Abstract: A surfactant composition for use in well treatment, particularly for removing oil-based mud deposits from a well prior to cementing, comprises an alkylpolyglucoside in a solution of a mutual solvent for water and hydrocarbon. The composition can be used to formulate a chemical wash by dissolving the composition at a concentration of about 1%-10% (e.g. 5%) by weight in water or brine.

Abstract: Disclosed is a process for cleaning wellbore walls, tubing or casings.

Abstract: An acidizing composition and a method of acidizing a hydrocarbon bearing subterranean formation in the presence of ferric ions are provided. The acidizing composition includes a mineral acid solution, an electron donor agent, a primary electron transfer agent and a secondary electron transfer agent. The primary electron transfer agent is a source of vanadium ions. The secondary electron transfer agent is a source of iodide ion or iodine. The electron donor agent and primary and secondary electron transfer agents function together to reduce ferric ion present in the mineral acid solution to ferrous ion which in turn prevents ferric hydroxide and/or free sulfur from precipitating out of the solution and reduces the formation of sludge in crude oil in the formation.

Abstract: Acid based micro-emulsions are disclosed comprising water, an acid blend, an anionic surfactant, a nonionic surfactant, a co-solvent, a solvent and an oxidizer. The micro-emulsions have particular utility in cleaning oil sludges and drilling mud residues from well cuttings, well formations and down hole and surface oil well drilling and production equipment.

Abstract: A method of preventing corrosion in pipelines comprising draining pipeline of all residual compounds, blowing through with nitrogen and rinsing with a corrosion inhibiting rinsing agent.

Abstract: A wellbore fluid composition effective to reduce oil-containing residue and water wet wellbore surfaces is provided. The fluid composition comprises a terpene composition and a surfactant. Methods for use of the fluid composition as a single spacer or as a multiple spacer in conjunction with a second fluid are provided. Methods for use of the composition in reduction or removal of oil-containing residue from wellbore surfaces, as a clean-up fluid, in wellbore completions, as a displacement fluid, and in wellbore treatment are provided.

Abstract: Encapsulated water soluble chemicals for use in controlled time release applications, methods of encapsulating the chemicals and methods of using the encapsulated chemicals are provided. The methods of encapsulating the chemicals are basically comprised of forming a first coating of a dry hydrophobic film forming material or a sparingly soluble material which provides a dry shield on the chemical and then forming a second coating of a porous cross-linked hydrophilic polymer on the first coating which prevents the substantial dissolution of the resulting encapsulated chemical for a selected period of time.

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: A method of preventing corrosion in pipelines comprising draining pipeline of all residual compounds, blowing through with nitrogen and rinsing with a corrosion inhibiting rinsing agent.

Abstract: An acidic fluid that is useful in stimulation and workover operations, and in particular, for the control of iron in acidizing operations, the removal of alkaline earth carbonate scale in scale removal operations, and matrix or fracture acidizing operations, comprises an acid, such as hydrochloric acid; water; and a hydroxyethylaminocarboxylic acid. Preferred hydroxyethylaminocarboxylic acids are hydroxyethylethylenediaminetriacetic acid (HEDTA) and hydroxyethyliminodiacetic acid (HEIDA). Also disclosed herein are methods of controlling iron, removing alkaline earth carbonate scale, or matrix or fracture acidizing, involving the use of the acidic fluid.

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: A sweep material is disclosed comprising barium sulfate that has been ground and sieved, preferably in the range of about −95% 30 mesh to about +95% 100 mesh. The sweep material is added to and circulated with the drilling fluid during drilling of a deviated, directional or horizontal well to remove cuttings beds accumulated on the lower side of the well. After the drill cuttings are dislodged, the drilling fluid is sieved or screened to remove the barium sulfate to avoid a change in density of the fluid. The drilling operation does not have to be stopped during the sweep or cleaning treatment.

Abstract: A method and composition for removing deposits of heavy hydrocarbonaceous materials and finely divided inorganic particulate matter from wellbore and flowline surfaces using a composition containing an alkyl polyglycoside, an ethoxylated alcohol, a caustic and an alkyl alcohol.

Abstract: The invention relates to a process for facilitating the disposal of flowable and pumpable working fluids based on emulsifiers containing W/O invert emulsions--more particularly corresponding auxiliaries of the type used in geological exploration, such as oil-based w/o invert drilling muds--and for the simplified cleaning of solid surfaces soiled therewith, if desired using flowable spraying aids, the process being characterized in that, by selecting and adapting the emulsifiers/emulsifier systems to the oil phase of the invert emulsion, temperature-controlled phase inversion is achieved at temperatures below the in-use temperatures of the w/o invert emulsions, but above the freezing point of the aqueous phase and in that disposal and cleaning are carried out at temperatures in and/or below the phase inversion temperature range.

Abstract: The invention relates to a process for drying out rock containing immobile formation water in the intake radius of natural gas wells and gas storage wells which deliver less than 50 l of water per 1000 m.sup.3 (S.T.P.) of natural gas produced, in which a dispersion comprising the componentsA) a water-repellent active compound,B) hydrophilic water-miscible dispersion medium, with or withoutC) a dispersant renders the water-containing rock hydrophobic.

Abstract: A method for cleaning a wellbore plugged with deposits of heavy hydrocarbons and finely-divided inorganic solids by circulating a surfactant composition containing an alkyl polyglycoside, an ethoxylated alcohol, a caustic and an alkyl alcohol through the wellbore with a coiled tubing.

Abstract: A process for the thermo-hydraulic control of gas hydrates in subsea production and injection wells as well as pipelines which transport liquid or gaseous hydrocarbons is described, the process making use of a Nitrogen Generating System foamed or in solution. The control may signify the prevention of the formation of the gas hydrates or the dissolution of the gas hydrate plug already formed. Under conditions of use designed for the prevention of the formation of gas hydrates the SGN fluid prevents the thermal conditions leading to the gas hydrate plugs. Under conditions of use designed to dissolve the already formed gas hydrate plugs, the SGN fluid alters the thermo-hydraulic conditions which favor the gas hydrate plugs, so that they are dissolved and return to the water+gas phase.

Abstract: A method and composition for removing deposits of heavy hydrocarbonaceous materials and finely divided inorganic particulate matter from wellbore and flowline surfaces using a composition containing an alkyl polyglycoside, an ethoxylated alcohol, a caustic and an alkyl alcohol.

Abstract: A method and composition for removing deposits of heavy hydrocarbonaceous materials and finely divided inorganic particulate matter from wellbore and flowline surfaces using a composition containing an alkyl polyglycoside, an ethoxylated alcohol, an acid and an alkyl alcohol.

Abstract: A composition for and an improved process of, enhancing petroleum recovery from a petroleum reservoir by injecting said composition into the reservoir through a wellbore are provided. The aqueous composition is derived from a concentrate which includes a defoaming agent, a demulsifying agent, and optionally a stabilizing agent suitable for stabilizing the concentrate as an aqueous emulsion. In one embodiment, the defoaming agent is dispersed in carrier solvent and the concentrate further includes an emulsifying agent suitable for emulsifying the carrier solvent in water. The composition is preferably injected at a high pumping rate directly into the formation through the tubing-casing annulus and allowed to permeate into the reservoir surrounding the wellbore before oil production commences. The composition and method are particularly suited for used in conjunction with steam injection oil recovery techniques.

Abstract: The present invention provides methods of cleaning up a producing interval of a well bore drilled using a synthetic oil-water emulsion drill-in fluid. The methods basically comprise contacting filter cake and drill-in fluid on the walls of the well bore with three treatment fluids in three stages, the first and second treatment fluids being comprised of water, a filter cake dissolving acid, a mutual solvent and an emulsion penetrating agent. The third treatment fluid is comprised of water, a filter cake dissolving acid and a water wetting surfactant.

Abstract: Blends of alkyl polyglycoside surfactants having an alkyl chain length of C11 to C16 and blends of alkyl polyglycoside surfactants, in the presence of an ethoxylated alcohol cosurfactant, will form Winsor type III microemulsions in a water-oil mixture in a hydrophile-lipophile balance range of at least about 9.8 to 10.8 at 130.degree. F. wherein the water may be a chloride brine. The compositions are particularly useful in oil and gas well cleanout operations, formation acidizing, and well cementing operations and provide superior cleaning ability for removal of oil based drilling fluids, hydrocarbons and oil based pipe sealant and lubricant compositions, for example.

Abstract: A chemical additive for cleaning a well drilling system and equipment includes an alcohol, preferably a terpene, and either an ether amine or a base fluid or combination of the two. The additive can be mixed with an aqueous solution that may be a water, salt or brine solution.

Abstract: The present invention provides a composition for in-situ decontamination of earth formations comprising:(a) from about 1,000 to about 25,000 parts by weight of a hydrophobically associating polymer per million parts by weight of water;(b) from about 25 to about 7,500 parts by weight per million parts by weight of water of one or more anionic or non-ionic surfactants; and,(c) from about 0.5 wt % to about 4 wt %, based on the weight of water, of salts selected from the group consisting of alkali and alkaline earth metal halides and mixtures thereof.

Abstract: The present invention provides a composition for in-situ decontamination of earth formations comprising:(a) from about 1,000 to about 25,000 parts by weight of a hydrophobically associating polymer per million parts by weight of water;(b) from about 25 to about 7,500 parts by weight per million parts by weight of water of one or more anionic or non-ionic surfactants; and,(c) from about 0.5 wt % to about 4 wt %, based on the weight of water, of salts selected from the group consisting of alkali and alkaline earth metal halides and mixtures thereof.

Abstract: A composition for, and an improved process of, enhancing petroleum recovery from a petroleum reservoir by injecting said composition into the reservoir through a wellbore are provided. The aqueous composition is derived from a concentrate which includes a defoaming agent, a demulsifying agent, and optionally a stabilizing agent suitable for stabilizing the concentrate as an aqueous emulsion. In one embodiment, the defoaming agent is dispersed in carrier solvent and the concentrate further includes an emulsifying agent suitable for emulsifying the carrier solvent in water. The composition is preferably injected at a high pumping rate directly into the formation through the tubing-casing annulus and allowed to permeate into the reservoir surrounding the wellbore before oil production commences. The composition and method are particularly suited for used in conjunction with steam injection oil recovery techniques.

Abstract: A method for controlling phosphonates which tend to precipitate with metal ions in water treatment operations comprising, adding to the water a water-soluble copolymer containing one or more of the following monomeric units:[a] ##STR1## in which: R is hydrogen or an alkyl group, R.sub.1 is an alkyl group and X is hydrogen, NH.sub.4.sup.+, a water soluble metal ion or organic base; and[b] a monocarboxylic acid monomer; and adding the copolymer to the water to be treated in an amount sufficient to prevent precipitation of said phosphonates.

Abstract: A method for the inhibition of scale deposition on the surfaces of a well coproducing oil and scale forming brines comprising injecting into the well reservoir an acidic aqueous solution at a first pH containing dissolved therein a scale inhibitor, multivalent metal ions, and a heat-sensitive pH-increasing substance containing no more than 10 carbon atoms, which decomposes at elevated temperatures liberating an alkaline compound such that the solution is inherently heated by the higher ambient reservoir temperature to a temperature at which the alkaline compound is liberated from the heat-sensitive substance thus raising the pH of the solution to a point at which a sparingly soluble multivalent metal salt of the scale inhibitor is phase separated from the solution on the porous surfaces of the reservoir rock formation, providing for a slow release of inhibitor into the produced brines when the well is in its production phase.

Abstract: Oil and gas wells and injection wells are cleaned of oil-based drilling muds, pipe thread compounds, other oil contaminants, cement and contaminants in injection water by a composition comprising fresh water or seawater, one-half to ten percent concentration of an alkyl polyglycoside surfactant and one to ten percent of a caustic agent such as sodium hydroxide, potassium hydroxide or ammonium hydroxide.