Abstract: Method of determining the permeability of an underground medium from NMR logs of the permeability of rock fragments from the medium, based on prior calibration of the permeability resulting from this measurements, from direct measurement on rock fragments, such as cuttings for example. The method mainly comprises measuring permeability (k) from rock fragments, measuring the signal produced by a device allowing NMR analysis of the rock fragments previously saturated with a protonated liquid (brine for example), obtaining optimum values for the parameters of a relation giving the permeability as a function of the NMR signal, and applying this relation to the well zones that have already been subjected to NMR logging but for which no direct permeability measurements are available. One example of one of the applications for the present invention is the evaluation of a hydrocarbon reservoir.

Abstract: A method for forming a model simulating production, by an underground reservoir subject to depletion, of hydrocarbons comprising notably relatively high-viscosity oils. From laboratory measurements of the respective volumes of oil and gas produced by rock samples from the reservoir subject to depletion, and the relative permeabilities (Kr) of rock samples to hydrocarbons, a model of the formation and flow of the gas fraction is used to determine a volume transfer coefficient (hv) by means of an empirical function representing the distribution of nuclei that can be activated at a pressure P (function N(P)) which is calibrated with reference to the previous measurements.

Abstract: A method with application for evaluation or production of a reservoir for determining multiphase flow parameters of a porous medium such as a rock, from the interpretation of displacement experiments. From an injection experiment on a rock sample, the saturation profiles are measured in different sections of the sample. The experimental data are then subjected to a preliminary interpretation by means of a numerical simulation code allowing production of simulated pressure profiles. These profiles are then combined with the measured saturation profiles so as to evaluate the local properties of the sample in terms of capillary pressure. These properties are then re-injected into the simulator as input data so as to finely interpret the flow parameters while respecting the evolutions of the differential pressure, of the displaced fluid production and of the saturation profiles.

Abstract: Method and device for determining the formation factor of underground zones from drill cuttings. The device comprises a cell (1) associated with a device for measuring the electrical conductivity of the cell with the content thereof. The cell containing the drill cuttings is filled with a first electrolyte solution (A) of known conductivity (?A). After saturation of the drill cuttings by first solution (A), the global electrical conductivity (?*A) of the cell with the content thereof is determined. After discharging first solution (A), the cell containing the drill cuttings is filled with a second electrolyte solution (B) of known conductivity (?B), and the global electrical conductivity (?*B) of the cell containing the second solution and the cuttings saturated with the first solution is determined. The cuttings formation factor (FF) is deduced therefrom by combination of the measurements.

Abstract: Method and device for determining the formation factor of underground zones from drill cuttings. The device comprises a cell (1) associated with a device for measuring the electrical conductivity of the cell with the content thereof. The cell containing the drill cuttings is filled with a first electrolyte solution (A) of known conductivity (?A). After saturation of the drill cuttings by first solution (A), the global electrical conductivity (?*A) of the cell with the content thereof is determined. After discharging first solution (A), the cell containing the drill cuttings is filled with a second electrolyte solution (B) of known conductivity (?B), and the global electrical conductivity (?*B) of the cell containing the second solution and the cuttings saturated with the first solution is determined. The cuttings formation factor (FF) is deduced therefrom by combination of the measurements.

Abstract: A method and device evaluate simultaneously, with the same equipment, physical parameters such as the absolute permeability and the porosity of fragments taken from a fragmented natural or artificial porous medium. The porosity of the fragments is measured by means of helium pressure tests according to a protocol known in the art. The chamber (1) containing the fragments is communicated with a tank (11) whose volume is also known and containing helium at a known pressure. At pressure balance, the value of the solid volume can be deduced. The rock envelope volume and the fragments mass are also measured. Combining these measurements allows to determine the porosity of the samples and the density of the rock. Their permeability is then measured by immersing them in a viscous fluid and by communicating the chamber with viscous fluid at a determined pressure contained in a vessel (9) so as to compress the gas trapped in the pores of the rock, according to two different protocols.

Abstract: A method of evaluating the capillary pressure curve of rocks of an underground reservoir from measurements on rock debris or fragments such as cuttings from the reservoir, over the total saturation range of these rocks, within a short period and at a low cost, from these measurements is disclosed. The method comprises measuring the permeability k of the debris, measuring the capillary pressure curve Pc as a function of the saturation of these fragments initially saturated with a fluid (brine for example) by subjecting them to centrifugation, and parametrizing a capillary pressure curve Pc satisfying empirical relations depending on adjustable parameters, constrained to adjust to an asymptotic part of the capillary curve measured by centrifugation, and to the value of permeability k measured on the cuttings, so as to obtain the whole of the capillary pressure curve. Applications include hydrocarbon reservoir evaluation.

Abstract: Method and device for evaluating, simultaneously and with a single equipment, physical parameters such as the absolute permeability and the porosity of fragments taken from a fragmented artificial or natural porous medium. The porosity of the fragments is measured by means of pressure tests using helium or any other gas, according to a protocol known in the art. Chamber (1) in which they are contained is communicated with a tank (11) of known volume containing helium at a known pressure. At pressure balance, the value of the solid volume can be deduced. The rock envelope volume and the mass in fragments are also measured. The porosity of the samples and the density of the rock are determined by combining these measurements. Their permeability is then measured by immersing them in a liquid and by communicating the chamber with a liquid initially at a predetermined pressure contained in an accumulator (9) so as to compress the gas trapped in the pores of the rock.

Abstract: A method with application for evaluation or production of a reservoir for determining multiphase flow parameters of a porous medium such as a rock, from the interpretation of displacement experiments. From an injection experiment on a rock sample, the saturation profiles are measured in different sections of the sample. The experimental data are then subjected to a preliminary interpretation by means of a numerical simulation code allowing production of simulated pressure profiles. These profiles are then combined with the measured saturation profiles so as to evaluate the local properties of the sample in terms of capillary pressure. These properties are then re-injected into the simulator as input data so as to finely interpret the flow parameters while respecting the evolutions of the differential pressure, of the displaced fluid production and of the saturation profiles.

Abstract: A method of evaluating the capillary pressure curve of rocks of an underground reservoir from measurements on rock debris or fragments such as cuttings from the reservoir, over the total saturation range of these rocks, within a short period and at a low cost, from these measurements is disclosed. The method comprises measuring the permeability k of the debris, measuring the capillary pressure curve Pc as a function of the saturation of these fragments initially saturated with a fluid (brine for example) by subjecting them to centrifugation, and parametrizing a capillary pressure curve Pc satisfying empirical relations depending on adjustable parameters, constrained to adjust to an asymptotic part of the capillary curve measured by centrifugation, and to the value of permeability k measured on the cuttings, so as to obtain the whole of the capillary pressure curve. Applications include hydrocarbon reservoir evaluation.

Abstract: Method and device for evaluating simultaneously, with the same equipment, physical parameters such as the absolute permeability and the porosity of fragments taken from a fragmented natural or artificial porous medium The porosity of the fragments is measured by means of helium pressure tests according to a protocol known in the art. The chamber (1) containing the fragments is communicated with a tank (11) whose volume is also known and containing helium at a known pressure. At pressure balance, the value of the solid volume can be deduced. The rock envelope volume and the fragments mass are also measured. Combining these measurements allows to determine the porosity of the samples and the density of the rock. Their permeability is then measured by immersing them in a viscous fluid and by communicating the chamber with viscous fluid at a determined pressure contained in a vessel (9) so as to compress the gas trapped in the pores of the rock, according to two different protocols.

Abstract: Method of determining the permeability of an underground medium from NMR logs of the permeability of rock fragments from the medium, based on prior calibration of the permeability resulting from these measurements, from direct measurements on rock fragments such as cuttings for example. The method mainly comprises measuring permeability (k) from rock fragments, measuring the signal produced by a device allowing NMR analysis of the rock fragments previously saturated with a protonated liquid (brine for example), obtaining optimum values for the parameters of a relation giving the permeability as a function of the NMR signal, and applying this relation to the well zones that have already been subjected to NMR logging but for which no direct permeability measurements are available. Applications: evaluation of a hydrocarbon reservoir for example.

Abstract: A method for forming a model simulating production, by an underground reservoir subject to depletion, of hydrocarbons comprising notably relatively high-viscosity oils. From laboratory measurements of the respective volumes of oil and gas produced by rock samples from the reservoir subject to depletion, and the relative permeabilities (Kr) of rock samples to hydrocarbons, a model of the formation and flow of the gas fraction is used to determine a volume transfer coefficient (hv) by means of an empirical function representing the distribution of nuclei that can be activated at a pressure P (function N(P)) which is calibrated with reference to the previous measurements.

Abstract: Capacitive probe measuring the level, in a vessel and with high precision, of the interface between a conducting fluid (F1) and a non-conducting fluid (a gas or oil for example), suited to work under high pressure and high temperature conditions. The probe comprises a preferably tubular insulating layer (3) made of a dielectric heat-resisting material (a metal oxide such as zirconia or alumina) baked at a high temperature, with a first face in contact with conducting fluid (Fl) and an opposite face in contact with a second electrode (4), consisting for example of a coating or of a layer made of a fusible alloy deposited on the opposite face of insulant (3), selected according to the temperature range within which the capacitive probe is intended to work, or possibly of an added tube. Alloys based on zinc, tin, copper, etc, can for example be used. A second capacitor of the same type used for temperature compensation of the first one can be placed within the tubular insulating layer.

Abstract: Method and device for evaluating, simultaneously and with a single equipment, physical parameters such as the absolute permeability and the porosity of fragments taken from a fragmented artificial or natural porous medium.

Abstract: Capacitive probe measuring the level, in a vessel and with high precision, of the interface between a conducting fluid (F1) and a non-conducting fluid (a gas or oil for example), suited to work under high pressure and high temperature conditions. The probe comprises a preferably tubular insulating layer (3) made of a dielectric heat-resisting material (a metal oxide such as zirconia or alumina) baked at a high temperature, with a first face in contact with conducting fluid (Fl) and an opposite face in contact with a second electrode (4), consisting for example of a coating or of a layer made of a fusible alloy deposited on the opposite face of insulant (3), selected according to the temperature range within which the capacitive probe is intended to work, or possibly of an added tube. Alloys based on zinc, tin, copper, etc, can for example be used. A second capacitor of the same type used for temperature compensation of the first one can be placed within the tubular insulating layer.

Abstract: Capacitive probe measuring the level, in a vessel and with high precision, of the interface between a conducting fluid (F1) and a non-conducting fluid (a gas or oil for example), suited to work under high pressure and high temperature conditions. The probe comprises a preferably tubular insulating layer (3) made of a dielectric heat-resisting material (a metal oxide such as zirconia or alumina) baked at a high temperature, with a first face in contact with conducting fluid (F1) and an opposite face in contact with a second electrode, consisting for example of a coating or of a layer made of a fusible alloy deposited on the opposite face of insulant (3), selected according to the temperature range within which the capacitive probe is intended to work, or possibly of an added tube. Alloys based on zinc, tin, copper, etc, can for example be used. A second capacitor of the same type used for temperature compensation of the first one can be placed within the tubular insulating layer.

Abstract: System of evaluating physical parameters such as the absolute permeability of porous rocks of a zone of an underground reservoir, from fragments taken from this zone, such as rock cuttings carried along by the drilling mud. Rock fragments (F) are immersed in a viscous fluid contained in a vessel (1). Pumping means (2, 3) first inject into vessel (1) a fluid under a pressure that increases with time, up to a determined pressure threshold, so as to compress the gas trapped in the pores of the rock. This injection stage is followed by a relaxation stage with injection stop. The pressure variation measured by detectors (7, 8) during these two successive stages is recorded by a computer (9). The evolution of the pressure during the injection process being modelled from initial values selected for the physical parameters of the fragments, the computer adjusts them iteratively so as to best get the modelled pressure curve to coincide with the pressure curve really measured. Application: petrophysical measurement.

Abstract: System of evaluating physical parameters such as the absolute permeability of porous rocks of a zone of an underground reservoir, from fragments taken from this zone, such as rock cuttings carried along by the drilling mud.

Abstract: A process involves placing a solid sample imbibed or saturated with a first fluid (for example water) in a closed chamber; injecting, via pressure means, another liquid under pressure at a first end of the chamber to drain or expel the first liquid from the sample; and sweeping an opposite end of the chamber with a low pressure liquid, circulated by pumping means, which carries or discharges the drained first liquid outside the chamber. A device for conducting the process includes measuring means for determining the pressure and saturation variations of the sample at at least one point of the length of the sample in the chamber, the amount of fluid discharged from the chamber, and the electrical resistivity of the sample. A progressive variation of the flow of the liquid injected allows complete draining and imbibition cycles to be performed while setting up capillary pressure variation curves and calculating relative permeabilities, without touching the sample.