Abstract: Organosilicon-modified polydienes having the formula: ##STR1## in which Z represents a chain terminating group,R.sup.1 is a hydrogen or methyl radical,R.sup.2, R.sup.3, and R.sup.4 are lower alkyl radicals with 1 to 4 carbon atoms, which can be the same or different within the polymeric molecule,R.sup.5 is a methyl radical or the O--(R.sup.8 O--).sub.s --R.sup.4 group;R.sup.6, R.sup.7, R.sup.8 are alkylene radicals with 2 to 4 carbon atoms,C:O ratio ofR.sup.6 O is 2.25 to 3:1,R.sup.7 O is 2 to 2.75:1,R.sup.8 O is 2 to 3:1however, the difference between the C:O ratio of R.sup.6 O and R.sup.7 O must be at least 0.25, and the C:O ratio of R.sup.8 O must be less than that of R.sup.7 O or greater than that of R.sup.6 O,a is 0 to 2,0<b<3, whereby 0<a+b<3,p, q, s.gtoreq.2,x, y.gtoreq.0, andz.gtoreq.3.The invention furthermore relates to a process for the synthesis of these compounds as well as to their use as emulsion breakers for crude oil/water emulsions.

Abstract: Petroleum crudes, particularly heavy oil crudes produced by thermal or other enhanced recovery procedures, are treated to break the water-in-oil emulsion and reduce the BS&W content by use of additives, advantageously ammonium bisulfite, which act upon inorganic sulfur contained in the crude.

Abstract: Particulate solids and water are removed from petroleum crude to bring the BS&W content of the crude within pipeline specifications by treating a blended and dewatered crude to destabilize the water-in-oil emulsion of the crude and providing in uniform distribution through the treated crude both produced water and an acid-reacting coagulating agent while maintaining the crude at a pH of at least 8, then maintaining the resulting treated crude at 52.degree.-88.degree. C. for at least a few minutes, separating the treated crude into at least an oil phase and a water phase, and recovering the oil phase as a clean blended crude oil having a BS&W content within pipeline specifications and in a yield significantly greater than that which can be recovered without use of produced water and coagulating agent.

Abstract: A process for recovering bitumen from oil-in-water (O/W) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are polymers of specific quaternary ammonium monomers or co-polymers of these quaternary ammonium monomers wth other types of monomers wherein the greater portion of the co-polymer is comprised of the quaternary ammonium monomers. To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 160.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: An oil-in-water emulsion of crude oil, water and hydrophilic surfactant is resolved by first heating said emulsion until it separates into a surfactant laden water layer and an oil-rich emulsion layer, removing the water layer from the oil-rich emulsion layer, treating the emulsion layer by the addition of from 20 to 40 volume percent of water containing a demulsifier and recovering the crude oil which separates from the water upon standing.

Abstract: A process for recovering bitumen from oil-in-water (O/W) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are polyamine salts prepared by contacting poly(ethyleneimines) with organic or inorganic acids. The polyamines have a molecular weight of at least 1,000. To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 160.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: A process for de-watering distillate fuel oil to render the final product clear and bright includes the steps of passing the fuel oil from the stripping step and after process heat recovery and prior to sending to storage to a first heat exchanger and then a separate second heat exchange system to sequentially reduce the temperature of the moisture laden oil before introducing the oil to a sand coalescer vessel where removal of the moisture takes place; the de-watered oil is then passed through the first heat exchanger to raise its temperature a small amount before being passed to a storage tank.

Abstract: A process for dewatering petroleum-containing sludges by a two-stage method using finely divided additives and organic flocculants, wherein(a) finely divided additives, such as ash, coal, sand or mixtures of these, in a free-flowing form or as an aqueous suspension, are homogeneously dispersed in the petroleum-containing sludge, in an amount such that the total solids content of the resulting mixture is from 10 to 30% by weight, especially from 12 to 20% by weight,(b) this sludge mixture is treated with an aqueous solution of an organic flocculant, preferably of anionic nature,(c) the greater part of the sludge water is removed by gravity filtration,(d) the pre-dewatered sludge mixture is treated with an aqueous solution of aluminum salts or trivalent iron salts and(e) this mixture is substantially dewatered by pressure filtration, in the course of which the greater part of the petroleum present is also removed.

Abstract: Very finely divided particulate solids are removed from unconventional whole heavy petroleum crudes, heavy petroleum crude fractions, and residua, syncrudes and syncrude fractions, particularly shale oil and shale oil fractions, by the use of novel surface active agents. The surface active agent is characterized as an admixture of (I) a surfactant comprised of (A) an ethoxylated or propoxylated ester, or ester constituted of a 1,4 sorbitan skeleton to which at least one and up to three ethoxy, propoxy, or mixed ethoxy-propoxy, and at least one and up to three fatty acid substituents are attached through oxygen to the 2,3,5 and 6 carbon atoms; and preferably this compound (A), or mixture thereof, is further admixed with (B) an organo sulfonic acid; and more preferably an admixture of (B) an organo sulfonic acid and (C) an ammonium ion substituted, a substituted amonium ion substituted, or alkali metal substituted sulfonate.

Abstract: A process for recovering bitumem from oil-in-water (O/W) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are water soluble polyethers prepared by the reaction between certain diepoxides and poly(ethyleneoxy) glycols. To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 160.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: Very finely divided particulate solids are removed from unconventional whole heavy petroleum crudes, heavy petroleum crude fractions, and residua, syncrudes and syncrude fractions, particularly shale oil and shale oil fractions, by the use of novel surface active agents. The surface active agent is characterized as an admixture of (I) a surfactant comprised of (A) an ethoxylated or propoxylated ester, or ester constituted of a 1,4 sorbitan skeleton to which at least one and up to three ethoxy, propoxy, or mixed ethoxy-propoxy, and at least one and up to three fatty acid substitutents are attached through oxygen to the 2,3,5 and 6 carbon atoms; and preferably this compound (A), or mixture thereof, is further admixed with (B) an organo sulfonic acid; and more preferably an admixture of (B) an organo sulfonic acid and (C) an ammonium ion substituted, a substituted ammonium ion substituted, or alkali metal substituted sulfonate.

Abstract: Very finely divided particulate solids are removed from unconventional whole heavy petroleum crudes, heavy petroleum crude fractions, and residua, syncrudes and syncrude fractions, particularly shale oil and shale oil fractions, by the use of novel surface active agents. The surface active agent is characterized as an admixture of (I) a surfactant comprised of (A) an ethoxylated or propoxylated ester, or ester constituted of a 1,4 sorbitan skeleton to which at least one and up to three ethoxy, propoxy, or mixed ethoxy-propoxy, and at least one and up to three fatty acid substitutents are attached through oxygen to the 2,3,5 and 6 carbon atoms; and preferably this compound (A), or mixture thereof, is further admixed with (B) an organo sulfonic acid; and more preferably an admixture of (B) an organo sulfonic acid and (C) an ammonium ion substituted, a substituted ammonium ion substituted, or alkali metal substituted sulfonate.

Abstract: The tendency toward ice or solid hydrate formation during cooling of a light hydrocarbon or hydrocarbon mixture such as LPG or NGL for storage or transport at sub-zero temperatures is eliminated by mixing it with aqueous methanol solution in a mixer 5, cooling the mixture in cooler 8 and thereafter separating the hydrocarbon and aqueous phase in a separator 10, the solution being chosen to be substantially insoluble in the hydrocarbon phase and freeze below the temperature to which the mixture is cooled, and at least part of the aqueous phase being recycled by pump 17 to the mixer 5 for re-use with methanol being added as required to restore its concentration in the recycling liquor towards that of the initial aqueous solution and some of the recycling liquor being removed as required to restore the quantity of circulating liquor towards its initial level.

Abstract: An oil and water mixture containing a dispersed phase and a continuous phase is passed for treatment through a rotating horizontal tumbler containing free bodies and a hydrocarbon diluent for the purpose of facilitating subsequent separation of the phases of the mixture. The free bodies tumbling with the mixture in the drum have affinity for the dispersed phase particles, and the hydrocarbon diluent reduces the viscosity of the oil phase thereby causing an increase in the particle size of the dispersed phase of the mixture. Some mixtures that may be treated include effluent streams from a hot-water oil sands extraction plant, oil-in-water emulsions from processes that use enhanced oil well recovery and bitumen froth.

Abstract: A process for recovering bitumen from oil-in-water (O/W) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are salts of polymers and/or co-polymers of specific cationic monomers. To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 160.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: A process for recovering bitumen from oil-in-water (O/W) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are ionenes prepared generally by reaction of ditertiary amines and dihalides. To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 160.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: A surface active agent characterized as an ethoxylated or propoxylated ester, or ester constituted of a 1,4 sorbitan skeleton to which at least one and up to three ethoxy, propoxy, or mixed ethoxy-propoxy substitutent, and at least one fatty acid substitutent is attached through oxygen to the 2,3,5 and 6 carbon atoms. The surfactant is useful for removing very finely divided particulate solids from unconventional whole heavy petroleum crudes, heavy petroleum crude fractions, and residua, syncrudes and syncrude fractions, particularly shale oil and shale oil fractions, by the use of novel surface active agents.

Abstract: A process for recovering bitumen from oil-in-water (O/W) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are salts of poly(tertiary amino)polyurethanes prepared by the reaction of polyisocyanates with diols containing at least one tertiary amino group which reaction product is then reduced in pH until water solubility is attained. To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 160.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: A process for recovering bitumen from oil-in-water (O/W) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are water soluble salts of polymers prepared by the reaction between certain polyoxyalkylene diamines with diepoxides. To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 160.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: A tractor trailer chassis compactly mounts a waste oil cleaning apparatus of hydraulically connected, primary components. A diesel fuel burner fired heater of vertical cylindrical form mounts at one end of the chassis. A blower feeds a large volume of air under pressure to a cylindrical fire box where a fuel air mixture is ignited and fed tangentially into the base of the central chamber within the heater where the products of combustion follow a helical path within the central heat exchange chamber. Waste oil is fed counterflow along a second helical path through an annular chamber separated by a cylindrical metal heat conductive wall from the chamber bearing the products of combustion. Heated waste oil is fed from the heater to a vibrating table type solids separator or shaker mounted at the opposite end of the trailer chassis from the heater where solids are separated from the heated waste oil.

Abstract: The invention relates to a continuous process for treatment of feed in the form of a heavy hydrocarbon-water dispersion or dispersions. The feed is diluted with a hydrocarbon solvent and contacted in a contactor with a water stream. A product stream containing bitumen oils and a discard stream comprising water and solids are separately removed from the contactor.

Abstract: The present invention relates to a process for the treatment of stable emulsions of water and quinoline insolubles in coal tar comprising thoroughly mixing the coal tar with at least one of a specific class of surface-active compositions, followed by a separation of water and quinoline insoluble components from the mixture. The invention also relates to a method of eliminating or minimizing the build-up of coal tar-derived deposits on surfaces in contact with the coal tar.

Abstract: Heavy oils, including oil sands, are recovered from mined or in-situ formation by a novel procedure which involves an initial emulsification of the oil with aqueous alkali, usually sodium hydroxide solution, at a pH above about 11. After separation of any residual solid phase, such as sand, the resulting oil-in-water emulsion is inverted by the use of slaked lime to form a water-in-oil emulsion and thereby regenerating part of the sodium hydroxide solution. The water-in-oil emulsion is dewatered to recover the oil phase while the aqueous phase is recycled to the initial emulsification, after removal of clay particles when oil sands are treated.

Abstract: Apparatus for dewatering flowing diesel fuel includes an agglomerator in a conduit, a sump containing an acid resin catalyst, a sensor in the sump for detecting water, and a conduit for injecting dimethoxyketal into the sump, in accordance with a signal generated by the sensor, the dimethoxy ketal reacting with the water in the diesel fuel in the presence of the catalyst whereby the flowing diesel fuel is dewatered.

Abstract: A process for recovering bitumen from oil-in-water (O/W) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are polymers of diquaternary ammonium monomers containing hydroxyl groups. To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 160.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: Emulsions of oil and water are broken by contacting the emulsions with a quaternized polyalkylene polyamine, e.g., the adduct of 2-hydroxy-3-chloropropyl trimethyl ammonium chloride and a polyethylene polyamine.

Abstract: A process for recovering bitumen from oil-in-water (o/w) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are branched water-soluble quaternary ammonium-containing polymers. To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 160.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: A process for recovering bitumen from oil-in-water (O/W) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are polyureas of average molecular weight greater than about 5,000 prepared by the reaction between a polyisocyanate and a polyoxyalkylenediamine. To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 160.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: A process for recovering bitumen from oil-in-water (O/W) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are cationic polymers of equal to or greater than about 2,000 molecular weight obtained by the reaction of polyalkoxydiamines with epihalohydrins. To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 160.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: A process for recovering bitumen from oil-in-water (O/W) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are combinations of chemical agents comprising(a) poly(amidoamine) or poly(ester-amine) salts, and(b) polycarbonates.To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 160.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: A process useful for breaking oil in water emulsions produced as the result of a surfactant flood oil recovery project is disclosed. The produced oil in water emulsion, stabilized with surfactants, content is treated with brine and a polyol or quaternary ammonium compound, or both, followed by mixing and settling to form a sprung oil phase and a brine phase.

Abstract: The water content of a crude oil containing surfactant is reduced to less than 0.5 weight percent by first conventionally drying the crude oil to a water concentration less than about 10%, then contacting the crude oil with a low molecular weight alcohol to effect a phase separation into an aqueous layer and an oil layer, thereafter separating these layers to obtain a dried oil and an aqueous alcoholic surfactant solution. The alcohol can then be separated from the aqueous alcoholic surfactant solution. The recovered alcohol can be recycled through the system and the recovered surfactant can be reused in another micellar flood.

Abstract: The present invention provides a method for the desalting of fuel oil by mixing the fuel oil and clean water, thereby separating and eliminating sodium salts and potassium salts contained in the fuel oil, and the method comprises separating a heavy portion including salt-containing water from the fuel oil which is a light portion, this heavy portion separated from the fuel oil being separated into water and a residue by an evaporator, the water being reused as a washing water and the residue being burnt to use the generated heat as a heat source for the evaporator, whereby the residue is decreased in volume and solidified to be made easy in the handling.

Abstract: A method for treating a water-containing waste oil comprising oils, water and solid constituents and forming a water-in-oil emulsion, which comprises adding to the water-containing waste oil having an aromatic oil ratio A as represented by the following formula: ##EQU1## at least 1% by weight, on the basis of the weight of the water-containing waste oil, of a treating oil having an aromatic oil ratio B(.vertline.A-B.vertline.>0.5 and excluding 0.4.ltoreq.B.ltoreq.0.6) thereby to separate the oil content.

Abstract: A process for recovering bitumen from oil-in-water (O/W) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are polyols of 2 and greater functionality containing predominantly mixed ethylene oxide and propylene oxide wherein the ethylene oxide content of the polyol (by weight) is greater than about 70% but less than about 95%. The molecular weight of these polyols is greater than about 10,000. To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 120.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: A process for recovering bitumen from oil-in-water (O/W) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are polyols of 4 and greater functionality containing discrete blocks of ethylene oxide and propylene oxide wherein the ethylene oxide content of the polyol is greater than about 50% but less than about 95%. The molecular weight of these polyols is greater than about 12,000. To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 120.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: A process for recovering bitumen from oil-in-water (O/W) emulsions is disclosed wherein water soluble demulsifiers are used. These demulsifiers are hydrophilic polyurethanes wherein the ethylene oxide content of the polyol portion of the polyurethane is greater than about 70% by weight. To resolve the bituminous petroleum emulsions, the process is carried out between 25.degree. and 120.degree. C. wherein the demulsifier of the invention is contacted with the bituminous emulsion.

Abstract: Disclosed is a process for breaking an oil-in-water emulsion, in particular a raw emulsion produced in in situ tar sand plants, by first contacting with a polyethylene polymeric resin having a molecular weight in the range of 100,000 and 7,000,000 the raw emulsions; allowing to stand for two to four hours; adding a hydrocarbon diluent, optionally containing a larger amount of resin and then removing a mixture of diluent and oil floating on the water surface.

Abstract: A process for recovering oil from oil-in-water petroleum emulsions stabilized with clay and/or other solids by subjecting them to the action of an optimum amount of non-ionic, water-soluble, aryl sulfonates-oxyalkylated phenol formaldehyde resins at a pH of 7.0 to 8.0 and then adding a saturated aqueous alkali metal halide solution to the resulting mixture. The process is carried out at between about 200.degree. F. and 240.degree. F. and the mixture is allowed to stand in the quiescent state for a period of about 1 to about 10 hours to allow the halide solution to increase the specific gravity of the resulting aqueous phase by at least 0.02 thereby causing the bitumen to float and facilitating recovery of the oil.

Abstract: There is disclosed a process for breaking emulsions in fluids from in situ tar sands producing areas by adding thereto from 30 to 50 volume percent of a hydrocarbon diluent; an effective amount of a non-ionic water-soluble polyethylene oxide polymeric resin having a molecular weight in the range of 100,000 to 1,000,000 followed by the addition of 500 to 800 ppm of an alkali metal hydroxide which reacts with clays tending to stabilize the emulsion to prevent and remove clay deposits in the treating equipment. The hydroxide also enhances the ability of the resin to break the emulsion.

Abstract: An oil-in-water emulsion of crude oil, water and surface active agents is broken by adding additional surface active agents, preferably relatively high equivalent weight petroleum sulfonates, to the emulsion and then subjecting the emulsion to conventional emulsion breaking techniques.

Abstract: Opaque macroemulsions comprising oil and brine are diluted with water to an electrolyte concentration at which rapid coalescence into three phases, oil, a transparent microemulsion, and water is achieved. This is of particular utility in post-primary oil recovery processes wherein said opaque macroemulsions are produced as effluents from producing wells. The opaque macroemulsions are collected and oil therein recovered by dilution as described herein.

Abstract: A method for preventing fouling of equipment used in hydrocarbon processing is provided comprising adding to said hydrocarbon a polyalkyleneoxy sulfoxy salt represented by the formula: ##STR1## wherein R is a linear alkyl radical having from about 6 to 15 carbon atoms or an alkyl phenyl radical wherein the alkyl group contains from about 8 to 10 carbon atoms, R.sub.1 is H or CH.sub.3, n is a number from 3 to 8, x is 3 or 4 and M.sup.+ is an ammonium or an alkali metal cation.An antifouling formulation is also provided which comprises an alcohol-water dispersion of the above antifouling agent and a surfactant comprising a fatty acid dialkanol amide.

Abstract: A process useful for recovering surfactant and oil of low water content in surfactant flood oil recovery projects is disclosed. A produced oil in water emulsion is treated with brine and partitioning agent, preferably isopropyl alcohol, by mixing and settling to form three phases, an oil phase containing a minor amount of surfactant, a partitioning agent phase containing most of the surfactant originally present in the produced emulsion, and a brine phase containing a minor amount of alcohol.

Abstract: Residual moisture and sulfur and other residual reducing agent impurities contained in automotive fuels and fuel oils are removed by adding to the fuel a chromate compound or a solid acid and circulating the fuel through a filter system comprising at least one filter made up of a cellulosic material attached to a D.C. power supply, and containing a chromate compound or a solid acid, whichever is not previously added to the fuel.

Abstract: A process for desalting crude petroleum comprises breaking down a stable emulsion of water and crude petroleum when formed in a desalter, by injecting a demulsifying agent, such as di-2-ethyl hexyl sulphosuccinate, into the desalter at a predetermined level, when the sample taken at this level contain a predetermined content of stable emulsion.An apparatus for carrying out this process continuously is also included.

Abstract: Process and apparatus for the desalting and dehydration of crude oil wherein, the crude oil is washed in one or several stages using fresh or recirculated hot water containing a demulsifier. The crude oil is also passed through a coalescence stage, and a settling stage aimed at obtaining a salt content to meet crude oil specifications. Subsequently the crude oil is led into a lower stripping compartment of a column, in which dehydration is carried out to the desired level by using fuel or combustion gas, the stripping temperature being reached by heating the crude or the gas or both, the gas-vapor mixture being cooled in the upper compartment of the column by a cooling fluid such as the untreated crude oil or recirculated or fresh water, depending upon the nature and salt content of the crude. The cooled gas is recirculated within the column or led to a pipeline for consumption, while the cooling fluid, in the case of water, is recirculated in the unit.

Abstract: A method for isolating a low molecular weight polymer from a solution of a low molecular weight polymer having a viscosity of 5 to 100,000 cps at 30.degree. C. and an inactivated catalyst in a hydrophobic organic solvent, which comprises mixing an acidic, alkaline or neutral water or a mixture of the water and a water-soluble organic solvent with the solution containing the low molecular weight polymer in the presence of an amphoteric, cationic or nonionic surfactant or a nonionic or cationic high molecular weight flocculating agent, whereby the separation of the organic layer and the aqueous layer is significantly improved.

Abstract: A method for dewatering tar-water mixtures obtained from the coking of coal is disclosed. The method involves adding to the tar from 150 to 3,000 ppm of a di-tri butyl ethoxylated phenol compound dissolved in water, heating the tar-water mixture, and then agitating it to allow contact with the chemical additive. This is followed by allowing the mixture to settle forming an aqueous upper phase and a lower dewatering tar phase.

Abstract: A process for recovering oil from either water-bituminous petroleum emulsions or from crude petroleum emulsions having a pH of 10 or less by adding thereto an optimum amount of non-ionic, water soluble polyethylene oxide polymers at a pH of 10 or less, and separating the oil from water. To resolve bituminous petroleum emulsions, the process is carried out at between 150.degree. F and 210.degree. F and a diluent is added to reduce the petroleum viscosity. The minimum effective concentration of the polymers used decreases as their molecular weight increases.In a modification of the process, an effective amount of an alkaline earth metal halide such as calcium chloride is added to improve coagulation and separation of any clay present.