Abstract: A method for determining a plasticity parameter of a hydrating, cement paste by mixing the components to obtain a cement slurry, pouring the cement slurry in a scaled oedometric cell, and performing an oedometric measurement operation within a predefined early-age time interval by applying a predefined axial stress path to the cement slurry over a predefined measurement duration and measuring an axial strain. A plasticity parameter of the hydrating cement paste is determined b a calibration processing operation comprising providing an initial value of a plasticity parameter of an elastoplastic model of hydrating cement paste, determining simulated axial strain values by solving the elastoplastic model of hydrating cement and comparing the simulated axial strain values with the axial strain measurements of the cement slurry.

Abstract: The present invention relates to a method for determining a time window in which a casing pressure test can be performed without damaging a cement sheath. The time window is determined by: determining the hydration degree of the cement at a given time for a considered pressure and temperature values in the well; and then comparing the determined hydration degree to a predetermined value. If the determined hydration degree is below the predetermined value, then the casing pressure test can be done without damaging the cement.

Abstract: This invention relates to a method for insulating sub-soil comprising mechanically destructuring the sub-soil, injecting an insulating material into the destructured sub-soil, and mixing the sub-soil and the insulating material. The thermal conductivity of the insulating material is strictly lower than the thermal conductivity of the sub-soil.

Abstract: A method for determining a plasticity parameter of a hydrating cement paste by mixing the components to obtain a cement slurry, pouring the cement slurry in a sealed oedometric cell, and performing an oedometric measurement operation within a predefined early-age time interval by applying a predefined axial stress path to the cement slurry over a predefined measurement duration and measuring an axial strain. A plasticity parameter of the hydrating cement paste is determined by a calibration processing operation comprising providing an initial value of a plasticity parameter of an elastoplastic model of hydrating cement paste, determining simulated axial strain values by solving the elastoplastic model of hydrating cement and comparing the simulated axial strain values with the axial strain measurements of the cement slurry.

Abstract: The present invention relates to a method for determining a time window in which a casing pressure test can be performed without damaging a cement sheath. The time window is determined by: determining the hydration degree of the cement at a given time for a considered pressure and temperature values in the well; and then comparing the determined hydration degree to a predetermined value. If the determined hydration degree is below the predetermined value, then the casing pressure test can be done without damaging the cement.

Abstract: The present invention relates to a method for determining mechanical parameters of a cementitious system, on the basis of time, and on the basis of the fineness of the cementitious system, pressure and/or temperature, representative of the in situ conditions found in wellbores. The initial composition of the cementitious system, the fineness ? thereof and the speed of the compression waves on the basis of time Vp(t) are the only input data of the method.

Abstract: This invention relates to a method for insulating sub-soil comprising mechanically destructuring the sub-soil, injecting an insulating material into the destructured sub-soil, and mixing the sub-soil and the insulating material. The thermal conductivity of the insulating material is strictly lower than the thermal conductivity of the sub-soil.

Abstract: A method for testing a curing composition, comprising includes a curing composition; injecting the curing composition into a mold; curing the curing composition into a cured composition, in the mold at a controlled curing pressure; measuring at least one physical or mechanical property of the cured sample at a controlled test pressure, in the mold; the mold being rigid relatively to the cured sample during the curing step.

Abstract: The present invention relates to a method for determining mechanical parameters of a cementitious system, on the basis of time, and on the basis of the fineness of the cementitious system, pressure and/or temperature, representative of the in situ conditions found in wellbores. The initial composition of the cementitious system, the fineness ? thereof and the speed of the compression waves on the basis of time Vp(t) are the only input data of the method.

Abstract: A method for testing a curing composition, comprising includes a curing composition; injecting the curing composition into a mold; curing the curing composition into a cured composition, in the mold at a controlled curing pressure; measuring at least one physical or mechanical property of the cured sample at a controlled test pressure, in the mold; the mold being rigid relatively to the cured sample during the curing step.

Abstract: The invention relates to a method of gasifying carbon-containing compounds incorporating mineral elements and/or potential contaminants, and it also relates to a gasification installation having means for containing a bath of molten slag, means for charging said compounds into said bath, means for injecting at least oxidizer into the bath so that the mixture of carbon-containing compounds and oxidizer is super-stoichiometric, whereby a first fraction of the compounds is pyrolyzed, a second fraction is subjected to a combustion reaction suitable for delivering heat energy to the bath of slag, and a third fraction diffuses into the bath, means for recovering the gas given off by the pyrolysis and the combustion of the first and second fractions, and means for lowering the temperature of a portion of the molten slag so as to allow it to solidify, thereby immobilizing at least a portion of the third fraction of the compounds containing mineral elements and/or potential contaminants.

Abstract: The present invention provides improved well cementing methods for use in cold environment, where the circulating temperature of the cement is typically within the range of 5 to 20° C. The improved well cementing methods include forming compositions that are essentially comprised of an aqueous fluid, a hydraulic cement binder and a set-accelerating admixture comprising an alkali or alkaline earth metal nitrate and an alkali or alkaline earth metal nitrite.

Abstract: Method of well cementing with a foamed slurry having a very low water content. When based on ordinary cement, the solid fraction of the slurry includes (by volume) 20-35% Portland cement, 35-65% particles ranging from 200 ?m to 600 ?m, and 5% to 25% of fine particles in the range 0.5 ?m to 5 ?m and the water content is less than 50% by volume. When based on micro-cement, the solid fraction includes (by volume) 50-75% micro-cement, 15-40% fine particles in the range 0.5 ?m to 5 ?m, and 0-20% particles in the rang 3 nanometers to 60 nanometers and the water content is less than 72% by volume.

Abstract: A plugging fluid for plugging a subterranean formation zone surrounding a drill hole comprises an emulsion comprising a dispersed aqueous phase containing an aqueous base and a continuous hydrophobic phase containing a polymer consisting of a grafted cellulose ether derivative, a surfactant and a crosslinking activator of the polymer. The polymer is preferably 2-hydroxyethyl cellulose grafted with vinyl phosphonic acid. Upon shearing, preferably through the drilling bit, the emulsion inverts so that the rupture of the emulsion droplets releases the crosslinking activator into the water phase thus forming a gel structure.

Abstract: A plugging fluid for plugging a subterranean formation zone surrounding a drill hole comprises an emulsion comprising a dispersed aqueous phase containing an aqueous base and a continuous hydrophobic phase containing a polymer consisting of a grafted cellulose ether derivative, a surfactant and a crosslinking activator of the polymer. The polymer is preferably 2-hydroxyethyl cellulose grafted with vinyl phosphonic acid. Upon shearing, preferably through the drilling bit, the emulsion inverts so that the rupture of the emulsion droplets releases the crosslinking activator into the water phase thus forming a gel structure.

Abstract: A well cementing slurry, includes a solid fraction and a liquid fraction and has a density of less than about 1500 kg/m3. The solid fraction includes a mixture of solid particulate materials including cement, having 60% to 90% by volume of the solid fraction of a first component with particles having a mean size lying in the range 20 microns to 400 microns and a density of less than 2000 kg/m3; and 10% to 30% by volume of the solid fraction of a second component having a mean particle diameter of less than 5 microns.

Abstract: The present invention provides a cementing composition for an oil well or the like with porosity of less than 50%, and with a solid phase constituted by 35% to 65% (by volume) hollow microspheres, 20% to 45% Class G Portland cement, and 5% to 25% of Class G Portland micro-cement. The invention is used to cement conductor pipes in arctic zones or in deep water holes.

Abstract: The invention relates to a cement slurry for cementing an oil well or the like, the slurry having a density lying in the range 0.9 g/cm3 to 1.3 g/cm3, and being constituted by a solid fraction and a liquid fraction, having porosity (volume ratio of liquid fraction over solid fraction) lying in the range 38% to 50%. The solid fraction is constitued by a mixture of lightweight particles, microcement and optionally portland cement and gypsum. Such cements have remarkable mechanical properties due to their very low porosity in spite of having very low density.

Abstract: The present invention provides improved well cementing compositions for use in cold environment, where the circulating temperature of the cement is typically within the range of 5 to 20° C. The improved well cementing compositions are essentially comprised of an aqueous fluid, a hydraulic cement binder and a set-accelerating admixture comprising an alkali or alkaline earth metal nitrate and an alkali or alkaline earth metal nitrite.

Abstract: A remote handling device includes a master arm and a slave arm adapted to reproduce the movements of the master arm. The slave arm is located within a confinement chamber. The master arm is located outside the confinement chamber. The master and slave arms are interconnected by a mechanism passing through a wall of the confinement chamber. The master arm is connected by a connection tube to the mechanism. The master arm and the connection tube are connected to coupling and uncoupling means adapted to permit their modular connection or disconnection.