US3029195A - Method of cathodically protecting well casing - Google Patents
Method of cathodically protecting well casing Download PDFInfo
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- US3029195A US3029195A US816942A US81694259A US3029195A US 3029195 A US3029195 A US 3029195A US 816942 A US816942 A US 816942A US 81694259 A US81694259 A US 81694259A US 3029195 A US3029195 A US 3029195A
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- metal
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- well
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- 229910052751 metal Inorganic materials 0.000 claims description 50
- 239000002184 metal Substances 0.000 claims description 50
- 238000002844 melting Methods 0.000 claims description 18
- 230000008018 melting Effects 0.000 claims description 12
- 238000004210 cathodic protection Methods 0.000 claims description 11
- 238000011065 in-situ storage Methods 0.000 claims description 3
- 229910045601 alloy Inorganic materials 0.000 description 22
- 239000000956 alloy Substances 0.000 description 22
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 10
- 238000005260 corrosion Methods 0.000 description 10
- 230000007797 corrosion Effects 0.000 description 10
- 229910000743 fusible alloy Inorganic materials 0.000 description 7
- 230000015572 biosynthetic process Effects 0.000 description 6
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- 238000010438 heat treatment Methods 0.000 description 5
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- 150000002739 metals Chemical class 0.000 description 5
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- 239000008188 pellet Substances 0.000 description 5
- 229910000831 Steel Inorganic materials 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- -1 Lithium-mercury Bismuth-lithium Bismuth-potassium Bismuth-sodium Lithium-tin Sodium-tin Zinc-tin Chemical compound 0.000 description 3
- 239000000155 melt Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- XTPMURFLEDRBCW-UHFFFAOYSA-N bismuth gallium Chemical compound [Ga].[Bi] XTPMURFLEDRBCW-UHFFFAOYSA-N 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 229910052738 indium Inorganic materials 0.000 description 2
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- 229910001092 metal group alloy Inorganic materials 0.000 description 2
- 230000000116 mitigating effect Effects 0.000 description 2
- 239000003129 oil well Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- UAZMXAXHGIZMSU-UHFFFAOYSA-N sodium tin Chemical compound [Na].[Sn] UAZMXAXHGIZMSU-UHFFFAOYSA-N 0.000 description 2
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 241000894006 Bacteria Species 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 1
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
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- 229910000861 Mg alloy Inorganic materials 0.000 description 1
- 208000036366 Sensation of pressure Diseases 0.000 description 1
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- 230000002378 acidificating effect Effects 0.000 description 1
- 239000010405 anode material Substances 0.000 description 1
- 229910002056 binary alloy Inorganic materials 0.000 description 1
- JYPVGDJNZGAXBB-UHFFFAOYSA-N bismuth lithium Chemical compound [Li].[Bi] JYPVGDJNZGAXBB-UHFFFAOYSA-N 0.000 description 1
- FSAJRXGMUISOIW-UHFFFAOYSA-N bismuth sodium Chemical compound [Na].[Bi] FSAJRXGMUISOIW-UHFFFAOYSA-N 0.000 description 1
- 239000012267 brine Substances 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- 229940044194 cadmium Drugs 0.000 description 1
- ZIXVIWRPMFITIT-UHFFFAOYSA-N cadmium lead Chemical compound [Cd].[Pb] ZIXVIWRPMFITIT-UHFFFAOYSA-N 0.000 description 1
- DGJPPCSCQOIWCP-UHFFFAOYSA-N cadmium mercury Chemical compound [Cd].[Hg] DGJPPCSCQOIWCP-UHFFFAOYSA-N 0.000 description 1
- KKCMQBCXXPZGTI-UHFFFAOYSA-N cadmium sodium Chemical compound [Na].[Cd] KKCMQBCXXPZGTI-UHFFFAOYSA-N 0.000 description 1
- CEKJAYFBQARQNG-UHFFFAOYSA-N cadmium zinc Chemical compound [Zn].[Cd] CEKJAYFBQARQNG-UHFFFAOYSA-N 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
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- 238000010586 diagram Methods 0.000 description 1
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- 239000008151 electrolyte solution Substances 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 1
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 235000000396 iron Nutrition 0.000 description 1
- JWZCKIBZGMIRSW-UHFFFAOYSA-N lead lithium Chemical compound [Li].[Pb] JWZCKIBZGMIRSW-UHFFFAOYSA-N 0.000 description 1
- 229910001338 liquidmetal Inorganic materials 0.000 description 1
- UIDWHMKSOZZDAV-UHFFFAOYSA-N lithium tin Chemical compound [Li].[Sn] UIDWHMKSOZZDAV-UHFFFAOYSA-N 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
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Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B41/00—Equipment or details not covered by groups E21B15/00 - E21B40/00
- E21B41/02—Equipment or details not covered by groups E21B15/00 - E21B40/00 in situ inhibition of corrosion in boreholes or wells
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
- C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
- C23F13/06—Constructional parts, or assemblies of cathodic-protection apparatus
- C23F13/08—Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto
- C23F13/12—Electrodes characterised by the material
- C23F13/14—Material for sacrificial anodes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S166/00—Wells
- Y10S166/902—Wells for inhibiting corrosion or coating
Definitions
- This invention relates to new and useful processes for mitigating corrosion, and more particularly to an improved means for providing cathodic protection of well casings from corrosion at relatively inaccessible points.
- Cathodic protection has been developed as a means for mitigating or preventing corrosion in underground structures and the like.
- this system of protection may consist of the introduction of a more reactive, sacrificial metallic anode in close proximity to the conduit in the region to be protected.
- the metallic conduit along its entire surface is transformed from a series of cathodic and anodic portions, differing slightly in the composition of their metallic constituents from point to point, into a single cathode.
- more reactive in this context is meant a metal of the electromotive series which, when placed in contact with a less reactive metal of the same series, becomes an anode while the less reactive metal becomes a cathode.
- the anode for the purpose of this invention, is defined as the electrode in a galvanic cell at which oxidation occurs.
- the cathode similarly, is delined as the electrode in a galvanic cell at which reduction occurs.
- the introduced sacrificial anode undergoes corrosion, but the anode may be replaced whenever necessary.
- the conduit or well casing, formerly subject to corrosion at numerous inaccessible points, is protected and preserved by use of the sacrificial anode.
- Another object of this invention is to provide a means for cathodically protecting an iron or steel well casing at a point which is relatively inaccessible.
- a feature of this invention is the provision of an improved means for cathodic protection of well casings by perforating the well casing at a desired point underground and forcing through the perforations relatively large amounts of a molten metallic composition which is an- As a result, corrosion due to such odic to the casing metal, and which, upon solidification, joins electrically with the structure to be: protected and forms a sacrificial anode.
- FIGURE 1 is a flow diagram indicating the steps of our improved process
- FIG. 2 is a diagrammatic view showing a section of the earth with a well casing in place and our improved means for cathodic protection. 7
- an oil-well casing is perforated at the depth where protection is desired, preferably opposite some zone known to be associated with external corrosion of the casing.
- a suitable packer is installed just below the lowest perforations, and an electric heater or other suitable heating means is lowcred on a cable to a level adjacent to the perforations.
- the requisite amount of a low-melting metal alloy, in pellet or other suitable form is dropped into the casing to rest on the packer and surround the electric heater.
- the heater is energized and the metal is melted, after which gas pressure is applied at the Well head to force the molten metal through the perforation into the formation.
- the metal used is a low-melting alloy which is anodic to the iron or steel well-casing.
- This preheating may be accomplished by the electric heater or by combustion in the well here at this point.
- the packer is removed, and excess anodic material which has solidified within the casing is removed by reaming or other conventional method. If desired, excess amounts of the anodic metal which do not interfere with the operation of the well may be left in place to provide cathodic protection against corrosion of the internal surfaces of the well casing.
- FIG. 2 a diagrammatic, vertical, sectional view of the earth and a well casing in position.
- a plurality of earth formations or strata 1, 2, and 3 through which there has been positioned a well casing 4.
- a suitable packer 5 is positioned.
- the well is perforated to provide holes 6 in casing 4 just above packer S.
- the perforation of well casing 4 is accomplished with any conventional perforating device such as a well-perforating gun or the.
- a combustible gas or volatile hydrocarbon may be introduced into the well and burned, adjacent to perforations 6, to heat the well casing and the surrounding formation to a temperature slightly above the melting point of the anodic metal which is to be applied in the well.
- a suitable heating device preferably an electric heater 7, is lowered into the well to the level of packer '5.
- a low-melting metal alloy, in pellet or other suitable form is dropped into the casing to rest on the packer. In general, approximately to 500 pounds of the anodic metal are used in this process.
- the electric heater 7 is energized and metal pellets 8 are melted.
- gas pressure e.g., compressed air, nitrogen.
- About the only low-melting anodic alloys which are excluded from this invention are ones which consist entirely of, or contain a hi h proportion of, the very active alkali metals.
- alloys of the alkali metals with other metals in which the alkali metal content is suliiciently small as to make the alloy not violently reactive with water or other constituents of the strata into which the metal is to be injected, are satisfactory.
- One alloy which may be used in the above-described process is the bismuthgallium alloy which melts at about 440 F.
- Another alloy which is satisfactory for the purpose of this invention is the gallium-indium alloy, containing about 80-90% indium, which melts in the range between about 190 and 250 F.
- Sodium-tin, zinc-tin, and lithium-magnesium alloys which melt elow 600 F. are preferred, from purely economic considerations.
- alloys which contain small amounts of the alkali metals are highly desirable in this process since the alkali metals react with moisture in the environment surrounding the well casing and create an alkaline environment around the casing which is effective in stifling the activity of sulfate-reducing bacteria and in neutralizing corrosive acidic constituents such as hydrogen sulfide.
- alloys listed above are all binary alloys, it is to be understood that any alloy can be used in this invention regardless of the number of constituents therein so long as the alloy is anodic with respect to the structure to be protected.
- this inventiondoes not exclude the use of pure metals, e.g., gallium, which have a melting point less than about 600 F.
- a method of providing cathodic protection to the exterior surface of metallic well casings which comprises forming perforations in the casing below ground, placing a low-melting metal anodic to the casing adjacent to sai perforations, melting said metal, and applying gas pres sure to the well to force the molten anodic metal through said perforations to form in-situ, sacrificial metal anodes in electrical contact with said casing.
- the low-melting alloy is selected from the group consisting of bismuth-gallium, gallium-indium, bismuth-cad mium, bismuth-lithium, bismuth-potassium, cadmiumlead, cadmium-mercury, cadmium-sodium, cadmium-tin, cadmium-zinc, lead-lithium, lithium-magnesium, lithiurnmercury, bismuth-sodium, lithium-tin, sodium-tin, and Zinc-tin alloys.
- a method of providing cathodic protection to the exterior surface of well casings formed of ferrous metal which comprises forming perforations in the casing below ground, placing a packing in said casing just below said perforations, placing heating means at said packing, placing on said packing a low-melting metal anodic to the casing, melting said anodic metal with said heating means, and applying gas pressure to said well to force the molten anodic metal through said perforations to form in-situ, sacrificial metal anodes in electrical contact with said casing.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Geochemistry & Mineralogy (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Physics & Mathematics (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Prevention Of Electric Corrosion (AREA)
Description
A ril 10, 1962 G. A. MARSH ETAL 3,
METHOD OF CATHODICALLY PROTECTING WELL CASING Filed May 29, 1959 PERFORATE WELL CASING PACK WELL CASING BELOW PERFORATIONS PLACE HEATER ADJACENT TO PACKING PLACE PELLETS OF LOW MELTING ALLOY ON PACKING MELT ALLOY PELLETS PPLY PRESSURE TO FORCE MOLTEN METAL THROUGH PERFORATIONS FIG.I
INVENTORS GLENN A. MARSH BY EDWARD SCHASCHL ATTORNEY United rates FatentGiifiQe 3,029,195 Patented Apr. 10, 1962 3,029,195 METHGD F ATH9DI CALLY PRQTEQTING WELL CASENG Glenn A. Marsh and Edward Schaschl, Crystal Lake, .liL,
assignors to The Pure (til Company, Chicago, Ill, a
corporation of Ohio Filed May 29, 1959, Ser. No. 816,942 10 Claims. (U. 294-148) This invention relates to new and useful processes for mitigating corrosion, and more particularly to an improved means for providing cathodic protection of well casings from corrosion at relatively inaccessible points.
it is well recognized that when different metals of the clectromotive series are placed in contact with each other within an electrolytic solution, such as brine or underground water, etc., an electric current flows between the two metals from the metal which serves as the anode to the metal which serves as the cathode. This electrolytic current is associated with the chemical oxidation of the anodic metal. Metal conduits such as oil well tubing and casings, have variations in composition from point to point such that some portions of the metal may be cathodic and other portions anodic at difierent points along the metallic surface. galvanic action at the internal or external surface of such well casings is so extensive that it has become a major problem in the efiicient operation of wells.
Cathodic protection has been developed as a means for mitigating or preventing corrosion in underground structures and the like. In one form, this system of protection may consist of the introduction of a more reactive, sacrificial metallic anode in close proximity to the conduit in the region to be protected. The metallic conduit along its entire surface is transformed from a series of cathodic and anodic portions, differing slightly in the composition of their metallic constituents from point to point, into a single cathode. By more reactive in this context is meant a metal of the electromotive series which, when placed in contact with a less reactive metal of the same series, becomes an anode while the less reactive metal becomes a cathode. The anode, for the purpose of this invention, is defined as the electrode in a galvanic cell at which oxidation occurs. The cathode, similarly, is delined as the electrode in a galvanic cell at which reduction occurs. The introduced sacrificial anode undergoes corrosion, but the anode may be replaced whenever necessary. The conduit or well casing, formerly subject to corrosion at numerous inaccessible points, is protected and preserved by use of the sacrificial anode.
In providing cathodic protection'to well casings, a serious problem has developed as a result of the relative inaccessibility of casings which are located some considerable distance underground. Attempts have been made to provide sacrificial anodes in a form which could be secured in place on the outside of a well casing at a considerable depth below ground. However, such attempts have not been entirely successful and a considerable demand exists for a satisfactory method of providing cathodic protection at relatively inaccessible points in a well casing.
It is therefore one object of this invention to provide an improved means of preventing corrosion of ferrousmetal well-casing at relatively inaccessible points.
Another object of this invention is to provide a means for cathodically protecting an iron or steel well casing at a point which is relatively inaccessible.
A feature of this invention is the provision of an improved means for cathodic protection of well casings by perforating the well casing at a desired point underground and forcing through the perforations relatively large amounts of a molten metallic composition which is an- As a result, corrosion due to such odic to the casing metal, and which, upon solidification, joins electrically with the structure to be: protected and forms a sacrificial anode.
Other objects and features of this invention will become apparent from time to time throughout the specification and claims as hereinafter related.
In the accompanying drawing, FIGURE 1 is a flow diagram indicating the steps of our improved process, and FIG. 2 is a diagrammatic view showing a section of the earth with a well casing in place and our improved means for cathodic protection. 7
According to our invention, an oil-well casing is perforated at the depth where protection is desired, preferably opposite some zone known to be associated with external corrosion of the casing. Then a suitable packer is installed just below the lowest perforations, and an electric heater or other suitable heating means is lowcred on a cable to a level adjacent to the perforations. Following this, the requisite amount of a low-melting metal alloy, in pellet or other suitable form, is dropped into the casing to rest on the packer and surround the electric heater. The heater is energized and the metal is melted, after which gas pressure is applied at the Well head to force the molten metal through the perforation into the formation. The metal used is a low-melting alloy which is anodic to the iron or steel well-casing. In practice, we prefer to preheat the formation surrounding the perforated section of the casing to a point just above the melting point of the anodic metal before dropping the metal into the casing, or before applying gas pressure to the molten metal. This preheating may be accomplished by the electric heater or by combustion in the well here at this point. After the anodic metal has been injected and allowed to solidify, the packer is removed, and excess anodic material which has solidified within the casing is removed by reaming or other conventional method. If desired, excess amounts of the anodic metal which do not interfere with the operation of the well may be left in place to provide cathodic protection against corrosion of the internal surfaces of the well casing.
Referring to the drawing by numerals of reference, there is shown in FIG. 2 a diagrammatic, vertical, sectional view of the earth and a well casing in position. In this drawing, there is shown a plurality of earth formations or strata 1, 2, and 3 through which there has been positioned a well casing 4. At a point within well casing 4, some considerable distance below ground, a suitable packer 5 is positioned. The well is perforated to provide holes 6 in casing 4 just above packer S. The perforation of well casing 4 is accomplished with any conventional perforating device such as a well-perforating gun or the.
like. In preparation for treatment of the well casing, a combustible gas or volatile hydrocarbon may be introduced into the well and burned, adjacent to perforations 6, to heat the well casing and the surrounding formation to a temperature slightly above the melting point of the anodic metal which is to be applied in the well. A suitable heating device, preferably an electric heater 7, is lowered into the well to the level of packer '5. Then a low-melting metal alloy, in pellet or other suitable form, is dropped into the casing to rest on the packer. In general, approximately to 500 pounds of the anodic metal are used in this process. The electric heater 7 is energized and metal pellets 8 are melted. Next, gas pressure, e.g., compressed air, nitrogen. or other inert gas, is applied to the well to force the molten anodic metal out through perforations d to solidify within the surrounding formation as indicated by dotted lines 9. After this metal has been injected and allowed. to solidify, the excess metal within the casing is removed by reaming or other conventional methods and the packer 5 is removed from the well. If desired, part or all of the anodic metal which remains within the well casingmay be left in place, if it does not interfere with operation of the well, to provide cathodic protection for the inner surfa'ceso'f well casings; W v h in carrying out this invention as described in the above example, it is preferred to use low-melting alloys which have melting points below about 600 F. Any metal or alloy which melts below about 606 F., and which is anodic with respect to the metal of the well casing, i.e., iron or steel, is satisfactory for the purpose of this invention providedonly that such metal not be violently reactive with the constituents of the strata into which it is to be injected through the perforations in the well casing. About the only low-melting anodic alloys which are excluded from this invention are ones which consist entirely of, or contain a hi h proportion of, the very active alkali metals. However, alloys of the alkali metals with other metals, in which the alkali metal content is suliiciently small as to make the alloy not violently reactive with water or other constituents of the strata into which the metal is to be injected, are satisfactory. One alloy which may be used in the above-described process is the bismuthgallium alloy which melts at about 440 F. Another alloy which is satisfactory for the purpose of this invention is the gallium-indium alloy, containing about 80-90% indium, which melts in the range between about 190 and 250 F. Sodium-tin, zinc-tin, and lithium-magnesium alloys which melt elow 600 F. are preferred, from purely economic considerations. Other alloys which melt in the desired temperature range and which are satisfactory for the purpose of this invention inciude:
Lithium-mercury Bismuth-lithium Bismuth-potassium Bismuth-sodium Lithium-tin Sodium-tin Zinc-tin It is to be noted that some of the above-listed alloys are not operative for protecting pure iron, since some of these alloys are not anodic with respect to pure iron. However, these alloys are included in the above list since they melt in the desired range and are ancdic with respect to certain alloy steels and thus can be used for protecting such alloys against electrolytic corrosion. Some of the above listed alloys which contain small amounts of the alkali metals are highly desirable in this process since the alkali metals react with moisture in the environment surrounding the well casing and create an alkaline environment around the casing which is effective in stifling the activity of sulfate-reducing bacteria and in neutralizing corrosive acidic constituents such as hydrogen sulfide. While the alloys listed above are all binary alloys, it is to be understood that any alloy can be used in this invention regardless of the number of constituents therein so long as the alloy is anodic with respect to the structure to be protected. Likewise, this inventiondoes not exclude the use of pure metals, e.g., gallium, which have a melting point less than about 600 F. and which are anodic with respect to the structure to be protected. In general, however, alloys are preferred to the pure metals because of their lower melting points. Additional information on low-melting alloys which are considered within the scope of this invention and which may be used in the manner above described may be found in the Liquid Metals Handbook, Richard N. Lyon, 2nd. ed., 1952, published jointly by the Atomic Energy Commission and the Bureau of Ships, Department of the Navy.
While we have described our invention fully and completely with special emphasis upon several preferred embodiments threof, we wish it to be understood that the invention is not limited to the recited embodiment and that within the scope of the appended claims, this invention may be practiced otherwisethan as specifically described.
What is claimed is:
1. A method of providing cathodic protection to the exterior surface of metallic well casings which comprises forming perforations in the casing below ground, placing a low-melting metal anodic to the casing adjacent to sai perforations, melting said metal, and applying gas pres sure to the well to force the molten anodic metal through said perforations to form in-situ, sacrificial metal anodes in electrical contact with said casing.
2. A method in accordance with claim 1 in which the anodic metal used is an alloy melting at a temperature less than about 600 F.
3. A method in accordance with claim 2 in which the low-melting alloy is selected from the group consisting of bismuth-gallium, gallium-indium, bismuth-cad mium, bismuth-lithium, bismuth-potassium, cadmiumlead, cadmium-mercury, cadmium-sodium, cadmium-tin, cadmium-zinc, lead-lithium, lithium-magnesium, lithiurnmercury, bismuth-sodium, lithium-tin, sodium-tin, and Zinc-tin alloys.
4. A method in accordance with claim 2 in which excess amounts of the low-melting alloy are removed from the casing bore after resolidification.
5. A method in accordance with claim 2 in which the alloy is melted with an electric heater.
6. A method of providing cathodic protection to the exterior surface of well casings formed of ferrous metal which comprises forming perforations in the casing below ground, placing a packing in said casing just below said perforations, placing heating means at said packing, placing on said packing a low-melting metal anodic to the casing, melting said anodic metal with said heating means, and applying gas pressure to said well to force the molten anodic metal through said perforations to form in-situ, sacrificial metal anodes in electrical contact with said casing.
7. A method in accordance with claim 6 in which the anodic metal used is an alloy melting at a temperature less than about 660 F.
8. A method. in accordance with claim 6 in which excess amounts of the low-melting alloy are removed from the casing bore after resolidification.
9. A method in accordance with claim 6 in which said heating means is an electric heater. i
10. A method'in accordance with claim 6 in which the well casing and surrounding formation is heated to a temperature just above the melting point of said anodic metal prior to the melting of said metal and application of pressure to force the molten rri'etal through said perforations into the surroundingformation.
References Cited in the file of this patent UNITED STATES PATENTS 1,613,461 Johnson Jan. 4, 1927 1,646,735 Mills Oct. 25, 1927 1,804,078 Baden May 5, 1931 2,157,180 Little May 9, 1939 2,298,129 Irons Oct. 6, 1942 2,304,372 OBannon -2. Dec. 8, 1942 2,363,269 Schlurnberger Nov. 21, 1944 2,846,385 Buchan Aug. 5, 1958
Claims (1)
1. A METHOD OF PROVIDING CATHODIC PROTECTION TO THE EXTERIOR SURFACE OF METALLIC WELL CASINGS, WHICH COMPRISES FORMING PERFORATIONS IN THE CASING BELOW GROUND, PLACING A LOW-MELTING METAL ANODIC TO TEH CASING ADJACENT TO SAID PERFORATIONS, MELTING SAID METAL, AND APPLYING GAS PRESURE TO THE WELL TO FORCE THE MOLTEN ANODIC METAL THROUGH SAID PERFORATION TO FORM IN-SITU, SACRIFICIAL METAL ANODES IN ELECTRICAL CONTACT WITH SAID CASING.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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US816942A US3029195A (en) | 1959-05-29 | 1959-05-29 | Method of cathodically protecting well casing |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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US816942A US3029195A (en) | 1959-05-29 | 1959-05-29 | Method of cathodically protecting well casing |
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US3029195A true US3029195A (en) | 1962-04-10 |
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Family Applications (1)
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US816942A Expired - Lifetime US3029195A (en) | 1959-05-29 | 1959-05-29 | Method of cathodically protecting well casing |
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3321305A (en) * | 1961-05-11 | 1967-05-23 | Aluminium Lab Ltd | Cathodic protection alloys |
WO2003072905A1 (en) * | 2002-02-27 | 2003-09-04 | Canitron Systems, Inc. | Liquified material squeezing method and apparatus for oil and gas wells |
GB2420361A (en) * | 2002-02-27 | 2006-05-24 | Canitron Systems Inc | Apparatus, casing and method for heating a material used for sealing faults within cement used for sealing an oil or gas well |
US10273778B2 (en) * | 2017-04-17 | 2019-04-30 | Schlumberger Technology Corporation | Systems and methods for remediating a microannulus in a wellbore |
US12228021B2 (en) | 2023-05-25 | 2025-02-18 | Carter D. Copeland | Bottom tubing cap for downhole pump systems |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1613461A (en) * | 1926-06-01 | 1927-01-04 | Edwin A Johnson | Connection between well-pipe sections of different materials |
US1646735A (en) * | 1924-07-21 | 1927-10-25 | Peter Q Nyce | Electrochemical method for preventing corrosion |
US1804078A (en) * | 1928-11-26 | 1931-05-05 | Baden Martin William | Means for preventing corrosion in pipes |
US2157180A (en) * | 1937-10-28 | 1939-05-09 | Anaconda Wire & Cable Co | Zinc ground rod |
US2298129A (en) * | 1938-03-29 | 1942-10-06 | Dow Chemical Co | Treatment of wells |
US2304372A (en) * | 1940-07-15 | 1942-12-08 | Walter A O'bannon | Pump plunger |
US2363269A (en) * | 1939-07-29 | 1944-11-21 | Schlumberger Well Surv Corp | Method for sealing borehole casings |
US2846385A (en) * | 1954-10-11 | 1958-08-05 | Exxon Research Engineering Co | Prevention of corrosion in wells |
-
1959
- 1959-05-29 US US816942A patent/US3029195A/en not_active Expired - Lifetime
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1646735A (en) * | 1924-07-21 | 1927-10-25 | Peter Q Nyce | Electrochemical method for preventing corrosion |
US1613461A (en) * | 1926-06-01 | 1927-01-04 | Edwin A Johnson | Connection between well-pipe sections of different materials |
US1804078A (en) * | 1928-11-26 | 1931-05-05 | Baden Martin William | Means for preventing corrosion in pipes |
US2157180A (en) * | 1937-10-28 | 1939-05-09 | Anaconda Wire & Cable Co | Zinc ground rod |
US2298129A (en) * | 1938-03-29 | 1942-10-06 | Dow Chemical Co | Treatment of wells |
US2363269A (en) * | 1939-07-29 | 1944-11-21 | Schlumberger Well Surv Corp | Method for sealing borehole casings |
US2304372A (en) * | 1940-07-15 | 1942-12-08 | Walter A O'bannon | Pump plunger |
US2846385A (en) * | 1954-10-11 | 1958-08-05 | Exxon Research Engineering Co | Prevention of corrosion in wells |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3321305A (en) * | 1961-05-11 | 1967-05-23 | Aluminium Lab Ltd | Cathodic protection alloys |
US6828531B2 (en) | 2000-03-30 | 2004-12-07 | Homer L. Spencer | Oil and gas well alloy squeezing method and apparatus |
US20050109511A1 (en) * | 2000-03-30 | 2005-05-26 | Canitron Systems Inc. | Oil and gas well alloy squeezing method and apparatus |
US7449664B2 (en) * | 2000-03-30 | 2008-11-11 | Spencer Homer L | Oil and gas well alloy squeezing method and apparatus |
WO2003072905A1 (en) * | 2002-02-27 | 2003-09-04 | Canitron Systems, Inc. | Liquified material squeezing method and apparatus for oil and gas wells |
GB2402957A (en) * | 2002-02-27 | 2004-12-22 | Canitron Systems Inc | Liquified material squeezing method and apparatus for oil and gas wells |
GB2420361A (en) * | 2002-02-27 | 2006-05-24 | Canitron Systems Inc | Apparatus, casing and method for heating a material used for sealing faults within cement used for sealing an oil or gas well |
GB2402957B (en) * | 2002-02-27 | 2006-09-20 | Canitron Systems Inc | Liquified material squeezing method and apparatus for oil and gas wells |
US10273778B2 (en) * | 2017-04-17 | 2019-04-30 | Schlumberger Technology Corporation | Systems and methods for remediating a microannulus in a wellbore |
US20190249517A1 (en) * | 2017-04-17 | 2019-08-15 | Schlumberger Technology Corporation | Systems and methods for remediating a microannulus in a wellbore |
US10711565B2 (en) * | 2017-04-17 | 2020-07-14 | Schlumberger Technology Corporation | Systems and methods for remediating a microannulus in a wellbore |
US12228021B2 (en) | 2023-05-25 | 2025-02-18 | Carter D. Copeland | Bottom tubing cap for downhole pump systems |
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