Abstract: Process for the dissolution of asphaltene sediments in oil wells which consists in introducing a solubilizing composition for the above asphaltenes into the oil wells, characterized in that the solubilizing composition comprises:(a) a basically hydrocarbon fraction consisting of at least 70%, preferably at least 80% by weight, of aromatic and alkyl aromatic hydrocarbons, the alkyl group being from C.sub.1 to C.sub.4 ;(b) a fraction basically consisting of quinoline and isoquinoline as such or alkyl substituted, preferably as such, the alkyl group being from C.sub.1 to C.sub.4 ; the weight ratio between fraction (a) and (b) being from 97.5/2.5 to 75/25, preferably from 97/3 to 90/10.

Abstract: A process for cleaning a well system and equipment has been developed using a chemical additive that includes an alkene alcohol, preferably a terpene, and either an ether amine or base fluid or combination of the two. The additive can be used in an aqueous or salt solution. The process includes circulating the chemical additive in the well system with spacer fluids.

Abstract: The basic method is to raise the temperatures of the tube, rod and liquid in the well into a range in which paraffin and asphaltene are removable by fluid flow in and from the well. The temperatures are raised by circulating the liquid through the well and a heat exchanger which heats the fluid which subsequently heats the well components. The well pump provides the circulation flow. In a preferred practice of the method, operation is such that the annulus of the well is essentially empty and the liquid recirculated until the difference between the temperatures of fluid flowing into the well and on the outer surfaces of the tube and fluid flowing out is within a desired range and then some of the fluid is diverted to storage while the remaining fluid is recirculated and heated to maintain the higher temperatures throughout the well as long as needed.

Abstract: A composition and method for acidizing a formation in the presence of ferric ion, free sulfur and/or sulfides is disclosed. The composition employs a ferric ion reducing agent and a sulfide reactant separately or in combination. The ferric ion reducing agent is a thioalkyl acid. The sulfide reactant compounds include .alpha.-diketones and saturated and .alpha.-unsaturated cyclic ketones. In another aspect, the reducing activity of the thioalkyl acid is accelerated by the presence of a catalytic quantity of a compound or mixture of compounds which yield in acid solution cuprous ion, cupric ion or combinations thereof with iodide ion.

Abstract: Compounds selected from the group consisting of ammonia, ammonium-containing compounds, urea, urea homologues and analogues, and mixtures thereof surprisingly lower the crystallization temperature of aqueous, carbon disulfide precursor (e.g., thiocarbonate)-containing solutions.

Abstract: Compounds selected from the group consisting of urea, urea homologues and analogues, and mixtures thereof are employed to synergistically increase the dewaxing efficacy of aqueous, carbon disulfide precursor (e.g., thiocarbonate)-containing solutions.

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 process for inhibiting the deposition or precipitation of wax in a hydrocarbon fluid such as, for example, a crude oil, and for operating a pipeline is disclosed. The process comprises combining an effective amount of a polymer with the hydrocarbon fluid wherein the polymer comprises random repeat unit of butadiene. Also provided is a composition which comprises a hydrocarbon fluid and a random copolymer which comprises repeat units of styrene and butadiene.

Abstract: An asphaltene removal composition comprising an alkyleneamine-fatty acid condensation reaction product and one or more polar aprotic high dielectric constant solvents is useful for removing and inhibiting asphaltene deposits from wells, pipelines and associated equipment.

Abstract: Asphaltenes may be dispersed in caustic treated petroleum crude oil, or in any fraction thereof by adding an effective dispersing amount of a mono or di substituted alkylphenol-formaldehyde resin and or a monosubstituted alkylphenol-polyethylenepolyamine-formaldehyde resin, such resins having a weight average molecular weight of from about 1,000 to about 20,000, and an alkyl substituent containing from about 4 to about 24 carbon atoms, which alkyl substituent may be linear or branched.

Abstract: Method and apparatus to facilitate the economical recovery of crude oil from an oil well having a string of tubing which extends to the level of the underground reservoir of crude oil. An Ion Collider is attached to the lower end of the tubing with the Ion Collider at the level of the crude oil reservoir. The Ion Collider consists of two spaced-apart cylindrical metal tubes whose common vertical axis coincides with the axis of the string of tubing. The Ion Collider's inner tube has its upper end capped and its lower end joined to the lower end of the outer tube whose upper end opens into the interior of the tubing. The Ion Collider's inner tube contains a multiplicity of spaced-apart holes in its cylindrical wall. The entire inner tube and the inner surface of the outer tube are made of an alloy of copper and nickel in which the copper comprises at least 80% of the alloy.

Abstract: Methods for removing paraffin wax deposits from the surfaces of oilfield production equipment during oil production by melting and subsequently dispersing the deposits. These methods utilize an acid compound and a neutralizer compound which react exothermally to melt the deposit and form a dispersant to remove the melted fragments of the deposit.

Abstract: Oil or water based drilling muds, together with other wellbore contaminants such as pipe thread sealants and lubricants are displaced from the well and the wellbore surfaces are cleaned by a system of four serially pumped fluid pills. The first stage fluid pill is a weighted spacer having an alkyl polyglycoside surfactant, a dispersant, a weighting agent and a viscosifier. The second stage pill is a drive fluid formed by water and a viscous polymer gel such as clarified xanthan gum having a viscosity/shear rate characteristic which minimizes mixing of the drive fluid pill with the displacement fluid pill. A buffer fluid pill comprising completion brine is interposed between the drive fluid pill and a fourth stage comprising a wash fluid pill using an organic solvent or a caustic alkyl polyglycoside as a final cleaning stage. The densities of the pills are controlled to minimize mixing and fingering of one pill into the other.

Abstract: A composition for and method of treating a subterranean hydrocarbon producing formation is provided. The treatment, when conducted in the presence of ferric ions, prevents the development of insoluble ferric iron-containing compounds and also prevents the development of sludge in heavy crude.

Abstract: A method of cleaning an oil or gas well includes mixing a caustic with a saline solution to precipitate hydroxide species from the saline solution and form a milky suspension. The suspension is contacted with contaminants in a well bore to entrap the contaminants. A polymeric flocculant is then mixed with the suspension in the well bore to aggregate the hydroxide species and the entrapped contaminants into flocs. The flocs are extremely strong and can withstand the highly turbulent flow existing in the well bore and can be readily flushed out of the well bore.

Abstract: Particular hydrocarbon composition constituted by saturated species, alkylbenzenes and polyaromatics, useful for dissolving asphaltenic residues present in oil wells.

Abstract: In accordance with the present invention, there is now provided a method for removing asphaltene deposits in a well environment such as the wellbore and near-wellbore regions, comprising the injection of deasphalted oil therein to solubilize the asphaltene deposits obstructing the well environment. More specifically, the method of the invention comprises the injection of deasphalted oil into the wellbore and the near-wellbore formation followed by a soaking period and a production period. The method of the present invention has the great advantage of readily dissolving precipitated asphaltene in a well environment without other costly treatments such as the use of solvents like xylene or toluene. Furthermore, the present method does not require the incorporation of any additives in the deasphalted oil.

Abstract: A method of stimulating injection wells having a wellbore. The method includes the steps of placing a heater at or near the bottom of the well, adjacent to the area to be treated, energizing the heater to release heat energy, flowing a solvent past the heater to the area to be treated to contact solid wax deposits to mobilize the wax deposits, removing the mobilized wax and the solvent from the well area, and injecting waterflood water into the well and into the passageways that were previously blocked by the wax deposits. In one embodiment there is a further pretreatment step of selecting an appropriate thief zone blocker fluid and injecting the same into the well to selectively obstruct the thief zones. In a further embodiment there is a further pretreatment step of choosing an appropriate oil zone blocking fluid and injecting the same into the well prior to the injection of the thief zone blocking fluid to protect the same.

Abstract: A method of reducing, preferably preventing, precipitation of asphalt from crude oil. In one aspect, crude oil is contacted in the borehole with at least one N,N-dialkylamide of a fatty acid having 8 to 22 carbon atoms. In an second aspect, precipitation is reduced during miscible flooding in an EOR process by adding to the flooding solvent at least one N,N-dialkylamide of a fatty acid having 8 to 22 carbon atoms.

Abstract: A method of stimulating production from an oil well by removing solid wax deposits from a production zone an electrical resistance heater comprised of a packed bed of spherical heating elements lowered through the tubing on a wireline and placed adjacent to the perforations. Solvent is pumped through the heater to raise its temperature by 200.degree. C. and then into the formation to contact wax deposits. The solid wax deposits are liquified and together with the oil and the solvent form a single liquid phase. The wax is then removed from the formation by placing the well back on production. Because the invention completely avoids the use of either water or gas, the saturation of the water and gas phases in the formation is minimized, thereby maximizing the mobility of the liquid phase containing the wax and facilitating the removal of the liquified wax from the treatment area before it reprecipitates.

Abstract: This invention describes a method of stimulating production from an oil well by removing solid wax deposits from a production zone. An electrical resistance heater comprised of a packed bed of spherical heating elements is lowered through the tubing on a wireline and placed adjacent to the perforations. Solvent is pumped through the heater to raise its temperature by 200.degree. C. and then into the formation to contact wax deposits. The solid wax deposits are liquified and together with the oil and the solvent form a single liquid phase. The wax is then removed from the formation by placing the well back on production. Because the invention completely avoids the use of either water or gas, the saturation of the water and gas phases in the formation is minimized, thereby maximizing the mobility of the liquid phase containing the wax and facilitating the removal of the liquified wax from the treatment area before it reprecipitates.

Abstract: Device for protecting wells from the risks of corrosion and deposits due to the nature of the fluid produced or present in the well. It is formed of a steel support casing (2), associated with a composite material production string (3), with a free annular space (6) particularly for the injection of inhibiting agents without stopping working. The string (3) is laid on the casing (2) via a device (4) which may be lowered at the same time as the string (3) and which has openings (13) ensuring the hydraulic continuity of the annular space (6). The device is particularly well adapted to wells conveying fluids which are aggressive with respect to traditional steel casings.

Abstract: Corrosion inhibitor additives are added directly to an aqueous acid solution used in acidizing subterranean formations. The additives comprise a bismuth compound, a quaternary compound, and a surfactant. The corrosion inhibitor is free of toxic Sb and acetylenic compounds.

Abstract: A process, based on the Nitrogen Generating System/Emulsion in the presence of organic solvents, which is useful for the dewaxing of producing formations, is disclosed. The heat generation with the nitrogen reaction system and organic solvents gives rise to a thermo-chemical, synergistic system for long lasting removal of paraffinic damage, oil production rates being restored and even increased. The process is relatively easy to implement and of low cost.

Abstract: An oil well tool and method for its use for removing accumulated deposits along an oil well tubing in a downhole pump operated oil well is disclosed. The tool when in use is untethered and adapted to be lowered through an oil well tubing under its own weight and the forces of gravity. The tool includes: a heating and scraping portion that removes the deposits as the tool is lowered through the tubing, a set of seals for preventing pumped fluids from passing through or around the tool, and a mechanism for setting the seals at a desired location along the tubing. With the seals set and the pump operating, the tool is raised up through the well tubing with the pumped fluids to a wellhead storage position.

Abstract: Solvent compositions for dissolution of both asphaltene and paraffin petroleum based deposits are described. Solvent compositions comprising kerosene and alkyl phenols, preferably cresol, have been found most efficient in oil well cleaning applications. This efficiency can be enhanced by the addition of an alkylamine. Compositions containing other aliphatic hydrocarbon solvents and more than 3% by volume alkyl phenols also exhibit good solvent properties for petroleum deposits. Oil production can be enhanced following well treatment in accordance with the disclosed invention.

Abstract: Many petroleum discoveries which have heretofore been regarded as intractable owing to the immobility of the petroleum can be economically recovered by a process involving local visbreaking of the intractable petroleum in order to produce a medium/heavy cracked gas oil which is injected into a subterranean formation of the intractable petroleum in order to recover the petroleum.

Abstract: The effectiveness of secondary and tertiary methods for recovering petroleum from a petroleum-bearing formations is enhanced by introducing into said formation a safe form of carbon disulfide comprising one or more salts of tri- and tetrathiocarbonic acid.

Abstract: A solid polymeric body comprising a polymer matrix containing a substantially water-insoluble reagent leachable into a substantially hydrocarbon liquid environment, the matrix being reagent permeative and the body preferably having a softening point substantially above that of the temperature of the liquid fluid environment in which it is to be employed. The body is useful for the introduction of an additive reagent into a substantially liquid hydrocarbon such as crude and refined oils.

Abstract: The invention discloses a process for reducing sludging during acid treatment of an oil well by adding phosphinic acid or a soluble salt thereof and a source of cupric or cuprous ion. The addition of an iodide ion source to this combination aids its effectiveness in stronger acids.

Abstract: Surfactant composition comprising an alkyl amine ethoxylate and a gel breaker, wherein the gel breaker is a random copolymer of ethylene oxide with propylene oxide/or butylene oxide.

Abstract: An aqueous acidic composition useful for conducting a formation acidizing method is disclosed. The composition, which is comprised of a blend of acetic acid, formic acid, a fatty alkyl quaternary ammonium salt, a fatty aralkyl quaternary ammonium salt and an alkanoic and/or alkenoic acid having at least four carbon atoms and at least two alcoholic hydroxyl groups per molecule, resists the formation of sludge, and insoluble ferric and calcium compounds.

Abstract: The invention relates to a valve suitable for use in high-pressure environment for transmitting a treatment fluid from exterior of which is affected by a pre-charged compression gas which keeps the bellows in contracted position and a piston preventing fluid communication between the tubing and the casing through the valve body. The interior of the bellows is affected by the tubing pressure, one half of which is transmitted to the bellows through radial sensing ports, and the other half of which is transmitted to the bellows through the bottom of the piston. When the pressure inside the bellows exceeds the pre-charged pressure, the bellows expands, pulling the piston upwardly and opening fluid communication from the tubing into the casing through the valve. A controlled-size fluid outlet port allows the tubing fluid to exit into the casing.

Abstract: A process for dissolving wax, paraffin and/or sulfur deposits in an oil or gas pipeline or well comprises providing at the site of the deposit an acid and a compound which liberates carbon disulfide upon contact with the acid, whereby the deposit is dissolved by the liberated carbon disulfide.

Abstract: An oil tool and method for controlling the accumulation of paraffin and deposits in downhole oil string and oil transmission flow lines is provided by employing at various locations in the downhole oil string or in the oil transmission flow lines a coupling device with an inside liner of a non magnetic material surrounded by a magnet and shield of a magnetic material. The preferred application employs at least two magnets having their north pole and south pole aligned in opposite directions held in place in relation to a magnetic outer shield or casing by a non magnetic restraining ring.

Abstract: The method consists in that the formation pressure is measured, and a solvent is fed through a well into the formation. Then a hydrophilizing solution is fed through the same well into the same formation. The supply of the solvent and hydrophilizing solution is effected while keeping the bottom hole pressure approximately equal to the formation pressure.

Abstract: A method and apparatus are provided for locating a solvent injection apparatus within a natural gas wellbore to reduce the deposition of hydrocarbonaceous solids which are at least partially soluble in the solvent.

Abstract: A method of inhibiting the deposition of paraffin wax, asphaltene, or mixtures thereof in a crude oil contaminated with paraffin wax, asphaltene, or mixtures thereof and susceptible to such depositions comprising the step of incorporating into said crude oil an effective deposition inhibiting amount of an oil soluble organic compound having at least one oleophobic and hydrophobic fluoroaliphatic group, and antideposition stabilized crude oil compositions containing said compound, are disclosed.

Abstract: Dewaxing control apparatus is adapted for use in a well casing containing a production tubing string defining an annulus within the well casing and a down hole pump which pumps oil upwardly through the production tubing. The apparatus has a housing adapted to be installed in-line with the production tubing. A passage in the housing places the annulus in communication with the interior of the production tubing for purposes of circulating a hot dewaxing oil. A cup packer positioned below the passage closes the annulus against downward liquid flows. A gas by-pass passage in the housing permits gases to be exhausted upwardly through the annulus during oil production despite the presence of the packer. A valve mechanism responsive to pressure developed by pumping hot dewaxing oil down the annulus closes the gas by-pass passage and opens the liquid transfer passage so that the dewaxing oil can flow into the production tubing and back up to the surface.

Abstract: A method of producing fluids from subterreanean reservoirs containing hydrogen sulphide and especially those reservoirs where elemental sulphur or hydrogen polysulphides are present. The method describes the use of a jet pump, chemical injection, and downhole electrical heaters to prevent the deposition of elemental sulphur within the production tubulars of wells penetrating such reservoirs by raising the pressure, temperature, and sulphur solvency of fluids being produced up these wells. In this way, subterranean reserves of sulphur and hydrogen sulphide which were previously unproducible or too expensive to produce can be commercially exploited.

Abstract: A method for reducing organic contaminants in a well initially breaks down complex organic compounds by radiation with gamma radiation. The remaining materials are subjected to oxygen radicals in the water, the oxygen radicals reacting with the materials to assist in the degradation. A carrier is formed with a plurality of containers fixed together by struts, and each container has a quantity of radioactive material to provide the radiation. Air, oxygen and or peroxide may be fed to the well to provide enough oxygen to produce the oxygen radicals, or the water may be cavitated to free the oxygen in the water.The apparatus & method may also be adapted with proper shielding for use in surface applications, such as surface water intakes (biofouling by Asiatic clams), general ground water and haz-waste treatment.

Abstract: A combination circulating valve and fluid unloader adapted for connecting in a tubing string disposed within the well bore of a producing well which is closed to downward flow of fluids therethrough. The valve includes a tubular member with ports through the wall thereof having a sliding sleeve disposed around the outside surface which is also provided with ports through the wall thereof for passage of fluid into the annulus. Opening and closing of the valve is accomplished by shifting the sliding sleeve between three positions by changing the pressure of the fluids contained in the tubing string to overcome the force exerted by a spring biasing the sliding sleeve toward a first, closed position. When the pressure of the fluid is increased to a first selected pressure, the sliding sleeve is shifted with respect to the tubular member to a second, circulating position in which the ports of the tubular member are in fluid communication with the ports of the sliding sleeve.

Abstract: A composition and method for stimulating the production of hydrocarbons from wells partially plugged by paraffins or mineral scale, the composition comprising hydrochloric acid, naphtha and an aqueous solution of hydrogen peroxide. According to the method of the invention, the reactants are serially introduced into the well bore and permitted to react to substantial completion, followed by flushing the wellbore with hot water.

Abstract: An apparatus and process for preventing the accumulation of paraffin deposits is disclosed. The invention is practiced by conveying the production fluids into contact with a metal which has a nickel content greater than seventy-five percent. In one embodiment of the invention, a gas anchor tool is disclosed which prevents the accumulation of paraffin solids.

Abstract: A self treating paraffin removing mechanism utilizing existing above ground equipment. The above ground equipment utilized is a heater treater normally employed at the typical well for separating oil from water and wastes. As desired, the operator, utilizing this invention, can direct heated oil from the heater treater to the well head annulus and then down hole and back up through the well string so that paraffin and other wastes are removed from the interior of the well piping. The oil and waste are then passed to the heater treater in the normal manner and the operation can be repeated as often as necessary or as desired. As a result, no costly insulation of the entire well string nor costly utilization of heater oil trucks is needed and an inexpensive flexible alternative is provided.

Abstract: A method and apparatus for reducing the accumulation of paraffin within an oil well that includes forming an electric circuit contact between the oil well sucker rod and tubing and connecting a power source to the sucker rod and tubing. An electric current is applied to the sucker rod in order to generate heat thereat. Preferably a rolling circuit contact is offset from the sucker rod to form a moving contact between the sucker rod and tubing, and in a preferred form a section of the sucker rod and pump is made of a material having a greater electrical resistance to increase the heat generated in a region of high paraffin accumulation. In another embodiment circuit assemblies are provided in the production string to alter the region being heated as the sucker rod reciprocates.

Abstract: A method of reducing the viscosity of asphaltenic crude oils by incorporating into said crude oil an effective viscosity reducing amount of an oil soluble organic compound having at least one oleophobic and hydrophobic fluoroaliphatic group, and optionally a low viscosity diluent, and compositions thereof.

Abstract: A method for removing flow-restricting matter such as paraffin, asphalts, clays, scales, or gyps from production equipment and producing formation of and in the vicinity of an oil or gas well. The method uses a combination of solutions consisting of mixed solvents and additives such as detergents, surfactants and acids. The solutions are electrolyzed along with the hydrocarbon product of the well in an above-ground reaction chamber. The electrolyzed mixture of solutions and hydrocarbon product are reintroduced immediately down the well casing and into the well formation.

Abstract: A method and apparatus of chemically inhibiting corrosion of a borehole and connected flowlines. A mixing tank receives flow from the chemical pump. The mixing device is connected to the borehole. A timer device operates to allow sequential flow to the mixing tank. The treatment fluid admixes with the formation fluid downhole.

Abstract: An asphaltic crude oil is produced via a well system comprising a horizontal drainhole section extending through the reservoir formation. Formation plugging due to in-situ precipitation of asphalt during production operations is avoided by adequately sizing the horizontal drainhole section in the resevoir, thereby establishing near-wellbore pressures in the reservoir above the asphalt saturation pressure, without sacrificing production rates.