Abstract: The process mainly consists in placing a sample previously imbibed with a first fluid into a vessel or bucket containing another fluid of different density and in applying a centrifugal force by rotating the bucket at the end of an arm, so as to study the displacements of the fluids in the sample during at least two distinct phases. During the first phase, the rotational speed is increased so as to drain the first fluid from the sample. During the second phase, the rotational speed is progressively decreased. In order to avoid a discontinuity and to allow an imbibition of the sample, it is important to keep the two fluids in permanent contact with the sample. The amount of fluid produced in the bucket by centrifugation may be determined. The fluid produced may also be transferred into a variable chamber, for example inside the same bucket or a second rotating bucket.

Abstract: In a process and apparatus for measuring the distribution of the concentrations of constituents of a centrifuged medium containing at least one fluid, during centrifuging, a mechanical signal, preferably a sound wave, is emitted from at least one emission point (19-22) in contact with or in the immediate vicinity of the medium (16). The emitted signal is received by at least one reception point (20-22) in contact with or in the immediate vicinity of the medium. For each emission-reception point pair, at least one propagation characteristic of the signal between the emission and reception points thereof is measured and, by an appropriate processor (15), the distribution of the concentrations of the constituents present in the medium is determined. A proposed application is the calculation of the relative permeability and capillary pressure curves of fluids in a porous medium in order to improve the working and operation of oil fields.