A method of using a gas control additive to provide gas migration control in a wellbore includes the steps of mixing the gas control additive with a cement to form a cement slurry, where the gas control additive includes a semi-permeable membrane and a scrubbing agent, such that the semi-permeable membrane forms a shell around a core such that the scrubbing agent is in the core, introducing the cement slurry to the wellbore, and reacting the scrubbing agent with an antagonistic gas to produce a helper byproduct, where the antagonistic gas migrates from a hydrocarbon-bearing formation into the wellbore and permeates through the semi-permeable membrane to the core of the gas control additive.

A method of monitoring conditions in a wellbore by disposing capsules with a signaling agent downhole, and monitoring the presence of the signaling agent released from the capsules that escape the wellbore. The capsules are formed by combining immiscible liquids, where one of the liquids contains the signaling substance, and each of the liquids contains a reagent. When combined, the liquids segregate into a dispersed phase and a continuous phase, with the dispersed phase having the signaling agent. The reagents react at the interfaces between dispersed and continuous phases and form polymer layers encapsulating the signaling agent to form the capsules. When disposed downhole, such as in casing cement, the capsule membranes can burst under pressure or temperature to release the signaling agent. Adjusting relative concentrations of the reagents varies membrane strength and permeability.

A method of using a gas control additive to provide gas migration control in a wellbore includes the steps of mixing the gas control additive with a cement to form a cement slurry, where the gas control additive includes a semi-permeable membrane and a scrubbing agent, such that the semi-permeable membrane forms a shell around a core such that the scrubbing agent is in the core, introducing the cement slurry to the wellbore, and reacting the scrubbing agent with an antagonistic gas to produce a helper byproduct, where the antagonistic gas migrates from a hydrocarbon-bearing formation into the wellbore and permeates through the semi-permeable membrane to the core of the gas control additive.

Capsules with a cement additive covered by a polymeric outer shell are added to wellbore cement. The additive is released from the shells by osmosis or shell ruptures. Capillary forces draw the additive into micro-annuli or cracks present in the cement, where the additive seals the micro-annuli and cracks to define a self-sealing material. The empty shells remain in the cement and act as an additive that modifies cement elasticity. The capsules are formed by combining immiscible liquids, where one of the liquids contains a signaling substance, and each of the liquids contains a reagent. When combined, the liquids segregate into a dispersed phase and a continuous phase, with the dispersed phase having the signaling agent. The reagents react at interfaces between dispersed and continuous phases and form polymer layers encapsulating the signaling agent to form the capsules. Adjusting relative concentrations of the reagents varies membrane strength and permeability.

A method of monitoring conditions in a wellbore by disposing capsules with a signaling agent downhole, and monitoring the presence of the signaling agent released from the capsules that escape the wellbore. The capsules are formed by combining immiscible liquids, where one of the liquids contains the signaling substance, and each of the liquids contains a reagent. When combined, the liquids segregate into a dispersed phase and a continuous phase, with the dispersed phase having the signaling agent. The reagents react at the interfaces between dispersed and continuous phases and form polymer layers encapsulating the signaling agent to form the capsules. When disposed downhole, such as in casing cement, the capsule membranes can burst under pressure or temperature to release the signaling agent. Adjusting relative concentrations of the reagents varies membrane strength and permeability.

Capsules with a cement additive covered by a polymeric outer shell are added to wellbore cement. The additive is released from the shells by osmosis or shell ruptures. Capillary forces draw the additive into micro-annuli or cracks present in the cement, where the additive seals the micro-annuli and cracks to define a self-sealing material. The empty shells remain in the cement and act as an additive that modifies cement elasticity. The capsules are formed by combining immiscible liquids, where one of the liquids contains a signaling substance, and each of the liquids contains a reagent. When combined, the liquids segregate into a dispersed phase and a continuous phase, with the dispersed phase having the signaling agent. The reagents react at interfaces between dispersed and continuous phases and form polymer layers encapsulating the signaling agent to form the capsules. Adjusting relative concentrations of the reagents varies membrane strength and permeability.

A method of monitoring conditions in a wellbore by disposing capsules with a signaling agent downhole, and monitoring the presence of the signaling agent released from the capsules that escape the wellbore. The capsules are formed by combining immiscible liquids, where one of the liquids contains the signaling substance, and each of the liquids contains a reagent. When combined, the liquids segregate into a dispersed phase and a continuous phase, with the dispersed phase having the signaling agent. The reagents react at the interfaces between dispersed and continuous phases and form polymer layers encapsulating the signaling agent to form the capsules. When disposed downhole, such as in casing cement, the capsule membranes can burst under pressure or temperature to release the signaling agent. Adjusting relative concentrations of the reagents varies membrane strength and permeability.

The present invention provides multilayer polymer redispersible powder (RDP) particles comprising a major proportion of from 50 to 90 wt. %, preferably, from 60 to 85 wt. %, based on total polymer solids, of epoxy resin resins having a calculated glass transition temperature (Tg) of from 0 to 40 C., a methacrylic acid containing alkali soluble polymer outer layer, and a divalent metal, such as zinc powder, having an aqueous pKa of 9.55 or more, or its acid salt having a pH of 7.0 or less, such as strong acid salts, e.g., chlorides, sulfates or phosphates, or organic acid salts, e.g., acetates, succinates and citrates, as well as to methods of making the same.

A mixture contains: (a) an acrylic core-shell redispersible polymer powder with a core polymer that is an acrylic having a glass transition temperature in a range of 40 to 50 degrees Celsius and a shell polymer that is alkali soluble and contains more carboxyl-group functionalities than the core polymer and containing a nucleating agent having a boiling point of 150-500 degrees Celsius and a water solubility of 3.5 weight-percent or less; and (b) a second redispersible polymer powder selected from acetate ethylene copolymer redispersible polymer powders and polymer powders of a blend of vinyl acetate ethylene copolymer and vinyl ester of versatic acid copolymer; where the concentration of (a) is more than 20 weight-percent and less than 100 weight-percent of the total combined weight of (a) and (b). The mixture can further contain: (c) a Portland cement; (d) alumina rich cement; and (e) calcium sulfate.

A mixture contains: (a) an acrylic core-shell redispersible polymer powder with a core polymer that is an acrylic having a glass transition temperature in a range of 40 to 50 degrees Celsius and a shell polymer that is alkali soluble and contains more carboxyl-group functionalities than the core polymer and containing a nucleating agent having a boiling point of 150-500 degrees Celsius and a water solubility of 3.5 weight-percent or less; and (b) a second redispersible polymer powder selected from acetate ethylene copolymer redispersible polymer powders and polymer powders of a blend of vinyl acetate ethylene copolymer and vinyl ester of versatic acid copolymer; where the concentration of (a) is more than 20 weight-percent and less than 100 weight-percent of the total combined weight of (a) and (b). The mixture can further contain: (c) a Portland cement; (d) alumina rich cement; and (e) calcium sulfate.