Abstract: Gelatin capsules containing oil field chemicals, preferably weighted with a heavy metal compound, are made more stable under certain conditions by the incorporation of a strong chelating agent. The microcapsules can provide an extended treatment period since many materials that would damage the microcapsules are controlled by the chelating agent.

Abstract: This invention relates to drilling fluid additives that suppress clay swelling within a subterranean well and to methods for controlling clay swelling during the drilling of a subterranean well. In one embodiment trihydroxy alkyl amine is reacted with an alkyl halide or a water soluble quaternary amine to form a quaternized trihydroxy alkyl amine. The reaction products can also include condensed reaction products of quaternized trihydroxy alkyl amines. In another embodiment a choline derivative is used. The quaternized reaction products and choline derivatives are characterized by low toxicity and compatibility with anionic drilling fluid components. The products are added to water base drilling fluids which are circulated throughout a well. The drilling fluid additives and the method of controlling clay swelling provide for improved control of the rheological properties of drilling fluids along with increased environmental and drilling fluid compatibility.

Abstract: An oil in water dispersion composition is disclosed that comprises a mixture of water and(A) an overbased non-Newtonian colloidal disperse system comprising(1) solid metal-containing colloidal particles predispersed in(2) a disperse medium of at least one inert organic liquid and(3) at least one member selected from the class consisting of organic compounds which are substantially soluble in the disperse medium, where the molecules of said organic compound have polar substituents and hydrophobic portions;(B) a water soluble associative thickener comprising a base-neutralized copolymer having copolymerized therein about 90 to about 99 mole percent of a carboxyl-containing, ethylenically unsaturated hydrocarbon and about 1 to about 10 mole percent of a nonionic surfactant acrylate having the formula: ##STR1## wherein R.sup.1 is hydrogen or methyl, R.sup.

Abstract: An oil-in-water emulsion composition is disclosed which comprises a mixture of water and(A) at least one oil comprising(1) a natural oil or synthetic triglyceride of the formula ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 are independently saturated or unsaturated aliphatic groups that contain from about 7 to about 23 carbon atoms;(2) a synthetic ester base oil comprising the reaction of a monocarboxylic acid or a dicarboxylic acid or an aryl carboxylic acid;(3) an olefin;(4) a polyolefin;(B) at least one phosphite ester of the formula ##STR2## wherein R.sup.11 and R.sup.12 are independently aliphatic, aryl or aliphatic substituted aryl groups that independently contain from 6 to 30 carbon atoms; and(C) at least one emulsifier.

Abstract: This invention relates to a composition comprising a mixture of a brine and a liquid oil, and (A) an emulsifying amount of (i) at least one reaction product of a hydrocarbyl-substituted succinic acylating agent, and at least one of (a) ammonia, (b) an alcohol, or (c) an amine, or at least one salt of the reaction product; or (ii) at least one reaction product of a hydroxyaromatic compound, an aldehyde, and an amine, and (B) at least one surfactant selected from the group consisting of a polyoxyalkylene amine, a polyoxyalkylene amide, a polyoxyalkylene alcohol, a polyoxyalkylene phenol, a polyoxyalkylene ester, a fatty acid salt, an amine or an alkaline earth or transition metal sulfonate, or a reaction product of a hydroxyamine or a polyalkylenepolyamine with an acylating agent selected from the group consisting of a fatty monocarboxylic acylating agents, a dicarboxylic acylating agent other than a succinic acylating agent, and a tricarboxylic acylating agent.

Abstract: The present invention provides amphoteric acetates, diacetates, and glycinates which may be added to drilling fluids in order to minimize hydration and prevent erosion loss of water-sensitive shale substrates.

Abstract: The present invention relates to a method and a solution for use in downhole drilling to reduce the torque necessary to rotate the drill string. The solution comprises a sulfonate according to the formula (RSO.sub.3).sub.x Me.sup.x, where R is selected from the group consisting of an alkyl group, an aryl group, an alkylaryl group, and mixtures thereof having a molecular weight between about 280 and about 650, x is the number of (RSO.sub.3) groups, and Me.sup.x is a metal ion having a valence x. The solution is pumped down a drill string as a slug in order to coat solids which accumulate in the well and allow them to be removed along with the drilling fluid.

Abstract: Low-toxicity invert emulsion fluids for well drilling are disclosed. The fluids comprise a non-hydrocarbon, non-mineral oil continuous phase and a dispersed aqueous phase. The continuous phase materials of the invention pass the 48 hour, LC50 Mysidopsis bahia bioassay test protocol.

Abstract: A composition and method for inhibiting corrosion by chlorine dioxide in oil field water flood systems are disclosed. The composition is comprised of an alcohol, an acid, a fatty imidazoline, an ethoxylated fatty diamine, and water. This composition has proven more effective than chromates at inhibiting the corrosion caused by chlorine dioxide, further without the serious toxicological effects caused by the use of chromates.

Abstract: The present invention relates to a method comprising the steps of introducing into a well borehole a composition, comprising water and an amount, sufficient to reduce drilling torque, prevent sticking or twisting of a pipe during drilling, or release a stuck pipe in a well borehole, of (A) at least one reaction product of (A-1) at least one hydrocarbyl-substituted carboxylic acylating agent and (A-2) at least one amine-terminated polyoxyalkylene having a number average molecular weight from about 600 to about 10,000, or at least one salt of the reaction product, and drilling the well borehole. Drilling torque, twisting and sticking of the pipe during drilling and releasing of stuck pipe in a well borehole are all effectively controlled by the methods and compositions of the present invention.

Abstract: This invention relates to a composition suitable for use in process for the removal of sulfides, especially hydrogen sulfide from a feed contaminated therewith. The composition comprises an aqueous solution of a chlorite and a corrosion inhibitor which is an amphoteric ammonium compound of the formula ##STR1## as herein defined. The inhibitor mitigates problems of corrosion associated with chlorite scavengers.