Abstract: A pressure regulator for dispensing CO2 gas from a pressurized cylinder which has a reduced probability of freezing when liquid carbon dioxide is converted to the gaseous phase. A plunger which is configured to increase the length of the gas flow path between the regulator inlet and the regulator outlet, and thus to allow liquid CO2 more time to convert to a gas before egressing from the regulator. In the preferred embodiment orifices are provided through the plunger head and spaces are provided about the periphery of the plunger head, which allow the CO2 liquid to flow from the underside of the plunger through the plunger head, over the top of the plunger and about the side of the plunger head before egressing through the regulator outlet.

Abstract: A pressure regulator for dispensing CO2 gas from a pressurized cylinder which has a reduced probability of freezing when liquid carbon dioxide is converted to the gaseous phase. A plunger which is configured to increase the length of the gas flow path between the regulator inlet and the regulator outlet, and thus to allow liquid CO2 more time to convert to a gas before egressing from the regulator. In the preferred embodiment orifices are provided through the plunger head and spaces are provided about the periphery of the plunger head, which allow the CO2 liquid to flow from the underside of the plunger through the plunger head, over the top of the plunger and about the side of the plunger head before egressing through the regulator outlet.

Abstract: A method of preventing gas breakthrough in an oil well, which includes first pumping a slug of an alkaline earth salt into the well bore, followed by a slug of spacer solution, and finally a slug of a fatty acid resin. The resin can comprise at least one fatty acid, a fat (or tall oil), and other components. The resin and alkaline earth salt advantageously react in situ to form a water and gas insoluble precipitate or gum that forms a sealing zone around the oil/gas interface of the well bore, and also allows the oil to dissolve the precipitate to facilitate recovery of the oil.

Abstract: A crosslinked acid gel comprising an emulsion polymer and an external activator is provided. Methods for acid fracturing subterranean formations using the crosslinked acid gel are also provided.

Abstract: A crosslinked acid gel comprising an emulsion polymer and an external activator is provided. Methods for acid fracturing subterranean formations using the crosslinked acid gel are also provided.