Abstract: A method of removing from and preventing scale from depositing in underground petroleum containing formations and upon equipment used to inject high brine scale forming waters into such formations which comprises treating such waters with a scale inhibiting amount of an acrylic acid polymer which contains from 0-95 mole percent of acrylamide and from 1-30 mole percent of amido C.sub.1 -C.sub.6 alkyl phosphonate groups from the group consisting of:a) Amidomethyl phosphonate groups,b) Alpha-hydroxy-beta-amidoethyl phosphonate groups,c) Alpha-hydroxy-beta-amidoisopropyl phosphonate groups, and,d) Amidopropyl phosphonate groups said polymer having a molecular weight range between 1,000-100,000.

Abstract: A method for controlling fouling of a heat exchange surface exposed to a high-enthalpy geothermal brine tending to form silica scale, but containing less than a saturated amount of cations capable of reacting with sulfates. The method adds a limited amount of sulfuric acid to the brine to form a mixture. The amount of sulfuric acid is limited to that required to produce sulfates sufficient to apparently complex with silica, but less than the amount required to increased the sulfates to above saturation amounts of sulfate reacting cations, significantly reducing or virtually eliminating sulfate and silica deposits and fouling. The addition is further controlled to an amount which reduces the pH of the mixture to no less than about 4.5. The addition does not significantly increase corrosion rates of mild steel heat exchanger materials of construction.

Abstract: An apparatus for stimulating production from oil and gas wells has a magazine which is sequentially actuated to allow chemical stimulant to be dispensed into the well to cause agitation of fluid loading up said well and allow the recovery of hydrocarbons therefrom.

Abstract: A system and method for inhibiting corrosion of oil field pipe exposed to corrosive material including hydrogen sulfide, carbon dioxide, and sodium chloride with a corrosion inhibiting film which is a precipitate film formed by the reaction of a polysulfide with ferrous iron. The ferrous iron may be a constituent of the fluid passing through the pipe or separately injected. The polysulfide is the reaction product of hydrogen sulfide as a constituent existing in the passing fluid and an oxidizing agent such as ammonium nitrate separately introduced into the passing fluid. The method includes the steps of continuously passing a fluid carrying corrodents through the pipe, continuously bringing a polysulfide into being within the fluid, and continuously bringing elemental ferrous iron into reaction with the polysulfide within the passing fluids to form a precipitated film which is an effectively amorphous film having a predominant amount of iron disulfide.

Abstract: A mudline tubing hanger is disclosed in which the tubing hanger is provided as an integral part of the tubing string and is set within the casing by an hydraulic setting mechanism driven through an external control line and actuated by a wireline shifted sleeve. Further manipulation of the sleeve isolates the setting mechanism from the tubing and external control line, establishing a chemical injection conduit with access to the tubing bore through the external control line.

Abstract: A method of preventing scale from depositing in underground petroleum-containing formations and upon equipment used to inject into or remove from such formations high brine, scale-forming waters. This method comprises treating such waters with a scale-inhibiting amount of an acrylic acid or acrylamide homopolymer or co-polymer of acrylic acid with acrylamide having a molecular weight within the range of 1,000-50,000 which have been modified to contain up to about 30 mole percent of amido(C.sub.2 -C.sub.6 alkyl)phosphinic acid groups and the alkali metal, ammonium and amine salts thereof.

Abstract: Corrosion and scale inhibitors in fluids produced from a subterranean formation are separated, detected, and quantified by thin layer chromatography through the use of selected developing solvents and visualization reagents.

Abstract: Asphalt precipitation in the flow path of an oil production well is inhibited by splitting the produced crude oil in a separator train into a light fraction containing gaseous and oil components having a relatively low aromaticity and molar weight and a heavy fraction having a relatively high aromaticity and molar weight and subsequently reinjecting at least part of the heavy fraction to a location in the flow path of the well where asphalt precipitation is expected to occur.

Abstract: A method for treating well tubulars and elements (e.g. tubing, casing, sucker rods, etc.) for corrosion, drag reduction, or the like wherein a mass of gelatin is passed downward through the tubular to deposit a protective layer onto the wall of the tubular and/or element. Preferably, the mass of gelatin contains a treating solution therein which forms part of the protective layer. Since such treating solutions can severely damage the production and/or injection formation, the mass is stopped before it completely travels through the tubular and circulation is reversed to return any remaining mass of gelatin and solution back up the tubular towards the surface.

Abstract: A chemical injection assembly and apparatus for treating production fluids in a bore-hole. The system includes a fixed packer having an opening passing therethrough for receiving a production tubing string, a closable orifice in the packer that is actuated by the tubing string and appropriate seals for preventing fluid transfer within the packer. When the tubing string is inserted into the packer, a collar on the tubing string engages a shiftable sleeve that places an orifice in the shifting sleeve in alignment with the orifice in the injection sleeve so that chemical treatment fluid from the surface can be forced down the bore-hole casing through the closable orifice in the packer and into the production fluid at the perforations near the producing formations. The treated fluids then enter the tail pipe of the packer and up the tubing string to the surface. When it is desired to plug the well, a plug is inserted into the tail pipe and the tubing string is withdrawn.

Abstract: A system for chemically treating water in a water well utilizes a small pipe for diverting a small percentage of water being pumped from the well. The diverted water flows through a chamber containing concentrated treatment chemicals for producing a solution of the water treatment chemicals and the solution is injected into the well casing. The volume between the casing and the standpipe serves as a retention chamber for treating water before being drawn from the well.

Abstract: A relatively high molecular weight polyvinyl sulfonate and a process for inhibiting scale deposition, particularly inorganic sulfate such as barium sulfate, wherein an aqueous fluid present in or produced from a subterranean formation is contacted with an aqueous solution having a relatively high molecular weight polyvinyl sulfonate dissolved therein. The aqueous fluid has a pH equal to or less than 6.0 and the polyvinyl sulfonate has a molecular weight of from about 9,000 to about 30,000.

Abstract: A method of removing iron from ground water located in a water well and of preventing production of hydrogen sulphide in such water including positioning a bubbling device in the well below the waterline. This device, which is connected to a source of pressurized air, is operated to produce a continuous flow of air bubbles in the water to render dissolved iron in the water insoluble so that the latter precipitates out and the well water aerobic. The insoluble iron can then be gathered from the well periodically. In one version, an iron collecting device in the form of a bag is placed around the bubbling device. The bag is removable from the well in order to remove and dispose of collected insoluble iron. Calcium carbonate can be used to adjust the pH level to pH 7. When the bubbling device is introduced into water containing sulphur, the air stream of bubbles has a double action and prevents hydrogen sulphide production.

Abstract: Gas hydrate formation in a gas well is prevented by injecting a carrier and an alcohol (e.g., glycerol or a glycerol derivative) into the well and connected facilities/pipelines.

Abstract: The deposition of metal-containing scale, such as iron silicate scale, from a hot aqueous geothermal brine, or the like, is controlled by blending into the brine sufficient reducing agent effective for reducing trivalent iron and manganese cations in a high temperature brine solution to divalent ions to cause an overall decrease in scale deposition, especially of iron silicate scale. Preferably, from 2 to 7 times the stoichiometric amount of reducing agent is used to effect a 70 to 90 percent reduction in the formation of iron silicate scale.

Abstract: Fountain permitting the release of active agents into water originating from a well, comprising a passage for circulating the water drawn from the well around a cartridge containing the active agent to be diffused and for keeping this cartridge immersed in water when water is not being drawn from the well.

Abstract: Wells producing oil and gas are treated with formation waters containing selected time-release scale inhibitors to reduce the deposit of scale in the wellbore and within the formation. The inhibitors are formed by cross-linking a polyacrylic acid compound of controlled molecular wright from about 1,000 to 10,000 with trivalent chromium cations to produce a water-soluble complex which progressively releases the inhibitor from the formation over an extended period of time.

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 geothermal water well is treated with an effective amount of a scale inhibitor formulation containing a Na acrylate/acrylamide copolymer to inhibit the buildings of CaCO.sub.3 scale therein.

Abstract: A method of inhibiting corrosion in an oil well comprises introducing into the well a pourable emulsion comprisinga. 50-95% of a discontinuous aqueous phase (such as ordinary water); andb. 5-50% of a continuous oil phase (such as kerosene or similar hydrocarbon) containing a corrosion inhibiting compound (such as an imidazoline).This method results in more consistent corrosion protection, even if longer treatment intervals are used.

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 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: Oil field chemicals are incorporated in polymeric particles of the condensation product of hydroxyacetic acid or the co-condensation product of hydroxyacetic acid and other compounds containing hydroxy-, carboxylic acid-, or hydroxycarboxylic acid moieties. The particles are introduced into an oil well bore and/or subterranean oil formation where the polymeric particles dissolve over a period of time and release the oil field chemicals.

Abstract: A process for recovering oil from a subterranean hydrocarbon-bearing reservoir having a hydrocarbon and penetrated by a wellbore. The process comprises injecting through the wellbore and into the subterranean hydrocarbon-bearing reservoir an emulsifying composition containing an aqueous phase and a minor amount of an emulsifying agent such that the emulsifying composition contacts at least a portion of the hydrocarbon to form an oil-in-aqueous phase emulsion within the subterranean hydrocarbon-bearing reservoir.

Abstract: Corrosion inhibition composition formed as a water-external emulsions having an oil soluble organic film forming type of corrosion inhibitor in the dispersed phase thereof are disclosed for downhole well applications, such emulsions having a stability at room temperature without agitation of from 2 to 30 minutes.

Abstract: A method for inhibiting the formation of scale in a well penetrating a subterranean formation for the production of fluids from the formation comprising injecting into the formation an acidic aqueous solution having a pH effective to form a water-soluble complex of the inhibitor and the polyvalent cation, preferably in the range of 2 to 3, containing a mixture of a polyacrylate scale inhibitor having a molecular weight range from 500 to 10,000 and a polyvalent cation wherein the equivalent ratio of polyvalent cation to polyacrylate scale inhibitor is less than or equal to 0.5 in the acidic aqueous solution and allowing natural conditions in the formation to raise the pH of the solution an amount sufficient to cause controlled precipitation and increased deposition of the scale inhibitor in situ in the form of the polyvalent cation-polyacrylate complex.

Abstract: A process for controlling biomass and cleaning water injection wells and oil producing wells by injecting an oxidant into the pumped water injection stream. Chlorine dioxide or sodium chlorite, depending on the reactants present in the well, may be injected by means of a stinger, a spool or a coiled tube into the pumped water injection stream. Chlorine dioxide is generated at the site and may be generated by any one of several known processes. Hydrochloric acid or other proton donor stream, a water stream, and a stream containing sodium chlorate, sodium chlorite, and optional sodium chloride may be mixed at an elevated pressure to create chlorine dioxide. The elevated pressure of the chlorine dioxide stream is maintained at or boosted to a level greater than the pressure of the water injection or oil-producing well to aid in the injection of the chlorine dioxide stream either from generation to the well or through a booster pump mechanism to the well.

Abstract: A method for inhibiting the deposition of wax in an oil well producing a wax-containing petroleum from a subterranean formation comprises injecting into the oil pool at the base of said well a copolymer comprised of ethylene and vinyl acetate and having an average molecular weight between about 15,000 and about 35,000.

Abstract: A column of high density well treatment composition in liquid or solid form is stored in the bottom portion of the well bore of a producing fluid well and is subjected to fluid pressure from the well fluid. The flow of production fluid is used to create a pressure differential between the treatment composition and a treatment fluid injection outlet, thereby causing the treatment fluid to flow through the injection outlet. By locating the outlet in the flow of production fluid, the resulting flowing pressure drop creates the necessary differential pressure. The rate of flow of treatment fluid is metered by a capillary tube at the outlet or by a flow-actuated positive displacement pump. In all but one of the embodiments, the inlet of the conduit is at the bottom of a column of treatment liquid and at the top of a column of treatment solids. In another embodiment formation, fluid percolates up through a bed of solid treatment particles and into the well bore.

Abstract: Formation of scale from radioactive components is monitored with a radiation detector. Upon indication of initiation of scale formation in a system, treatment with inhibitor is carried out.

Abstract: Treatment fluid is injected into the production fluid of a well from a bladder contained in a canister at the bottom portion of the well bore. The flow rate is predetermined through use of a capillary tube connecting the bladder and an injection outlet. Differential pressure between the bladder and the outlet to actuate the flow of treatment fluid is created either by restricting the flow of production fluid adjacent the outlet or by compressing the bladder through the use of water-expansible material in contact with the bladder in the canister. An aperture in the bottom of the canister is provided to expose the bladder to the well fluid.

Abstract: The deposition of metal-containing scale, such as iron silicate scale, from a hot aqueous geothermal brine, or the like, is controlled by blending into the brine sufficient reducing agent effective for reducing trivalent iron and manganese cations in a high temperature brine solution to divalent ions to cause an overall decrease in scale deposition, especially of iron silicate scale. Preferably, from 2 to 7 times the stoichiometric amount of reducing agent is used to effect a 70 to 90 percent reduction in the formation of iron silicate scale.

Abstract: Apparatus for and method of introducing aqueous chlorine dioxide solution into a high pressure water-containing pipeline without causing corrosion of the pipeline.

Abstract: A method and apparatus for treating oil and gas wells by automatically pre-flushing the well casing annulus with production fluid, pumping treatment chemicals into a rapidly flowing production fluid line for uniform mixing and introduction into the casing annulus, and post-flushing with production fluid.

Abstract: An oil well tool for in situ release of treatment fluid into an oil well is disclosed. A tubular body is insertable into an oil well casing, which tubular body carries a bladder containing treatment fluid. The body is closed at a lower end and has at an upper end a fishing neck connector. A weight slideable within the tubular body compresses the treatment fluid within the bladder and forces the treatment fluid under a constant pressure through a fluid passageway. The size and length of the fluid passageway, combined with the pressure applied and viscosity of the treatment fluid, dictate the flow rate at which the treatment fluid is deposited into the oil well. The treatment fluid mixes with other fluids being circulated through the well formation. The primary purpose for the treatment fluid is to inhibit scale buildup and corrosion. This is accomplished by slow release of the treatment fluid over an extended period of time.

Abstract: A composition is provided which, when applied to a metal surface, forms a corrosion-inhibiting film thereon. The composition comprises an epoxy resin, and a petroleum sulfonate, usually in a hydrocarbon diluent. The composition can further comprise a polyamine, an alcohol or both. The composition is applied by contacting the metal surface with the composition as one solution or as a hydrocarbon solution of the epoxy resin and a solution comprising the petroleum sulfonate. The composition is particularly useful in the treatment of downhole metal surfaces in oil and gas wells to inhibit the corrosion of the metal.

Abstract: The present invention relates to an improved system and method for recovering oil. The system includes a subsoil pump for pumping oil to the surface having an opening in its casing through which an assisting, treatment, or maintenance fluid may be added in a desired quantity. The opening is located substantially at the level of the pump's oil inlet and communicates with a supply of fluid via a passageway having a check valve for admitting only precise quantities of fluid to the opening.

Abstract: Treatment composition is released into a well by lowering a container filled with the composition to the bottom of the well. The corrosive well fluid dissolves the composition through the open upper end of the container and corrodes away the walls of the container from the inside out. The outer surface of the container walls is coated with a material, such as tetrafluoroethylene, which acts as a barrier to the well fluid to prevent it from directly contacting the outer wall surface. In this manner treatment composition is gradually released from the top end of the ever-diminishing length of container and the container is degraded in the well.

Abstract: Production of at least a gaseous product containing a substantial amount of hydrogen sulphide via a bore-hole from an underground formation containing besides the hydrogen sulphide at least elemental sulphur by(a) injection of a liquid substantially consisting of hydrocarbons into the bore-hole or into the underground formation near to the end of the bore-hole;(b) producing a gaseous and a liquid fraction from the underground formation;(c) separating the gaseous fraction from the liquid fraction;(d) if necessary, separating an aqueous fraction of the product liquid fraction from the hydrocarbons-containing fraction;(e) heating the hydrocarbons-containing fraction preferably in the presence of hydrogen and a hydro-desulphurization catalyst, in order to remove elemental sulphur; and(f) reinjection of at least a part of the thus treated hydrocarbons-containing fraction into the bore-hole or into the underground formation near to the end of the bore-hole.

Abstract: The utilization of hydroxyethylacrylate/acrylic acid copolymer as a zinc sulfide scale inhibitor in oil well production processes.

Abstract: The present invention relates to a method for drawing up a crude oil containing a great amount of wax or a high-viscosity crude oil. The method of the present invention is characterized by cracking or fractionating the crude oil which has been drawn up, in order to prepare a cracked oil or a gas oil, and by drawing up the crude oil, while injecting a part of the cracked oil or the gas oil into an oil well. According to the present invention, an efficient drawing operation can be achieved.

Abstract: A composition is provided which, when applied to a metal surface, forms a corrosion-inhibiting film thereon. The composition comprises an epoxy resin, and a petroleum sulfonate, usually in a hydrocarbon diluent. The composition can further comprise a polyamine, an alcohol or both. The composition is applied by contacting the metal surface with the composition as one solution or as a hydrocarbon solution of the epoxy resin and a solution comprising the petroleum sulfonate. The composition is particularly useful in the treatment of downhole metal surfaces in oil and gas wells to inhibit the corrosion of the metal.

Abstract: A method of improving production of heavy crude oil from a well by mixing a first solution of water soluble surfactant and water, and preferably forming a mixture of the first solution and an oil solvent, and pumping the mixture into the well to mix with the heavy crude oil to be produced. A desirable surfactant is a water soluble ethoxylated nonylphenol and a desirable oil solvent is kerosene distillate.

Abstract: Injecting fluid by inserting a coil tubing having a fluid outlet and a valve above the outlet into a well conduit, biasing the valve to a closed position with a sufficient force to at least balance the hydrostatic force of injection fluid in the tubing, inserting a fluid to be injected in the conduit, and pressurizing the fluid in the coil tubing for opening the valve and injecting the fluid through the fluid outlet. The fluid is ejected in a circumferential direction from the tubing and the tubing may be moved relative to the well conduit while injecting. The upward flow of well fluids in the well conduit may be used to disperse the injected fluid around the interior of the well conduit. The interior of the well conduit may be wiped after injecting the fluid for more evenly spreading the injected fluid. An ejector is connected to the bottom of the coil tubing which initially overbalances the hydrostatic force of the fluid in the coil tubing and opens by injection pressure.

Abstract: Method and apparatus of inhibiting corrosion of well tubing. A corrosion monitor detects the concentration of a corrosive element in fluid produced from well tubing. Corrosion inhibitor is injected into the tubing by a pump at the depth at which water vapor condenses. A computer is programmed with a formula which generates an optimum concentration of corrosion inhibitor for a given concentration of the corrosive element. The computer is operatively connected to the monitor and receives data therefrom to generate a signal which is used to control the pump speed.

Abstract: An apparatus for chemical treatment of a fluid pumped from a well through a production tubing includes a tubing anchor with slips adapted to be set hydraulically and mechanically against the casing in the well without rotating the production tubing. A branch line from a chemical injection line communicates with a setting pressure chamber in the anchor which, when pressurized, is used to initially set the slips. Thereafter, a straight pull on the tubing mechanically completes setting of the slips and a plug blocking the injection line is removed enabling the delivery of a treatment chemical to the well fluid upstream of a pump utilized in removing the fluid in the well.

Abstract: Corrosion inhibiting of well production tubing, such as for an oil or gas well, is provided in a simple and effective manner without interrupting well production. A portable skid has a chemical tank, water tank, pumps, conduits, and controls mounted on it, and is transported to the production well site. A mix of corrosion-inhibiting chemical and water is supplied from the tanks to an end conduit, and the end conduit is connected to an injection string, or an annulus associated with a side mandrel, of the production well. A computer control is provided for controlling the pumps, and other components, so that any desired amounts and proportions of a mix of chemical and water is continuously injected into the well to inhibit corrosion of the well production tubing string without interruption of production.

Abstract: An improved method of acidizing sour gas wells involving the injection of an aqueous acidizing solution comprising: water, an acid, an effective amount of an iron complexing agent (e.g., EDTA) capable of stabilizing the ferrous, Fe(II), ion in solution in the presence of H.sub.2 S and an effective amount of an iron reducing agent (e.g., erythorbic acid, ascorbic acid and mixtures thereof) capable of reducing the ferric, Fe(III), ion in solution to ferrous Fe(II), ion at a pH of about 6.0 or less. Such a process is effective in reducing and inhibiting the precipitation of Fe(OH).sub.3, FeS and S in sour wells.

Abstract: A method and apparatus for distributing fluids within a subterranean borehole wherein a submersible pump is introduced into the borehole at a first location. An intake port of the pump is connected to the first end of an intake duct having an unconnected second end located at a second location within the wellbore from which location fluid is to be withdrawn. An output port of the pump is connected to a first end of a second duct having an unconnected second end at a third location within the wellbore into which location fluid is to be introduced. By activating the pump, fluids, such as scale and corrosion inhibitors, are distributed from above the intake of a production pump to as low in the borehole as is required to protect wellbore contents.

Abstract: An injection mandrel and method for introducing treating fluids into a well comprise a center pocket mandrel having a check valve in fluid communication with treating fluid in the annulus of the well and with a chemical injection valve in the mandrel. Treating fluid is pumped through the check valve and the chemical injection valve into the produced fluids in the mandrel, while reverse flow is prevented. In another embodiment a dip tube communicating with the injection valve pocket places treating fluid at a preselected location in the well.