Abstract: A method of corrosion inhibition using a gelled inhibitor is disclosed. The method comprises consecutively introducing into an annular region of a jacketed pipeline a hydrogel slurried in an environmentally innocuous oil medium and a corrosion inhibitor dissolved in an aqueous medium. The liquid media are contacted to form a gelled corrosion inhibitor in the annulus. The method is particularly useful in buried pipelines where corrosion monitoring is difficult.

Abstract: The concentration of a water soluble corrosion inhibitor formulation in the water of an aqueous system is monitored by a UV absorption method which is based upon the measurement of the absorbance of a component of corrosion inhibitor formulation. The method is particularly suited to on-site determinations of inhibitor residuals in large aqueous systems, such as in oil field applications, which have an acute need for rapid and adaptable assays, so as to provide precise information before corrosion damage can occur.

Abstract: A process for running scrapers for subsea petroleum well lines has, according to a first embodiment, launching of a scraper through the line to be disobstructed, towards the wellhead on a step-by-step basis. The operation proceeds by sending the scraper along successively larger sections via reversing flow through the obstructed line to limit passage of the scraper to that obstructed line, until the whole line is swept. Furthermore, according to a second embodiment, the process consists of the launching of one or more scrapers from a chamber installed in the subsea production system, towards the platform, sweeping only the whole obstructed line, all at once. Preferably one or more scrapers are launched from a chamber installed in the subsea equipment towards the surface platform and sweeping the entirety of a first obstructed line.

Abstract: An apparatus is provided for continually adding chemicals to a producing oil and gas well. A mixing chamber is provided having an inlet and an outlet. A subassembly is provided for diverting a flow of production fluid from the well and directing the flow of production fluid to the inlet of the mixing chamber. A subassembly is provided for admitting an amount of chemical into the mixing chamber. The fluid mixture of the production fluid and the chemical is exhausted from the mixing chambers through the outlet. A flow control system is provided, in fluid communication with the outlet of the mixing chamber, for permitting only a predetermined flow rate of the fluid mixture to exit from the mixing chamber. An adjustment control is provided for adjusting the flow rate of the fluid mixture through the mixing chamber to selectively increase and decrease the predetermined flow rate. An exhaust system is provided for conveying the fluid mixture from the outlet, through the flow control, and into the well.

Abstract: A composition is provided which, when applied to a metal surface, forms a corrosion-inhibiting film thereon. The composition comprises an epoxy resin, an effective amount of a curing agent for the epoxy resin, an alcohol, and a hydrocarbon diluent. 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 alcohol and the curing agent. The composition is particularly useful in the treatment of down-well metal surface in oil and gas wells to inhibit the corrosion of the metal.

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: 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 down-hole oil well heater for improved recovery of oil includes a heating element comprising a sheet of electrically conductive paper which generates heat as a result of resistance to current flow therethrough and spaced apart, primary conductor elements preferably in the form of thin metal strips attached, as by sewing, to the conductive paper to provide uniform distribution of current flow through the paper from one conductor element to the other. Secondary conductor elements are electrically connected to said primary conductor elements and controller means are electrically connected to such secondary conductor elements for controlling the flow of electricity to the electrically conductive paper. The heating element covers a portion of conventional oil well tubing and is sandwiched between layers of electrically nonconductive, insulating material.

Abstract: An apparatus and method for injecting chemicals into a hydrocarbon producing well is disclosed. The invention includes a vessel which holds the chemical and a pressurized gas which exerts a pressure on the chemical. A pressure regulator and a valve selectively control the injection of the chemical into the well as the pressurized gas urges the chemical out of the vessel. The pressurized gas drives the chemical through the regulator, valve, and into the well without venting the chemical or pressurized gas into the ambient environment.

Abstract: An apparatus and method for injecting chemicals into a hydrocarbon producing well is disclosed. The invention includes a first vessel for containing the chemical, a second vessel for containing a pressurized gas, a conduit for permitting the pressurized ga to pressurize the chemical, and a valve for selectively permitting the chemical to exit the first vessel The pressurized gas drives the chemical through the valve and into the well without releasing the chemical into the ambient environment.

Abstract: An apparatus and method for injecting chemicals into a hydrocarbon producing well is disclosed. The invention includes a valve attached to a vessel. A chemical is contained by the vessel, and a pressurized gas in the vessel pressurizes the chemical. The valve can be operated to selectively control the release of the chemical from the vessel and into the well. The pressurized gas drives the chemical through the valve and into the well without releasing the chemical into the ambient environment.

Abstract: An apparatus and method for injecting chemicals into a hydrocarbon producing well is disclosed. The invention includes a vessel which is divided with a baffle into a first chamber and a second chamber. The chemical is installed in the first chamber, and a pressurized gas is injected in the second chamber. A valve is connected to the first chamber to selectively control the injection of chemical into the well as the pressurized gas urges the baffle to pressurize the chemical within the first chamber.

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 method is disclosed for volatile inhibition and transport of inhibitor in the volatile phase to produced liquids of corrosion in a gas lift process in which a lift gas is pumped into a well to facilitate petroleum production of the well. The method comprises introducing to the lift gas a corrosion-inhibiting amount of a dihydrothiazole of the formula ##STR1## wherein R, R', R", R'", and R.sup.4 are independently selected from among hydrogen and alkyl groups of up to about 3 carbon atoms, provided that the total number of carbon atoms of R, R', R", R'" does not exceed about 14.

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 method of stimulating production from an oil or gas well comprising the steps of (a) injecting a desiccant through the well bore to dehydrate the well bore and a production zone within several feet around the well bore, (b) injecting an anhydrous acid into the production strata, the anhydrous acid being formulated to be gaseous at bottom hole temperature and pressure so that the gaseous anhydrous acid permeates through the dehydrated production strata and dissolves in connate water to form an acidic solution, and (c) shutting in the well for a period to allow the acidic solution formed in situ to react with the materials of the formation thereby increasing the permeability of the production strata and stimulating production from the well. A alcohol/polyglycol desiccant with exceptional lubricating, heat stability, and corrosion inhibiting characteristics is used to dehydrate the well and to form a corrosion resistant film on surfaces of the production string and casing.

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: This invention relates to a downhole activated device for providing cathodic protection for pipes in a wellbore for the production of hydrocarbons. The downhole activated devices are carried within either the pipe casing or the collars or both and remain generally within the maximum outward profile of the pipe string so as not to interfere with the movement and placement of the pipe string in the wellbore. The pipe string may be rotated, reciprocated and circulated which enhances the ability of the installer to place the pipe string in a deviated or long reach wellbore. Once the pipe string is in place, the devices may be deployed by one of several methods such that pistons mounted in openings in the peripheral wall of the pipe string move outwardly to contact the wall of the wellbore. Such contact with the walls of the wellbore insures that the sacrificial material in the pistons will corrode in preference to the remainder of the pipe.

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: A process for inhibiting corrosion in oil production fluids resides in adding to the oil production fluids an effective amount of betaine or ampholyte of the formulas 1 or 2 ##STR1## wherein R.sup.1 is C.sub.10 -C.sub.20 -alkyl or C.sub.10 -C.sub.20 -alkenyl, preferably C.sub.14 -C.sub.18 -aklyl or C.sub.14 -C.sub.18 -alkenyl and R.sup.2 and R.sup.3 are C.sub.1 -C.sub.4 -alkyl, preferably methyl.

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: An oil well tubing joint coated with a carbide blast coating provides an elongated, hollow tubing section having an open ended continuous cylindrical internal bore and a continuous carbide coating over substantially all of the tubing section outer surface. An internally threaded connection portion of the bore at a first end of the tubing section is provided with an externally threaded connection member being positioned at the second end of the tool bore. The tubing section has a larger constant external diameter that extends over a majority of its length and three reduced external diameter portions that extend a distance from each end of the tubing, including one reduced diameter portion adjacent one end of the tubing joint and two of the reduced diameter portions being adjacent the second end of the tubing joint.

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 coupon holder apparatus for measuring the rate of corrosion caused by formation fluid contained downhole in a borehole. The apparatus is useful when used in conjunction with a pumping unit of the type having a pump located at the bottom of a borehole and a sucker rod string extending downhole through a tubing string to actuate the pump. The apparatus has a main body which is connected in the rod string and suspended downhole in the borehole where it is in contact with the well fluids. An axial chamber is formed within the main body and radial ports extend through a sidewall of the main body to communicate the axial chamber with the borehold fluids.

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 composition is provided which, when applied to a metal surface, forms a corrosion-inhibiting film thereon. The composition comprises an epoxy resin, an effective amount of a curing agent for the epoxy resin, an alcohol, and a hydrocarbon diluent. 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 alcohol and the curing agent. The composition is particularly useful in the treatment of down-well metal surfaces in oil and gas wells to inhibit the corrosion of the metal.

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: Apparatus for running tools suspended from a wireline into a wellbore under pressure, while simultaneously cleaning and treating the wireline with treatment fluid to inhibit the wireline against corrosion. A lubricator barrel and a cylinder is connected to the upper end of a wellbore and a wireline extends through the axial centerline of the barrel. Several packet devices are arranged for squeezing and surrounding a length of the wireline to strip liquid and debris from the outer surface thereof. Spacers keep the packer devices arranged in axially spaced relationship within the cylinder and form a treatment chamber between adjacent packers and a cleaning chamber between other adjacent packers. A pressure differential is applied across a ram device which reciprocates within the cylinder and this compresses each packer device simultaneously. A pump is connected to actuate the ram device and set the packet devices.

Abstract: Cathodic corrosion protection of a metallic structure in contact with the earth employs a backfill material which is a mixture of a carbonaceous solid and a clay. The backfill mixture is used to fill around at least one anode which is positioned in a borehole in the earth. A DC voltage is applied to the metallic structure and anode to provide the corrosion protection. The backfill mixture is highly electrically conductive and is relatively impermeable to water so as to assist in preventing intermingling, and possible contamination, of different aquifers through which the borehole penetrates.

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 is described whereby quick-kill and maintenance antimicrobials are used to control biofouling of oil production water injection systems.

Abstract: A composition for use in enhanced oil recovery procedures comprises steam, carbon dioxide, carbonic acid, and a corrosion inhibitor. In one version of the invention, the corrosion inhibitor is a carbonate-containing buffering agent and in another version of the invention, the corrosion inhibitor is a pH-adjusting agent.

Abstract: Method and apparatus for corrosion inhibition in an electromagnetic heating system for heating a portion of a mineral fluid deposit adjacent an oil well or other mineral fluid well, in situ. The preferred apparatus includes a power source, that develops a high amperage heating current, over 100 amperes, at a heating frequency usually in a range of from 0.01 Hz or lower to 35 Hz, in a heating circuit that includes a main heating electrode downhole of the well and a return electrode. The power source also supplies a very low amplitude, controlled D.C. bias current to those electrodes, maintaining the main electrode at a neutral or negative polarity for corrosion protection. The D.C. bias current is monitored and maintained below a given minimum level, usually about one ampere, to extend the effective life of the return electrode and to minimize corrosion protection costs.

Abstract: A method of stimulating production of hydrocarbons from a well capable of production from oil and gas bearing strata wherein a desiccant is delivered through the well to dehydrate the well and a zone around it and then an anhydrous carrier for an anhydrous acidizing agent such as hydrogen chloride, hydrogen fluoride, or carbon dioxide is injected at a pressure sufficient for the gaseous materials to permeate through the strata and react with connate water to form a mixture of carbonic, HCl, or HF acids which will react with rocks forming the strata to increase the permeability of the strata and thereby stimulate production from the well.

Abstract: An acid soluble mercury metal salt intensifier is provided to inhibit corrosion in conjunction with a corrosion inhibitor when a steel surface is present in an acid environment. The mercury metal salt may be a mercuric halide, such as mercuric chloride or may be a mercuric acetate, mercuric oxide, mercuric nitrate or mixtures of all of these. An acid soluble copper metal salt, such as cuprous halide, for example, cuprous chloride, copper acetate, cupric formate, cuprous nitrate and mixtures thereof, may also be present as a co-intensifier. In one application, the mercuric salt intensifier is used in a fluid for treatment of a subterranean well for the acid enhancement of production within the well by introduction of the fluid through a high alloy steel conduit positioned within the well. Methods of inhibiting acidic corrosion when steel surfaces are in an acid environment, particularly steel surfaces containing chrome, and methods of treating a subterranean well for enhanced production are also presented.

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: The present invention relates to a system for improving the production of crude oil for underground reservoirs by the injection of treatment fluids. The system includes a subsurface oil pump for pumping oil from the reservoir to the surface and includes a metering mechanism for selectively introducing treatment fluids into the pumping chamber during oil recovery. A specific feature of the present invention is the provision of a seating nipple for sealingly receiving the pump within the production tube of the well. In accordance with a particular feature of the present invention, a metering value is incorporated within the pump barrel thereby allowing the pump barrel and metering valve to be removed from the production tube as a unit for easy replacement and repair thereof. Furthermore, by selecting differently designed connecting adaptors, both insert type and tubing type subsurface pumps can be used with the metering valve assembly.

Abstract: Disclosed is a method of preventing fluids in the ground from rising around an oil well pipe by filling the space around the pipe with an oil well completion fluid comprising water, about 50 to about 65% by weight, based on total fluid weight, of dipotassium phosphate, and at least about 10 ppm hexavalent chromium. The fluid can be prepared by neutralizing wet process phosphoric acid with potassium hydroxide to a pH of less than 12 and filtering off any solids. Also disclosed is an oil well employing the completion fluid.

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 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: An economical, corrosion-resistant, wireline set and retrievable, downhole coupon holder is disclosed that has a non-metallic, elongated member having recessed slots and a mounting means for mounting the coupons within the recessed slots. Preferably, there are six pairs of slots, with each pair of slots being on opposite sides of the elongated member. Each pair of slots shares a common mounting means that fixes the ends of coupons within that pair of slots.

Abstract: Corrosion inhibition apparatus in an electromagnetic heating system for in situ downhole heating in an oil well or other mineral fluid well that includes an A.C. power source for a high amperage, low frequency heating current (e.g. over 50 amperes at 0.01 to 35 Hz) and a D.C. bias source for generating a low amplitude (e.g., less than one ampere) current for corrosion inhibition, both sources connected to a downhole electrode. The bias source includes at least one semiconductor device, connected in the main A.C. heating circuit, in a bias circuit that develops a net D.C. voltage differential of the polarity required for corrosion inhibition in response to the A.C. heating current.

Abstract: A method is provided for transporting in a duct a fluid comprising gas and water, and being under conditions where at least one hydrate is formed, the hydrates being formed from said gas and said water, wherein, before or during the formation of the hydrate or hydrates, an additive is injected into said fluid for reducing the tendency to agglomeration of the hydrate so as to obtain one or more hydrates in dispersed form, and said fluid is transported containing said hydrate or hydrates in dispersed form.

Abstract: The present invention relates to an improved method for controlling pH in the liquid and vapor phases of wet steam having such phases formed in a steam generation system from feedwater having therein at least one carbonate species which in the presence of steam forms a vapor phase component tending to lower the pH of the vapor phase of the steam upon condensation and a liquid phase component tending to raise the pH of the liquid phase of the steam. It comprises: (a) converting the feedwater in a steam generation system to steam having a vapor phase and a liquid phase; and (b) adding to the steam generation system, a heterocyclic, multifunctional, nitrogen-containing compound capable of forming a nonvolatile anionic component and a cationic component that, in the presence of said system, yields hydrogen ions for reducing the pH of the liquid phase of said steam and an alkaline component for increasing the pH of the vapor phase of said steam upon condensation.

Abstract: In its broadest aspect, the present invention provides a method for inhibiting silica dissolution in the vicinity of a well penetrating a hydrocarbon-containing formation. It includes: (a) adding an amount of a chmeical compound to a wet steam which forms an alkaline component in the vapor phase of the wet steam effective to inhibit corrosion in the vicinity of the vapor phase condensate; (b) separating the wet steam into the liquid phase and the vapor phase; (c) removing an amount of the liquid phase from the wet steam effective to reduce silica dissolution in the vicinity of the liquid phase; and (d) injecting the wet steam into the formation.

Abstract: A method for inhibiting permeability damage of a hydrocarbon formation containing clay minerals in the vicinity of a well penetrating the formation. It comprises: injecting a wet steam that includes (a) an amount of ammonia in the vapor phase of the wet steam to produce a concentration of ammonium ions in the vapor phase condensate of the wet steam effective to inhibit permeability damage of the formation in the vicinity of the vapor phase, and (b) an amount of a bicarbonate salt of the alkali metals, or mixtures thereof, effective to raise the liquid phase pH of the wet steam to within the range of about 7.5 to about 10.5.

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: A device and method for continuously adding chemicals to a producing oil well to prevent the formation of paraffins, emulsions, scale and to prevent corrosion is described. The device includes an above ground mixing chamber having an inlet and an outlet. A portion of the flow of production oil is diverted from the production tubing to the inlet. Chemical are added in the mixing chamber, and the mixture is then flushed down through the well casing to the bottom of the well to be pumped up the production tubing. The device includes a sight glass on the mixing chamber to visually observe the mixture, a bleed valve on the mixing chamber to remove samples and the like, and a pressure gauge for registering the internal pressure within the chamber. A line check valve is provided at the inlet to close the inlet in the case of excessive back pressure to prevent a flow of chemicals back through the inlet, and a choke with a predetermined orifice is provided at the outlet to regulate the flow rate therethrough.