US2979133A

US2979133A - Oil well tubing cleaners

Info

Publication number: US2979133A
Application number: US679266A
Authority: US
Inventors: Winegar Robert Lee
Original assignee: JM Huber Corp
Current assignee: JM Huber Corp
Priority date: 1957-08-20
Filing date: 1957-08-20
Publication date: 1961-04-11
Anticipated expiration: 1978-04-11

Description

April 1961 R. L. WINEGAR 2,979,133

on. WELL TUBING CLEANERS Filed Aug. 20, 1957 IN VEN TOR.

L v RoBERT Lee WINEGAR BY PM HUT: I $71-84 L ATTORNEYS.

- the attachment of the blade :to the sucker rod,

2,979,133 H. WELL TUBHIG CLEANERS Robert Lee Winegar, Borger, Ten, assignor to J. M. Huber Corporation, Borger, Ten, a corporation of New Jersey Filed Aug. 20, 1957, Ser. No. 679,265

2 Claims. (Cl. 166-176) This invention relates to tubing cleaners for preventing and removing accumulations of paraffin and other substances which tend to clog the tubing of an oil well and thereby restrict the flow of oil therethrough.

The oil well tubing cleaners heretofore provided for this purpose have all been deficient in various respects. Some of them have used scraper blades of spring steel mounted by spring tension upon sucker rods; but in these cases the spring steel blade often does not grip the sucker rod sufficiently and tends to creep along the rod during the well pumping operation. In some cases a flat scraper blade lying in a plane parallel to the axis of a sucker rod is secured to the rod by U bolts which embrace the rod, but such U bolts tend to loosen during operation so that the blade not only can move along the sucker rod but sometimes becomes detached and falls to the bottom of the well.

Scraper blades have been fastened securely to sucker rods by providing long blades secured by U-shaped bands or clamps which embrace the sucker rod and are welded at their ends to the scraper blade, with the blade lying tangentially against the cylindrical surface of the rod, so that the clamps grip the rod by shrinking as they cool after the welding operation. These long blades are clamped at two or more locations along the suckerrod in order to secure satisfactory rigidity, and the scraper blade thus acts as a very strong stiffening member along the portions of the sucker rod embraced by the U-shaped bands or clamps welded to the blade. During the welding the scraper blade and spaced portions of the rod are heated intensely yet unevenly, and as the heated parts cool the sucker rod is placed under strains tending to cause bending of the rod. These strains lead to breaks of the sucker rods which occur just outside the bands well tubing cleaner comprises a substantially flat bladewhich lies in a plane parallel to the axis of the sucker 2,979,133 Patented Apr. 11, 1961 The above, and other objects, features and advantages of the invention, will be apparent in the following detailed description of illustrative embodiments thereof which is to be read in connection with the accompanying drawing, forming a part hereof, and wherein:

Fig. 1 is a front view of an oil well tubing cleaner embodying the present invention, and shown attached to a sucker rod;

Fig. 2 is a cross section through the blade and rod showing the clamp and welding beads in end elevation; and

Fig. 3 is an end elevational view of the blade structure of Fig. 1.

Referring to the drawing in detail, and initially to Figs. 1 and 2 thereof, it will be seen that an oil well tubing cleaner embodying the present invention, and there generally identified by the reference numeral 10, includes a substantially flat scraper blade 11, a single, generally U-shaped band or clamp 12 which embraces the sucker rod 13, and welding beads 14 joining the opposite end edges of the band 12 to the scraper blade 11.

The method employed in securing the oil well tubing :Cleaner 10 to the sucker rod 13 is'preferably that disclosed in United States Letters Patent No. 2,468,508 to R. C. Lister and, in accordance therewith, the inner curved surface of the band 12 is substantially semi-cy- The inner depth A (Fig. 2) of the band '12, that is,

the distance from the inner surface of the semi-cylindricalportion of the band to the ends of the legs thereof,

measured in the direction parallel to the legs, is slightly less than the diameter d of therod 13 so that, when the band 12 is placed over the rodl3 with the ends extending toward the scraping blade 11 and the latter abutting rod and is secured to the latter by a single, generally l U-shaped clamp embracing the sucker rod and having its opposite end edges welded to the blade in a way to grip the rod securely by shrinkage as the clamp cools, and the blade has a length along its outside or scraping edges, in the direction of the axis ofthe sucker rod, which is from one-half to one and one-half times the maximum dimension of the blade measured in the direction perpendicular to said axis, thereby to make feasible the attachment of'the blade to the sucker rod by a single clamp, while the clamp itself has a length in the direc-y,,f tion of the axis of the sucker rod at least as large as the diameter of the rod and at least one-thirdthe length of any straight edge of the blade extending parallel 'tolthe axis of the rod, in order torensuresuitable rig' tangentially against the surface of the rod 13, each end edge of the band lzwill be spaced a small distance from the surface of the blade ilto provide a clearance for the formation of the welding beads 14. Preferably, the clear- "ance for accommodating the welding heads is from about to about%4'of an inch, whichclearance has been i found toproducethe desired amount of clamping pres sure onthe rod 13 while making it possible to form the necessary welding .beads..

An apparatus, as disclosed in the above identified patent to Lister, is employed for exerting a substantial The welding beads Mare formed'either simultaneously orone immediately after theother, and-whenbo'th beads 1 i4 navebeen formed they are quicklyrcooled by directing one or more streams of cool fluid thereagainst, thereby to avoid the transfer of heat to the sucker rod 13 which It is apparent that the time required' for the formation of the welding beads 14 isdep'endent,'to.a large .extent, upon the lengths of such beads, and will. determine the extent ofthe heattransfer to-the sucker rodgl3. Lin accordance' with the, present. invention,;the, length lsi bf-the outside orscraping-edges' l5 ofifthebladein [-ths'ep onection' of the axis' of the rod is limited to a i irnension which' isffrom One haIf tofone an'd. one half be less than 2. inches or 3 inches, and the greatest dimension of the blade lengthwise of the sucker rod is less than 3 inches or 4 /2 inches, as the case may be.

' It has been found that, in order to provide a suitably rigid attachment of the cleaner to the rod 13, the length l of the band 12 in the direction of the axis must be at least as large as the diameter a? of the'sucker rod 13 and at least one-third the length of any straight side or edge of the blade 11 extending parallel to the axis of the sucker rod. In Fig.1, compare the length l with the length. L of the straight, opposite side edge portions 15 of blade 11.

Although the length l of the band or clamp 12, should be at least as large as the diameter d of the rod 13 and at least one-third the length L of the straight edges 15 of the blade 11 extending parallel to the axis of the sucker rod, to ensure adequate rigidity in the attachment of the oil well tubing cleaner to the sucker rod, and, in some cases, the length of the U-shaped band or clamp may be substantially less than the length of the blade, as in the embodiment of Figs. 1 and 2, it is to be understood that the maximum length of the U-shaped band or clamp inthe direction of the axis of the sucker rod is limited only by the length of the scraper blade in the same direction.

In accordance with the illustrated embodiment of the invention, a generally flat scraper blade 11 is of uniform width W over only the length L of the central portion thereof having straight, opposite side edge portions 15 extending parallel to the axis of the sucker rod 13, while the opposite end portions 17 of the blade taper, or have converging side edges. 7

Further, as seen in Figs. 1 and 3, the! ends of the tapering end portions 17 of the scraper blade 11 are bent into arcuate configurations, as at 18 (Fig. 3), conforming to the surface of the sucker rod 13 and embracing the latter, thereby to contribute to the rigidity of the attachment of the cleaner 10 to the sucker rod.

It will be apparent that, in each embodiment of the invention, the scraper blade is proportioned to permit its tached, for example, an'angular displacement as small as five degrees occurring at the bottom of the stroke of the sucker rod, permits the edges of the scraper blade to cut a new open path through the deposit within the oil well tubing during each upward and downward movement of the sucker rod. Actually, such limited angular displacement of the scraper blade results in more effective cleaning than relatively great angular displacement or rotation of the blade which may only cause the latter to cut grooves in the deposit.

Various changes and modifications may be effected in the illustrated embodiments of the invention without departing from the scope or spirit of the invention defined in the appended claims. a

What is' claimed is: I r

1. An oil well tubing cleaner comprising a sucker rod, a generally flat steel scraper blade predominantly lying at one side of said rod in a plane parallel to the axis of said rod, and a single rigid U-shaped clamp having its central portiontightly'fitted upon said rod from one side of said rod with its legs embracing and extending to the opposite side of said rod and there welded at their ends to said blade by welding beads covering substantially the full length of the end of each of said legs, said blade comprising a central portion formed at opposite sides of said rod with opposite scraping edges substantially parallel to the axis of said rod, and comprising tapering opposite end portions each having opposite side edges sloped toward said rod from ends of said parallel side edges, the end of at least one of said tapering end portions being cupped into an arcuate configuration embracing the surface of said rod to enhance the rigidity of the blade, the length of said blade at said scraping edges being from one-half to one and one-half times the greatest width of said blade, and the length of each of said leg ends and welding beads being at least as great as the diameter of said rod, whereby said blade is permanently and rigidly clamped upon said rod, Without recrystallization or uneven straining of the rod in the region of the welding beads, for movement with reciprocation and limited rotation of the rod to scrape deposits from the inside of oil well tubing.

'2. An oil well. tubing cleaner comprising a sucker rod,

a generally ,flat steel scraper blade predominantly lying I atone side of; said rod in a plane substantially tangent to the surface of the rod, and a single rigid U-shaped clamp having its central portion tightly fitted upon said rod from attachment to the sucker rod by a single U-shaped band or clamp which is shrink welded to the blade and which has a relatively limited length in the direction of the 'longitudinal axis of the sucker rod, to produce a suitably rigid attachment while avoiding the use of relatively long welding beads which, during the formation thereof, would result in excessive heat transfer and consequent objectionable straining or crystallization of the sucker rod.

By employing a single U-shaped band or clamp which embraces the sucker rod at the side of the latter opposite from the scraper blade, the oil well tubing cleaners embodyingthis invention ensures the substantially uniform stifiening of the. sucker rod at the opposite sides found that the most effective cleaning or cutting action 7 of such blades is not a direct function of the rotation {of the sucker rod but is caused, almost entirely, by the cutting action of the edge of the, flat scraper blade as it v reciprocates with the sucker rod within the oil welltubv ing. 'An 'angular displacement fof the scraper blade ,j through onl'y.. -a-few degrees at anypoint'alongthe recip rocating stroke of the; s lclrer ro'd. to .;vvhich it is at,-

one side of said rod with its legs embracing and extending to the opposite side of said rod and there shrink-welded at their ends to said blade by welding beads covering substantially the full length of the end of each of said legs, said blade comprising a central portion formed at opposite: sides of said'rod with straight outside edges substantially parallel to the axis of the rod, and compris ing tapering opposite end portions each having opposite side edges sloped toward said rod from ends of straight side edges, the end of each of said tapering end portions being bent into an arcuate configuration embracing the surface of said rod to enhance the'rigidity of the blade, the length o fjsaid blade along said outside edges being from one-half to one and one-halt times the greatest widthtof said blade, and the length of each of said leg ends and welding beads being at least as great as the diameter of, said rod, :whereby said blade and said clamp are permanently and rigidly shrink-Welded upon said rod, without recrystallization'or uneven straining of the rod in the region of the welding beads, for movement with reciprocation and limited rotation of the rod to scrape deposits from the inside of the oil well tubing;

References Cited in the file of this patent "UNITED srArns PATENTS