Process for producing aqueous polyacrylamide solutions by polymerizing an aqueous solution comprising at least acrylamide thereby obtaining an aqueous polyacrylamide gel and dissolving said aqueous polyacrylamide gel in water, wherein the manufacturing steps are allocated to two different locations A and B and the process comprises the step of transporting an aqueous polyacrylamide gel hold in a transportable polymerization unit from a location A to a location B. The transportable polymerization unit comprises a cylindrical upper part, a conical part at its lower end, feeds for the aqueous monomer solution, a closable bottom opening, and means allowing to deploy the polymerization unit in a vertical manner.

Process for producing aqueous polyacrylamide solutions by polymerizing an aqueous solution comprising at least acrylamide thereby obtaining an aqueous polyacrylamide gel and dissolving said aqueous polyacrylamide gel in water, wherein the manufacturing steps are allocated to two different locations A and B and the process comprises the step of transporting an aqueous polyacrylamide gel hold in a transportable polymerization unit from a location A to a location B. The transportable polymerization unit comprises a cylindrical upper part, a conical part at its lower end, feeds for the aqueous monomer solution, a closable bottom opening, and means allowing to deploy the polymerization unit in a vertical manner.

Process for producing aqueous polyacrylamide solutions by polymerizing an aqueous solution comprising at least acrylamide thereby obtaining an aqueous polyacrylamide gel and dissolving said aqueous polyacrylamide gel in water, wherein the manufacturing steps are allocated to two different locations A and B and the process comprises the step of transporting an aqueous polyacrylamide gel hold in a transportable polymerization unit from a location A to a location B. Modular, relocatable plant for manufacturing aqueous polyacrylamide solutions wherein the units of the plant are located at two different locations A and B.

Systems and methods for sealing a lost circulation zone associated with a subterranean well include a drill string with a circulating port and a lost circulation material. A lost circulation shape is a hollow body having an outer skin and an open interior chamber. The outer skin includes a plurality of perforations that extend through the outer skin, providing fluid communication between an exterior of the lost circulation shape and the open interior chamber. The plurality of perforations are sized to prohibit a passage of lost circulation material between the exterior of the lost circulation shape and the open interior chamber.

Methods of capturing carbon dioxide in a wellbore can include installing a sealing element in the wellbore. The sealing element swells in the presence of carbon dioxide and can be used for capturing the carbon. The sealing element can include a carbon-swelling material, such as a carbon-swelling polymers, metal-based materials, or combinations of elastomeric polymers and metal-based materials. The sealing element can also include combinations of different carbon-swelling materials, fillers or other compounds, and materials that are not carbon swellable. The sealing element can create a seal, form an anchor, or create a seal and form an anchor in the wellbore after swelling.

A body defines a central flow passage. A check valve is located within the central flow passage. The check valve is supported by the body. The check valve is arranged such that a fluid flow travels in a downhole direction during operation of the float collar. An auxiliary flow passage is substantially parallel to the central flow passage and is defined by the body. The auxiliary flow passage includes an inlet upstream of the check valve and an outlet at a downhole end of the float collar. A rupture disk seals the inlet of the auxiliary flow passage. The rupture disk is configured to burst at a specified pressure differential.

A body defines a central flow passage. A check valve is located within the central flow passage. The check valve is supported by the body. The check valve is arranged such that a fluid flow travels in a downhole direction during operation of the float collar. An auxiliary flow passage is substantially parallel to the central flow passage and is defined by the body. The auxiliary flow passage includes an inlet upstream of the check valve and an outlet at a downhole end of the float collar. A rupture disk seals the inlet of the auxiliary flow passage. The rupture disk is configured to burst at a specified pressure differential.

The invention includes methods for stimulating a hydrocarbon-bearing formation by perforating a wellbore and introducing an acidic composition in the wellbore. A preferred embodiment includes inserting an isolation plug in the wellbore at a predetermined location followed by inserting a perforating tool and a breakdown acid into the wellbore. The wellbore is perforated by the tool to create a perforated area. The breakdown acid is allowed to come into contact with the perforated area for a predetermined period of time sufficient to prepare the formation for stimulation. The tool is then removed from the wellbore wherein stimulation of the perforated area is thereby initiated. Also disclosed is a corrosion inhibiting composition for use with the acidic composition.

A reversible gel composition including nanosilica and polyethylene oxide, the nanosilica and polyethylene oxide present at concentrations operable to allow for the reversible gel composition to be a flowable liquid at pH greater than about 8 and operable to allow for the reversible gel composition to be a substantially solid gel at pH less than about 8.

An epoxy resin system composition and a loss circulation material including the reaction product of the epoxy resin system are provided. The epoxy resin system includes a polyhedral oligomeric silsesquioxane (POSS) epoxy resin with at least one reactive group, a curing agent, and a CO.sub.2 gas-generating compound. The CO.sub.2 gas-generating compound generates CO.sub.2 during the reaction such that a volume of the lost circulation material is greater than a volume of the epoxy resin system. A method of treating a defect in a wellbore includes introducing the epoxy resin system into the wellbore such that epoxy resin system is proximate to a face of the defect, and maintaining the epoxy resin system at the face of the defect such that the epoxy resin system cures and a lost circulation material forms and fluidly seals the defect in the wellbore.