Abstract: The invention relates to a method for producing steam comprising the successive steps of: providing feedwater containing carbonate and/or sulfate ions; adding a crystallizing reagent able to react with carbonate and/or sulfate ions to the feedwater, in order to produce carbonate and/or sulfate crystals; filtering the feedwater with a ceramic membrane to produce a permeate stream; supplying the permeate stream to a boiler; and generating steam in the boiler. The invention also relates to an installation adapted for implementing said method, as well as to a process for extracting hydrocarbons from a subterranean formation using the abovementioned method for producing steam.

Abstract: The invention concerns a treatment fluid for wells drilled in oil mud in the form of an emulsion of water in oil comprising: a continuous organic phase comprising at least one emulsion-breaking organo-soluble additive; a dispersed aqueous phase including at least one solid-dissolving agent for the controlled destabilization of the processing fluid; at least one emulsifying agent; at least one weight-increasing agent; the proportion and the nature of the hydrosoluble additive being chosen so as to obtain a delay effect for the destabilization of the emulsion so as to be compatible with the tank fluids. The invention also concerns a method of processing wells bored with oil-based muds, using said processing fluid.

Abstract: The invention relates to a method for producing steam comprising the successive steps of: providing feedwater containing carbonate and/or sulfate ions; adding a crystallizing reagent able to react with carbonate and/or sulfate ions to the feedwater, in order to produce carbonate and/or sulfate crystals; filtering the feedwater with a ceramic membrane to produce a permeate stream; supplying the permeate stream to a boiler; and generating steam in the boiler. The invention also relates to an installation adapted for implementing said method, as well as to a process for extracting hydrocarbons from a subterranean formation using the abovementioned method for producing steam.

Abstract: A temperature-stable, non eco-toxic oil-base well fluid that is particularly suitable for high pressure/high temperature drilling comprises an emulsification system comprising at least one superamide that may or may not be polyalkoxylated, optionally associated with a non-ionic co-surfactant. The oil-base well fluid comprising such a system can be used at temperatures of up to about 200° C. due to the production of highly temperature-stable reverse emulsions.

Abstract: The present invention relates to a method and to a fluid for drilling or workover in a well running through a porous permeable formation, wherein a water-based well fluid circulates in said well. In the method, at most 3% by weight of a composition obtained from fat, or an oil, and an alcohol, is added to the fluid in addition to the conventional constituents for such a fluid, the chain lengths of the acid and alcohol parts being chosen such that the ester thus obtained has sufficient dispersion in water, compatibility with said constituents, does not form an emulsion with the reservoir oil and adsorbs sufficiently on the porous formation.

Abstract: An organic based emulsion-breaking formulation for use in treating well bores drilled in oil-bearing mud that is not eco-toxic and is optimally compatible with formation fluids comprises: as the emulsion-breaking agent, at least one constituent selected from non-ionic amphiphilic compositions obtained by reacting at least one polymerized vegetable oil with at least one aminoalcohol and alkyl esters (for example C1 to C8) of fatty acids derived from natural, vegetable or animal oils; optionally, at least one wetting agent selected from anionic surfactants; and optionally at least one solvent; the assembly being as a mixture in an organic base. Such a formulation can be weighted by mineral fillers.

Abstract: An oil-based demulsifying formulation which can be used in the treatment of drains bored in oil-based mud, non ecotoxic and optimally compatible with formation fluids, comprises at least one wetting agent chosen from anionic surfacetants and at least one demulsifier (or “emulsion breaker”) chosen from copolymers of ethylene oxide and propylene oxide, alcohol or phenol derivatives with alkoxylated or polyalkoxylated chain formations, polyalkyleneglycols, polyamines, alkoxylated or polyalkoxylated derivatives of amines, quaternary ammonium salts, quaternized alkanolamine esters, alkyl esters of fatty acids or natural oils, possible alkoxylated or polyalkoxylated, and silicated derivatives such as polysiloxanes.

Abstract: The method essentially comprises acquiring initial data obtained by laboratory measurements of the values, according to the initial permeability of the formations surrounding the well, of the thickness of the cakes and of the damaged permeability and restored permeability values of this zone, as a function of the distance to the wall of the well. Then the damaged zone is discretized by a 3D cylindrical grid pattern forming blocks of small radial thickness in relation to the diameter of the well, and the diffusivity equation, modelling the flow of the fluids through the cakes, is solved in this grid pattern by taking account of the measured initial data. Finally, the evolution of the permeability is modelled as a function of the flow rates of fluids flowing through the cakes, so as to deduce therefrom the optimum conditions to be applied for producing the well.

Abstract: A well drilling method comprises removing the drilling cuttings using an aqueous drilling fluid such as a foam including a foaming agent which includes at least one mono-(aliphatic hydrocarbyl) phosphate ester. More specifically, the drilling fluid takes the form of a potassium and/or alkanolamine and/or alkylalkanolamine salt, the foam also comprising a foam stabiliser.

Abstract: The invention relates to a well drilling method consisting in removing the drilling cuttings using an aqueous drilling fluid such as a foam including a foaming agent which is, or includes, at least one mono-(aliphatic hydrocarbyl) phosphate ester. More specifically, the drilling fluid takes the form of a potassium and/or alkanolamine and/or alkylalkanolamine salt, said foam also comprising a foam stabiliser.

Abstract: The present invention relates to a borehole fluid comprising a lubricating compound containing at least one amphiphilic non-ionic compound obtained by reacting at least one vegetable oil or fatty acid as such or in a polymerized state on at least one amino alcohol. In one variant, the compound can be mixed with a solvent. The invention also relates to a method for verifying the lubrication power of a water-based fluid. The invention further relates to the application of said method to borehole fluids with a high pH.

Abstract: A temperature-stable, non eco-toxic oil-base well fluid that is particularly suitable for high pressure/high temperature drilling comprises an emulsification system comprising at least one superamide that may or may not be polyalkoxylated, optionally associated with a non-ionic co-surfactant. The oil-base well fluid comprising such a system can be used at temperatures of up to about 200° C. due to the production of highly temperature-stable reverse emulsions.

Abstract: The present invention relates to a method and to a fluid for drilling or workover in a well running through a porous permeable formation, wherein a water-based well fluid circulates in said well. In the method, at most 3% by weight of a composition obtained from fat, or an oil, and an alcohol, is added to the fluid in addition to the conventional constituents for such a fluid, the chain lengths of the acid and alcohol parts being chosen such that the ester thus obtained has sufficient dispersion in water, compatibility with said constituents, does not form an emulsion with the reservoir oil and adsorbs sufficiently on the porous formation.

Abstract: The present invention relates to a well fluid for releasing tubular elements stuck in the well. The fluid comprises a part A consisting of one or more esters obtained by reaction of a linear or branched monocarboxylic acid (A.1) having between 8 and 24 carbon atoms and a linear or branched polyol (A.2) having between 2 and 20 carbon atoms, a part B consisting of one or more linear or branched monocarboxylic acids having between 8 and 24 carbon atoms, where the carboxylic acid (A.1 and part B) is a mixture of at least 80% carboxylic acids having between 1 and 3 insaturations, and a part C consisting of a different ester or olefins, the quantity of part C is determined in relation to the other components in such a way that the viscosity of the fluid is lower than 40 mPa·s at 40° C. The invention also relates to a method for releasing drillpipes stuck in a well.

Abstract: An organic based emulsion-breaking formulation for use in treating well bores drilled in oil-bearing mud that is not eco-toxic and is optimally compatible with formation fluids comprises:

Abstract: The present invention relates to more or less substituted acrylamide or acrylate and zwitterion monomer hydrosoluble copolymers.

Abstract: An oil-based demulsifying formulation which can be used in the treatment of drains bored in oil-based mud, non ecotoxic and optimally compatible with formation fluids, comprises at least one wetting agent selected from the group consisting of anionic surfactants and at least one demulsifier (or “emulsion breaker”) selected from the group consisting of copolymers of ethylene oxide and propylene oxide, alcohol or phenol derivatives with alkoxylated or polyalkoxylated chain formations, polyalkyleneglycols, polyamines, alkoxylated or polyalkoxylated derivatives of amines, quaternary ammonium salts, quaternized alkanolamine esters, alkyl esters of fatty acids or natural oils, possibly alkoxylated or polyalkoxylated, and silicated derivatives such as polysiloxanes.

Abstract: The invention concerns a water-based additive for well fluid, comprising an acrylamide and branched styrene sulphonate copolymer. It also concerns a water-based fluid comprising an acrylamide and branched styrene sulphonate copolymer. The additive is useful for controlling the filtering of a well fluid through the wall. The invention is advantageously applicable to drilling and/or completion of oil wells having a temperature higher than 120° C.

Abstract: Hydrosoluble copolymers made of hydrophilic monomers, e.g., acrylamide, and of silane or siloxane derivative-based hydrophobic monomers, e.g., a silane or or siloxane acrylate, is obtained by micellar or heterogeneous radical copolymerization, and such copolymers can be used as rheology control agents in, e.g., a well bore.

Abstract: The invention concerns a water based foaming composition and the method of making it. The composition is optimized in that it contains a surfactant specifically selected according to the polymer also present in the composition. The surfactant and the polymer are selected so that they are oppositely charged. The invention is very useful in drilling or treating wells.