Abstract: Compositions and methods for treating systems, especially oil and/or gas wells, characterized by metal sulfide deposits are provided. Compositions according to the invention generally comprise a thioacid, an amine salt, and a diphosphonic acid. Methods according to the invention may comprise introducing such composition into a system characterized by metal sulfide deposits, or alternatively, introducing into the system individual quantities of the composition components.

Abstract: Improved mud additive compositions are provided which are especially formulated to control hole enlargement due to salt bed erosion during drilling, and to assist in solubilization of deposited salt during well operations. The compositions include a first ingredient such as sodium or potassium ferrocyanide and mixtures thereof, and a second ingredient such as the a phosphonic acid, alkali or alkaline earth metal phosphonic acid salts, or mixtures thereof. The first ingredient is generally present at a level of from about 50-95% by weight in the particulate, dilutable form of the invention, whereas the second ingredient is present at a level of from about 5-50% by weight. The compositions hereof may be added to drilling mud during drilling operations or to fresh water for removing salt depositions.

Abstract: A scale dissolver composition and method for using the composition is provided. Broadly, the dissolver compositions are formed by adding a base such as ammonium hydroxide to a mixture comprising a salt of a chelating agent, a carbonate, and a component selected from the group consisting of organophosphorus compounds, carboxylic acids, and mixtures thereof. The preferred organophosphorus compound is aminotrismethylidine diphosphonic acid while the preferred chelating agent salt is EDTA tetrasodium salt. In use, the dissolver composition is preferably heated to a temperature of from about 100-170° F. and then contacted with the target scale. The compositions are particularly useful for removing barium sulfate and calcium sulfate scales from gas and oil well and pipeline equipment in an efficient and cost-effective manner.

Abstract: The invention generally concerns methods for the synthesis of dialkyl carbonates, and more specifically dimethyl carbonate (DMC) and diethyl carbonate (DEC). Methods according to the invention generally comprise reacting an alcohol or diol, a base and a halogen in the presence of an amine salt catalyst thereby forming a first intermediate. The first intermediate is reacted with carbon monoxide forming a second intermediate which then reacts with the alcohol or diol in the presence of the amine salt catalyst forming the dialkyl carbonate product.

Abstract: An improved method for the chlorine dioxide treatment of oil and/or gas well bores is provided, which eliminates the need for costly and complex chlorine dioxide-generating equipment and yields very high concentrations of chlorine dioxide down hole. The preferred method involves the introduction of reactant(s) into a well and causing a reaction to generate chlorine dioxide in situ. Chlorite and hypochlorite ion sources (e.g., sodium chlorite and sodium hypochlorite) are introduced into the well along with an acid. The well may then be flushed with water to force the reactants and chloride dioxide downwardly to the well formation.

Abstract: An improved process for the removal of cyanide ion from aqueous dispersions (e.g., aqueous spent cadmium plating solutions or plating rinse water solutions) is provided wherein a source of Fe+2 ion is reacted with a cyanide ion-containing aqueous dispersion at low pH to form a relatively insoluble reaction product complex, whereupon the reaction product is removed by filtration or the like. In preferred practice, the pH of a waste water is adjusted to a level of up to about 2, followed by the addition of ferrous ammonium sulfate.

Abstract: A scale dissolver composition and method for using the composition is provided. Broadly, the dissolver compositions are formed by adding a base such as ammonium hydroxide to a mixture comprising a salt of a chelating agent, a carbonate, and a component selected from the group consisting of organophosphorus compounds, carboxylic acids, and mixtures thereof. The preferred organophosphorus compound is aminotristmethylidine diphosphonic acid while the preferred chelating agent salt is EDTA tetrasodium salt. In use, the dissolver composition is preferably heated to a temperature of from about 100-170° F. and then contacted with the target scale. The compositions are particularly useful for removing barium sulfate and calcium sulfate scales from gas and oil well and pipeline equipment in an efficient and cost-effective manner.

Abstract: Solid, slowly dispersible well treatment composites are provided which have a sufficiently high melting point to prevent melting of the composite in hot weather. The composites have a low solubility and high specific gravity compared to prior art treatment agents; thus the composites readily sink in well and pipeline fluids and slowly release treatment ingredients over time, depending on the downhole and pipeline conditions. The composites include a nonylphenol ethoxylate having at least about 50 moles of ethylene oxide per mole of nonylphenol and a fatty acid amide having from 14-20 carbon atoms. Preferably, the composites further include a weighting agent and active ingredients selected from the group consisting of corrosion inhibitors, scale inhibitors, bactericides, scale converters, foaming agents, and mixtures thereof. In one embodiment, the composites are spherical in shape and are passed through pipelines for maintenance and treatment of the pipelines.

Abstract: Solid, slowly dispersible well treatment composites are provided which have a sufficiently high melting point to prevent melting of the composite in hot weather. The composites have a low solubility and high specific gravity compared to prior art treatment agents; thus the composites readily sink in well and pipeline fluids and slowly release treatment ingredients over time, depending on the downhole and pipeline conditions. The composites include a compound selected from the group consisting of nonylphenol ethoxylates having at least about 50 moles of ethylene oxide per mole of nonylphenol, fatty acid amides having from 14-20 carbon atoms, and mixtures thereof. Preferably, the composites further include a weighting agent and active ingredients selected from the group consisting of corrosion inhibitors, scale inhibitors, bactericides, scale converters, foaming agents, and mixtures thereof.

Abstract: Iron-complexing or scavenging compositions are provided having particular utility as downhole well treatments or as a part of regenerating media for cation exchange resins. The compositions may be in dry or liquid form and preferably include stannous chloride, an acid selected from the group consisting of phosphorous acid, phosphoric acid and mixtures thereof, and sodium hexametaphosphate.

Abstract: Solid, slowly dispersible well treatment composites are provided which have a sufficiently high melting point to prevent melting of the composite in hot weather. The composites have a low solubility and high specific gravity compared to prior art treatment agents; thus the composites readily sink in well fluids and slowly release treatment ingredients over time, depending on the downhole conditions. The composites include a nonylphenol ethoxylate having at least about 50 moles of ethylene oxide per mole of nonylphenol and a fatty acid amide having from 16-20 carbon atoms. Preferably, the composites further include a weighting agent and active ingredients selected from the group consisting of corrosion inhibitors, scale inhibitors, bactericides, scale converters, foaming agents, and mixtures thereof.