US 3329212 A
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Description (OCR text may contain errors)
y 1967 M. E. POURCHOT 3,329,212
PARAFFIN SCRAPER AND ROD GUIDE Filed Sept. 17, 1964 I NVENTOR.
Me/wh E pourc/vaf BY United States Patent homa Filed Sept. 17, 1964, Ser. No. 397,182 6 Claims. (Cl. 166-176) This invention relates to improvements .in paraffin scrapers and rod guides and more particularly, but not by way of limitation, to a combined guide, parailin scraper and insulator for use with reciprocating rods in a well bore.
The Well fluid in many producing oil or gas wells usually contains paraffln in solution therein. The temperature of the Well fluid in the lower portions of the well bore is usually sufliciently high to retain the paraflin in a liquid state. However, as the well fluid is raised to the surface of the ground through the well tubing during the producing operation, the temperature of the fluid is reduced and the paraffin tends to solidify and accumulate on the inner periphery of the tubing. In many producing wells, the paraffin content is so great that the accumulation of the paraffin may substantially close portions of the Well tubing, thus greatly restricting the flow of fluid therethr-ough. In order to overcome this problem, it is common practice to provide a plurality of paraffin scraping devices spaced longitudinally on the reciprocating rod, normally called the sucker rod, whereby the paraffin will be scraped from the inner periphery of the tubing during reciprocation of the rod. Many of the scraping devices have certain disadvantages in that the paraflin will often accumulate on the scraper itself necessitating pulling of the sucker rods at frequent intervals for clean ing of the scraper devices and often replacement thereof. In addition, the scraping devices must be very tightly secured around the outer periphery of the rod in order to preclude accidental or unwanted longitudinal movement of the devices along the rod as the rod is reciprocated within the tubing. Many of the presently available scraping devices require the use of special tools and equipment for securely fixing the devices to the rod and not only is the special equipment expensive, but the installation of the devices is time consuming. Since the producing well must usually be shut down during this installation operation, it is desirable to provide a simple and quick installation as well as a very secure engagement with the rod.
The present invention contemplates a novel paraflin scraper, rod guide and rod insulator which may be quickly and easily secured around the outer periphery of a rod and securely held within position thereon. The novel paratfin scraper and rod guide comprises two substantially identical half sections having a plurality of radi ally extending flanges and a complementary spiral shoul der for effecting a scraping action throughout a full circumference of the rod as the rod is reciprocated within the well tubing. The two half sections may be quickly and easily disposed in substantial alignment around the rod and held in position thereon by means of complementary fastening devices, particularly designed and constructed for retaining the scraper firmly in position around the rod in a manner substantially precluding longitudinal slippage thereof during reciprocation of the rod. In addition, the novel paraflin scraper is constructed from molydisulphide nylon which is found to be extremely resistant to impact, abrasion and the corrosive effects of well fluids and chemicals used in conjunction therewith. As a result of tests using the novel scraper, it has been found that paraflin will not adhere to this material. Thus, not only does the novel paraflin scraper reduce the accumulation of paraflin on the inner periphery of the well tubing, but
also substantially eliminates accumulating of paraffin on the scraper itself. Furthermore, the molydisulphide nylon functions to insulate the rod, which is normally metallic, from the well tubing which is also normally metallic, and consequently reduces electrolysis of the rod and tubing. The device also functions as a rod guide since the outwardly extending flanges and spiral shoulders are preferably of a size corresponding to the inner dimensions of the well tubing in order to guide the reciprocal movement of the rod within the tubing thereby reducing wear of the rod during operation thereof. The novel scraper, guide and insulator greatly prolongs the eflicient and useful life of the sucker rods and reduces the necessity of pulling the rods due to paraflin build up and corrosion. The novel paraflin scraper is simple and efficient in operation and economical and durable in construction.
It is an important object of this invention to provide a novel paraffin scraper and guide which may be quickly and easily installed around the outer periphery of a rod.
Another object of this invention is to provide a novel paraflin scraper which may be easily secured around the outer periphery of the rod in a manner substantially precluding accidental slippage thereof along the rod.
Another object of this invention is to provide a novel scraper and rod guide for a sucker rod constructed from a material particularly selected for the quality of substantially precluding adherence of paraflin thereto.
Still another object of this invention is to provide a novel paraflin scraper and rod guide for a sucker rod which functions as an insulator for the rod to greatly reduce corosion due to electrolysis.
A further object of this invention is to provide a paraffin scraper and rod guide having novel fastening means for facilitating securing thereof to a rod.
Other and further objects and advantageous features of the present invention will hereinafter more fully appear in connection with a detailed description of the drawings in-which:
FIGURE 1 is an exploded perspective view of a paraffin scraper, rod guide and insulator embodying the invention.
FIGURE 2 is a sectional elevational view'of a fastening member utilized in the invention.
FIGURE 3 is a perspective view of the fastening device depicted in FIGURE 2.
FIGURE 4 is a broken elevational view of a rod having a plurality of paraflin scraper devices embodying the invention secured thereon.
Referring to the drawings in detail, reference character 10 generally indicates a combination paraflin scraper, rod guide and insulator for a rod 12 such as a reciprocating sucker rod for an oil well bore (not shown), or the like. The scraper 10 comprises a pair of substantially identical half sections 14 and 16 preferably constructed from molydisulphide nylon. Since each half section 14 and 16 is substantially identical, only one will be de scribed in detail herein. The half section 14 comprises a central longitudinally extending semi-cylindrical portion 18 having an inner periphery 20 complementary to the size and shape of the outer periphery of the rod 12. A first pair of oppositely disposed radially outwardly extending flanges 22 and 24 are provided on the central body 18 and a similar pair of radially outwardly extending flanges 26 and 28 are spaced from and in substantial co-planar alignment with the flanges 22 and 24 for a purpose as will be hereinafter set forth.
The rib or flange 22 is provided with an upper shoulder 30 having a compound taper whereby the shoulder 30 extends downwardly at an angle in the radial direction from the body 18 and is beveled with the bevel extending around the upper end 32 of the central body por tion 18. The shoulder 30 terminates at the outer extrem- 3 ity thereof in a substantially vertical or straight portion 34 which extends in communication with an angularly disposed portion 36 extending from the straight portion 34 to the body portion 18.
The-flange 28 is substantially identical to the flange 22, but is reversed and oppositely disposed with respect thereto as clearly shown in FIGURE 1. The flange 28 is provided with a lower shoulder 40 similar to the shoulder 30, but oppositely disposed and reversed with respect thereto. The lower shoulder 40 is beveled and the bevelextends arounds the lower end 41 of the body 18 as shown in FIGURE 1. The shoulder 40 terminates in a substantially straight or vertical portion 4-2 and a second 'angularly disposed portion (not shown) similar to the angled portion 36 extends from the straight portion 42 to the body portion 18. An outwardly extending spiral shoulder 44 extends between the straight portion 34 of the flange 22 and the straight portion 42 of the flange '28 and is of a radial dimension complementary to the inner periphery of the Well tubing (not shown), or the like, through which the rod 12 extends.
The flange 24 is provided with" an upper shoulder 46 extending outwardly from the body 18 with a compound taper similar to, but oppositely disposed from that of the shoulder 30. The shoulder 46 terminates in a substantially vertical or straight portion 48 contoured similar to the straight portion 34, but reversed with respect thereto and a lower tapered portion 50 extends from the straight portion 48 to the body 18. The plane of the straight portion 48 extends rearwardly from the plane of the flange 24, as viewed in the drawings, at an angle for facilitating the flow of fluid around the flange 24.
The flange 26 is generally similar to the flange 24, but is oppositely disposed and reversed with respect thereto. The flange 26 is provided with a lower shoulder 52 similar to the shoulder 46, but reversed with respect thereto and terminates in a generally vertical or straight portion 54 of a configuration similar to the straight portion 48. The angular relationship between the plane of the straight portion 54 and the plane of the flange 26 is clearly shown at 49. An upper angular shoulder 56 is provided on the flange 26 and extends from the straight portion 54 to the body portion 18. The flat portions 34 and 48 and 42 and 54 are spaced from the body 18 in a radial distance sufficient for scraping parafiin from the inner periphery of the well tubing during reciprocation of the rod 12, but allowing sufficient clearance between the device and the inner periphery of the well tubing to preclude interference during operation or reciprocation of the rod 12.
As hereinbefore set forth, the half section 16 is substan tially identical with the half section 14. Accordingly, the flanges 22', 24', 26' and 28 are substantially identical to the flanges 22, 24, 26 and 28, respectively. Flange 22' is provided with an upper compound tapered shoulder 30' terminating in a vertical or straight portion 34' and having a lower angled portion 36 corresponding to the respective elements of the flange 22. The flange 24' is provided with a tapered shoulder 46', an outer vertical or straight portion 48 and a lower tapered shoulder 50' corresponding to the respective elements of the flange 24. Similarly, the flange 26 is provided with converging shoulders 52' and 56 and upper tapered shoulder 43' corresponding to a similar shoulder on the flange 28 but which is not depicted in the drawings. The straight or vertical portions 42 and 34 are connected by a spiral shoulder 44 corresponding to the spiral shoulder 44. Thus, when the two half sections 14 and 16 are disposed in alignment surrounding the outer periphery of the rod 12, as shown in FIGURE 4, the spiral shoulders 44 and 44 will cooperate to provide a spiral shoulder extending completely around the outer circumference of the body 18.
An aperture or bore 58 is provided in the flange 22 and is in substantial horizontal alignment with an aperture 60 provided in the flange 24. A similar bore or aperture 62 is provided in the flange 28 and is in substantial horizontal alignment with a bore 64 provided in the flange 26. Of course, similar bores 56', 66', 62 and 64' are provided in the flanges 22, 24, 28 and 26', respectively. Thus, disposition of the two half sections 14 and 16 on opposite sides of the rod 12 and in substantial alignment therearound will position the apertures of the half section 14 in substantial alignment with the apertures of the half section 16 for a purpose as will be hereinafter set forth.
A plurality of fastener elements, such as generally indicated at 66, are utilized in combination with a threaded stud member 68 for retaining the half sections 14 and 16 securely in position around the rod 12. The fastener member 66 comprises an enlarged head portion 76 providing a circumferential shoulder 72 for engaging the surface of the flange, such as flange 22, when the fastening element 66 is inserted within a bore such as the bore 58 thereof as will be hereinafter set forth. The outer periphery of the shank portion 74 of the element 66 is fluted or provided with radially extending circumferentially spaced pointed or sharp members which bite into the inner periphery of the bore 58 as the element 66 is forced or pressed into position therein. This securely fastens the element 66 within the flange 22 and precludes rotation of the element 66 with respect to the flange. A central threaded bore 76 extends through the element 66 for receiving one of the stud members 68 therethrough. Of course, the stud member 68 will be inserted through the aperture in alignment with the element 66 such as aperture of the flange 24 for threaded engagement with the element 66 secured within the bore 58. The threaded stud member 68 is preferably provided with a socket head 78 whereby a suitable wrench (not shown) may be utilized in the usual manner for threadedly securing the stud 68 to the fastening element 66. Each pair of aligned apertures on the adjacent flanges of the two half sections 14 and 16 disposed around the rod 12 is provided with a complementary pair of stud members '68 and fastening elements 66. As particularly shown in FIGURE 1, it is preferable to stagger or alternate the fastener elements 66 and studs 68 whereby two of the fastening elements 66 will be carried by the half section 14 and two of the elements 66 will be carried by the half section 16. However, it is to be noted that the invention is not limited in any manner to such an arrangement.
As shown in FIGURE 4, it may be preferable to provide alternate left hand and right hand scrapers, as generally shown at 16 and 10, respectively, for the rod 12. Of course, the scrapers 10 and 10 are of a substantially identical but reversed construction. In actual field conditions, it has been found that alternate spacing of left and right hand units provides a more eflicient paraflin scraping operation.
Operation When it is desired to provide the sucker rod 12 with a paraflin scraper 10, the two half sections 14 and 16 may be disposed on opposite sides of the rod and in substantial alignment with each other. It is preferable that each half section 14 and 16 be provided with at least two of the fastening elements 66. For example, a fastening element 66 may be disposed in the bores 58 and 62 of the half section 14 and in the bores 58' and 62' of the half section 16. Thus, each pair of axially aligned bores of the two half sections will be provided with one fastening element 66. The fastening element 66 may be pressed or otherwise forced into the aperture whereby the fluted shank 74 will bite into the inner periphery of the aperture. This precludes rotation of the fastening element 66 with respect to the bore. The corresponding stud member 68 may then be inserted through the aperture in axial alignment with each fastening element 66 and threadedly secured thereto. A suitable wrench (not shown) may be utilized in any well known manner in combination with the socket head 78 for tightening the stud 68 within the fastening element 66. In this manner, the half sections 14 and 16 will be drawn together around the rod and may be very securely retained in position therearound in a manner substantially precluding any slippage or longitudinal movement of the device along the rod 12.
Substantially any number of the devices 10 may be spaced along the rod 12, as desired, for scraping the inner periphery of the well tubing (not shown) during reciprocation of the rod. However, as hereinbefore set forth in actual practice, it has been found desirable to provide alternate left hand and right hand scraping devices to provide a more eflicient scraping operation.
As the rod 12 is reciprocated within the well tubing, the spiral shoulders 44 and 44 scrape the inner periphery of the well tubing for substantially precluding any accumulation or build up of paraflin thereon. In addition, the spiral shoulder as well as the vertical portions of the flanges 22, 24, 26 and 28 cooperate for guiding the longitudinal movement of the rod 12 within the tubing. Thus, the tubing is maintained substantially centrally disposed Within the well tubing during reciprocation of the rod thereby greatly reducing wear of the rod. Furthermore, the molydisulphide nylon material from which the devices 10 and 10 are constructed tends to shed paraflin, thus reducing or substantially eliminating any paraflin build up or accumulation thereof on the scraping devices themselves. Therefore, the rod 12 may be reciprocated within the tubing throughout a prolonged period of time without the necessity of removal thereof from the well tubing for cleaning of the scraping devices. The molydisulphide nylon material also functions to insulate the metallic rod 12 from the metallic well tubing, thus greatly reducing deterioration of the rod due to electroylsis.
From the foregoing, it will be apparent that the present invention contemplates a novel paraflin scraper, rod guide and insulator which may be quickly and easily installed on the sucker rod at the well site and in a manner substantially precluding longitudinal slippage or movement of the scraper idevice along the rod. The material from which the paraflin scraper is constructed substantially eliminates accumulation of parafiin thereon and functions to insulate the rod from the well tubing. The novel parafiin scraper, rod guide and insulator is simple and eflicient in operation and economical and durable in construction.
Changes may be made in the combination and arrangement of parts as heretofore set forth in the specification and shown in the drawings, it being understood that any modification in the precise embodiment of the invention may be made within the scope of the following claims, without departing from the spirit of the invention.
What is is claimed is:
1. A paratfin scraper and rod guide for a reciprocal rod comprising sectional body means surrounding the rod and having the inner periphery disposed adjacent the outer periphery of the rod, spiral shoulder means provided on the outer periphery of said sectional body to provide a combined scraping and guiding action, said sectional body means being provided with a plurality of pairs of aligned apertures for receiving complementary fastening members therethrough, said complementary fastening members comprising a first element disposed in at least one of each pair of aligned apertures, a second element extending through the other of each pair of aligned apertures and into threaded engagement with the respective first fastening element, said threaded engagement between said complementary first and second elements securing the sectional body means around the rod in a manner for substantially precluding slippage of the body means along the rod.
2. A paraflin scraper and rod guide for a reciprocating rod comprising a pair of substantially identical half sections disposed around the rod, each of said half sections provided with a central semi-cylindrical body portion engaging the outer periphery of the rod, a plurality of radially outwardly extending flanges provided on each scmi-cylindrical body portion, a spiral shoulder provided on each semi-cylindrical body portion, each of said flange members being provided with at least one aperture in alignment with a corresponding aperture of the other half section, fastening means extending through the aligned apertures, said fastening means comprising a first element having gripping means for securing thereof in the respective manner precluding rotation thereof with respect to the flange, and a second element extending through the aligned aperture and into threaded engagement with the first element whereby the half sections are tightly engaged around the outer periphery of the rod in a manner substantially precluding slippage of the paraflin scraper and rod guide along the rod.
3. A paraflin scraper as set forth in claim 2 wherein the half sections are constructed from molydisulphide nylon.
4. A paraflin scraper and rod guide for a reciprocal rod comprising a pair of half sections disposed around the outer periphery of the rod, outwardly extending spiral shoulder means provided on the outer periphery of each half section to provide a scraping edge and guiding surface during reciprocation of the rod, each of said half sections being provided with aligned and complementary radially outwardly extending flanges, complementary pairs of aligned apertures provided for each pair of aligned flanges, and threaded fastening means extending through and cooperating with each pair of aligned apertures for securing the half sections around the rod in a manner substantially precluding slippage of the paraffin scraper and rod guide along the rod.
5. A paraffin scraper and rod guide as set forth in claim 4 wherein the threaded fastening means comprises a first fastening element secured in at least one of each pair of aligned apertures, said first fastening element being provided with a threaded bore extending therethrough and having a fluted shank for biting engagement with the respective aperture to preclude rotation of the first fastening element with respect to the flange, a second fastening element comprising a threaded stud extending through the other of each pair of aligned apertures and into threaded engagement with the threaded bore of the first fastening element, and said second element being provided with means whereby the threaded engagement thereof with the first element may be sufiiciently tightened for securing the half sections around the rod in a manner substantially precluding slippage of the paraffin scraper and rod guide along the rod.
6. A parafi in scraper and rod guide as set forth in claim 4 wherein each of said flanges is provided with converging upper and lower edge portions having a compound taper for facilitating the flow of a fluid around the paraffin scraper and rod guide during operation thereof.
References Cited UNITED STATES PATENTS 821,274 5/1906 Ames 3084 1,907,825 5/1933 Johnson 308-4 2,253,675 8/1941 Arnold 3084 X 3,000,420 9/1961 Spokes 15141.73 3,079,998 3/1963 Renter et a1. 166176 3,141,505 7/1964 Tripplehorn 166176 X 3,193,857 7/1965 Kahn 15141.73 X 3,197,263 7/1965 Holcombe 308--4 CHARLES E. OCONNELL, Primary Examiner. D. H. BROWN, Assistant Examiner.