US2518275A - Well swab - Google Patents

Description

Aug. 8, 1950 Filed July 18, 1947 H. E. B'OWERMA-N 2,518,275

WELL SWAB 2 Sheets-Sheet 1 1950 H; E. BOWERMAN 2,518,275

mu. SWAB Filed July 18. 1947 2 Sheets-Sheet 2 Patented Aug. 8, 1950 UNITED STATES PATENT OFFICE WELL SWAB Hulie E. Bowerman, Grand Prairie, Tex. Application July 18, 1947, Serial No. 761,773

3 Claims.

This invention relates to the art of well swabs, and more particularly to sealing members or cups of the basket type having rigid sections for carrying the loads encountered in deep wells and resilient sections whereby a working seal is effected between the supporting mandrels and the pipe through which the swabbing operation is carried on. Further the invention relates to novel arrangements of re-inforcing members or wires as related to the rigid sections and resilient sections of the cup; the details of which will later be pointed out.

In swabbing deep wells loads are encountered which frequently range above one thousand pounds pressure per square inch. It is therefore necessary to provide suitable supports for the resilient or sealing, sections and also to protect them from over expansion into such deformities as the spaces commonly occurring between ends of pipe sections within couplings. If

,this were not done the resilient sections might be sheared or torn oif upon forced passages of the swab over such points in the pipe string.

In the swabbing art, it has heretofore been a common practice to associate the cups or sealing members with mandrels which have fluid passages centrally disposed therethrough, and provided with ball checks or other such devices to prevent the escape of the fluid above the swab as it is moved upwardly through the pipe string.

In my invention I efiect this result with my replaceable cup member in a novel manner wherein the conventional ball or check valve is omitted.

cutting of the members at this point, which added destruction of the parts due to their initially defective functioning.

My invention provides for passage of the fluid between the cup and supporting mandrel; effective sealing of this passage, which sealing means is renewed with each replacement of one of these parts, and novel means for relating the reinforc- 2 ing wires to the rigid and resilient sections of the cups. These and other novel features will readily be understood, by those skilled in the art, from the following specification together with the accompanying drawings in which:

Fig. I is a phantom view of a swab cup mountedon a mandrel in the sealed or closed position;

Fig. II shows similar structure in the open position;

Fig. III shows a modified form of the cup and support shown in Fig. I;

Fig. IV shows still another modified form of my cup;

Fig. V shows yet another form of my cup assembly, fragmentally.

Fig. V1 is a method of joining a multiple number of units together;

Fig. VII is a section along line 'I-I of Fig. I;

Fig. VIII is a top plan view of one of the parts, while Fig. IX is a side elevation of same.

Fig. X is a top plan view of a modified form of the part shown in Fig. VIII, while Fig. XI is a side elevation of same.

Like references indicate similar parts in the several drawings, wherein; I5 is a mandrel provided with a threaded end section l6 and havin cup guide. members or projections l1 spaced about its periphery to provide fluid passages thereabout and through the cups as will be more fully pointed out later in this specification. The projections are provided with enlarged sections l8 which serve to limit the movement of the cup in one direction therealong. The opposite end of mandrel I5 is provided with a threaded section ISI for removably engaging a member 20 which serves as a support for the cup and provides a cooperating sealing contact therewith, which in Figs. 1, II, IV, and V1 is shown as a bevel-faced recess or groove 2|, while in Fig. III it is shown as a bevel-faced projection Me.

My cup includes a rigid member 22 provided with a projection 23 having openings 24 therein 1 for receiving reinforcing yieldable members or wires 25. Another projection 26 may be proprene, or other suitable material is molded about portions of the members 22 and 25, and serves to secure them in operable relation to each other and to the assembly, and extends upwardly to comprise an elongated or extended cup portion 3| for sealing engagement with a pipe section. not shown, and downwardly to form a sealing projecting contact as at 32 in Figs. I, II, IV, and VI, with recess 2| of element 20. This sealing contact is shown in Fig. III as a projection 2la of element 20 received by a recess or groove 2") of the resilient portion of the cup. In the several forms it will be noted that as the rigid members are brought together their surfaces approach in different planes thus impinging the resilient element therebetween with a wedge-likemotion to securely effect the seal. It will be observed from Fig. VII that fluid passages 33 are provided between my cup and mandrel. In the several views a shoulder 3| in resilient member 30 is shown, which engages with enlarged sections of pro,iec tions l8 of member I! to limit the movement of the cup upwardly of the swab assembly. In Fig.

V I have shown a ring 35 of smaller diameter than the cup body, having openin s 36 for receiving the upper ends of wires 25 which may be bent over as at 31 to secure the ring in assembled relation to the other elements of thecup.

This will also serve to secure the wires in predetermined position with reference to the mandrel and the pipe through which the swab is run, and is especiall valuable where light wires are used in connection with softer sealing elements in cases where swabbing is to be conducted in shallow wells and there is a light load to be lifted. Other of the views show the upper ends of wires 25 as being formed or bent inwardly so as not to engage with obstructions, such as joints in the pipe string. when being drawn through the latter. In either form the wires not only reinforce the resilient member, but act as a guide and protection for the entire assembly.

It will be particularly observed that the cross section of the resilient member at the point of sealing with support 20 is less than the body of the cup. This is important in effecting a working seal between the parts as later will more -fullv appear.

Elements 20 are shown in Fig. VI as having their lower ends threaded to receive the top threaded ends of IS of mandrels l5, and by this methodI can assemble as many sealing elements or cups as is desired, and each will have its seal independent of the other cups of the assembly. Heretofore conventional swabs provided a single 1 seal against the down passage of the fluid without regard for the number of cups employed. The assembly of the elements comprising my swab, and its operation is as follows:

I assemble wires 25 with one of be rigid elements 22 and mold'thereabout, the resilient element 30, then form the upper ends of wires 25 as desired, and assemble them with ring 35 if I am to use that form of assembly. Otherwise the operations are similar. I then pass the cup over the mandrel section I and threadedly engage element 20 therewith. My cup then may move freely along and upon projections II of the mandrel with the limits I8 and 2| (or 2|a as shown in Fig. 111) I will then assemble the number of units desired as indicated in Fig. VI, andto the top of this string of units I connect the customary sinker bar, as by threadedly engaging mandrel l5, at [6. The sinker bar is of course supported by the swabbing line. I now introduce the swab into the 'well pipe and as it passes downwardly therein and reaches the fluid, the friction of the sealing element with the .pipe and the supporting effect of the fluid will cause the cups to move up on the mandrels as shown in Fig. 11, whereupon the fluid rises through passages 33 (Fig. VII) between the cups and mandrels as the swab continues its downward motion to the depth desired. As the swab is started on its upward pass-age through the well pipe the friction of the sealin element with the pipe, and the downward pressure, and resistance of the fluid, will cause the cup to move into sealing engagement with element 20 at which moment the load above and inside the cup will cause it to expand and offer sealing engagement with the .pipe. This, at the same time, increases the c oss section of the resilient member and increases the friction with the pipe. As the seal is effected, the static head or pressure is relieved below the cup, and the weight of the fluid load and friction effect is passed down through passages 33 in the cup body between the projections I1 and increases the pressure at the point of seal between the cup annular ring 32, and the annular recess 2Ia of its support 22. cup body is greater than its sealing contact with the support, which latter is, in effect, the relatively thin section of resilient cup material im-..

pinged between the rigid element 22 of the cup and element 2|). It will be noted that in the modifications shown the rigid members 26 and 22 offer support to the resilient member 30 at the point of seal therebetween, and member 22 supports resilient member 30 in resisting pressures inside the cup and that wires 25, bearing directly against the pipe, also support-the resilient member and guide it past unevennesses in the pipe wall. I

It will be obvious to those skilled in the art that other modifications of my invention, than those shown herein, may be made without departing from the principles set forth above, and all such are meant to be included as fall within the scope of the following claims.

What I claim is:

1. A swab including a mandrel and a resilient cup moveably related and having a fluid passage therebetween, means for limiting said movement in one direction without closing the fluid passage, a second means for limiting said movement in the opposite direction and closing the fluid passage, the latter means having a sinuous recess for receiving a correspondingly shaped portion-of the cup whereby as the second means and cup are brought together their surfaces approach in different planes thus impinging the resilient cup therebetween with a wedge-like motion.

2. A swab including a mandrel and a cup movably related and having a fluid passage therebetween, the cup having a rigidportion and a resilient portion, means for limiting said movement in one direction, and a second means closing the fluid passage by impinging some of the resilient portion of the cup between its rigid portion and the second means, said second means havinga sinuous recess whereby as the second means and cup are brought together their surfaces approach in different planes thus impinging the resilient cup therebetween with a wedge like motion.

3. A swab including a mandrel and a cup moveably related and having a fluid passage therebetween, the cup having a rigid portion and a resilient portion, eans for limiting said move-.

The cross section of the ment in one direction, and a. second means clos- REFERENCES CITED ing the fluid passage by impinging some of the resilient portion of the cup between its rigid por- 2 3 g ig g are or record m m tion and the second means, said second means having a, sinuous recess whereby as the second UNITED STATES W means and cup are brought together their sur- Number I Name Date faces approach in diflerent planes thus imping- 1,695,406 Young Dec. 18, 1928 ing the resilient cup therebetween with a Wedge- 1,983,523 Crowell Dec. 11, 1934 like motion, the rigid portion of the cup having 2,144,997 Theheld Jan. 24, 1939 openings, and yieldable reinforcing members for 10 Y the cup. engaged with said openings.

' HULIE E. BOWERMAN.

Images