US3097282A - Casing heater - Google Patents
Casing heater Download PDFInfo
- Publication number
- US3097282A US3097282A US55802A US5580260A US3097282A US 3097282 A US3097282 A US 3097282A US 55802 A US55802 A US 55802A US 5580260 A US5580260 A US 5580260A US 3097282 A US3097282 A US 3097282A
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- Prior art keywords
- heater
- core
- array
- casing
- magnetic
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- Expired - Lifetime
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- 230000005291 magnetic effect Effects 0.000 claims description 25
- 238000004804 winding Methods 0.000 claims description 8
- 230000008093 supporting effect Effects 0.000 claims description 6
- 230000008878 coupling Effects 0.000 claims description 4
- 238000010168 coupling process Methods 0.000 claims description 4
- 238000005859 coupling reaction Methods 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- 239000007769 metal material Substances 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 description 10
- 238000003491 array Methods 0.000 description 4
- 230000006698 induction Effects 0.000 description 3
- 238000003475 lamination Methods 0.000 description 3
- 239000000696 magnetic material Substances 0.000 description 2
- 229910000976 Electrical steel Inorganic materials 0.000 description 1
- 241000364021 Tulsa Species 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 238000004382 potting Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/10—Sealing or packing boreholes or wells in the borehole
- E21B33/13—Methods or devices for cementing, for plugging holes, crevices or the like
- E21B33/14—Methods or devices for cementing, for plugging holes, crevices or the like for cementing casings into boreholes
-
- 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
- E21B36/00—Heating, cooling or insulating arrangements for boreholes or wells, e.g. for use in permafrost zones
- E21B36/04—Heating, cooling or insulating arrangements for boreholes or wells, e.g. for use in permafrost zones using electrical heaters
Definitions
- This invention relates to oil and gas well heaters and particularly to induction type heaters which are adapted for down-hole usage.
- Down-hole heating tools find usage in several operations in well service. For example, heating well casing to accelerate the setting time of cement lying between the casing and the annulus of the Well bore and heating the tubing in a well to prevent the deposition of parafii-n or other materials contained in formation fluids are uses of such devices.
- Down-hole heating tools are either of a combustion type or are electrically energized. So called induction heating units are known for such service in wells, but have not proven as satisfactory as has been desired from the standpoint of cost, eflieiency of operation, or freedom from operational difiiculties or maintenance.
- a principal object of this invention is to provide an improved down hole heating tool which is especially adapted for use as a casing heater.
- Another object of this invention is to provide an improved, economical and efiicient down-hole heating tool.
- a down-hole casing heater comprising, disposed about an axially disposed central core composed of metallic tubing of non-magnetic material such as aluminum, for example, a plurality of magnetic core elements each comprising a number of C-shaped laminations made of silicon steel, for example.
- the (Z-shaped core elements are radially mounted around the core with the ends of the C facing outwardly.
- a coil of magnet wire is disposed around the core and core elements between the ends of the core elements.
- the heater may comprise a plurality of arrays of coils and magnetic core elements disposed along the central core.
- the heater may be provided with housing to protect it from physical harm while in the well bore. Cable leads for energization of the heater extend from the housing for coupling to power means.
- FIG. 1 is a side elevation-ail view, partly in section, of a down-hole casing heater in accordance with this invention
- FIG. 2 is a sectional View taken along the line 22 of FIG. 1.
- a tubing heater indicated generally by the number 10, comprising a core '12, threaded at each end, which has a pair of arrays of 'C-sh-aped magnetic core members 18 disposed between non-magnetic end supports 16 which are bonded to the core 12 as by fillets 14.
- Each array of laminated core members '18 has 4 members disposed radially at approximately 90 intervals around the periphery of the core 12, although a greater or lesser number of core members 18 could be used.
- the members 18 are held in position by means of a plurality of bolts 20 which threadedly engage the core 12.
- Each of the arrays of laminated core members 18 has a coil 22, 22a of magnet wire disposed around the core and members 18 between the legs thereof.
- the number of turns and size of wire used is dependent on good transformer design practice and the energization capabilities available down the well bore.
- Pairs of leads 24, 26 for energizing the coils 22, 22a are 3,097,282 Patented July 9, 1963 provided.
- coil 22 is illustrated as being connected in series with coil 22a, but parallel connections of the two coils may also be made.
- the coil assembly is, in practice, usually potted in a suitable potting compound (not shown).
- the core 12 is coupled to a line or string of tubing and lowered into the well bore near to the location along the casing where heating is needed.
- the transformer core windings 22, 22a are then energized by any suitable means, usually a down-hole cable connected to an alternating current source located at or near to the well head.
- the casing adjacent to the heater tool 10 constitutes a single turn shorted secondary winding of the casing heating transformer (windings 22, 22a being the primary winding).
- the maximum diameter of the tool 10 measured across the ends of the magnetic return members 18, should be such that the tool fits closely but freely slidably within the casing.
- Such an arrangement reduces air gap losses in the magnetic return path of the tool.
- the casing is therefore heated by the large amount of current flowing through it as the primary winding or windings are energized. Because of the magnetic return provided by the laminations of the core members, the casing (not shown) is heated by induction to a greater extent when the coils 22, 22a are energized than occurs when electrically energized prior art heaters of corresponding size are used.
- leads 24 are diagrammatically shown as passing along the outside of the core 12, they are, in practice, coupled to suit-able fluid-tight terminal means (not shown).
- the invention has been illustrated as comprising a heater having two primary coils 22, 22a.
- a single coil or more than two coils may be used, however, depending on convenience of manufacturing or the amount of energization of the heater which is intended.
- the heater of the invention is applicable for use in other applications where a section of hollow tubes is to be heated.
- magnetic return elements 14 are customarily equally spaced around the core section 12, non-symmetrical spacing may sometimes be used, but with some loss in efficiency of the device.
- a casing heater adapted to be lowered on a tubing string into a string of Well casing comprising an elongated body section made of non-magnetic metal material, said body section having means at each end for rigidly coupling said heater to said tubing string in end to end relationship therewith, at least one array of generally C-shaped magnetic return elements each having a pair of open end ends, said magnetic return elements being symmetrically disposed around said tubular section with their open ends facing outwardly and with their sides being disposed contiguous to said core section, and an electrical primary coil winding being disposed around said core and said magnetic return elements between their ends, said array being disposed between axially aligned non-magnetic metal supporting structures at each end, said supporting structure being frusto-conical in configuration and axially aligned with respect to the heater, the diameter of the supporting structure which is closest to said array being at least as great as the maximum diameter of said array.
- a casing heater adapted to be lowered on a tubing 3 string into a string of well casing comprising an elongated body section having means for rigidly coupling said heater to said tubing, end parts and flattened sides between said end parts, said end parts being Efrusto-conical in configuration with their bases facing each other, said flattened sides being of uniformly dimensioned square transverse cross sectional configuration, at least one array of four magnetic members having integral base and leg elements, each of said members having its base abutting against a side of said body section with the leg elements pointed away from said body, the diameter of said end parts of the body section being at least as great as the diameter across any pair of said magnetic members, the members of said array being similarly disposed with respect to the length of the body, a mult-i-turn electrical primary coil being disposed around said body and the base of said magnetic members between the legs of said magnetic members, and means whereby said coil may be energized, the maximum dimension between the ends of corresponding legs of opposed magnetic members being slightly less than the inner diameter of
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- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- General Induction Heating (AREA)
Description
July 9, 1963 L. c. CRONBERGER 3,097,232
CASING HEATER Filed Sept. 13, 1960 I N VEN TOR. Lu/Aer C. Croneryer United States Patent M 3,097,282 CASING HEATER Luther C. Cronberger, Tulsa, Okla assignor to The Dow Chemical Company, Midland, Micl1., a corporation of Delaware Filed Sept. 13, 1960, Ser. No. 55,802 7 Claims. (Cl. 219-1049) This invention relates to oil and gas well heaters and particularly to induction type heaters which are adapted for down-hole usage.
Down-hole heating tools find usage in several operations in well service. For example, heating well casing to accelerate the setting time of cement lying between the casing and the annulus of the Well bore and heating the tubing in a well to prevent the deposition of parafii-n or other materials contained in formation fluids are uses of such devices.
Down-hole heating tools are either of a combustion type or are electrically energized. So called induction heating units are known for such service in wells, but have not proven as satisfactory as has been desired from the standpoint of cost, eflieiency of operation, or freedom from operational difiiculties or maintenance.
Accordingly, a principal object of this invention is to provide an improved down hole heating tool which is especially adapted for use as a casing heater.
Another object of this invention is to provide an improved, economical and efiicient down-hole heating tool.
In accordance with this invention there is provided a down-hole casing heater comprising, disposed about an axially disposed central core composed of metallic tubing of non-magnetic material such as aluminum, for example, a plurality of magnetic core elements each comprising a number of C-shaped laminations made of silicon steel, for example. The (Z-shaped core elements are radially mounted around the core with the ends of the C facing outwardly. A coil of magnet wire is disposed around the core and core elements between the ends of the core elements. The heater may comprise a plurality of arrays of coils and magnetic core elements disposed along the central core. The heater may be provided with housing to protect it from physical harm while in the well bore. Cable leads for energization of the heater extend from the housing for coupling to power means.
The invention, as well as additional objects and advantages thereof, will best be understood when the following detailed description is read in connection with the accompanying drawing, inwhich FIG. 1 is a side elevation-ail view, partly in section, of a down-hole casing heater in accordance with this invention, and
FIG. 2 is a sectional View taken along the line 22 of FIG. 1.
Referring to the drawings, there is shown a tubing heater, indicated generally by the number 10, comprising a core '12, threaded at each end, which has a pair of arrays of 'C-sh-aped magnetic core members 18 disposed between non-magnetic end supports 16 which are bonded to the core 12 as by fillets 14. Each array of laminated core members '18 has 4 members disposed radially at approximately 90 intervals around the periphery of the core 12, although a greater or lesser number of core members 18 could be used. The members 18 are held in position by means of a plurality of bolts 20 which threadedly engage the core 12.
Each of the arrays of laminated core members 18 has a coil 22, 22a of magnet wire disposed around the core and members 18 between the legs thereof. The number of turns and size of wire used is dependent on good transformer design practice and the energization capabilities available down the well bore.
Pairs of leads 24, 26 for energizing the coils 22, 22a are 3,097,282 Patented July 9, 1963 provided. As shown, coil 22 is illustrated as being connected in series with coil 22a, but parallel connections of the two coils may also be made. The coil assembly is, in practice, usually potted in a suitable potting compound (not shown).
In operation the core 12 is coupled to a line or string of tubing and lowered into the well bore near to the location along the casing where heating is needed. The transformer core windings 22, 22a are then energized by any suitable means, usually a down-hole cable connected to an alternating current source located at or near to the well head.
.The casing adjacent to the heater tool 10 constitutes a single turn shorted secondary winding of the casing heating transformer ( windings 22, 22a being the primary winding). For best results the maximum diameter of the tool 10, measured across the ends of the magnetic return members 18, should be such that the tool fits closely but freely slidably within the casing. Such an arrangement reduces air gap losses in the magnetic return path of the tool. The casing is therefore heated by the large amount of current flowing through it as the primary winding or windings are energized. Because of the magnetic return provided by the laminations of the core members, the casing (not shown) is heated by induction to a greater extent when the coils 22, 22a are energized than occurs when electrically energized prior art heaters of corresponding size are used.
While the leads 24 are diagrammatically shown as passing along the outside of the core 12, they are, in practice, coupled to suit-able fluid-tight terminal means (not shown).
The invention has been illustrated as comprising a heater having two primary coils 22, 22a. A single coil or more than two coils may be used, however, depending on convenience of manufacturing or the amount of energization of the heater which is intended.
While the present invention has been described in connection with the heating of down-hole casing strings, the heater of the invention is applicable for use in other applications where a section of hollow tubes is to be heated.
Although the magnetic return elements 14 are customarily equally spaced around the core section 12, non-symmetrical spacing may sometimes be used, but with some loss in efficiency of the device.
What is claimed is:
1. A casing heater adapted to be lowered on a tubing string into a string of Well casing comprising an elongated body section made of non-magnetic metal material, said body section having means at each end for rigidly coupling said heater to said tubing string in end to end relationship therewith, at least one array of generally C-shaped magnetic return elements each having a pair of open end ends, said magnetic return elements being symmetrically disposed around said tubular section with their open ends facing outwardly and with their sides being disposed contiguous to said core section, and an electrical primary coil winding being disposed around said core and said magnetic return elements between their ends, said array being disposed between axially aligned non-magnetic metal supporting structures at each end, said supporting structure being frusto-conical in configuration and axially aligned with respect to the heater, the diameter of the supporting structure which is closest to said array being at least as great as the maximum diameter of said array.
2. A casing heater in accordance with claim 1, wherein said magnetic return elements each comprise a plurality of laminations.
3. A casing heater in accordance with claim 1, wherein said heater has a plurality of primary coils disposed in side by side relationship along said core section and each primary coil has an array of magnetic return elements disposed around the coil.
4. A casing heater adapted to be lowered on a tubing 3 string into a string of well casing, comprising an elongated body section having means for rigidly coupling said heater to said tubing, end parts and flattened sides between said end parts, said end parts being Efrusto-conical in configuration with their bases facing each other, said flattened sides being of uniformly dimensioned square transverse cross sectional configuration, at least one array of four magnetic members having integral base and leg elements, each of said members having its base abutting against a side of said body section with the leg elements pointed away from said body, the diameter of said end parts of the body section being at least as great as the diameter across any pair of said magnetic members, the members of said array being similarly disposed with respect to the length of the body, a mult-i-turn electrical primary coil being disposed around said body and the base of said magnetic members between the legs of said magnetic members, and means whereby said coil may be energized, the maximum dimension between the ends of corresponding legs of opposed magnetic members being slightly less than the inner diameter of the easing into which said heater is adapted to be lowered.
5. A casing heater in accordance with claim 4, wherein said body is composed of non-magnetic material.
6. A casing heater in accordance 'with claim 4, wherein said magnetic elements are secured to said body;
7. A casing heater in accordance with claim 4, wherein a plurality of arrays of magnetic members each having a primary coil wound around the base and between the legs are disposed along said body.
References Cited in the file of this patent UNITED STATES PATENTS 2,472,445 Sprong June 7, 1949 2,513,242 inrna-n June 27, 1950 2,810,053 Messner Oct. 15, 1957
Claims (1)
1. A CASING HEATER ADAPTED TO BE LOWERED ON A TUBING STRING INTO A STRING OF WELL CASING COMPRISING AN ELONGATED BODY SECTION MADE OF NON-MAGNETIC METAL MATERIAL, SAID BODY SECTION HAVING MEANS AT EACH END FOR RIGIDLY COUPLING SAID HEATER TO SAID TUBING STRING IN END TO END RELATIONSHIP THEREWITH, AT LEAST ONE ARRAY OF GENERALLY C-SHAPED MAGNETIC RETURN ELEMENTS EACH HAVING A PAIR OF OPEN END ENDS, SAID MAGNETIC RETURN ELEMENTS BEING SYMMETRICALLY DISPOSED AROUND SAID TUBULAR SECTION WITH THEIR OPEN ENDS FACING OUTWARDLY AND WITH THEIR SIDES BEING DISPOSED CONTIGUOUS TO SAID CORE SECTION, AND AN ELECTRICAL PRIMARY COIL WINDING BEING DISPOSED AROUND SAID CORE AND SAID MAGNETIC RETURN ELEMENTS BETWEEN THEIR ENDS, SAID ARRAY BEING DISPOSED BETWEEN AXIALLY ALIGNED NON-MAGNETIC METAL SUPPORTING STRUCTURES AT EACH END, SAID SUPPORTING STRUCTURE BEING FRUSTO-CONICAL IN CONFIGURATION AND AXIALLY ALIGNED WITH RESPECT TO THE HEATER, THE DIAMETER OF THE SUPPORTING STRUCTURE WHICH IS CLOSEST TO SAID ARRAY BEING AT LEAST AS GREAT AS THE MAXIMUM DIAMETER OF SAID ARRAY.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US55802A US3097282A (en) | 1960-09-13 | 1960-09-13 | Casing heater |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US55802A US3097282A (en) | 1960-09-13 | 1960-09-13 | Casing heater |
Publications (1)
Publication Number | Publication Date |
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US3097282A true US3097282A (en) | 1963-07-09 |
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US55802A Expired - Lifetime US3097282A (en) | 1960-09-13 | 1960-09-13 | Casing heater |
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US (1) | US3097282A (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2559855A1 (en) * | 1984-02-21 | 1985-08-23 | Schlumberger Cie Dowell | PROCESS FOR IMPROVING THE CHARACTERISTICS OF A CEMENT LAYER FOR WELL CEMENT |
FR2658972A1 (en) * | 1990-02-23 | 1991-08-30 | Elf Aquitaine | Device for heating the production string (casing, column) of a well and method for fitting the heating windings |
US20040084442A1 (en) * | 2002-11-06 | 2004-05-06 | Canitron Systems, Inc. | Downhole electromagnetic heating tool and method of using same |
WO2004042188A2 (en) * | 2002-11-06 | 2004-05-21 | Canitron Systems, Inc. | Down hole induction heating tool and method of operating and manufacturing same |
US20040104045A1 (en) * | 2002-11-06 | 2004-06-03 | Larovere Thomas A. | Cement heating tool for oil and gas well completion |
GB2449702A (en) * | 2007-06-01 | 2008-12-03 | Statoil Asa | Setting cement using electromagnetic or magnetic fields |
US20100186955A1 (en) * | 2007-06-01 | 2010-07-29 | Arild Saasen | Method of well cementing |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2472445A (en) * | 1945-02-02 | 1949-06-07 | Thermactor Company | Apparatus for treating oil and gas bearing strata |
US2513242A (en) * | 1945-10-11 | 1950-06-27 | Hollis C Inman | Electric fluid heater |
US2810053A (en) * | 1955-09-26 | 1957-10-15 | Ohio Crankshaft Co | High frequency inductor for small diameter holes |
-
1960
- 1960-09-13 US US55802A patent/US3097282A/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2472445A (en) * | 1945-02-02 | 1949-06-07 | Thermactor Company | Apparatus for treating oil and gas bearing strata |
US2513242A (en) * | 1945-10-11 | 1950-06-27 | Hollis C Inman | Electric fluid heater |
US2810053A (en) * | 1955-09-26 | 1957-10-15 | Ohio Crankshaft Co | High frequency inductor for small diameter holes |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2559855A1 (en) * | 1984-02-21 | 1985-08-23 | Schlumberger Cie Dowell | PROCESS FOR IMPROVING THE CHARACTERISTICS OF A CEMENT LAYER FOR WELL CEMENT |
EP0154365A1 (en) * | 1984-02-21 | 1985-09-11 | Etudes et Fabrication Dowell Schlumberger | Cement mixing process and apparatus |
FR2658972A1 (en) * | 1990-02-23 | 1991-08-30 | Elf Aquitaine | Device for heating the production string (casing, column) of a well and method for fitting the heating windings |
US20040084442A1 (en) * | 2002-11-06 | 2004-05-06 | Canitron Systems, Inc. | Downhole electromagnetic heating tool and method of using same |
WO2004042188A2 (en) * | 2002-11-06 | 2004-05-21 | Canitron Systems, Inc. | Down hole induction heating tool and method of operating and manufacturing same |
US20040104045A1 (en) * | 2002-11-06 | 2004-06-03 | Larovere Thomas A. | Cement heating tool for oil and gas well completion |
US20040149443A1 (en) * | 2002-11-06 | 2004-08-05 | Canitron Systems, Inc. | Resistive down hole heating tool |
WO2004042188A3 (en) * | 2002-11-06 | 2004-09-02 | Canitron Systems Inc | Down hole induction heating tool and method of operating and manufacturing same |
US6926083B2 (en) | 2002-11-06 | 2005-08-09 | Homer L. Spencer | Cement heating tool for oil and gas well completion |
US6942032B2 (en) | 2002-11-06 | 2005-09-13 | Thomas A. La Rovere | Resistive down hole heating tool |
GB2449702A (en) * | 2007-06-01 | 2008-12-03 | Statoil Asa | Setting cement using electromagnetic or magnetic fields |
US20100186955A1 (en) * | 2007-06-01 | 2010-07-29 | Arild Saasen | Method of well cementing |
GB2449702B (en) * | 2007-06-01 | 2011-12-21 | Statoilhydro Asa | Setting cement using electromagnetic or magnetic fields |
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