US2070135A - Method of repairing pumping apparatus in the well - Google Patents

Description

H. L. LAUGHINGHOUSE 2,070,135

Feb. 9, 1937.

METHOD OF REPAIRING PUMPING APPARATUS IN THE WELL Filed Feb. 20, 1933 Patented Feb. 9, 1937 UNITED STATES PATENT OFFICE METHOD OF REPAIRING PUMPING APPA- RATUS IN THE WELL 1 Claim.

This invention has to do generally with means "for repairing broken sucker rods of well pumps, and, as a particular feature, this means is effective for splicing broken sucker rods without elevating the lower section of the broken sucker rod string from the pump tubing.

According to common prior practice, when a break occurs in a sucker rod string, the string above the break is pulled from the tubing,bringingwithit the upper section of the broken sucker rod. The broken rod is replaced in the string by a fishing tool or grapple and the string reentered in the tubing and manipulated in a manner to engage the grapple with the broken rod left therein. Then the string is again pulled from the tubing, bringing with it the broken rod section and the rods and pump plunger extending therebelow. It normally requires a considerable pull to free the plunger from the working barrel of the pump, particularly in the case of employment of a Garbutt rod or other connection between the pump plunger and standing valve, when the standing valve must be pulled from its tight, force-fit in the shoe, as is well understood in the art. This of course frequently entails subjecting the sucker rods to great tensile strains, especially where the standing valve is tightly sanded in its shoe, and as a result the sucker rod string is often stretched with a resulting indeterminate permanent elongation.

After thus raising the lower section of the string and the pump plunger and standing valve, 2. new sucker rod is substituted for the broken one, whereupon the string with plunger attached there- 5 to is again lowered and returned to operating position. It will be seen that there is involved a number of costly, time-consuming elevating and lowering operations, first to take out the upper section of the broken string, second, to lower the grapple, third, to raise the grapple and the lower section of the string, together with the pump plunger and standing valve, and fourth, to relower the repaired string. It will also be evident that should the lower rod section have become elongated in pulling the plunger, the overall length of the sucker rod string will have increased and the amount of such increase will not be known. As a result, when the string with the substituted rod is reentered in the tubing the pump plunger is supported lower in the Working barrel, thus altering the stroke limits from those to which the reciprocating mechanism is adjusted, with obvious disadvantage, and, where the stretch is sufficient, with decidedly harmful results.

It is therefore a principal object of the present invention to avoid the above objectionable occurrences by providing means for splicing a broken sucker rod string without pulling the lower rod section.

This is preferably accomplished, speaking generally, by first pulling the upper section of the broken sucker rod string and fastening the splicing device of the present invention directly to that broken section. The string is then lowered in the pump tubing until the splicing device reaches the upper end of the sucker rod section remaining in the tubing. The splicing device is of such character that when lowered it grapples the upper broken end of the lower sucker rod section, and the device is provided with serrated wedge slips which securely grip the broken rod and complete the splice. These wedge slips are mounted in the splicing tool in a manner such that they cannot rotate therein, and the rod engaging teeth are so formed as to grip the rod against rotative as well as longitudinal movement within the slips.

There is thus effected a rapidly made, permanent and rigid splice, accomplished without raising the lower section of the broken sucker rod string, or the pump plunger and standing valve connected thereto. Hence no pulling strains are put on the rods during the operation, so the original pumping conditions are restored and pumping may proceed with a minimum loss of time and without re-adjustment of the reciprocating mechanism or change in rod-length. Moreover, since the pump plunger and standing valve have not been pulled, no oil is lost back into the well, and production proceeds at once from where it left ofi when the break occurred.

The various features and objects of the invention will be best understood without further preliminary discussion by now referring to a present preferred embodiment of the invention, reference for this purpose being had to the accompanying drawing, in which:

Fig. l is a somewhat diagrammatic section of a pump tubing and pump showing a broken sucker rod string and the splicing device of the present invention. being lowered thereto;

Fig. 2 is a View similar to Fig. 1 but showing the sucker string after the splice is made;

Fig. 3 is a longitudinal medial section through the splicing device of the present invention, showing a sucker rod in the upper end of the splicer;

Fig. 4 is a view similar to Fig. 3 but taken in a plane at 90 from Fig. 3, and also showing two broken sucker rod ends spliced together by the present invention;

Fig. 5 is a section on line 55 of Fig. 3, the sucker rod, however, not being shown;

Fig. 6 is a detail view showing the inner face of a wedge slip; and

Fig. 7 is a section on line 1-? of Fig. 1, showing typical proper relative diameters of sucker rod, pump tubing and splicer.

The splicer is shown in Figs. 3 and 4 to consist of a body IE3 made up of member I2 and sleeves I I and I3 at opposite ends thereof, body member I2 having pin ends I 4 adapted to screw thread into box ends I5 of duplicate end sleeve members II and I3. When the couplings of the string to be repaired are furnished with right hand threads, these members II and I3 are screw threaded to member I2 with left hand threads |3a for a purpose which will appear hereinafter.

Since the present embodiment sleeve members I I and I3 and their contained parts are duplicates, a detailed description of the lower member l3 and its contained parts will suffice for both, although it will be understood that it is not essential to certain aspects of the invention that duplicate ends be used on the splicer. The parts of 'theupper sleeve will be given primed numbers corresponding to the numbers of the similar part of'the lower sleeve.

Sleeve member I 3 has an inwardly and upwardly diverging tapered bore ll leading from its outer or' lower end, the taper of said bore preferably, though not necessarily, terminating short of the screw threads of its inner or box end, as shown. The-outer end of said sleeve is inwardly beveled, as at I8, to form a conical mouth adapted to receive the sucker rod end and guide it into bore IT, as will appear. Within said tapered bore I I are segmental wedge slips 20. While any desired number of complementary slip segments may be used, I have illustrated them as two in number.

In the form of my invention here illustrated, wedge slips 20 are formed at their inner ends with inwardly projecting flanges 2I which are adapted to be received in an outwardly facing annular groove 22 of slip-carrier ring 23, which is of a diameter to move freely through bore II. The ring flange 24, that defines groove 22 is received in an annular groove 24a cut in the slip immediately below the flange 23. The carrier thus holds the slip segments from relative longitudinal movement though leaving them free for limited relative radial movement. A compression spring 25 is disposed between an annular seat 26 on the adjacent end of central body member I2 and an annular shoulder 2! on slip carrier 23, and acts at all times to force the wedge slips towards the reduced end of the tapered bore and therefore toward contracted or gripping position. Spring 25 is centered within the relatively larger bore 29 of member I2 by depending annular flange 33, which defines the lower end of relatively reduced axial bore 32 extending upwardly in member I 2 to provide a socket for taking, with slight clearance, the upper end of a broken sucker rod.

It will be understood that in the embodiment here illustrated the two ends of body portion I2 are symmetrical. Thus sucker rod sockets 32 and 32' extend inwardly from opposite ends. Preferably a central wall or head 34 is left between the inner ends of sockets 32 and 32', the purpose of which is to provide abutment filters against which the rod ends may engage to enable the rods easily to be positioned properly in the splicer, though this particular positioning provision is not essential to the invention considered in its broader aspects.

The inner arcuate faces 20a of slip 20 are out with rod engaging teeth or serrations 36. These teeth point inwardly with reference to the sleeve so as to grip the sucker rod against removal, and are cut diagonally relative to their longitudinal axis so as resist relative rotation of the rod within the slips. In the form illustrated the teeth on each slip are cut in sets of diagonal rows running diagonally in two directions and meeting to form a vertical line of rod engaging points 31 which are directed against withdrawal of the rod from the splicer, as clearly shown.

The slips are preferably splined in the tapered bore in order to hold them against rotation with relation to the sleeve. For instance, the tapered bore is shown as cut with diametrically opposite longitudinal grooves 38 within which keys 39 are Welded or otherwise suitably secured. The outer faces of the slips are provided with key-ways II! to take these keys, whereby the slips are held against rotation, but are free to move longitudinally with respect to their respective sleeves. Since the diagonal slip teeth prevent rotation between rod and slip, it will be seen that relative rotation between rods and sleeves is prevented.

In the preferred form of my invention here illustrated, the inner ends of the wedge slips engage the non-contractible, carriers 23, although it will be understood that this provision is not limitative on the invention. Where such a carrier is used, it will be noticed that flanges 2| and 24 on the slip and carrier, respectively, are less in thickness than the width of grooves 22 and 24a in which they are received, giving a loose connection whereby the slips are capable of limited pivotal movement on the lower flange 24 of the ring as the slips are moved toward the restricted outer end of the tapered bore. To permit such pivotal action inwardly toward one another the slips are given the necessary clearance between their side edges, as indicated at 42. The normal diameter of the bore defined by the slips is such as to pass the sucker rod when the slips are moved upwardly, from the position of Fig. 3 lower end. As the slips subsequently tend to move toward the reduced end of the bore, the tapered walls of bore II cause them to contract, pivoting inwardly on the ring flange 24, whereupon the teeth of the slip are moved into rod gripping position.

In the position of the parts in the lower sleeve of Fig. 3, the slips are moved their maximum distance towards the reduced end of the bore, their movement in that direction being limited by the non-contractible portion of the slip unit immediately about the carrier coming into engagement with the tapered wall surface. In this position the slips are contracted and the diameter of the bore defined by the slip teeth is slightly less than the diameter of a sucker rod.

The method of splicing a sucker rod in a well tubing without raising the lower sucker rod section will now be explained. Figs. 1 and 2 show conventionally a well tubing 8Q with a pump plunger 6| adapted to be reciprocated through the working barrel in the pump shell am at the lower end thereof, by means of a string of sucker rods 62 coupled together at 63. The sucker rod string is shown broken, the lower end of the broken rod, left in the tubing, being indicated at 62a, and the upper end of the broken rod being indicated at 62b. Rod section 6217 is first withdrawn from the tubing by pulling the string of rods thereabove, as usual. The lower end of broken section 62b is then engaged with the splicer as follows. Sleeve II, into which the rod ehd is to be inserted is preferably first unscrewed from member l2 a few turns (see the upper sleeve in Fig. 3). The lower end of rod section 521) is then inserted between the inwardly beveled outer ends 5| of the slips and forced inwardly, the slips giving inwardly against spring 25, and expanding radially as they move through the diverging bore of the sleeve. A comparatively short inwardly longitudinal movement of the slips permits them to expand radially sufficiently for the rod to be forced through and on until its end engages the shoulder formed by central abutment 34. The rod is then fully home in socket 32' of the body member 52, and, due to the engagement of the slip teeth with the rod, a subsequent pull on rod 62b tends to wedge the slips between tapered wall I! and the rod and thus clamp the rod within the splicer. Spring 25 prevents the slips from dropping except under pressure from the rod and has a constant tendency to wedge the slips into tighter wedging engagement with the rod. The parts are then in the positions illustrated at the upper end of Fig. 3.

The sleeve is then screwed fully home (Fig. 4), with the result that the tapered bore thereof forces the slips radially inwardly into tighter gripping engagement with the rod and causes the slip teeth to bite further into the rod.

The rod cannot subsequently be withdrawn from the splicer without unscrewing sleeve H and permitting the slips to expand. Moreover, the characteristic formation of the slip teeth prevent rotation of the rod within the slips, while the splined connection between the slips and sleeve prevents rotation of the slips within the sleeve, and hence of the rod with relation to the sleeve.

Section 621), with the splicer attached as above, is then lowered on the end of the sucker rod string in the manner shown in Fig. 1. However, sleeve I3 is screwed home on pin l4 before the splicer is lowered. The largest exterior diameter of the splicer is sufficiently small compared to the diameter of the pump tubing that the splicer will not materially interfere with passage of the oil therepast in subsequent pumping, but the lower inwardly beveled mouth of the splicer is sufiiciently wide to gather in the upper end of rod section 62a without difliculty. In case the sucker rod is against the wall of the pump tubing, the inward bevel of the splicer mouth assures the gathering of the rod into the splicer, particularly since the relation of the inside diameter of the tubing, and the outside diameter of the rod and the outside diameter of the body It! is such that the splicer cannot pass the end of the broken rod section. In other words, the diameter of splicer body It plus the diameter of the rod is greater than the inside diameter of the tubing, so that in all possible relative positions of the rod and splicer body as the latter is lowered the splicer must engage the rod and be prevented from passing. Suitable relative diameters for the rod, splicer and well tubing to accomplish this result are indicated in Fig. 7.

The splicer is thus lowered until the end of rod section 62a is within the splicer mouth, and is then further lowered to force wedge slips 20 up against spring 25 until they will take the rod, as described in connection with application of the splicer to section 6212, whereupon the splicer moves down until its abutment 34 is engaged by the rod end. A subsequent pull on the rod above the splicer, aided by the action of spring 25, wedges the slips between sleeve l3 and the rod,

also as described in connection with the application of the other end of the splicer, and rod section 62a is thus securely gripped within the splicer, the upwardly pointing slip teeth preventing separation of the lower sucker rod section and the splicer, and the diagonal direction of the teeth and the splined connection 39, 40 between the slips and the sleeve preventing rotation of the rods within the splicer, so that the two rod ends are rigidly held against both relative longitudinal movement and relative rotation.

Since the rods are thus held against swiveling within the splicer, and for the further reason that left handed screw threads are provided between the several sections of the splicer (assuming couplings 63 are threaded right handedly), the sucker rod string can be rotated left handedly to carry out back-01f on screwing operation either above or below the splicer without regard for the presence of the splicer, since the left handed rotation employed in backing-off is in the direction tending to tighten the splicer sections. Of course, if couplings 63 are threaded left-handedly as is sometimes the case, the splicer sections will be coupled by right-hand threads.

It will be noticed that the ends of sections 62a and 621) within the splicer are separated only a slight distance and accordingly the distance between the joints 63 of the spliced sucker rod is substantially the same as it was before the break. Also, since the repair operation has not necessitated the pulling of the pump plunger and the subsequent stretching of rods, the total length of the string is substantially the same after the break as before, and pumping operations can immediately proceed without necessity of further adjustment of sucker rod length. Furthermore, since the lower sucker rod section is not pulled, the repairing operation is accomplished without losing the column of oil back into the well, and production therefore immediately proceeds from the point at which it left off when the rod break occurs.

While I have described the splicer as being symmetrical, it will be understood such symmetry is not essential to the invention, considered in its broader aspects, in which, for instance, the illustrated grip for attachment to rod section 6% may be considered merely as illustrative of any type of rod clamp suitable for the purpose. particularly since this attachment is made when the splicer is accessible for adjustment and application, as distinguished from the blind grappling accomplished by the lower end of the splicer.

It will be understood that the drawing and description are to be considered merely as illustrative rather than restrictive upon the broader claim appended hereto, for various changes in design, structure and arrangement may be made without departing from the spirit and scope of said claim.

I claim:

The method of reconnecting in a well a severed pump rod normally operating a pump plunger having a predetermined stroke without removing the plunger and its attached broken rod section from the well, without substantially affecting the original pump rod length or the plunger stroke, and without disturbing the column of fluid standing above the plunger; which consists in removing the upper severed rod section from the well without disturbing the lower severed rod section and its associated parts;

aifixing a grappling coupling to the broken off lower end of said upper section without any substantial change in that section; lowering the said upper rod section and grappling coupling into the well; and operatively connecting said grappling coupling with the broken off end of said lower rod section without disturbing said lower rod section or its attached plunger, to bring the two parted rod ends into end to end and closely adjacent relation, to permit resumption of pumping operations, with said pump rod retaining substantially its normal length, with the pump plunger travelling its normal predetermined stroke, and without disturbing or losing back into the well the column of fluid standing above the plunger.

HARRY L. LAUGHINGHOUSE.

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