interface between the first electrically-conductive fluid and the second fluid of lower density, a spacer disposed in each main chamber made of a nonporous material with the volume of the spacer being selected so that, in operation, the interface between the first electrically-conductive fluid and the second fluid of a lower density does not come into contact with the sample, the detector in each vessel including a sonde with a metallic rod coated with a layer of a dielectric material, each sonde being placed in the side chamber having a conducting wall adjacent the main chamber and a system, outside the centrifuging assembly, connected with each sonde through a rotating electric connector which measures capacitance variation detected by each sonde in contact with the first electrically-conductive fluid and the second fluid of lower density in each vessel resulting from an immersion thereof in the first electrically-conductive fluid, and which determines a volume of fluid displaced.