US3560060A

US3560060A - Rod guide and centralizer

Info

Publication number: US3560060A
Application number: US784667A
Authority: US
Inventors: Nate Morris
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-12-18
Filing date: 1968-12-18
Publication date: 1971-02-02
Anticipated expiration: 1988-02-02

Abstract

A POLYURETHANE ROD GUIDE AND CENTRALIZER FOR USE ON SUCKER RODS EXTENDING LONGITUDINALLY THROUGH PRODUCTION TUBING SUCH AS US USED IN PUMPING FLUIDS TO THE SURFACE IN OIL WELLS WHEREIN THE ROD GUIDE AND CENTRALIZER SURROUND THE ROD TO POSITION IT GENERALLY AXIALLY OF THE TUBING TO PREVENT ENGAGEMENT OF THE ROD WITH THE TUBING WHEN SUCH RODS ARE RECIPROCATED THEREIN FOR ACTUATING AS WELL PUMP CONNECTED TO THE SUCKER RODS.

Description

Feb. 2, 1971 N. MORRIS ROD GUIDE AND CENTRALIZER Filed bee. 18. 1.968

M0 f7 J INVENTOR 71 f 0 6 A -iQKQxAQAAQ 7 i: Ii ...i| lllllll 0 4 a a ATTORNEYS United States Patent Oifice 3,560,060 Patented Feb. 2, 1971 3,560,060 ROD GUIDE AND CENTRALIZER Nate Morris, 10234 Metronome, Houston, Tex. 77042 Filed Dec. 18, 1968, Ser. No. 784,667 Int. Cl. E21b 17/10; F16c N26 US. Cl. 308-4 1 Claim ABSTRACT OF THE DISCLOSURE A polyurethane rod guide and centralizer for use on sucker rods extending longitudinally through production tubing such as is used in pumping fluids to the surface in oil wells wherein the rod guide and centralizer surround the rod to position it generally axially of the tubing to prevent engagement of the rods with the tubing when such rods are reciprocated therein for actuating as well pump connected to the sucker rods.

BACKGROUND OF THE INVENTION (1) Field of the invention The present invention pertains to a polyurethane sucker rod guide and centralizer for use in production tubing and particularly plastic-lined tubing to permit low friction engagement between the sucker rod guides and the tubing at those points along the string of sucker rods Where engagement between such rods and tubing occur to provide a minimum of wear and damage to the plastic coated inner surface of the tubing.

(2) Description of the prior art In mechanical oil well pumping apparatus, lengths of solid rods, known as sucker rods, are coupled together so as to extend down into a string of production tubing for connecting mechanical pumping equipment at the surface to a well pump disposed in the well. As the sucker rod string is reciprocated in the tubing to actuate the pump for pumping well fluids upwardly through the production tubing to the surface, such string of sucker rods normally engages the inner surface of the tubing at various spaced points because, more often than not, the string of tubing and the well bore are crooked rather than straight. The engagement by the reciprocating sucker rods with the inner surface of the tubing at various points causes wear on the rods and the tubing when the rods are reciprocated therein. Various rod guides have been suggested to position the sucker rod string so as to minimize engagement between the sucker rods and the tubing; however, the rod guides frequently cause wear and are particularly troublesome when employed in a tubing string that is internally coated or lined with a plastic film which is provided to inhibit corrosion of the tubing.

SUMMARY The present invention pertains :to a polyurethane rod guide and centralizer which is secured to a sucker rod and which comprises a longitudinally extending cylindrical body having annular surfaces at its opposite ends tapered inwardly toward the rod on which a rod guide is carried and which includes a plurality of circumferentially spaced longitudinally extending flutes or channels which are proyided in the outer surface of the cylindrical body and tralizer which reduces rod, coupling and tubing wear in sucker rod pumped wells and facilitates the use of internally coated tubing having a plastic lining in such wells.

Another object of the present invention is to provide a new and improved sucker rod guide and centralizer wherein the guide comprises a longitudinally extending polyurethane body having an outer cylindrical surface and having annular surfaces at its opposite ends tapered inwardly toward the longitudinal axis of such cylindrical body. A plurality of circumferentially spaced longitudinally extending fiutes or channels are disposed at an angle to the longitudinal axis of the sucker rod guide or body and extefid longitudinally of the body from one of the annular tapered end surfaces to the other to provide relatively sharp edges for cutting or scrapping paraffin off of the inner -surface of the production tubing when such rod guides engage or rub against such tubing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. Us a longitudinal view partly in section and partly in elevation showing the sucker rod guide and centralizer of the present invention positioned on a sucker rod disposed in a plastic-lined joint of tubing;

FIG. 2 is a sectional view taken on line 2-2 of FIG. 1 showing -details of construction of the sucker rod guide and centralizer apparatus of the present invention; and

FIG. 3 is a sectional view taken on line 3--3 of FIG. 1 showing additional details of construction of the sucker rod guide apparatus of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Briefly, as shown in FIG. 1 of the drawings, the sucker rod guide and centralizer apparatus of the present invention is designated generally G and is shown mounted on a solid sucker rod 4 that extends generally axially of the length of tubing 6 which, as shown, is internally coated or linedlwith a plastic film 7. The sucker rod guide G is formed of polyurethane and comprises a generally cylindrical body 11 having annular

tapered end portions

12 and 13 which are inclined inwardly toward the longitudinal axis of such cylindrical body. Laterally extending

surfaces

19 and 20 which are transverse of the longitudinal axis of the body 11 are provided adjacent each end of the

tapered surfaces

12 and 13. The body 11 is split longitudinally at 21 to enable the body to be installed on the rod 4 by spreading the split portion and inserting the rod 4 laterally into the central longitudinally extending opening or passage at 23 which extends axially through the body 11. An epoxy resin 20' or other suitable bonding agent is employed to glue or bond the facing edges of the split portion 21 together and for also securing the body 11 to the rod 4.

circumferentially spaced flutes or channels 24 are provided on the exterior of the body 11 and extend longitudinally thereof to facilitate the flow of well fluids around the guide G through the tubing 6. As shown, such flutes or channels 24 extend from one tapered end portion 12 to the tapered end portion 13 at the opposite end of the body 11.

The flutes or channels 24 are preferably formed with a bottom surface 26 and with

side surfaces

27 and 28 being disposed at substantially right angles to such surface 26.

It will be noted that the flutes 24 are disposed at an angle to the longitudinal axis of the body 11 so that the edges 29, formed at each end of the channels where the

sides

27 and 28 intersect the

tapered ends

12 and 13, present a sharp cutting edge which tends to cut or scrape any parafiin off of the inner surface of the tubing 6 when the guide body 11 bumps or rubs against such tubing.

In using the polyurethane sucker rod guide and centralizer of the present invention, it will be appreciated that the body 11 may be atfixed to the sucker rod 6 or to the sucker rod box couplings at the ends of the rods (not shown) at desired intervals either by molding the body 11 onto the rod 6 or by securing the body 11 thereon with a suitable bonding agent such as epoxy resin. With the bodies 11 thus positioned on the sucker rod at longitudinally spaced intervals, the sucker rod string may be reciprocated in the tubing 6 with a minimum of rubbing or abrasion between the inner surface of the tubing 6 and the rod string 4. Also, it will be appreciated that the polyurethane sucker rod guides G are chemically resistant to Well fluids and gases encountred in oil and gas wells as Well as to chemicals normally used in treating oil wells and that such polyurethane guide G does not produce a paraffin build up as parafiin does not readily adhere well to such polyurethane guides.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made within the scope of the appended claim Without departing from the spirit of the invention.

What is claimed is:

1. A sucker rod guide and rod centralizer for use in plastic coated tubing comprising:

(a) a body having a cylindrical outer surface extending longitudinally thereof;

(b) an annular end surface at each end of such cylindrical outer surface tapered inwardly toward the longitudinal axis of such cylindrical body;

(0) a plurality of circumferentially spaced longitudinally extending flutes formed in said body, said flutes being disposed at an angle to the longitudinal axis of said body and communicating the tapered annular end surfaces at the opposite ends of said body;

(d) said flutes including a flat bottom surface and a pair of circumferentially spaced side surfaces disposed at substantially right angles to said bottom surface and intersecting the outer cylindrical surface of said body;

(e) said body being split longitudinally along the bottom surface of one of said flutes; and

(f) a suitable bonding agent bonding the faces of the split together and securing the body on the rod.

References Cited UNITED STATES PATENTS 2,690,934 10/1954 Holcombe 3084 3,049,382 8/1962 Ell 3084 3,360,846 l/l968 Schellstede et al. 166241X 3,414,337 12/1968 Sable 308-4 MANUEL A. ANTONAKAS, Primary Examiner US. Cl. X.R.