US3438404A - Method of mounting well equipment - Google Patents

Description

April 1969 J. c. TRIPPLEHORN 3,438,404

METHOD OF MOUNTING WELL EQUIPMENT Filed July 11, 1966' 7 INVENTOR JAMES c. TRIPPLEHORN Wand ATro Nm United States Patent U.S. Cl. 140-93 2 Claims ABSTRACT OF THE DISCLOSURE The method of attaching a resilient rod guide body to a rod to which the body can be applied by flexing, for instance spreading the guide and sliding it over the end of the rod, or parting it at a longitudinal slot, the method including Winding of a wire-like material onto the annular body to compress it tightly against the rod, the opposite ends of the wire terminating near the ends of the body and the central portion of the wire going either over or under the body so that a single length of wire can be used. The opposed ends of the wire are then prevented from unwinding by one of several different methods, including a longitudinal locking member passed under the body and extending to its ends to receive the ends of the wire.

This invention relates to improvements in well equipment such as centralizers, stabilizers, and parafiin scrapers, and more particularly relates to the combination of improved body structures cooperating with improved means for operatively attaching the structures to rods or tubing. The invention also teaches an improved method of applying such bodies to well rod or tubing.

It is a principal object of the invention to provide improved resilient body structures which are especially designed to cooperate with winding means to provide a very tight grip of the body on the rod or tubing, and at the same time provide large-area engagement therebetween so that the body is in substantially full contact with the rod, as distinguished from contact at a few points, such as is experienced where the engagement is metal-to-metal.

It is another important object of the present invention to provide improved windings and improved techniques for locking the windings on the body. In one preferred embodiment the locking means is located at only the upper end of the body in view of the fact that most of the wear, impact, and damage tends to occur at the lower end of the body.

Still another object of the invention is to provide improved body structures made of resilient plastic material such as nylon or rubber and being shaped in an optimum manner to cooperate with the winding means which hold the body on the rod or tubing.

The present invention is described with reference to several illustrative embodiments which generally comprise a resilient body surrounding a length of rod or tubing, hereinafter referred to as the rod, by windings located at both ends of the body. In the event the body is a scraper or centralizer, the central portion of the body can include raised ribs or scraper members. The illustrative embodiments show round-wire windings, although it is to be understood that the windings need not be circular-cross-section wire but may comprise other strip or tape-like materials. All such winding materials will be included in the term wire as used hereinafter. There are a number of different Ways in which the windings can be wound on to the bodies and locked thereon, but some winding procedures have advantages over others. For instance, it can be desirable to apply the windings starting near the center of the body and then winding outwardly toward the ends, especially in the case of a rubber body in view of the fact that the rubber will be caused to flow away from the central portion toward the ends as the windings are applied, thereby forming ridges of rubber at the extreme outer ends of the body and beyond the winding areas to that the windings do not tend to slip off of the ends of the body. Winding slippage in the axial direction can be prevented on nylon bodies by molding the end portions with helical thread-like grooves for receiving and locating the wires. It may also be desirable to split the body longitudinally to facilitate application thereof to rods having enlarged ends, for instance at upsets. In the case of rubber bodies it may also be desirable to add reinforcement fabrics to control the amount of rubber flow.

The winding of attaching means onto a body is especially advantageous since it provides a better grip than a bolted or riveted collar of reasonable size. For example, using wire of approximately one-eighth inch diameter it was found that when a winding was applied around a rubber body with only pounds of tension on the Wire as it was applied, a 2,500 pound end load applied to the assembly formed in this fashion failed to cause axial slippage thereof, or dislodgement of the wire from the body.

As previously mentioned, it is desirable to have the wire ends locked in the vicinity of the upper end of the body, or at least away from the lower end thereof when applied to a sucker rod. Several different Winding procedures have been found useful for this purpose. For example, the wire can be placed beneath the body and then wound in both directions toward the center of the body and locked by twisting the ends of the Wire to gether in the central body zone. Another satisfactory procedure is to place a metal strip beneath the body and then wind the wire on the body departing in both directions from the center thereof, the metal strip having lugs at both ends to receive and lock the outer ends of the windings, for instance by hammering the lugs down on the wire. Still another way of accomplishing this purpose is to provide a hollow tube which extends longitudinally through the body. Wire can then be wound onto the body starting at one end, passing over the central zone of the body, and then completing the winding at the other end of the body, the latter end of the wire then being passed through the tube and locked to the first end of the Winding by twisting the ends together. In the case of a nylon body the tube can be eliminated and the body can be provided with a longitudinal groove or bore running adjacent to the central bore through which the sucker rod passes. There are a number of other winding procedures which can be used to accomplish a similar purpose, these various procedures sharing a common advantage: namely, the wire windings tend to be self-equalizing so that a uniform grip is provided all along the body. Tight squeezing of the body against the sucker rod prevents the entry of oil or other liquids into the area where the body engages and grips the rod, thereby preventing any lubrication of this area which might assist slippage under extreme axial-loading conditions.

It is another important object of the present invention to provide an improved method for applying a resilient body to a rodlike member by winding wire thereon, and more particularly, by winding the wire onto the body following a certain procedure in order to obtain maximum grip.

Other objects and advantages of the present invention will become apparent during the following discussion of the drawings, wherein:

FIG. 1 is an elevation view of a resilient centralize! 3 or scraper body secured on a sucker rod by windings on its ends;

FIG. 2 is a sectional view taken along line 22 of FIG. 1;

FIG. 3 is a diagrammatic view showing the outline of the body and sucker rod in dashed lines and showing the placement of windings upon this structure such that their ends are locked together in the central zone of the body;

FIG. 4 is a diagrammatic view similar to FIG. 3 but showing a metal strip located beneath the body and serving to lock both ends of the windings just beyond the outer ends of the body;

FIG. 5 is a view similar to FIG. 3 but showing the winding ends locked at only one end of the body, preferably the upper end;

FIG. 6 is an elevation view of a plastic body made according to the present invention and having an external shape similar to the body shown in FIGS. 1 and 2; and

FIG. 7 is a partial view of a nylon body similar to FIG. 6 but wherein the end portions of the body are provided with helical grooves to positively prevent slippage of the windings longitudinally of the body.

Referring now to the drawings, the tubing or rod-like member R to which the present structure is to be attached will ordinarily have a cylindrical periphery, and since it v is extremely important in connection with oil well rods that the surface not be nicked in any way or welded to, the present structure must grip the rod securely without damaging its surface or requiring heating of its metal during installation. The present invention illustrates in FIGS. 1 and 2 a suitable rubber body 1%, and in FIGS. 6 and 7 suitable plastic bodies, preferably made of a material which can be conveniently molded, such as nylon which also exhibits a considerable degree of resilience. In FIGS. 3, 4 and 5, the body portion is generally referred to by the reference numeral it), although it is to be understood that this reference is not intended to exclude the plastic body 36. The body has an enlarged central portion 11 which in the present embodiment includes scraper or centralizer blade portions 12 separated by grooves 13 through which fluids can bypass the body structure as it is reciprocated up and down on the sucker rod. The outer ends of the body are substantially conical as at 14 to reduce tendency to snag, although these outer ends could be modified in shape, for example made cylindrical if desired for an alternative embodiment. The plastic bodies shown in FIGS. 6 and 7 have similar shapes which include blade portions 32 separated by grooves 33 in the central portion 31 of the body. These bodies are also shown as having conical end portions 34. In FIG. 7 the end portions include helical thread-like grooves 35 which are molded to receive the particular crosssectional shape and diameter of the winding strip material to be applied, and which serve the purpose of preventing slipping of the winding in the axial direction represented by the arrow A.

The plastic body 36 should be longitudinally divided as for instance along the lines D since in all probability the body cannot be slipped over the end of a sucker rod or length of tubing because of the tool joints at the ends thereof. The rubber body shown in FIGS. 1 and 2 may be likewise divided in two as shown at D in FIGS. 6 and 7, or the body may be slit along one side only so that it can be flexed open to receive the rod R. In any event the body is provided with a central bore 16, or 36, to receive the rod R and its bore should be sized to be a snug fit on the rod prior to the application of the windings.

In the case of a rubber body as shown in FIGS. 1 and 2 the resilience of the body would probably be suflcient to permit the passage of the wire or locking strap through the bore 16 by merely displacing some of the rubber adjacent the rod R, although a longitudinal groove may advantageously be provided for this purpose, the groove opening into the bore 16. On the other hand, in connection with a harder plastic body 36 a groove such as the groove 37 has to be molded into the body so that it communicates with the bore 36. Alternatively, the groove 3-7 may comprise a completely separate bore passing through the body and offset somewhat from the main rod receiving bore 36.

The windings shown in the present drawings employ Wire of circular cross-section made of a suitable material to resist elongation, corrosion, electrolysis or other damaging effects in the Well. The wire is generally referred to by the reference numeral 20' and comprises windings 21 and 22 located respectively on the end portions 14, 34, or 35 of the body. The windings also include a central portion 23 which passes through one of the grooves 13 in order to join the two windings 21 and 22. In FIG. 1, the specific locking means by which the winding ends are held in place are not illustrated, but various means are shown in FIGS. 3, 4 and 5, wherein portions of the windings which correspond to those illustrated in FIG. 1 are provided with similar reference numerals.

Referring now to FIG. 3, this figure illustrates an example in which the wire has a central portion which is passed through an opening in the body, the opening generally being referred to by the reference character 17. In some instances it may be desirable to line the opening 17 using a rigid tube 18 so that the opening cannot be collapsed. This may also be true where the windings take the form shown in FIG. 5 in which it may be desirable to pass the finish end 22a of the winding through the body so that it can be locked to the first turn of the winding 21a. Whenever a relatively rigid plastic body is used having an premolded or drilled bore 37 therethrough, the addition of tubing 18 is unnecessary since the pressure of the wire winding will not crush the opening 37 to any considerable extent, as would be the case where a rubber body is used. In FIG. 3, the embodiment of the winding shown has its central portion 24 passed through the body 16 initially. The windings 21 and 22 are then wound from the outside toward the center 11 of the body, and the final ends of the windings 21a and 22a are then twisted together as at 25 in the bottom of one of the grooves 13 or 33.

FIG. 4 shows an alternative embodiment in which a metal strap 26 is laid against the rod R prior to placing of the body on the rod. A more rigid plastic body would have to have a molded groove 38 along the bore 36 to receive the metal strip 26. The strip 26 might also comprise a separate length of wire which would pass through the body and extend a short distance out at both ends. The purpose of the member 26 is to lock the windings ends 21b and 22b. With this type of arrangement, the central portion 23 of the winding is first laid in the bottom of the groove 13 and the winding is then applied, extending from the center out toward the ends of the body portions 14. When the winding has been fully applied, its ends 21b and 2211 are passed through metal tabs 26a and 26b which are then hammered or crimped down in some suitable and well-known fashion in order to lock the wires. In the case where the member 26 comprises a short length of wire, its ends can then be twisted together with the ends 21b and 22b to provide a lock. The metal strip is preferable because it has less tendency to shift circumferentially of the rod R. As can be seen in FIG. 1, when the windings 21 and 22 are wound from the center outwardly on a rubber body, a ridge of the rubber is pushed outwardly along the end portions 14 of the body, so that when the last turn of the winding has been applied, there remains a ridge 19 extending most of the way around the end portion and tending to hold the last turn of the winding in place.

The further embodiment shown in FIG. 5 is modified to the extent that the underlying portion of the winding 24 passes through the body and is provided with a hook 24a at one end. The winding 22 is first applied and then the central portion 23 is passed over the central portion of the body through a groove 13. Then the winding is applied, terminating in a hook 21c which is interwound with the hook portion 24c. Viewing the left end of FIG. 5 as the bottom end of the scraper, this would provide only one lock located at the top of the scraper, which has the advantage of placing the locking means of the winding away from the lower end of the body assembly, which lower end takes more wear and is more likely to be damaged than the upper end of the assembly.

The type of winding shown in the drawing provides a novel securing method for applying a body to a rod, in which a length of the winding wire always passes the central portion of the body and joins ends of the windings whose other ends are locked against unwinding by other locking means so as to maintain the winding tension. In addition to the length of wire that is disposed longitudinally of the central portion of the body, there is always one other locking means which is also disposed longitudinally of the body and attached to the windings. The latter may be a separate wire or metal strip, or it may comprise another portion of the winding wire itself.

The present invention is not to be limited to the exact embodiments shown in the drawings for obviously changes may be made therein within the scope of the following claims.

I claim:

1. The method of attaching a resilient annular body having at least one longitudinal passage therethrough to a rod-like member including the steps of applying the annular body to surround the rod-like member; passing a length of wire winding material longitudinally through the passage in the body; winding the material under tension plural times around both end portions of the body to compress them against the rod-like member, and locking the ends of the wire material to maintain the tension and prevent unwinding thereof.

2. The method set forth in claim 1 wherein the outer central portion of the body has plural longitudinally ex- 5 tending passages, including the step of passing a locking member longitudinally under substantially the full length of the body between it and the rod-like member, passing said length of wire material longitudinally through one 10 of said passages in the central portion of the body and winding the latter in opposite directions toward the ends of the body, and securing the ends of the wire material to the opposite ends of said locking member.

15 References Cited UNITED STATES PATENTS 1,950,678 3/1934 Hogan 140-111 2,094,169 9/1937 Germany 166176 2,335,038 11/1943 Bridges 14093 30 3,099,889 8/1963 Verneuil 43--24 FOREIGN PATENTS 549,747 12/1957 Canada. 25 1,360,248 3/1964 France.

CHARLES W. LANHAM, Primary Examiner.

L. A. LARSON, Assistant Examiner.

0 U.S. Cl. X.R.

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