Abstract: A method for making a quasi-incompressible phase-change material (PCM) having low thermal conductivity includes combining with a phase-change material (PCM) in liquid state a thickening agent selected to reduce significantly thermal convection, the formed material having, depending on the combinations performed, a gelled structure or a colloidal dispersed system. The PCM may be a mixture of chemical compounds of the family of alkanes, paraffins, waxes, fatty alcohols, fatty acids and the like, and the thickening agent may be organic (aromatic ureas), organometallic (alkaline or alkaline earth soaps) or purely inorganic (silica, silico-aluminates such as bentonite made oleophilic). The material is useful for thermal isolation of containers or pipes, and in particular for thermal insulation of hydrocarbon carrying pipes.

Abstract: The present invention relates to a composition comprising a mixture of polymer material (4) and of mineral fillers (5) allowing to obtain a sealing barrier to hydrocarbons. The mixture comprises a predetermined proportion of specific mineral fillers for adsorption of all or part of the hydrocarbons that pass through the material by permeability. The proportion is determined depending on the permeability of the polymer material. The invention also relates to its applications to hydrocarbon tanks (gasoline, diesel oil, solvents) for example for motor vehicles, or hydrocarbon-carrying lines.

Abstract: A method for thermal insulation comprises positioning a gel formed between an insulating liquid base, which may or may not be a phase change material, and at least one gelling agent comprising at least one polysiloxane, which may or may not be modified, and in situ cross linking of the gelling agent, optionally in the presence of at least one compatibilizing agent. More particularly, it is used to insulate a flowline or a pipeline, in particular for ultradeep operations at temperatures of 2° C. to 200° C. Cross-linkable formulations, the various cross-linking processes and the insulating gels obtained are described.

Abstract: The present invention relates to a method intended for heat insulation of a pipe (1), comprising the following successive stages of depositing, on the outer surface of the pipe moving longitudinally, a thickness (3) of an insulating material made of elastomer having an elastic type behavior, substantially without irreversible plastic deformation, forming at least one circumferential slot (4) in the thickness of the material substantially orthogonally to the axis (2) of the pipe, and coating the insulating material thickness with a sealed sheath. In a variant, the slot is machined in the thickness of the insulant. The invention further relates to a heat-insulated pipe.

Abstract: A method is intended for the thermal insulation of a flexible pipe. The method includes a first step of depositing a thickness of extrudable and rigid insulating material on an outer surface of the pipe, with the pipe moving longitudinally. The insulating material is cooled over a substantially rectilinear part downstream from the deposition area. Then, at least one circumferential slot is formed in the thickness of the rigid insulating material so as to restore flexibility of the pipe coated with the rigid insulating material. The thus-formed pipe includes a flexible inner pipe, a layer of rigid insulating material surrounding the flexible pipe, and at least one circumferential slot cut in the layer of rigid insulating material to allow flex of the heated insulated pipe.

Abstract: The present invention relates to a method intended for heat insulation of a pipe (1), comprising the following successive stages of depositing, on the outer surface of the pipe moving longitudinally, a thickness (3) of an insulating material made of elastomer having an elastic type behaviour, substantially without irreversible plastic deformation, forming at least one circumferential slot (4) in the thickness of the material substantially orthogonally to the axis (2) of the pipe, and coating the insulating material thickness with a sealed sheath. In a variant, the slot is machined in the thickness of the insulant. The invention further relates to a heat-insulated pipe.

Abstract: The present invention relates to a method intended for heat insulation of a pipe (1), comprising the following successive stages: depositing, on the outer surface of the pipe moving longitudinally, a thickness (3) of an insulating material made of elastomer having an elastic type behaviour, substantially without irreversible plastic deformation, forming at least one circumferential slot (4) in the thickness of the material, substantially orthogonally to the axis (2) of the pipe, coating the insulating material thickness with a sealed sheath. In a variant, the slot is machined in the thickness of the insulant. The invention further relates to a heat-insulated pipe.

Abstract: The present invention relates to a reinforced flexible pipeline for conveying an effluent, the pipeline having a sheath (2, 3) of polymer, the internal surface of which is in contact with the effluent and the external surface of which is in contact with reinforcing wires (4) when under pressure. The sheath has an internal layer (2) of polymer or copolymer with no external plasticizer and an external layer (3) of polymer possibly containing plasticizers so as to obtain given mechanical characteristics. Application of the pipeline proposed by the invention for conveying an effluent under pressure and at high temperature.

Abstract: The present invention relates to a method intended for heat insulation of a pipe (1), comprising the following successive stages:

Abstract: Bituminous compositions of the bitumen-polymer type, in homogenous phase, contain at least one bitumen base and are prepared from at least one polymer of the thermoplastic polyolefin type. These compositions have a thermoplastic polyolefin content of at least 1% by weight of which the crystallinity rate is greater than or equal to 30%, a melting temperature greater than or equal to 110° C. and a penetrability at 25° C. less than or equal to 300 tenths of a millimeter.

Abstract: A process for insulating a tubing string placed in a pipe and through which a fluid circulates, the insulant being a non-rigid foam produced from a liquid solution and placed in the annular space defined by the outside of the tubing string and the walls of the pipe in which these tubings are placed. A production well (1) opens, in the lower part thereof, onto a producing rock containing a fluid to be extracted. Tubing (2) is placed in production well (1). A zone (3) represents the annulus defined between the outside (5) of the tubing string and the walls of well (1) in which the tubing string is placed. A tube for injecting a liquid and/or gaseous fluid (4) is placed in annulus (3) and a liquid and/or gaseous fluid injection nozzle (6) opens into zone (3).

Abstract: Bituminous compositions of the bitumen-polymer type, in homogenous phase, contain at least one bitumen base and are prepared from at least one polymer of the thermoplastic polyolefin type. These compositions have a thermoplastic polyolefin content of at least 1% by weight of which the crystallinity rate is greater than or equal to 30%, a melting temperature greater than or equal to 110.degree. C. and a penetrability at 25.degree. C. less than or equal to 300 tenths of a millimeter.

Abstract: The present invention relates to flexible pipes with metal armors and metal tubes having a sheath made of an extrudable thermoplastic material for manufacturing an acid gas tight barrier.The sheath comprises a determined proportion of at least one charge of a product chemically active with acid gases so as to irreversibly annihilate the corrosive effects of these gases, the proportion being determined as a function of the gas permeability of the thermoplastic material.

Abstract: A process for degrading thermoplastic polyolefins, in particular high or medium density polyethylenes, uses as a catalyst a mineral solid containing copper or a mineral solid containing aluminium and silicon and with an acid nature, at a temperature of 200.degree. C. to 450.degree. C., degradation being accompanied by incorporation of the degradation products into a heavy hydrocarbon such as a bitumen base.Incorporating degraded thermoplastic polyolefins, in particular degraded high or medium density polyethylenes, into heavy hydrocarbons can produce compositions with industrial and road applications.

Abstract: Crosslinkable compositions with a polyethylene base are described which comprise a major proportion, for example 65 to 95% by weight, of at least one polymer selected from the polyethylenes grafted by a silane and ethylene-triethoxyvinylsilane copolymers; a minor proportion, for example, from 5 to 35% by weight, of at least one polymer selected from the hydrophilic polymers which are incompatible with ethylene polymers; as well as, added to the total weight of polymers (a) and (b), a small proportion, for example, from 1 to 10% by weight, of at least one polymer selected from the copolymers and the terpolymers with an ethylene base to react chemically with said incompatible hydrophilic polymer; and a catalytic proportion, for example of 0.001 to 0.3% by weight, of at least one hydrolytic catalyst. These crosslinkable compositions can be shaped by extrusion, extrusion blow-molding or injection molding and then crosslinked by heating in the presence of water.

Abstract: Fibre-reinforced tubes made of a thermoplastics material are manufactured using a method of extruding thermoplastics material in a drawplate with a diverging end zone, the end zone of which has a diverging annular flow space which has a ratio A.sub.s /A.sub.e between the exit area and entry area of at least 1.2, and a ratio between the length 1 of the lower edge of the annular exit space of the diverging zone and the width e of the straight section of said annular space which is less than 5; the extrusion operation being carried out in the presence of a liquid lubricant which is incompatible with said thermoplastics material at extrusion temperatures, said lubricant being present at the level of the external wall and at the level of the internal wall of said flow space. Tubes which are manufactured by way of this method are particularly resistant to a high degree of bursting and have an improved surface quality.

Abstract: A filler and floatability material is an extruded admixture of a thermoplastic resin material and a mineral or organic load lightening material that resists against hydrostatic pressure. The admixture contains 50 to 80% by volume of a polyolefin or a polydiolefin homo- or copolymer as the thermoplastic resin material and 50 to 20% by volume of hollow microspheres as the load lightening material that resists against hydrostatic pressure. The filler and floatability material displays a density ranging from 0.65 to 0.85, elasticity which is greater than 10% distortion, uniaxial compression strength equal to at least 60 bar and water absorption under 50 bar pressure which is lower than 5% by weight.

Abstract: New compositions, useful as viscosity additives, having dispersing properties in various hydrocarbon oils, are disclosed, which comprise:recurrent units derived from one or more acrylic or methacrylic esters (e.g. 55-99.8% by weight),recurrent units derived from one or more nitrogenous vinyl monomers obtained by reacting triallylcyanurate with aliphatic amines or polyamines (e.g. 0.2-10% by weight), and optionallyrecurrent units derived from one or more vinyl aromatic monomers (e.g. 0-35% by weight).These copolymer compositions generally have a weight average molecular weight from 30,000 to 800,000 and a polydispersity generally lower than 5. They can be prepared by any radical copolymerization process using for example azoic or peroxydic initiators.The copolymer compositions considered are used as additives for improving the rheological properties of hydrocarbon oils. In addition, they exhibit good dispersing properties.

Abstract: New compositions, useful as viscosity additives, having dispersing properties in various hydrocarbon oils, are disclosed, which comprise:recurrent units derived from one or more acrylic or methacrylic esters (e.g. 55-99.8% by weight),recurrent units derived from one or more nitrogenous vinyl monomers obtained by reacting triallylcyanurate with aliphatic amines or polyamines (e.g. 0.2-10% by weight), and optionallyrecurrent units derived from one or more vinyl aromatic monomers (e.g. 0-35% by weight).These copolymer compositions generally have a weight average molecular weight from 30,000 to 800,000 and a polydispersity generally lower than 5. They can be prepared by any radical copolymerization process using for example azoic or peroxydic initiators.The copolymer compositions considered are used as additives for improving the rheological properties of hydrocarbon oils. In addition, they exhibit good dispersing properties.

Abstract: This invention concerns a new filler and floatability material as well as its manufacturing process.For instance, this new material can be used as a filler and floatability material (A) which separates tubes or cables (1,2) in a tubular unit that includes an external sheath (B) surrounding a harness of tubes or cables (1,2).In view of its make-up this material also participates in the thermal insulation of said tubes.The invention concerns also such tubular units which incorporate the new material.