A prefabricated composite concrete element for use in a corrosive sewer environment. The concrete element has a hollow reinforced cast concrete portion with at least one end having connection details, a premolded corrosion resistant inner plastic liner. The plastic liner lines an interior of the hollow concrete element and the connection details to provide abutting liner faces in an assembled joint to limit exposure through said joint of said concrete portion to corrosive materials arising in said sewer environment. At least two prefabricated composite concrete elements may be assembled end to end at a joint to form a concrete sewer system. Also disclosed are a method of prefabricating such a composite concrete element.

Graphene quantum dots are functionalized by covalently bonding a corrosion inhibitor molecule thereto. In a useful method, a corrosion inhibitor compound is blended with a graphene quantum dot-tagged corrosion inhibitor compound, and the blend is applied to a metal surface, such as the interior of a carbon steel pipe. The blend inhibits corrosion arising from contact with produced water generated by hydrocarbon recovery from one or more subterranean reservoirs. The produced water having the blend dispersed therein is irradiated with a source of light having a selected first range of wavelengths, and the luminescent emission of the graphene quantum dot-tagged corrosion inhibitor is measured at a selected second range of wavelengths, thereby providing for real-time measurement of corrosion inhibitor concentration within the pipe.

A method for producing a steel underwater pipe for carrying a corrosive fluid, includes the successive steps: applying a layer of corrosion-resistant steel alloy on a terminal part of the internal wall of each pipe element from its end to be welded; the application of a plastic coating, on the internal wall of each pipe element; covering only a first part of the layer of metal alloy, a terminal part of the layer of metal ally on the side of the end to be welded of each pipe element not being covered by the plastic coating; the coaxial insertion and the crimping of a compression ring against the terminal part of the plastic coating; and the assembly by welding directly together the ends of two pipe elements by a corrosion-resistant steel alloy weld.

A method of inhibiting corrosion of metal which will be in contact with aqueous, and possibly acidic, solution comprises contacting the metal with a corrosion inhibiting composition containing more than 30% by weight of one or more organic corrosion inhibiting constituents which are water-insoluble hydrophobic material, and a corrosion inhibitor which contains one or more polymerisable groups containing double or triple bonded carbon, before contacting the metal with the aqueous solution. The method may be used to protect coiled tubing used for matrix acidizing of an oil well by propelling a slug of the corrosion inhibiting composition along the coiled tubing before pumping acid through the tubing.

A connector for lined pipelines includes a tube having opposed male interface elements extending inwardly from respective ends of the tube. One or more circumferential permeable chokes project radially from each male interface element. The chokes minimise flow of oxidising fluid from the bore into the micro-annulus between the liner and the pipe while maximising flow of fluid from the micro-annulus into the bore in the event of catastrophic pressure drop in the bore. To maintain gaps between the tube ends and the pipe liners for fluid flow, shoulder formations extend circumferentially around the tube. The connector may be used in a joint arrangement where each liner includes a body, an end of lesser thickness and greater bore than the body that terminates short of an end of the pipe, an inner step between the body and the end, and an outer step between the end and the pipe.

Methods and systems for cleaning, coating and sealing leaks in existing pipes, in a single operation. A piping system can be cleaned in one pass by dry particulates forced and pulled by air throughout the piping system by a generator and a vacuum. Pipes can be protected from water corrosion, erosion and electrolysis, extending the life of pipes such as copper, steel, lead, brass, cast iron piping and composite materials. Coatings can be applied to pipes having diameters up to approximately 6″. Leak sealants of at least approximately 4 mils thick can cover insides of pipes, and can include novel mixtures of fillers and epoxy materials, and viscosity levels. A positive pressure can be maintained within the pipes during applications. Piping systems can be returned to service within approximately 96 hours.

A petroleum pipeline safety system for preventing contamination of an environmentally sensitive area close to a pipeline includes an upstream portion of the pipeline supplying a flow of fluid material, a crossing portion of the pipeline receiving the flow of fluid material from the upstream portion and conveying the flow of fluid material through the environmentally sensitive area to a downstream portion of the pipeline, the downstream portion, a pipeline pressure activated valve selectively capable of blocking the flow of fluid material from entering the crossing portion based upon a change in pressure within the crossing portion, and a fluid capacitor connected to the upstream portion configured to filter out a pressure spike in the upstream portion associated with the valve blocking the flow of fluid material.

Method for rotolining metallic hollow articles with metallocene-produced polyethylene.

In the coating method, a pipe for transporting oil and/or gas mined from underground is provided. An acid curable resin is passed through the pipe to adhere the acid curable resin to at least a part of an inner wall of the pipe. Then, an acid curing agent is passed through the pipe to allow the acid curing agent to make contact with the acid curable resin such that the acid curable resin is cured.

A device (1) for applying a coating of hardenable plastic to an inner side of a wall of a tubular construction, for example a sewage pipe, includes a supply chamber (3) for containing a hardenable plastic, a delivery head (2) including an outlet (5) for letting out the hardenable plastic from the delivery head (2), and a pump (11) for transporting the hardenable plastic from the supply chamber (3) to the outlet (5). During use, the outlet (5) is positioned at various angular positions with respect to a rotation axis (40), so that the entire circumference of the inner side of the wall of the tubular construction can be provided with the hardenable plastics coating. The supply chamber (3) includes a flexible wall for optimal maneuverability of the device (1), whereby broad application of the device (1) is possible.