Abstract: The pore-size distribution of a porous sample of variable porosity is modeled achievement of, allowing laboratory studies on the behavior of the medium modeled in relation to fluids. The porosity of the porous medium is modeled on one or more parting surfaces by means of a network (R) of intersecting channels (C) whose nodes form pores (P), the size of these channels showing physical properties of the medium and being selected from one or more discrete channel size distributions. In order to model the porosity of a heterogeneous sample exhibiting very different porosity zones, several discrete channel distributions are preferably used, these distributions being disjoint or not, and modeling with different zones, zones of low permeability and zones of higher permeability.

Abstract: Enhanced (WAG type) oil recovery process in an underground reservoir uses forced injection, through one or more wells, alternately of fluid slugs and gas slugs, and recovery, through one or more production wells, of petroleum fluids displaced by the wetting fluid and the gas injected. The process includes dissolving a pressurized gas in the liquid of certain slugs and, after injection, relieving the pressure prevailing in the reservoir so as to generate gas bubbles by nucleation in the smallest pores, which has the effect of driving the oil away from the less permeable zones into the more permeable zones (with large pores or with fractures) where the oil is swept by the gas slugs injected later on. Implementation of the process considerably increases the oil recovery ratio that is usually reached with WAG type processes.

Abstract: The invention is used to manufacture an inhomogeneous medium whose porosity and permeability undergo rapid transitions from one point to another of its volume, by juxtaposing different materials without creating a barrier. Such a transition is made by juxtaposing a first material and a second material with a different porosity to the first. One of them can be a rock sample such as sandstone for example, the other can be a composite material obtained by agglomerating pyrex powder for example, the whole being heated according to a specific temperature cycle up to a temperature (TR) lower than the melting point of the two materials but sufficient to achieve partial melting of one of the materials at the interface with the other material, but without formation of a continuous or discontinuous capillary barrier between them, or an interzone with preferred passage for fluids. Thus, different composite materials can be juxtaposed to constitute the inhomogeneous medium.

Abstract: The method according to the invention is aimed at increasing the efficiency of the conventional enhanced petroleum fluid (O) recovery method (WAG) in an underground reservoir, according to which displacement is achieved towards production wells by means of alternate injections of water slugs (W) and of gas slugs (G) into one or more injection wells. It is characterized in that a substance (alcohol for example) allowing the spreading coefficient (S) to be made negative is added to one or more water slugs. The proportion to be added is selected as a function of the pressure and temperature conditions of the reservoir to be swept. The petroleum fluid to be displaced is distributed in the form of meniscuses that reduce the mobility of the gas and improve the sweep capacity thereof. The method allows to better control the input profile, and a greater and therefore more efficient injection pressure can be used. The method can be used in the field of enhanced oil recovery.

Abstract: A sample S is placed in a rigid body 1 of a device, in a containment cell laterally delimited by a supple sheath 21 and, at the two opposite ends thereof, by two cell ends 13, 14. Channels (15, 16) in these ends communicate with the sample, by means of semipermeable membranes (17, 18), and with fluid circulation means including a pump (39) providing a first fluid (such as water), a column (28) for injecting a second fluid such as oil, two burets (33, 36) receiving the fluids displaced out of the sample and a supply assembly (43, 46) associated with valves, providing gas that can be applied to the injection column (28) in order to push the second fluid injected into the containment cell for measurements with three-phase fluids. The device and its method of operation can be used for studying geologic samples, for example.

Abstract: The device is suited for taking measurements on more or less porous samples of geologic origin, for example physical parameters: wettability, capillary pressure, saturations, etc, in the presence of multiphase fluids that are displaced during drainage and imbibition operations. It comprises a modular cell whose length can be suited to that of a sample by adding tubular sections (24) of equal or different lengths that are interposed between two sleeves (1A, 1E). The containment cell is provided at its opposite ends with ends (13, 14) possibly fitted with semipermeable membranes, to which fluid lines (15, 16) are connected. Joining pieces (9) possibly provided with a control valve (10) can be fitted to all the sleeves (1A to 1E) for the connection of pressure detectors, gas injection means, etc. The device can be applied to optimization of hydrocarbon recovery in underground reservoirs.