US2103601A - Withdrawable sucker rod assembly - Google Patents

Description

28, 1937. w. H. STIG'ALL WI-THDRAWABLE SUCKER RO D ASSEMBLY 2 Sheets-Sheet 1 Filed Aug. 11, 1936 Dec. 28, 193?. w. H. STIGALL WITHDRAWABLE SUCKER ROD ASSEMBLY Filed Ailg. 11, 1936 ,2 Sheets-Sheet 2 Patented Dec. 28, 1937 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to pumping wells, and in particular to the type comprising a reciprocatory sucker rod assembly of the valved type operating within a casing, and by way of comparison 5 with prior art devices, the novelty resides chiefly in an especially constructed sectional sucker rod assembly, the major portion of which is susceptible of being withdrawn from the casing if and when the valve 10 in place. 7 I

Stated otherwise, the invention in particular is used in conjunction with sucker rods in pumping wells and provides a positive means for releasing the rod from the pump when the pump 15 becomes sanded or the standing valve stuck, making it substantially impossible to pull the pump. The incorporation of the invention in the substantially otherwise standardized assembly makes it possible to release the rod from the pump without the danger of loosening any sucker rod joints above the release device, since the releasing action is accomplished by turning the rod in a right-hand or'clock-wise direction simultaneously tightening all of the joints with the exception of the releasable special joint forming a part of the arrangement.

It is a matter of common knowledge that when a pump is ordinarily being pulled, many of the sections of the sucker rod are apt to become accidentally disconnected and drop into the well casing, causing the tubing and sometimes the casing to part. This necessitates resorting to expensive fishing jobs. The common method now in use in unscrewing rods is by turning them to n the left or anti-clockwise which gives them a chance to break at each joint or approximately every'30 feet. Thus is created a hazard of rods and other accompanying disadvantages. The use of thefpresent invention makes it possible to remove substantially all of the rods or sections in the sucker rod assembly. by simple separable means, thus saving two or three hours time on each stripping job according to the depth of the well.

Briefly described, the preferred embodiment of the invention comprises latch-equipped separa- 'ble joint means'located just above the valve at the bottom of the well, said means coming automatically into play when the entire sucker rod, as a unit, is turned in a clockwise direction whereby to allow all .of the rod sections above said latch-equipped joint to be satisfactorily pulled.

Other features and advantages will become more readily apparent from the following description and drawings.

becomes sanded and stuck In the drawings, wherein like numerals are employed to designate corresponding parts throughout the views:

Figure 1 is a view partly in section and partly in elevation showing a well casing and reciprocatory pump or sucker rod assembly embodied there'- in and including the improved automatically releasable coupling or joint.

Figure 2 is a view showing the disconnectible parts of the coupling or joint separated.

Figure 3 is an elevational view of the double oppositely threaded member. forming an important part of the latch-equipped coupling or joint.

Figure 4 is a top plan view of the part shown in Figure 3. I

Figure 5 is a longitudinal sectional view through the double threaded upper section or member of the joint structure.

Figure 6 is a top plan view of said upper section, that is, the part shown in Figure 5.

Figure '7 is a perspective view of the T-shaped latch or key.

, Figure 8 is an enlarged sectional and elevational view showing the parts and the key or latch in its normal part-locking position.

Figure 9 is a longitudinal section through the right hand threaded lower member or section ofthe releasable joint structure.

Figure 10 is a sectional view of the spring accommodation or adapter cup.

Figure 11 is an elevational view of the latch thrust or operating member.

Figure 12 is a cross-section taken approximately on the plane of the line l2-- l2 of Figure 8.

Attention isfirst invited to Figure 1 wherein it will'be observed that the pump or well casing is denoted by the numeral l3. This part is of conventional form. So is the so-called sucker rod assembly I l. That is to say, this is of the reciprocatory type and serves to operate a traveling valve at the bottom of the well (not shown). As is customary, it is composed'of a plurality of sections l5 which in the present instance are all joined together by right hand screw threads. The only exception to this is the left hand screw threads appearing as a part of special automatically releasable coupling or joint meansunitarily denoted by the numeral Iii. This means l6 comprises an internally screw-thread lower coupling member or sleeve [1 which is shown in Figure 9 and is provided with right hand screw threads l8. Threaded into this is the correspondingly threaded head IQ of the thrust rod 20 which is in ,effect a trip member. This has right hand threaded connections 2 I with a suitable union 22 which in turn connects with the operating means for the reciprocatory valve (not shown).

The right hand screw-threaded extension 23 on the lower end of the intermediate section or part 24 of the joint structure threads into the upper correspondingly threaded end of said sleeve IT as shown in Figure 8. This part 24 is longitudinally bored to accommodate the rod or stem 25 of the T-shaped latch. The upper head 26 on the rod is normally seated in a, keeper notch- 21 formed on the extreme upper end or projection 28 of the extension 29 on the upper end of the intermediate coupling member 24. This part 29 is formed with left hand screw threads which tap into the correspondingly threaded lower end.

' keyways for the projecting ends of the key or latch head 26;. The lower. end of the latch rod 25 projects down into the screw-threaded portion of the sleeve I! where it is secured by a pinto a spring accommodation socket or cup 36. The spring is indicated at .i'l and isa suitable coil spring and surrounds the lower end of the stem or rod 25, one end resting in' the cup 36 and the other end bearing against the plug-like. extension 23. The result is that this spring is. normally tensioned to keep the latch in the locking position shown in Figure 8, at which time the head 28 is located in the notch 21 with the'ends thereof projecting into the keyways 35. This looks the left hand screw-threaded parts temporarilyor normally together, so that when the parts are as shown in Figure 8 the entire sucker rod can be bodily turned in a direction toward the right, that is clockwise, without affecting the left handed screw-threaded connection, that is, the features 29 and 30.

Whenever it is necessary to pull the pump rod, thatris, the sucker rod assembly above the joint l6, which is necessary when the valve. becomes stuck, it is obvious that the entire string including sections l5 isv turned bodily in a right hand 'direction which in eifect tightens all of the threaded connections between the respective'sections or parts l5. By referring to Figure 8, it will be observed that while this rotary movement is carried out, the joint l6 feeds down in relation to the trip or thrust rod 28. That is to say, the sleeve l'l threads down on the head l9. In due time the head l9 comes into contact with the spring-pressed cup 36 and presses the latch rod 25 upwardly. At a predetermined time the looking or connecting latch head 26 rides out of the keeper notches 21. Continued rotation of the sucker rod in the same direction thus unscrews the. part 3! from the part 24, as is obvious, allowing the sucker rod to break from the lower portion thereof, as shown for example in, Figure 2, so that it can be pulled out from, the casing. In this way all of the sections appearing above the joint I6, as shown in Figure 2, can be retrieved in an obvious and reliable manner.

In order that the succeeding claims may be more satisfactorily interpreted, it may be stated that the major portion of the sucker rod as-. sembly above the special releasing joint l6 can be conveniently referred to as the upper portion of the pump rod or removable part thereof. The part below the'joint i6, which is relatively stationary because of binding or anchorage from sticking, may be either referred to as the non.- removable or lower part of said pump rod. The joint I6 between the two parts is an automatically releasable operating connection.

It is thought that the description taken in connection with the drawings will enable a clear understanding of the invention to be had. Therefore, a more lengthy description is thought unnecessary.

While the preferred embodiment of the invention has been shown and described, it is to be understood that minor changes coming within the field of invention claimed may be resorted to if desired.

'I claim: V V

1. In a structure of the class described, a sucker rod construction including a plurality of complemental. sections joined by right hand. screwthreaded joints, an upper coupling member carried. on. the lowermost'section of said sucker rod construction and provided with an internal screw-threaded socket, the threads being: left handed, a second longitudinally spaced. axially alined lower coupling member in the form of a sleeve internally screw-threaded with right hand threads, a trip device comprising a rod having a.

screw-threaded head threaded into said sleeve, a jointing member between said upper and lower coupling members, Said jointing member being longitudinallybored and: having a threadedextension at its lower end, the threads of which are right. handed and tapped into the right hand threads in said sleeve, said jointing member being rovided at its upper end with a similar extension' having left hand threads tapped into said correspondingly threaded socket, said upper coupler member being provided with a central bore and keyway, a reciprocatory spring-pressed latch member mounted in the bore in said jointing member and provided at its upper end with a cross-head normally connected with said jointing member, whereby to permit said parts to be separated automatically under predetermined rotative conditions. 7 Q

2. In a Safety joint. for a sucker rod assembly of the class described an intermediate jointing member longitudinally bored and provided at its upper-end with a screw-threaded extension, the threads of which are left handed, said extension being provided with a projection having keeper notches formed therein, the lower end ofsaid member being provided was a screw-threaded extension, the threads of which are right handed, a rod mounted for sliding in said bore and provided at its upper end with a crossehead located in said notches, spring retention means 7 connected to the lower end of said rod to hold the cross-head in said notches, a sleeve having right hand threads threadedly connected to the lower extension on said jointing member, a thrust rod having a right hand screw-threaded head mounted in said sleeve for engagement with the springequipped end of said latch rod, an upper coupling member having right hand threads at its top connectible' with an adjacent section of the sucker rod assembly, and having a screw-threaded socket at its lower end, the threads of which are left handed and connected with the extension on the adjacent upper end of said jointing member, the intermediate portion of said upper coupling member being provided with diametrically opposite keyways into which the end portions of said head project to normally look the several parts of the coupling together, said head being releasable from the keeper notches upon threading the sleeve down on the head of said trip rod in themanner and for the purposes described.

3. As a component part of an assemblage of the class described, a sucker rod and traveling valve jointing assembly comprising a jointing member longitudinally bored and provided at its upper end with a screw-threaded extension, the threads of which are left-handed, said extension terminating with a projection having keeper notches, the lower end of said jointing member being provided with a screw-threaded extension, the threads of which are right-handed, a latch rod slidably mounted in said bore and provided at its upper end with a cross-head located in said keeper notches, the ends of said head extending outwardly beyond said notches, the lower end of said rod extending downwardly beyond the adjacent screw-threaded extension, an abutment on the lower end of said rod, a coiled spring surrounding the lower end portion of the rod and bearing at its lower end against said abutment and at its opposite end against the adjacent screw-threaded extension to hold said cross-head in said keeper notches, a sleeve having internal right-hand screw-threads separably joined to the lower extension on said jointing member, and a trip rod having a screw-threaded portion threaded into said sleeve in a position to engage the spring-equipped end of said latch rod in the manner and for the purposes described.

WILLIAM H. STIGALL.

Images