Abstract: A remedial method for repairing a damaged cement sheath, especially for use in wells in which fluids with a pH lower than 6 are injected, stored or extracted, comprises placing an acid swellable composition adjacent to the cement sheath. In the event of cement-matrix failure, or bonding failure between the cement/casing interface or the cement/borehole- wall interface, the composition may be injected into or adjacent to the cement sheath so that the material swells when contacted by acid gases, including carbon dioxide and hydrogen sulfide. The swelling seals voids in the cement matrix, or along the bonding interfaces, thereby restoring zonal isolation.

Abstract: A self-adaptive cement formulation includes cement, water, block copolymer and asphaltite-mineral particles. The set cement demonstrates self-healing properties when exposed to methane, and is particularly suited for well-cementing applications. After placement and curing, the self-healing properties help maintain zonal isolation should bonding be disrupted between the set cement and the formation or a casing string, should cracks or defects appear in the set-cement matrix, or both.

Abstract: This invention relates to methods for servicing subterranean wells, in particular, fluid compositions and methods for remedial operations during which the fluid compositions are pumped into a wellbore and make contact with well cements placed during primary cementing or previous remedial cementing operations.

Abstract: A self-adaptive cement formulation includes cement, water and asphaltite-mineral particles. The set cement demonstrates self-healing properties when exposed to methane, and is particularly suited for well-cementing applications. After placement and curing, the self-healing properties help maintain zonal isolation should bonding be disrupted between the set cement and the formation or a casing string, should cracks or defects appear in the set-cement matrix, or both.

Abstract: A self-adaptive cement formulation includes cement, water, block copolymer and asphaltite-mineral particles. The set cement demonstrates self-healing properties when exposed to methane, and is particularly suited for well-cementing applications. After placement and curing, the self-healing properties help maintain zonal isolation should bonding be disrupted between the set cement and the formation or a casing string, should cracks or defects appear in the set-cement matrix, or both.

Abstract: The invention provides a system comprising: a tubular containing a first surface comprising a coating made of a first swellable material coating said first surface, wherein said coating has a second surface and said first swellable material is able to swell in contact with a first fluid on said second surface; and a composition made of a settable material and a second swellable material able to swell in contact with a second fluid. The invention also discloses the method associated with the use of such a system.

Abstract: A self-adaptive cement system includes cement, water and at least one additive that reacts or/and expands in contact with oil and gas. Several chemical products have been identified including rubber alkylstyrene, polynorbornene, resins such precrosslinked substituted vinyl acrylate copolymers and diatomaceous earth. These additives have the effect of making the cement self-healing in the event of physical failure or damage such as micro-annuli. The self healing property is produced by the contact with subterranean hydrocarbon fluids, the potential repair mechanism is thus activated if and when needed in case of start of loss of zonal isolation. In another embodiment, the expansion is deliberately induced by pumping a hydrocarbon fluid in the vicinity of the set cement.

Abstract: The invention provides a cementing composition for use in oilfield application, wherein a significant amount of cement is left intentionally un-hydrated when the cement is set; such that said amount of un-hydrated cement becomes hydrated when the set cement is damaged.

Abstract: A self-healing cement system includes cement, water and at least one additive that swells in contact with water from reservoir or from formation in the case of a structural failure in the set cement to provide a physical barrier in the zone of failure. Examples of such material include particles of super-absorbent polymer. These additives have the effect of making the cement self-healing in the event of physical failure or damage such as micro-annuli. The self healing property is produced by the contact of the water itself, the potential repair mechanism is thus activated if and when needed in case of start of loss of zonal isolation. Several super-absorbent polymers have been identified such as polyacrylamide, modified crosslinked poly(meth)acrylate and non-soluble acrylic polymers.

Abstract: A self-adaptive cement formulation includes cement, water and thermoplastic block-polymer particles. The set cement demonstrates self-healing properties when exposed to methane, and is particularly suited for well-cementing applications. After placement and curing, the self healing properties help maintain zonal isolation should bonding be disrupted between the set cement and the formation or a casing string, should cracks or defects appear in the set-cement matrix, or both.

Abstract: Compositions containing an alkali swelling polymer and a pH buffer with a pH between 3 and 7 may be used to treat a wellbore. The pH buffer prevents the swelling of the alkali swellable polymer. The compositions may be placed in the wellbore, whereupon they contact another material with pH increasing properties. The pH of the compositions increases, causing the compositions to swell and form a seal. The alkali swelling polymer may be an alkali swelling latex.

Abstract: The disclosure relates to a composition for well cementing in a subterranean formation comprising a pumpable slurry of cement, water and at least one additive that swells in contact with underground fluid (hydrocarbon, water or brines and mixtures thereof) in case of failure of the cement matrix and to a method of cementing a well using said composition. The swelling additive is an elastomer compounded with an aqueous inverse emulsion of particles of a polymer comprising a betaine group.

Abstract: The disclosure relates to a system (10) for improving zonal isolation in a well in a subterranean formation, comprising: a tubular (1) having a outer surface (11); and a swellable coating (2) coating the outer surface (11) of said tubular (1), said swellable coating (2) having an external surface (21); and/or a composition (20) provided in an annular space outside said tubular (1). The swellable coating (2) is made of a first swellable material (3) able to swell in contact with a first fluid (6) on said external surface (21) and/or the composition (20) is made of a second swellable material (4) able to swell in contact with a second fluid (7), and wherein said first (3) and/or said second (4) swellable materials include an elastomer compounded with an aqueous inverse emulsion of particles of a polymer comprising a betaine group, said elastomer being able to swell in contact with hydrocarbon and saline aqueous fluids.

Abstract: The invention provides a cementing composition for use in oilfield application, wherein a significant amount of cement is left intentionally un-hydrated when the cement is set; such that said amount of un-hydrated cement becomes hydrated when the set cement is damaged.

Abstract: A self-adaptive cement formulation includes cement, water, block copolymer and asphaltite-mineral particles. The set cement demonstrates self-healing properties when exposed to methane, and is particularly suited for well-cementing applications. After placement and curing, the self-healing properties help maintain zonal isolation should bonding be disrupted between the set cement and the formation or a casing string, should cracks or defects appear in the set-cement matrix, or both.

Abstract: A self-adaptive cement formulation includes cement, water and asphaltite-mineral particles. The set cement demonstrates self-healing properties when exposed to methane, and is particularly suited for well-cementing applications. After placement and curing, the self-healing properties help maintain zonal isolation should bonding be disrupted between the set cement and the formation or a casing string, should cracks or defects appear in the set-cement matrix, or both.

Abstract: Methods of characterizing the self-healing properties of a set cement based material in contact with hydrocarbons in an oil- and/or gas-well are described. The methods comprise: providing a test cell (10); providing said test cell (10) with a sample (31, 40) of the set cement based material; damaging the sample to simulate a loss of zonal isolation resulting from damages made to the set cement based material in the oil- or gas-well; injecting a hydrocarbon fluid in the test cell; allowing the cement based material to heal by itself; measuring the differential pressure (?P) across the sample (31, 40); and characterizing the self-healing properties of the cement based material from the measure of said differential pressure (?P).

Abstract: Cementing compositions for use in oilfield applications are designed such that, after setting, a significant amount of cement remains unhydrated. After placement in a subterranean well, the unhydrated cement remains dormant. If the cement sheath becomes damaged, the unhydrated cement hydrates upon exposure to formation fluids, thereby restoring zonal isolation in the wellbore. The compositions comprise emulsions that allow a substantial reduction of the water-to-cement ratio, yet the rheological properties remain suitable for placement in the well.

Abstract: Fluid compositions comprising an aqueous epoxy resin, a hardener and particles comprising silica, aluminosilicate or both are useful for establishing hydraulic isolation in cemented subterranean wells. Upon entering voids and cracks in or adjacent to the cement sheath, and contacting the set-cement surfaces, the composition reacts and forms a seal that prevents further leakage.

Abstract: A self-adaptive cement system includes cement, water and at least one additive that reacts or/and expands in contact with oil and gas. Several chemical products have been identified including rubber alkylstyrene, polynorbornene, resins such precrosslinked substituted vinyl acrylate copolymers and diatomaceous earth. These additives have the effect of making the cement self-healing in the event of physical failure or damage such as micro-annuli. The self healing property is produced by the contact with subterranean hydrocarbon fluids, the potential repair mechanism is thus activated if and when needed in case of start of loss of zonal isolation. In another embodiment, the expansion is deliberately induced by pumping a hydrocarbon fluid in the vicinity of the set cement.