CA2063939A1 - Hollow plastic sucker rod assembly - Google Patents
Hollow plastic sucker rod assemblyInfo
- Publication number
- CA2063939A1 CA2063939A1 CA 2063939 CA2063939A CA2063939A1 CA 2063939 A1 CA2063939 A1 CA 2063939A1 CA 2063939 CA2063939 CA 2063939 CA 2063939 A CA2063939 A CA 2063939A CA 2063939 A1 CA2063939 A1 CA 2063939A1
- Authority
- CA
- Canada
- Prior art keywords
- rod
- sucker rod
- hollow
- sucker
- glass fibre
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000004033 plastic Substances 0.000 title description 9
- 239000011152 fibreglass Substances 0.000 claims abstract description 18
- 239000003365 glass fiber Substances 0.000 claims abstract description 10
- 239000011159 matrix material Substances 0.000 claims abstract description 8
- 239000000088 plastic resin Substances 0.000 claims abstract description 8
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 7
- 239000003129 oil well Substances 0.000 claims abstract description 3
- 238000010276 construction Methods 0.000 claims description 7
- 239000011347 resin Substances 0.000 claims description 2
- 229920005989 resin Polymers 0.000 claims description 2
- 239000011505 plaster Substances 0.000 claims 1
- 238000005452 bending Methods 0.000 abstract description 3
- 239000002184 metal Substances 0.000 description 6
- 229910000831 Steel Inorganic materials 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000032798 delamination Effects 0.000 description 1
- 229910052595 hematite Inorganic materials 0.000 description 1
- 239000011019 hematite Substances 0.000 description 1
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Landscapes
- Moulding By Coating Moulds (AREA)
- Reinforced Plastic Materials (AREA)
Abstract
Abstract An improved form of sucker rod assembly for oil wells comprises a fibreglass sucker rod which is in the form of a hollow cylindrical tube having an outside diameter and an inside diameter. The annular body portion thus formed comprises a plastic resin matrix containing a plurality of longitudinally extending glass fibre rovings spaced from one another and distributed throughout the cross-section of the rod, with each being embedded in and completely surrounded by the plastic resin matrix. The inner and outer diameters of the sucker rod are also provided with a reinforcing, e.g.
glass fibre matting, which serves to prevent collapse of the hollow rod due to compressive or bending loads. Novel end fittings are also provided for the sucker rod assembly of the invention.
glass fibre matting, which serves to prevent collapse of the hollow rod due to compressive or bending loads. Novel end fittings are also provided for the sucker rod assembly of the invention.
Description
2~39~9 Hollow Plastic Sucker_Rod Assembly Backqround of the Invention 1. Field of the Inventio_ This invention relates in general to plastic sucker rods for well strings in oil wells and, more particularly, to a novel hollow fibreglass sucker rod.
2. Prior Art Conventional sucker rods have in the past been fabricated of metal in lengths of about 25 to 40 feet. These lengths are connected to form sucker rod strings useful for well pumpiny purposes. Because metal sucker rod strings are relatively heavy, it has become commonplace to use sucker rods which include non-metallic components. For instance, U.S. Patent 3,212,582, issued October 19, 19~5, describes plastic sucker rods. Other plastic, and particularly fibreglass, sucker rods are described in U.S. Patents 4,024,913, 4,360,288, 4,401,396, 4,585,368 and 4,597,688.
Fibreglass sucker rods properly desiyned, installed and used, can significantly increase oil production, reduce lifting costs and reduce capital expenditures. The fibreglass rods, made with fibreglass in a plastic resin base, feature lightweight and high strength and offer many advantages over conventional steel sucker rods, including increased oil production.
The fibreglass sucker rods must also be designed to be compatible with standard tools used in the oil production industry with a requirement for end fittings on the ends of the fibreglass sucker rods compatible with standard elevators, rod wrenches and power tongs. In keeping with this 3G requirement, it has been the standard practice to manufacture fibreglass sucker rods in the form of a solid cylindrical rod such that the fibreglass rod is essentially a fibreglass substitute for a traditional metal rod.
It is, therefore, a principal object of the present invention to provide a plastic, e.g. fibreglass, sucker rod with further advantages and savings in materials and weight.
Summary of the Invention , . ~, :. . ' :
- .
.
. . .
~Ofi3939 The improved sucker rod assembly o~ the present invention comprises a fibreglass sucker rod which is in the form of a hollow cylindrical tube having an outside diameter and an inside diameter. The annulax body portion thus formed 5 comprises a plastic resin matrix containing a plurality of longitudinally extending glass fibre rovings spaced from one another and distributed throughout the cross-section of the rod, with each being embedded in and completely surrounded by the plastic resin matrix. The inner and outer diameters of lo the sucker rod are also provided with a reinforcing which serves to prevent collapse of the hollow rod due to compressive or bending loads.
The reinforcing for the inside and outside diameters is preferably in the form of glass fibre matting. For optimum results, a mat of randomly and/or 0 and 90 oriented glass fibers is used. Such matting is available with continuous strand or chopped strand in varying degrees and for the purposes of the present invention continuous strands are preferred.
The continuous strands are preferably not stiff because stif~ continuous strand matting may give delamination problems, particularly in small radius configurations of the sucker rod. The chopped strand mats are not desirable because there is a tendency for them to tear during resin wetting prior to entry into a tube forming dye.
The hollow sucker rods of the present invention can be manufactured with the typical outside diameters for plastic sucker rods, i.e. about 5/8 to 1 1/4". For the desired strength characteristics, the annular wall thickness of the tube is typically in the order of about 1/4".
A preferred embodiment of the invention relates to a sucker rod assembly comprising the hollow fibreglass sucker rod as described above having metal fittings at each end that may be threadably connected to interconnecting threaded couplings to other like sucker rods. Each end fitting includes a longitudinally extending generally central cavity for receiving a sucker rod and adhesive means for joining the .
, ~' . -en~ connector -to the fibreylass sucker rod.
Preferably, the hollow central part of the hollow sucker rod is filled by a cylindrical plug in the region of the end fitting. Thus, the portion of the hollow sucker rod which is encased by the end fitting contains a cylindrical plug.
Preferably, a portion of this plug extends beyond the end of the hollow sucker rod and connects to a portion of the central cavity of the end fitting. It is also preferable to have the cylindrical plug extend a short distance into the hollow o sucker rod beyond the inner end of the end fitting. Th.is central plug serves an important purpose of increasing the contact surface area for making a strong end connection.
In order to provide a connection to down-hole equipment through a sucker rod string, a small axial hole may be provided in each cylindrical plug and end ~ittiny. In this manner, a small opening can be provided through the entire sucker rod string.
It is common practice in the use of plastic sucker rods to provide one or more steel rods on the lower end of a string. This serves the purpose of keeping the entire string in tension. In accordance with the present invention such steel rod at the lower end o~ the string may be replaced by one of the hollow fibreglass sucker rods of the present invention which has the hollow core thereof filled with a weighting agent, such as hematite. This provides the weighting characteristics of a steel rod while avoiding the corrosion problems thereof.
Brief DescriPtion of the Drawinqs Further features of the present invention are set forth in the following detailed description and accompanying drawings:
Figure l is a partial sectional view of a hollow sucker rod and assembly according to the present invention;
Figure 2 is a sectional view of a metal end fitting;
Figure 3 is a cross-sectional view of a sucker rod of the invention;
Figure 4 is a plan view o~ 0 and 90 oriented 2~3939 reinforcing mesh for the cylindrical walls; and Figure 5 is a plan view randomly oriented reinforced mesh for the cylindrical walls.
Referring now more particularly to Figures 1 & 2 of the accompanying drawings, a first prePerred embodiment of the improved sucker rod assembly o~ the present invention is schematically depicted in cross-sectional view. Thus, the assembly includes a hollow sucker rod 10 having an outside diameter 11 and an inside diameter 12. Mounted within the end of the hollow central portion of sucker rod 10 is a cylindrical plug 13, which may be manufactured from metal, plastic, fibreglass, etc. As shown in Figure 1, the plug 13 preferably extends beyond the outer end of the hollow sucker rod 10.
The end portion of sucker rod 10 and the outwardly projecting portion of plug 13 are arranged to be mounted within an end fitting 14 having a central cavity including an outer central cavity portion 17 and a coaxial inner cavity portion 19. The outer cavity 17 includes a shoulder portion 18, while the inner cavity 19 includes a shoulder portion 20.
An abutment 21 is provided between the inner and outer cavities.
The outer face of the end fitting 14 includes a collar 15 and a threaded portion 16. The end fitting also has an outer end 23 and an inner end 22. The inner end of end plug 13 preferably extends inwardly a short distance beyond the inner end 22 of end fitting 14.
Details of the construction of the sucker rod itself can better be seen from the cross-sectional view in Figure 3.
Thus, it includes a plastic resin matrix within which is positioned a plurality of longitudinal rovings 25. The sucker rod shown in Figure 3 has an O.D. of about 1 1/4" and a wall thickness of about 1/4"; for this rod the rovings 25 are arranged evenly throughout the cross-section and number in the order of about 145. For rods of smaller diameter, the number of rovings will be reduced proportionally.
It has also been found that in order for the sucker rods 2~63939 of this invention to have the necessary compressive and bending strengths, some Eorm of fixed reinforcing i5 required adjacent the inner and outer diameters of the sucker rod. It has been found that this can conveniently be done by embedding a layer of fibreglass matting 26 into the plastic resin matrix adjacent the inner and outer diameters of the tube. This matting is preferably in the form of continuous strands of glass fibre 27 and 28 oriented in the oo and soo directions respectively as shown in Figure 4 or randomly oriented strands of glass fibre 29 as shown in Figure 5.
While there has been illustrated and described a single embodiment of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all of those changes and modifications which fall within the true spirit and scope o~ the present invention.
:
-:
' . ~ .
. .
2. Prior Art Conventional sucker rods have in the past been fabricated of metal in lengths of about 25 to 40 feet. These lengths are connected to form sucker rod strings useful for well pumpiny purposes. Because metal sucker rod strings are relatively heavy, it has become commonplace to use sucker rods which include non-metallic components. For instance, U.S. Patent 3,212,582, issued October 19, 19~5, describes plastic sucker rods. Other plastic, and particularly fibreglass, sucker rods are described in U.S. Patents 4,024,913, 4,360,288, 4,401,396, 4,585,368 and 4,597,688.
Fibreglass sucker rods properly desiyned, installed and used, can significantly increase oil production, reduce lifting costs and reduce capital expenditures. The fibreglass rods, made with fibreglass in a plastic resin base, feature lightweight and high strength and offer many advantages over conventional steel sucker rods, including increased oil production.
The fibreglass sucker rods must also be designed to be compatible with standard tools used in the oil production industry with a requirement for end fittings on the ends of the fibreglass sucker rods compatible with standard elevators, rod wrenches and power tongs. In keeping with this 3G requirement, it has been the standard practice to manufacture fibreglass sucker rods in the form of a solid cylindrical rod such that the fibreglass rod is essentially a fibreglass substitute for a traditional metal rod.
It is, therefore, a principal object of the present invention to provide a plastic, e.g. fibreglass, sucker rod with further advantages and savings in materials and weight.
Summary of the Invention , . ~, :. . ' :
- .
.
. . .
~Ofi3939 The improved sucker rod assembly o~ the present invention comprises a fibreglass sucker rod which is in the form of a hollow cylindrical tube having an outside diameter and an inside diameter. The annulax body portion thus formed 5 comprises a plastic resin matrix containing a plurality of longitudinally extending glass fibre rovings spaced from one another and distributed throughout the cross-section of the rod, with each being embedded in and completely surrounded by the plastic resin matrix. The inner and outer diameters of lo the sucker rod are also provided with a reinforcing which serves to prevent collapse of the hollow rod due to compressive or bending loads.
The reinforcing for the inside and outside diameters is preferably in the form of glass fibre matting. For optimum results, a mat of randomly and/or 0 and 90 oriented glass fibers is used. Such matting is available with continuous strand or chopped strand in varying degrees and for the purposes of the present invention continuous strands are preferred.
The continuous strands are preferably not stiff because stif~ continuous strand matting may give delamination problems, particularly in small radius configurations of the sucker rod. The chopped strand mats are not desirable because there is a tendency for them to tear during resin wetting prior to entry into a tube forming dye.
The hollow sucker rods of the present invention can be manufactured with the typical outside diameters for plastic sucker rods, i.e. about 5/8 to 1 1/4". For the desired strength characteristics, the annular wall thickness of the tube is typically in the order of about 1/4".
A preferred embodiment of the invention relates to a sucker rod assembly comprising the hollow fibreglass sucker rod as described above having metal fittings at each end that may be threadably connected to interconnecting threaded couplings to other like sucker rods. Each end fitting includes a longitudinally extending generally central cavity for receiving a sucker rod and adhesive means for joining the .
, ~' . -en~ connector -to the fibreylass sucker rod.
Preferably, the hollow central part of the hollow sucker rod is filled by a cylindrical plug in the region of the end fitting. Thus, the portion of the hollow sucker rod which is encased by the end fitting contains a cylindrical plug.
Preferably, a portion of this plug extends beyond the end of the hollow sucker rod and connects to a portion of the central cavity of the end fitting. It is also preferable to have the cylindrical plug extend a short distance into the hollow o sucker rod beyond the inner end of the end fitting. Th.is central plug serves an important purpose of increasing the contact surface area for making a strong end connection.
In order to provide a connection to down-hole equipment through a sucker rod string, a small axial hole may be provided in each cylindrical plug and end ~ittiny. In this manner, a small opening can be provided through the entire sucker rod string.
It is common practice in the use of plastic sucker rods to provide one or more steel rods on the lower end of a string. This serves the purpose of keeping the entire string in tension. In accordance with the present invention such steel rod at the lower end o~ the string may be replaced by one of the hollow fibreglass sucker rods of the present invention which has the hollow core thereof filled with a weighting agent, such as hematite. This provides the weighting characteristics of a steel rod while avoiding the corrosion problems thereof.
Brief DescriPtion of the Drawinqs Further features of the present invention are set forth in the following detailed description and accompanying drawings:
Figure l is a partial sectional view of a hollow sucker rod and assembly according to the present invention;
Figure 2 is a sectional view of a metal end fitting;
Figure 3 is a cross-sectional view of a sucker rod of the invention;
Figure 4 is a plan view o~ 0 and 90 oriented 2~3939 reinforcing mesh for the cylindrical walls; and Figure 5 is a plan view randomly oriented reinforced mesh for the cylindrical walls.
Referring now more particularly to Figures 1 & 2 of the accompanying drawings, a first prePerred embodiment of the improved sucker rod assembly o~ the present invention is schematically depicted in cross-sectional view. Thus, the assembly includes a hollow sucker rod 10 having an outside diameter 11 and an inside diameter 12. Mounted within the end of the hollow central portion of sucker rod 10 is a cylindrical plug 13, which may be manufactured from metal, plastic, fibreglass, etc. As shown in Figure 1, the plug 13 preferably extends beyond the outer end of the hollow sucker rod 10.
The end portion of sucker rod 10 and the outwardly projecting portion of plug 13 are arranged to be mounted within an end fitting 14 having a central cavity including an outer central cavity portion 17 and a coaxial inner cavity portion 19. The outer cavity 17 includes a shoulder portion 18, while the inner cavity 19 includes a shoulder portion 20.
An abutment 21 is provided between the inner and outer cavities.
The outer face of the end fitting 14 includes a collar 15 and a threaded portion 16. The end fitting also has an outer end 23 and an inner end 22. The inner end of end plug 13 preferably extends inwardly a short distance beyond the inner end 22 of end fitting 14.
Details of the construction of the sucker rod itself can better be seen from the cross-sectional view in Figure 3.
Thus, it includes a plastic resin matrix within which is positioned a plurality of longitudinal rovings 25. The sucker rod shown in Figure 3 has an O.D. of about 1 1/4" and a wall thickness of about 1/4"; for this rod the rovings 25 are arranged evenly throughout the cross-section and number in the order of about 145. For rods of smaller diameter, the number of rovings will be reduced proportionally.
It has also been found that in order for the sucker rods 2~63939 of this invention to have the necessary compressive and bending strengths, some Eorm of fixed reinforcing i5 required adjacent the inner and outer diameters of the sucker rod. It has been found that this can conveniently be done by embedding a layer of fibreglass matting 26 into the plastic resin matrix adjacent the inner and outer diameters of the tube. This matting is preferably in the form of continuous strands of glass fibre 27 and 28 oriented in the oo and soo directions respectively as shown in Figure 4 or randomly oriented strands of glass fibre 29 as shown in Figure 5.
While there has been illustrated and described a single embodiment of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all of those changes and modifications which fall within the true spirit and scope o~ the present invention.
:
-:
' . ~ .
. .
Claims (8)
1. A sucker rod construction for use in oil wells, said sucker rod construction comprising:
a hollow cylindrical fibreglass rod having an outside diameter and an inside diameter;
a plurality of longitudinally extending glass fibre rovings arranged evently throughout the cross section of the rod and each being embedded in and completely surrounded by a plastic resin matrix; and reinforcing means on the inner and outer diameter of the hollow rod and serving to prevent collapsing of the hollow rod from compressive or banding loads.
a hollow cylindrical fibreglass rod having an outside diameter and an inside diameter;
a plurality of longitudinally extending glass fibre rovings arranged evently throughout the cross section of the rod and each being embedded in and completely surrounded by a plastic resin matrix; and reinforcing means on the inner and outer diameter of the hollow rod and serving to prevent collapsing of the hollow rod from compressive or banding loads.
2. A sucker rod construction according to claim 1 wherein the reinforcing means comprises glass fibre mat layers embedded in the plaster resin matrix.
3. A sucker rod construction according to claim 2 wherein the glass fibre mat is in the form of a randomly oriented or 0° to 90° oriented mesh of continuous strands.
4. A sucker rod construction according to claim 2 wherein the outside diameter is in the range of about 5/8" to about 1 1/4".
5. A sucker rod construction according to claim 4 wherein the hollow rod has an annular wall thickness of about 1/4".
6. A sucker rod assembly comprising a hollow sucker rod according to claim 1 with end fittings mounted on opposite ends of said hollow rod, each end fitting having a rod end receiving cavity and means for bonding the end fittings to the rod ends.
7. A sucker rod assembly according to claim 6 which includes cylindrical end plugs mounted in the opposite ends of the hollow rod.
8. A sucker rod assembly according to claim 7 wherein the cylindrical end plugs extend outwardly beyond the outer ends of said hollow rod, and said end fitting cavities include portions for receiving said outwardly extending portions of said end plugs.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US68373191A | 1991-04-11 | 1991-04-11 | |
| US683,731 | 1991-04-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2063939A1 true CA2063939A1 (en) | 1992-10-12 |
Family
ID=24745221
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2063939 Abandoned CA2063939A1 (en) | 1991-04-11 | 1992-03-25 | Hollow plastic sucker rod assembly |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2063939A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102900376A (en) * | 2012-11-01 | 2013-01-30 | 东北石油大学 | Continuous oil pumping rod |
| WO2017186021A1 (en) * | 2016-04-25 | 2017-11-02 | 张建功 | Oil extraction system |
| CN108286415A (en) * | 2018-01-24 | 2018-07-17 | 中国石油大学(华东) | Carbon fibre pumping rod and pumping rod made by steel jointing and its installation method |
-
1992
- 1992-03-25 CA CA 2063939 patent/CA2063939A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102900376A (en) * | 2012-11-01 | 2013-01-30 | 东北石油大学 | Continuous oil pumping rod |
| WO2017186021A1 (en) * | 2016-04-25 | 2017-11-02 | 张建功 | Oil extraction system |
| CN108286415A (en) * | 2018-01-24 | 2018-07-17 | 中国石油大学(华东) | Carbon fibre pumping rod and pumping rod made by steel jointing and its installation method |
| CN108286415B (en) * | 2018-01-24 | 2019-09-13 | 中国石油大学(华东) | Carbon fibre pumping rod and pumping rod made by steel jointing and its installation method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2076391E (en) | Composite tubular member with axial fibers adjacent the side wall | |
| US5097870A (en) | Composite tubular member with multiple cells | |
| US5555696A (en) | Filament wound architectural column | |
| EP0361639B1 (en) | Bar-like molding made of fiber-reinforced plastic material and method of manufacturing the same | |
| SU528025A3 (en) | Reinforced plastic pipe | |
| US5236018A (en) | Boring casing for boring machines | |
| US5946880A (en) | Filament wound tubular column | |
| RU2497675C2 (en) | Method of making structural part of organic-matrix composite and part thus made | |
| US4662774A (en) | Parabolic end fitting | |
| US5294151A (en) | Composite ski pole | |
| CA1207592A (en) | Sucker rod | |
| US20240247746A1 (en) | Tubular with screw thread | |
| US20040206576A1 (en) | Scaffolding member and production method | |
| CA2063939A1 (en) | Hollow plastic sucker rod assembly | |
| US4522529A (en) | Pre-stressed fiber-resin sucker rod and method of making same | |
| US7121767B1 (en) | Rugged foam buoyancy modules and method of manufacture | |
| US3820573A (en) | Tubular laminate and a method of making a tubular laminate | |
| US4853060A (en) | Method of forming a composite tubular structure | |
| FI76739B (en) | FOERSTAERKNINGSSTAONG FOER VULSTEN AV ETT YTTERDAECK. | |
| US4497866A (en) | Sucker rod | |
| US4717182A (en) | Plastic coupling sleeve for pipes | |
| US4942904A (en) | Hollow section, in particular a tube, of long fibre reinforced plastic | |
| GB2108900A (en) | Fibre-reinforced sucker rod | |
| RU111560U1 (en) | REINFORCEMENT ELEMENT | |
| JPH05302490A (en) | Fiber-reinforced concrete wall body of departure/ arrival part in tunnel excavation shaft |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |