US2767794A - Oil well packer construction - Google Patents

Description

Oct. 2-3, 1956 J. LYNES 2,767,794

OIL WEZL PACKER CONSTRUCTION Filed Jan. 17, 1955 5 Sheets-Sheet l JOA 5 F1 j ATTORNEYS Oct. 23, 1956 J. LYNES OIL WELL PACKER CONSTRUCTION 3 Sheets-Sheet 2 Filed Jan. 17, 1955 65, INVENTOR,

(ATTORNEYS Jo/m Cyn BY fm O D 8 w 4 e o 5 M p 0 b 0 3 2 a J 4 w Oct. 23, 19516 J. LYNES 2,767,794

OIL WELL PACKER CONSTRUCTION Filed Jan. 17, 1955 I v s Sheets-Sheet 5 IMlENTOR,

aATTORNEYfi United States Patent OIL WELL PACKER CONSTRUCTION John Lynes, Albuquerque, N. Mex., assignor to Oil Recover-y Corporation, Albuquerque, N. Mex., a corporation of New Mexico Application January 17, 1955, Serial N 0. 482,145

7 Claims. (Cl. 166-196) This invention relates to a new and improved packer construction for oil and gas well tools useful in the sealing off of oil bearing formations for the purposes of treating them in order to render them productive, and to. recover the oil therefrom.

The present specification covers a tool which, generallyspeaking, has the same objects and advantages as those mentioned in my prior copending application Serial No. 307,958, filed September 5, 1952, entitled Oil Well Tool, in my prior copending application Serial No. 3,41 ,896, filed March 12, 1953, entitled Oil Well Treating and Production Tool, in my prior copending application Serial No. 374,888, filed August 18, 1953, entitled Packer Construction for Oil Well Tools, in my prior copending application Serial No. 445,411, filed July 23, 1954', entitled Oil Well Packer Construction and in my prior copending application Serial No. 445,412, filed Iuly 23', 19.514, entitled Oil Well Packer Construction, of which applications this application constitutes a continuationvin-part. The disclosures of said applications are hereby incorporated herein by this reference. In the order given, these became patented on March 13, 1956. under the following numbers: 2,738,013; 2,738,018; 2,738,017; 2,738,014 and 2,738,015.

'As previously explained, many valuable oil bearing formations are never successfully exploited after their discovery because of the great difiiculty of gaining access to them. According to modern rotary drilling methods acolumn of drilling fluid or mud is present in the well which. presents a formidable barrier to the driller in sealing off and gaining access to a productive formation which would produce if the proper conditions were present. Many packer tools have been devised to produce conditions favorable to recovery, but these have failed to; keep Pace with the progress made in drilling deep wells where pressures and temperatures deter the successful operation of such tools and make them shortlived.

Packer tools usually are designed to seal off a formation from the well liquids above and below it, by means of locating expansible members above and below the selected formation. When actuated, these members are intended to enlarge into contact with thebore hole to efiect the seals. If this operation is successful, the formation may be relieved of the inhibiting pressures presented by tluid in the bore hole, and the oil induced to flow into ducts. contained in the tool between the packers, then to the surface. Preliminar-ily, treating fluids, such as acids, may be injected into the selected formation to break it d w Providing. a tool which 'will operate accordingly has proved exceedingly difficult.

A particular. object of the present invention relates to important improvements in the packer construction which renders such packers more rugged and capable of successfuland sure operation.

As wi-llbe understood from my prior applications listed phone, the packer component must comprise a resilient 2,767,794 Patented Oct. 23, 19 56 element of rubber or a rubber-like substitute which must be enlarged with great force into. contact with the bore hole walls in order to provide an effective seal. Accord? ing to my prior inventions, I prefer to use a special type of packer. element consisting of plural layers of resilient compressible material, each layer being bonded or vulcanized to its adjacent layers at the ends of the packer, each layer having an open seam longitudinally of its body. These seams are located to avoid overlapping, and where necessary to insure this result, the seam may be omitted from the outer ply. The plies, if desired, may be formed of materials of differing elasticity in order to achieve the best results.

A packerelement so constructed is capable of lateral enlargement when compressed longitudinally, which I accomplish by means of an hydraulically operated piston forcing the packer to bunch or wad together on its supporting means, the result being that its center portion enlarges laterally into firm contact with the well walls. In contrast to most packers which operate by hydraulic inflation the packer of my invention is not subject to as much internal stress and hence lasts longer.

Furthermore, the capability of my packer constructionto enlarge from a small diameter to a relatively large one is highly satisfactory. The packer may be constructed to a small initial diameter which insures that it may be lowered into a well of any usual size without jamming. It may then be enlarged to an extent of which conventional packers are incapable. For example, a packer constructed according to my invention will enlarge from a diameter of 4 inches to 8 /2 inches upon the application of 2,000 lbs. pressure p. s. i.

A particular problem, to which this invention is re lated, has been to confine the packer ends so that longi tudinal compression of the packer will not cause the material to escape from the compressive force exerted between the piston and the body member providing the support points for the packer ends. If the packer ends were not confined, this compressive force would be dissipated and the consequent wadding action of the packer body would be lost, and the packer would not achieve suf ficient expansion in a lateral direction to engage the, well walls. Further, rupture or tearing of the packer material would inevitably occur.

In my aforesaid prior applications, I have disclosed means for confining the packer ends which take the form of collars of various design, among the common characteristics of said collars being that they overlie or overlap the packer ends, and that they contain, in some form, one or more resilient elements tending to exert pressure against the lateral enlargement of the packer. Each of these collars operates so as to expand along with the packer material in the manner of an enlarging cone,-the internal ends of the'collars finally making contact with the walls of the bore hole, thus presenting a bridge from the tool to the bore hole walls confining and preventing the escape of the flexible material of the packer elements.

According to the present invention I provide other means for the same general purpose which are also of unique design. These means may be described as ex pansible knuckle-jointed collars composed of a plurality of medially pivoted links, located closely adjacent, but not overlapping, the respective packer ends.

These collar means require no resilient elements and have other'advantages. Among them is the unique design of the respective links which define a complete cylinder whenclosed, in which condition the collars are substantially the sameouter diameter as the tool body, and present no projecting surfaces likely to jam in the well when it, is being lowered or raised therein.

The collar links are furthermore designedv in ashape and mounted in a manner to be described in more detail, which minimizes the efiect of the gaps which become present when they are jack-knifed into open or operative position. The collars therefore present a maximum amount of uninterrupted surface area acting as a barrier to the escape of the packer material.

Cooperating with these collars is a stop sleeve which both maintains the jointed links in slightly bent position, so that they will spring open outwardly without jamming, and also limits the amount to which the collars can jackknife open, the limit being selectively adjustable to the diameter of any well bore by using sleeves of various lengths.

The collars of the present invention are furthermore immediately susceptible to the pressure delivered by the piston at the beginning of its stroke, so that they jackknife open prior to the time of delivery of any appreciable pressure to the packers, and are thus in expanded or operative position against the walls of the well long before any longitudinal compression of the packers tends to cause the latter to seek to escape or telescope along the tool. When in open position, the collar knuckles are designed to slide along in contact with the walls of the bore hole until the piston has completed its stroke, at all times presenting ring-like barriers to the ends of the packer elements disposed between.

More precise advantages of the invention will be explained in connection with the drawing, wherein:

Fig. 1 shows in perspective two views of a tool embodying the invention, as they would appear if located in bore holes of oil wells adjacent a formation selected for operations, the tool at the left being shown prior to actuation of the packers, the tool to the right being shown after the packers have made contact with the bore hole above and below a selected formation;

Fig. 2 is an elevation, with parts in section, of a packer unit embodying the invention, the unit being in collapsed or inoperative condition;

Fig. 3 is an elevation similar to Fig. 2, with parts in section, of the packer unit in enlarged or operative condition with the knuckle-jointed collars expanded against the walls of a bore hole;

Fig. 4 is an exploded view, partly in perspective, of elements of the knuckle-jointed collar, seven of the eight jointed linkages being omitted for clarity, the top and bottom ring mounts being in plan view;

Fig. 5 is a diagrammatic end view of two links of the knuckle-jointed collar assembly, slightly opened to show the design and shape of the collar links; and

Fig. 6 is a sectional view on lines 66 of Fig. 2 showing the multi-ply split sleeve construction of the packer member.

The invention is illustrated in Fig. 1 as a tool suspended in bore holes and 21 (the bore holes being shown in section), from a string of supporting pipe 27. The tool as shown is composed of two packer units 23 and 24 located above and below a formation 22 selected for exploitation. The tool in bore hole 20 is shown as it would appear just subsequent to lowering in the well to the desired location, with packer units 23 and 24 in collapsed condition. The tool in bore hole 21 has been actuated so that packers 23 and 24 are providing effective seals in the well above and below formation 22, whereupon formation 22 may be treated or produced through central ports 26.

The control means whereby the packers are actuated and whereby ports 26 are operated do not form a direct part of the present invention, and may be those control means described in my Serial No. 307,958 or my Serial No. 341,896, now Patent 2,738,018. Of these means it sufiicies to say that in the lowering position of the tool shown in bore hole 20, fluid pressure may be delivered through pipes 27 and through a port system to cylinders formed in body members 28 and 29 and containing ring-type packer operating pistons to actuate the 4 packers. With the packers actuated, as in bore hole 21, the tool is locked in the bore hole, and pipe 25 may then be shifted relative to the tool to close off the packer cylinders with the pressure retained therein, and at the same time the central ports 26 are opened to formation 22. At this stage a fluid line connection exist between formation 22, via ports 26, and pipes 25 and 27 to the top of the well, whereupon treating or production operations may take place. A return shifting of pipe 25 relative to the tool will close ports 26 and open the port system to the packer cylinders, relieving the pressure and returning the packers 23 and 24 to a collapsed condition.

In Figs. 2 and 3, I show a packer unit 23 in enlarged scale, it being understood that the construction of packer unit 24 of Fig. 1 is substantially the same. The packer unit 23 is suspended from the inner pipe 25 which in turn is coupled to supporting pipe 27, shown in Fig. 1.

Each packer unit comprises an upper body member 39 and a lower body member 28 held in spaced relationship by a mandrel 31 externally of pipe 25. The lower body member is formed with an internal recess which constitutes a ring-type cylinder containing ring-type piston 32, to which fluid pressure may be delivered from inner pipe 25 by port means described above but not shown in these views.

As seen in Figs. 2, 3 and 6, the resilient compressible packer element of unit 23 is composed of a plurality of overlapping plies of material, three being illustrated at 34, and 36. The ends of these plies are secured together, or preferably bonded, as by vulcanization. Preferably, between each bonded end each ply is provided with a longitudinal split seam, ply 34 having seam 39, ply 35 having seam and ply 36 having seam 41. These seams are arranged on alternate sides per layer, or at least so arranged that the seams of adjacent plies will not register or overlap. The purpose of these seams is to aid in the lateral expansion of the packer unit, whereas the open seams are staggered in adjacent plies to prevent undue entry of well fluid between the plies. Under some conditions it may be desirable to omit the seam 39 in the outer ply; however, the presence of the seams in the internal plies is very important to the expansible qualities of the packer element, when compressed in the longitudinal direction.

Packer 23 is slidably mounted externally of mandrel 31 and pipe 25. The ends of packer 23 are preferably confined to a limited extent by the end bands 4243, Figs. 2-3.

With the construction so far described, it will be understood that when the piston is actuated, the packer 23 will be subjected to a powerful compressive force longitudinally of the tool so that it will wad together in the manner of an accordion and be forced against the bore hole walls. During this movement the packer unit would tend to splay out or tear loose from its fastenings so far described, without additional collar means to confine them.

The collar construction of the present invention comprises upper and lower knuckle-jointed collar members 45 and 45a mounted on mandrel 31 above and below packer 23. The upper ring mount 46 of collar 45 is threaded to upper housing 30, whereas lower ring mount 47 is slidable on mandrel 31 and normally abuts the up per end of packer 23. Pivoted to rings 46 and 47 are pairs of links, eight pairs being shown, the shape of which may best be seen in Figs. 4 and 5. Each pair of links consists of an upper link 48 and a lower link 50 jointed to the rings 46 and 47 by lugs 51 and 52, and pins 53. Links 48 and 50, of equal length, form knuckle-joints 60 at the connection made by lugs 54, 55 and pin 56.

Links 4850 straddle a stop sleeve 57 (Figs. 2-3) which is slidably mounted on mandrel 31 between rings 46 and 47. Sleeve 57 is of less length than the distance between rings 46 and 47 when links 48-50 are in inoperative or closed position, as shown in Fig. 2, leaving the gaps or spaces indicated at 5,8, 59. When these spaces are closed by the Operation of collar 45, as shown in Fig. 3, the joints 6t cannot jack-knife any further away from the tool body. The length of, sleeve 57 may con,- sequently be pre-selected to limit the amount of enlargement of the collar 45.

It will also be noted that sleeve 57 is progressively slightly thicker toward its midsection, so that the links 48-50, when in collapsed condition, as shown in Fig. 2, nevertheless form a slight outward angle from the perpendicular, to prevent joints 60 from locking when the collar is actuated.

Referring further to Figs. 4 and 5, the unique sectional shape and mounting. of the links 48-50 should be noted. It should be understood that a ring of such link pairs, eight being needed to form a complete ring, form a perfeet cylinder when in closed position. Each link is formed with outer and inner arcuate walls which are not radially aligned with the axis of the cylinder, these arcuate walls being connected by flat surfaces cut non-radially to the axis of the cylinder.

This construction should be contrasted to the more obvious mode of forming such links, i. e., as mere pieshaped segments of a cylinder with abutting flat side walls being formed in the direction of the cylinder axis. Such a construction, when the joints were expanded, would fan open and the separated joints would provide gaps leading directly into the body of the collar. With such a condition present, under the great pressures present in the wall, and also exerted on the packer material by the operation of the tool, the collar would tend to become clogged with packer material entering such gaps, and also by entry of solids from the well.

By the collar construction according to the invention, however, the gaps between links when the collar is actuated tend to take the shape shown by gap 65, Fig. 5, the inner space between the links remaining substantially closed. It is thus clear that this construction, when operated as in Fig. 3, continues to form a substantially more eificient blockade for the packer material forced against it.

The construction of lower collar 45a is substantially similar to that of collar 45, except that its mounting is reversed in the sense that upper ring mount 47a abutting packer 23 is slidable on mandrel 31, and lower ring mount 46a is threadedly connected to the head of piston 32' and is movable therewith. The parts of collar 45a which correspond to those of collar 45 carry the same reference numbers in Figs. 2 and 3 with the designator "a and hence require no further description.

It will be understood that the lower packer unit 24 shown in Fig. 1 is similarly equipped with collars 4545a of the nature just described.

An operating cycle will now be described. In Fig. 2 the packer unit 23 and its protective collars 45--45a are in collapsed condition, as the tool would appear during or after lowering it into the well bore 20. In this condition it will be noted that the tool presents a smooth appearance, the various parts assuming approximately the same diameter and offering no projecting parts which might jam in the well. Likewise, ample clearance between the tool diameter and well diameter is afforded.

Upon actuation of the piston 32, by means previously described, a compressive force is delivered by the piston 32 against the packer 23 and its collars 45--45a intervening between the piston and upper body member 30.

As soon as this force is applied, the resistance thereto being greater in the resilient packer, than in the collars, both collars will spring open, as shown in Fig. 3, to the extent permitted by the stop sleeves 57-57a, which as aforesaid are adjusted to the known diameter of the well being exploited, it being desirable that the collars be permitted to open to a diameter at the knuckles 60-60a slightly greater than the diameter of the bore.

This adjustment will insure on one hand that the collar knuckles open into effective engagement with the bore holewa ls thus presenting an effective barrier, while on the other hand they willv not expand to such an extent that the collars. gouge into and lock in the bore hole walls, preventing further movement of the piston.

Further movement of the piston will cause the packers to assume the position of packer 23, Fig. 3, the compressi-ve force of the piston having compressed the packer in a longitudinal direction, causing it to wad together in the manner of an accordion and consequently enlarge laterall-y into firm contact with the walls of bore hole 21. During this movement lower collar 45a will travel upwardly along with the piston in the. direction of the arrow, knuckle joints 6.0a being designed to slide a.ong the bore hole walls. The force exerted by piston 32 being very great, the flexible material of the packer 23 will develop a strong tendency to escape from the longitudinal com.- pression delivered to it. This tendency will be counteracted, however, by the presence of the expanded collars 45c.-45a, which present ruggedly constructed and effective barriers against escape of the packer material.

Release of the piston will cause the packer 23 and collars 45-45a to. collapse back into the condition shown in 2, whereupon the. tool may be withdrawn from or relocated inthe well.

The drawings are not intended to show precise scale. In particular it should be realized that the packer units actually constructed according to the invention are more elongated than shown, being, for example, nine feet overall in a tool of four-inch diameter, the piston being constructed for a stroke of five feet. Compared to the expansion characteristics of conventional packers which seldom are capable of expanding more than an inch in diameter, and hence have to be made in many sizes with scant clearance in the bore hole, the tool according to this invention may be constructed of an initial diameter of four inches and is capable of enlarging to a diameter of fifteen inches, this size being in excess of that needed in the largest bore holes drilled by standard tools.

What is claimed is:

1. In a well tool of the type described, a packer unit consisting of a pair of body members held in spaced relationship by a connecting member, said members being adapted for suspension in a well by a string of supporting pipe, one of said body members containing a cylinder and piston movable therein in the direction of said other body member, means for actuating said piston, a compressible resilient packer member disposed between said piston and said other body member, and means for confining the end sections of said packer member when the piston is actuated, each means comprising a collar member of links medially pivoted in pairs, said pairs of links being adapted to open into contact with the well upon actuation of the piston.

2. In a well tool or" the type described, a packer unit consisting of a pair of body members held in spaced relationship by a connecting member, said members being adapted for suspension in a well by a string of supporting pipe, one of said body members containing a cylinder and piston movable therein in the direction of said other body member, means for actuating said piston, a compressible resilient packer member disposed between said piston and said other body member, and means for confining the end sections of said packer member when the piston is actuated, each means comprising a collar supported on said connecting member adjacent each packer end, said collars being formed of a pair of rings connected by pairs of links formed with knuckle joints, said rings being movable toward each other on said connecting member upon actuation of the piston to force said knuckle joints into engagement with the well.

3. In a well tool of the type described, a packer unit consisting of a pair of body members held in spaced relationship by a connecting member, said members being adapted for suspension in a well by a string of supporting pipe, one of said body members containing a cylinder and piston movable therein in the direction of said other body member, means for actuating said piston, a compressible resilient packer member disposed between said piston and said other body member, and means for confining the end sections of said packer member when the piston is actuated, each means comprising a collar supported on said connecting member adjacent each packer end, said collars being formed of a pair of rings connected by pairs of links formed with knuckle joints, said rings being movable toward each other on said connecting member upon actuation of the piston to force said knuckle joints into engagement with the well, and a stop sleeve carried by said supporting member between said rings, said sleeve having a pre-selected length limiting the movement of said rings toward each other and consequently the angular movement of said knuckle joints in the direction of the surrounding well.

4. The invention according to claim 3, said stop sleeve having a center portion of enlarged diameter to prevent locking of said knuckle joints.

5. The invention according to claim 1, the links being formed to define a cylinder when in collapsed position, the abutting sides of said links being formed at angles out of radial alignment with the axis of the collar.

6. The invention according to claim 1, wherein the packer member is formed of a plurality of tubular overlapping plies of compressible material, the ends of said plies being secured together, and open seams formed substantially lengthwise in adjacent plies of said material, the seams in said adjacent plies being located to avoid substantial overlapping.

7. In a well tool of the type described, a packer unit consisting of a compressible resilient packer member, means for supporting said packer member from a string of supporting pipe, means carried by said supporting means for compressing said packer member longitudinally to force said packer to expand laterally into contact with the well, and a collar member carried by said supporting means adjacent each end of said packer, each said member being formed of links medially pivoted in pairs, said pairs of links opening into contact with the well to inhibit further longitudinal expansion of the packer material beyond the respective locations of said collar members when the means for compressing said packer is actuated.

References Cited in the file of this patent UNITED STATES PATENTS 235,712 Stewart Dec. 21, 1880 1,549,168 Townsend Aug. 11, 1925 2,196,658 Burt Apr. 9, 1940 2,643,722 Lynes et a1 June 30, 1953

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