US3392105A - Use of a soluble oil in the extraction of hydrocarbons from oil sands - Google Patents

Description

9, 1968 F. H. POETTMANN ET AL 3,392,105

USE OF A SOLUBLE OIL IN THE EXTRACTION OF HYDROCARBONS FROM OIL SANDS Filed April 15. 1965 SOLVENT SOLVENT STORAGE TAR STORAGE IN VE N TORS SOLID WASTES FRED H. POETTMANN JOE T KELLY A TTORNEY/ United States Patent Oflice 3,392,105 Patented July 9, 1968 3,392,105 USE OF A SOLUBLE OIL IN THE EXTRACTION OF HYDROCARBONS FROM OIL SANDS Fred H. Poettmann and Joe T. Kelly, Littleton, Colo.,

assignors to Marathon Oil Company, Findlay, Ohio, a

corporation of Ohio Filed Apr. 15, 1965, Ser. No. 448,372 7 Claims. (Cl. 208-11) This invention relates to the recovery of hydrocarbons and more particularly to the recovery of hydrocarbons from oil sands.

Such sands represent a tremendous potential reserve of hydrocarbon. Estimates of the hydrocarbon content of the McMurray formation of the Athabasca area vary between 300 and 500 billion barrels of oil. This compares favorably with the current free worlds crude oil reserves of 400 billion barrels. Industry has taken several steps toward the recovery of hydrocarbons from the sands. In one process, the oil sands are contacted with steam and ammonia to reduce the viscosity of the tars and emulsify the hydrocarbon. The emulsified hydrocarbon separates from the sands and is recovered. This process can be carried out either in situ or in aboveground processing plants. In another approach, both cocurrent and countercurrent in situ combustion have been tried. The costs of these processes are quite high and, at the present time, the large scale recovery of hydrocarbons from the oil sand has not been effected.

US. Patent 3,057,404 teaches an in situ process wherein air, steam, and a cutting oil are injected into a subterranean formation to induce separation of the oil from the oil sands so as to allow the sand to settle downwardly. The separated oil is then removed.

The above method is confounded by subsidence and other problems. The subsidence causes bending and closure of well tubing. Soluble oils must be formulated which contain surfactants soluble in the crude and which will not precipitate from solution when contacted by ions in the crude. This is a problem in subterranean deposits as the ion content of the crude changes from place to place.

Applicants process overcomes some of the problems inherent in the prior art processes. The amount of extractant liquid required in the extraction processes is reduced and the corrosion-resistant metals are not needed as in the combustion processes.

Essentially, the process of this invention comprises contacting the oil sands with soluble oils, thereafter diluting the tar sand-soluble oil mixture with a solvent-diluent, and separating the sand from the resulting relatively low viscosity solution. The term soluble oil, as used in this specification and claims, refers to solutions of surfactants in non-polar solvents with the ability to emulsify Water when admixed therewith. For purposes of this invention, the term is also intended to include transparent emulsions. The substantially anhydrous soluble oils and transparent emulsions are well known and generally formulated from hydrocarbons, one or more surfactants or nonsurfactant surface-active materials, and a stabilizing agent which is usually an alcohol but which may be other semipolar compounds. Several suitable soluble oils are found in US. Patent 2,356,205. Other and preferred formulations are set out in copending US. patent application Ser. No. 324,216, filed on Nov. 18, 1963, by William B. Gogarty and Russell W. Olson. Obviously, the soluble oil must be stable to the oil and water in the oil sands and at process temperatures.

Essentially, our invention comprises a combination of separation and dilution steps which are to be carried out aboveground. In our preferred process, comminuted oil sands are contacted with a soluble oil to form a slurry in a mixer unit. The slurry is then mixed with a solvent-diluent and separated.

This process is more fully illustrated with reference to the accompanying drawing where conveyer 1 passes comminutedoil sands 2 into hopper 3. Comminutedoil sands 2 pass through star feeder 4, or other suitable valving mechanism, intoslurry preparation tank 5. Soluble oil fromstorage tank 6 passes throughvalve 7 in line 8 toslurrypreparation tank 5 Where it is rapidly mixed withoil sands 2 by stirringdevices 9. Normally, from at least about 0.1-10, and preferably at least from about 05-15, volumes of soluble oil per volume of oil sand produce a desired slurry. A mixture of four parts tar sand and one part of a soluble oil comprising straight run gasoline, isopropanol (about 4% and water (about 25%) creates a loose slurry on mixing. After a slurry of suitable viscosity, preferably from about 500 to about 50,000 cps., is prepared, it passes throughvalve 10 into dilution tank 11 Where it is mixed with solvent. Solvent fromsolvent storage 12 passes throughvalve 13 inline 14 into dilution tank 11 where it serves to further reduce the viscosity of the slurry. A mixture of four parts of the above loose slurry and one part straight run gasoline gives a solution which appears to have a viscosity approximating that of kerosene. Normally, from at least about 0.515 volumes of solvent are added per volume of slurry. The amount of solvent added depends upon the viscosity of the solvent, the temperature of the solvent and the slurry, etc. Solvents such as straight run gasoline, liquefied petroleum gases, xylene, isopropanol, dimethyl-formamide, furfural, phenol, etc., and combinations thereof, can be used in this process. When diluted to a desired degree, for example, from about 30 to about 1000 cps., the diluted mixtures pass throughvalve 15 intoseparator 16.Separator 16 is depicted as a cyclone separator but can be any desired liquidsolid separator. On separation, the sand and other solid wastes pass throughvalve 17 to a waste disposal means. The liquids pass fromseparator 16 throughline 18 intodistillation tower 19 where the light, low-boiling solvent is distilled from the mixture. The solvent is then recycled throughline 20 tosolvent storage 12. The bituminous bottoms are then removed to storage tank 1. From storage, the bituminous materials are transported to market, etc.

Temperatures, for example, up to from about 30 to about C., can aid in the desired separation. The use of heat, of course, would depend on its availability, solvent, soluble oil, etc., costs and the like. The optimum viscosities outlined as useful at various stages in the process will vary with the equipment and temperatures used in carrying out the process.

In a preferred embodiment of the above invention, a soluble oil which takes up water only poorly can be used to advantage. Such soluble oils are, of course, miscible with the oil from the oil sands. In this particular embodiment, large amounts of steam can be introduced into the solvent oil-oil sands mixture to effect the desired reduction in the viscosity of the mixture so as to aid in separating sands from the mixture. To further aid in the formation of the desired slurry, the oil sands can be preheated.

Now having described our invention, what we claim is:

1. The process for recovering oil from tar sand comprising contacting, in a mixing unit, a substantially solid tar sand with a soluble oil to form a mixture of tar, sand, and soluble oil; contacting the said mixture with sufiicient diluent fluid to form a lower viscosity solution; and separating the sand therefrom.

2. The process for recovering oil from tar sands comprising contacting, in a mixing unit, sized lumps of substantially solid tar sands with at least about 0.1-10 volumes of soluble oil per volume of tar sand to form a mixture of tar, sand, and soluble oil; contacting the said mixture with at least about 05-15 volumes of diluent fluid per volume of said mixture to form a relatively low viscosity solution of tar and diluent; and separating the sand therefrom. 7

3. The process for recovering oil from tar sands comprising agitating, in a mixing unit, a substantially solid tar sand with at least about 0.5l5 volumes of soluble oil per volume of tar sands to form a mixture of tar, sand, and soluble oil having a viscosity of from about 500 to about 50,000 cps.; contacting the said mixture with sufficient diluent fluid to form a relatively lower viscosity solution of tar and diluent and soluble oil; and separating the sand therefrom.

4. The process for recovering oil from tar sands comprising agitating, in a mixing unit, a substantially solid tar sand with at least about 0.515 volumes of soluble oil per volume of tar sand to form a mixture of tar, sand, and soluble oil having a viscosity of from about 500 to about 50,000 cps; contacting the said mixture with at least about 0.515 volumes of diluent fluid per volume of said mixture to form a mixture having a viscosity of from about 30 to about 1000 cps. at operating temperatures; and separating the sand therefrom.

5. The process for the recovery of oil from tar sands comprising contacting, in a mixing unit, sized substantially solid tar sand particles with a soluble oil to form a mixture of tar, sand, and soluble oil; contacting the said mixture with suflicient diluent fluid to form a relatively lower viscosity mixture; separating the sand from the relatively low viscosity mixture to form a substantially solidfree solution; separating the diluent fluid from the substantially solid-free solution; and contacting additional amounts of said tar, sand, and soluble oil mixture with the separated diluent fluid.

6. The process for recovering oil from tar sands com- 4 solid tar sand particles with at least about 0.1-10 volume of soluble oil per volume of tar sand to form a mixture of tar, sand, and soluble oil; agitating the said mixture with at least about 0.5-15 volumes of a diluent fluid per volume of said mixture to form a relatively lower viscosity liquidsolid mixture; separating the sand therefrom to form a substantially solids free liquid isolution; separating the diluent fluid from said solids free liquid solution; and contacting additional amounts of said tar, sand, and soluble oil mixture with the separated diluent fluid.

7. The process for recovering oil from tar sands comprising contacting, in a mixing unit, a substantially solid tar sand with at least about 0.515 volumes of soluble oil per volume of tar sands to form a mixture of tar, sand, and soluble oil having a viscosity of from about 500 to about 50,000 cps; contacting the said mixture with at least about 05-15 volumes of diluent fluid per volume of said mixture to form a liquid-solid mixture having a viscosity of about 301000 cps. at operating temperatures; separating the sand from said liquid-solid mixture to form a substantially solids free liquid solution; separating the diluent fluid from said solids free liquid solution; and contacting additional amounts of said tar, sand, and soluble oil mixture with the separated diluent fluid.

References Cited UNITED STATES PATENTS 3,050,289 8/1962 Gerner 2081l 3,082,822 3/1963 Holm et al. 166-9 3,126,952 3/1964 Jones 166-9 3,163,214 12/1964 Csaszar 2528.55

DANIEL E. WYMAN, Primary Examiner.

P. E. KONOPKA, Assistant Examiner.

Claims (1)

1. THE PROCESS FOR RECOVERING OIL FROM TAR SAND COMPRISING CONTACTING, IN A MIXING UNIT, A SUBSTANTIALLY SOLID TAR SAND WITH A SOLUBLE OIL TO FORM A MIXTURE OF TAR, SAND, AND SOLUBLE OIL; CONTACTING THE SAID MIXTURE WITH SUFFICIENT DILUENT FLUID TO FORM A LOWER VISCOSITY SOLUTION; AND SEPARATING THE SAND THEREFROM.

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