US2946388A - Well apparatus - Google Patents

Description

July 26, 1960 R. T. EVANS 2,946,388

WELL APPARATUS Filed Sept. l2, 1955 3 Sheets-Sheet 1 July 26, 1960 R. T. EVANS 946,38

WELL APPARATUS Filed Sept. 12, 1955 3 Sheets-Sheet 2 an w INVENTOR. Ff 5. B Haw/ 7.' Evans.

2,4 LV-,Wm Mmm/Ey.

R. T. EvANs 2,946,388

WELL APPARATUS 5 Sheets-Sheet 3 IN1/wrox. Rober! I Evans, 15:1/ 90nd A r TOR/ver.

FIG. 9.

FIG.

WELL APPARATUS Robert T. Evans, Duncan, Okla., assigner to Halliburton Oil Well Cementing Company, Duncan, kla.

Filed Sept. 12, 1955, Ser. No. 533,610

16 Claims. (Cl. 16o- 120) This invention relates to apparatus for use in oil and gas wells or the like and, more particularly, to a well packer and a releasable connection for coupling the packer in a string of equipment of the type which is lowered into a well bore.

It is a general object of this invention to provide an improved well packer assembly useful for eifecting a fluid-tight seal with the wall of a well bore into which the assembly has been lowered.

It is another object of this invention to provide an improved well packer which may be used as a retrievable bridge plug or with another packer in a straddle arrangement without an interconnecting pipe or tubing therebetween.

It is another object of the invention to provide an improved well packer and an improved releasable connection for coupling the packer in an equipment string of the type which is lowered into a well bore. v

It is another object of the invention to provide an improved well packer assembly including a packer and a releasable connection for coupling the packer to other apparatus, the connection being adapted to be selectively broken and formed, but only after the packer has been at least partially set or expanded.

VIt is another object of the invention to provide an irnproved well packer having provision whereby upon being set or expanded in a well bore it may be held in such set or expanded position and released or disconnected from apparatus included thereabove in the equipment string lowered into the well and, if desired, also having provision whereby it may thereafter be retrieved and withdrawn from the well bore or moved to another 1ocation therein.

It is another object of the invention to provide an improved releasable connection or safety joint for releasably coupling a well packer or other apparatus inan equipment string of the type which is lowered into a'well bore.

In accordance with the invention, two parts of'an assembly of the type which is adapted to be lowered into a well bore are coupled together by a releasable connection for which there is provided supporting means which initially prevents the connection from being broken or separated due to relative movement between such parts. Associated with the connection supporting means is an operating member which is movable upon suicient force being applied thereto by iiuid under pressure supplied to the assembly. Upon the operating member being thus moved, the connection supporting means is removed or rendered inoperative, whereupon the releasable connection may thereafter be selectively broken and formed, as desired, by the application of forces causing relative movement between the parts interconnected thereby.

In accordance with another aspect of the invention, the assembly includes in one part thereof a well packer which is adapted to be set or expanded upon suicient force being applied thereto by Huid under pressure supplied to thev assembly. The assembly also includes initially open valve means which is associated with the operating member and is adapted upon movement of such member, as aforesaid, to close and thereby confine or entrap fluid in the assembly so as to hold the packer in at least a partially set or expanded position.

Inoue arrangement, the operating member is adapted to move, as aforesaid, upon the pressure of the uid supplied to set `or expand the packer reaching a predetermined value with respect to the pressure of fluid in the well outside the assembly. Thus, the releasable connection remains supported by the connection supporting means until after the packer has been at least partially set or expanded, whereupon the operating member moves to close the initially open valve means and at the same time remove or render the connection supporting means inoperative.

The assembly preferably also includes means whereby additional force may, if desired, be applied to further set or expand the packer after the connection supporting means has been removed or rendered inoperative. Also, the assembly preferably includes means whereby, if desired, the connection supporting means may be replaced or rendered operative again and the packer returned to its unexpanded position, thus permitting the entire assembly tobe Withdrawnfrom the well bore or moved to another location therein.

The foregoing and other objects and advantages of the invention will be more apparent from the following description when read in connection with the accompanying drawing in which similar reference characters refer to similar parts and wherein:

Figure l is a side elevational view of a well packer assembly having the invention incorporated therein, the assembly including upper and lower well packers shown releasably coupled together, such as during the lowering thereof into a well casing;

Figure 2 is a longitudinal sectional view taken along the line 2-2 of Figure 1, showing in greater detail the lower packer and one type of releasable connection for coupling it in the assembly;

lFigure 2A is an enlarged fragmentary View of the re* leasable connection of Figure 2, showing in greater detail the lconstruction ofra portion thereof; Figures 3 to 6, inclusive, are views similar to that of Figure 2, but respectively showing theparts of the packer and releasable connection in the positions occupied by them at selected later stages of operation;

Figure 7 is a longitudinal sectional view of an arrangement similar to that of Figure 2 and also in accordance with the invention, but having incorporated therein another type of releasable connection, the parts being shown lin the positions occupied by them during the lowering of the assembly;

Figure 8 is a transverse sectional View taken along the line 8-8 of Figure 7; and

.Figure 9 is a view similar to that of Figure 7, but partly in elevation and showing the parts in the respective positions occupied by them at a later stage of operation.

Referring to the drawing in detail, and lirst to Figure l thereof, the invention is there illustrated -and is hereinafter described, by way of example, as being applied to well packer assembly lil shown positioned within, acasing 11 after having been lowered to a desired depth therein on a drill pipe i12.

Theassembly 10 is shown as including generally anupper well packer 13 and alower well packer 14 arranged for -use as straddle packers, such as in connection with a treating, testing, fracturing or other well operation in the performance of which it is desired to effect luid-tight seals gator near the upper and lower limits of an underground zoneor formation traversed by the bore of the well. A series of perforations have been suitably provided in thecasing 11 opposite the zone or formation (not shown) upon which the well operation is to be performed; f

Theupper packer 13 may be of conventional design and it is believed unnecessary to describe it in detail. The packer A13 is shown threadedly or otherwise connected at its upper end to the lower end portion of thedrill pipe 12, which extends upwardly therefrom to the surface of the ground (not shown). A pipe ortubing 16 extends downwardly from thepacker 13 and is secured at its lower end to acoupling member 17.

Thelower packer 14 is adapted to be set or expanded hydraulically and includes .an elongated body orcase 18 upon which are mounted one or more resilient and expansible members, such as a packing sleeve l19 and a set ofslips 20. Extending upwardly from the case 1S is amandrel 21 which, as will appear more fully hereinafter, is at times movable longitudinally therein. Between thecoupling member 17 and the upper end portion of themandrel 21 there is a releasable connection which, as will appear more .fully hereinafter, is initially supported so as .to securely couple or lock .the packers v13 and 14 together.

Referring now to Figure 2, the case 1.8 is hollow and is shown with its lower end closed. Within thehollow case 13 there is provided below themandrel 21 an upper chamber A and a lower chamber B. The upper chamber A is adapted to be supplied with fluid through apassageway 22 which extends upwardly therefrom generally lengthwise of themandrel 21, into thecoupling member 17 which is hollow, and thence upwardly through thetubing 16, theupper packer 13 and .the drill pipe 12 (see Figure l) to the surface of the ground. Sealing rings 2.3 or the like are preferably provided between themandrel 21 .and thecase 18 and between themandrel 21 and thecoupling member 17, so as to prevent the escape of the fluid to the exterior of theassembly 10.

The chambers A .and B are separated by aninner partition 24 which has provided therein one or more openings through which uid is at times permitted to pass. The .arrangement is such that the operation of thepacker 14 may be controlled by controlling the passage of fluid into and out of the lower chamber B through the openings in thepartition 24, as will appear more fully hereinafter.

As illustrated, thepacking sleeve 19 is slidably mounted on a reduced portion of thehollow case 18 and has its lower end disposed adjacent to a lower .abutment orshoe 25, which is secured to thecase 18 and supports thesleeve 19 against relative downward movement thereon. The upper end of thesleeve 19 is dsposed adjacent to an upper orsliding shoe 26, which is movable longitudinally of the case 1S and is shown supported in its uppermost position thereon by the inherent resiliency of thesleeve 19.

Thesliding shoe 26 has an upwardly extendingskirt portion 27 which encircles the upper portion of the wall of thecase 18, with the result that a.chamber 28 is provided between theshoe 26 and the reduced portion of the case .13. Apassageway 29 extending through the wall of thecase 18 provides liuid communication between thechamber 23 and the lower chamber B. Sealing rings 30 or the like are preferably provided between theshoe 26 and thecase 18 above and below thechamber 28, so as to prevent the escape of fluid to .the exterior of theassembly 10.

As illustrated, the slips are movably mounted within a series ofrecesses 31 angularly spaced about the 'wall of thecase 18 below the ,lower .abutment or shoe 2S. Theslips 20 may be made of metal or the like and each preferably has .a plurality ofteeth 32 on the exposed outer surface thereof. Each of the recesses 311 has associated therewith an upper lip orflange 33 and a lower lip orange 34, theanges 33 and 34 being -se- 4 cured to thecase 18 and overlapping the upper and lower ends, respectively, of each of theslips 20. Aspring 35 or the like is preferably mounted between each of theilanges 33 and 34 and the corresponding end of theslip 20 overlapped thereby, so as to normally retain the slips 2t? in their innermost or unexpauded positions within therecesses 31.

A plurality ofpassageways 36 extending through the wall of the case 1S provide duid communication between each of therecesses 31 and the lower chamber B. A resilient andexpansible pad 37 or the like is preferably closely fit-ted -within each of therecesses 31 behind theslip 20 mounted therein, with the result that fluid entering therecesses 31 throu@ thepassageways 36 is not permitted to escape to the exterior of theassembly 10.

The arrangement is such that upon duid under pressure being supplied to the lower chamber B through openings in thepartition 24, as will appear more fully hereinafter, uid pressure builds up within each of therecesses 31 and .applies forces tending to move thepads 37 and slips 20 radially outward and to move the exposedteeth 32 on the slips 2t) into biting engagement with the surrounding casing 11 (see Figure 3). fluid pressure builds up within thechamber 28 and applies a .force tending to move the slidingshoe 26 downwardly, thus compressinglthe sleeve 19 between theshoes 25 and 26 and expanding it outwardly into sealing engagement with the surrounding casing 1.1.

The `flow of tluid from the upper chamber A into the lower chamber B through openin-gs provided in the partition 24- is controlled by valve means which is responsive to forces applied thereto by the lluid supplied to the interior of thecase 18 through thepassageway 22.

As illustrated, thepartition 24 includes .an upwardly extendingcylindrical portion 38 having alateral port 39 provided therein. Thepartition 24 also includes an upper portion which extends radially inward from the upper end of thecylindrical portion 38 and preferably has acentral opening 41 provided therein.

As will appear more fully presently, it is desirable for the flow of fluid through thelateral Aport 39 to be controlled by a val-ve which is initially open and is adapted to close upon the force applied thereto by iluid pressure in the upper chamber A becoming greater by a predetermined amount than an opposing force exerted thereagainst by a fluid pressure, such as .the luid pressure in the annular space surrounding the assembly 10., which is substantially independent of the duid supplied to set or expand .the packer `14. rOn the other hand, it is desirable .for the flow of uid through Athe centr-al opening 41 to be controlled by a one-way check valve which is normally closed and is adapted to open upon the force applied thereto by iluid pressure in the upper chmaber A becoming sufficiently greater than an opposing force exerted thereagainst by uid pressure in the lower vchamber B.

In the arrangement shown the flow of fluid through thelateral port 39 is controlled by a sliding sleeve valve including asleeve 42 `which Yencircles thecylindrical portion 38 of the parti-tion 24. Thesleeve 42 when in its downward position within thecase 18 is normally supported by yieldable means', such as ayielda'ble snap ring 43, which must be overcome in order to move thesleeve 42 to its upward position within thecase 18. Alateral port 44 is provided in thesleeve 42 and, when thesleeve 42 is in such downward position, as shown in Figure 2, the port -44 is aligned with thelateral port 39 in thepartition 24. As as result, the sliding sleeve valve is initially held open, permitting the tluidv initially supplied through thepassageway 22 to the upper chainber A to pass into the lower chamber B so as to set or expand thepacker 14, as hereinbefore described.

Theyieldable snap ring 43 may be a split-type ring made of metal or the like and may be adapted to be overpme by radial expansion thereof resulting from rela- At the same time,

tive longitudinal movement occurring between thesleeve 42 and thepartition 24. In Figure 2 thering 43 is shown mounted at rest in its unexpanded position within an innerannular recess 45, which is provided in thesleeve 42 and is preferably of suiicient depth to receive theentire ring 43 upon radial expansion thereof.

It will be noted that when thering 43 is at rest, its inner portion protrudes to some extent from therecess 45. Also, it will be noted that when thesleeve 42 is in its downward position within thecase 18, the protruding portion of thering 43 registers with agroove 46 extending peripherally about thecylindrical portion 38 of thepartition 14. As a result, thering 43 resists relative upward movement of thesleeve 42 within thecase 18, and thus initially holds the sliding sleeve valve in its open position.

As illustrated, thesleeve 42 is the lower portion of an operatingmember 47, which includes atransverse wall 48 extending radially inward from the upper end of thesleeve 42. Thewall 48 has extending therethrough one ormore perforations 49 which provide fluid communication between the portions of the chamber A above and below thewall 48. Accordingly, the wall 4S has its lower surface 50 exposed to the fluid pressure in the chamber A.

The operatingmember 47 also includes an elongatedupper portion 51 which is secured at its lower end to thetransverse wall 43 and is closely, but slidably fitted within acentral bore 52 of themandrel 21. Thebore 52 is closed at its upper end, such as by a wall or plug 53, and includes achamber 54 provided therein above the operatingmember 47. Thechamber 54 communicates with the exterior of theassembly 10 through aninterior passageway 55 and anannular recess 56 provided, respectively, in and on theelongated portion 51, and through alateral passageway 57 provided in themandrel 21. As a result, the operatingmember 47 has its upper end surface 5S exposed to whatever iiuid pressure exists in the annular space between the assembly 1G and the surroundingcasing 11.

In operation thesleeve 42 remains in its open or downward position, as aforesaid, until such time as the force applied to the operatingmember 47, such as to the lower surface 50 of itstransverse wall 48, by the uid pressure in the chamber A becomes suiiicient to overcome any opposing force applied to theupper end surface 58 ofsuch member 47 by the fluid pressure in thechamber 54 and also to overcome theyieldable snap ring 43.

Thering 43 is selected so that a predetermined force tending to move the operatingmember 47, and thus thesleeve 42, upwardly within thecase 13 is required to be applied in order to expand thering 43 radially outward `to a position within therecess 45 in which themember 47 is permitted to move to its upward position, as shown in Figure 4. Similarly, a predetermined force may be required to be applied in order to overcome thering 43 and permit the operatingmember 47 to be returned to its downward position within thecase 18.

To facilitate such radial expansion of thering 43 due to relative longitudinal movement between the operatingmember 47 and thecase 18, the upper and lower surfaces of the inner portion of thering 43 and the surfaces of thepartition 24 engageable thereby may be suitably tapered, as shown, or otherwise arranged.

Sealing rings 59 or the like are preferably provided between thesleeve 42 and thepartition 24 and are preferably spaced apart and arranged so that Huid-tight seals are eifccted above and below thelateral port 39 upon the operatingmember 47 being moved to its upward position within the case 18 (see Figure 4). Also, sealing rings 60 or the like are preferably provided between the elongatedupper portion 51 of the operatingmember 47 and the bored portion of themandrel 21, so as to isolate the chamber A of thecase 18 from thechamber 54 provided in themandrel 21.

As will appear more fully hereinafter, it is desirable for the operatingmember 47 to remain in its downward position within thecase 18 until thepacker 14 has been set or expanded sufficiently to support itself against longitudinal displacement within thecasing 11. If desired, thesnap ring 43 may be selected so as to retain thesleeve 42 and thus the operatingmember 47 in its downward position until thepacker 14 has been fully set or expanded, whereupon thering 43 will be overcome and the sleeve valve will close, lthus confining or entrapping fluid in the lower chamber B and thereby holding thepacker 14 in its set or expanded position.

With such an arrangement only one opening need be provided in thepartition 24, but an additional, separately controlled opening is preferably provided so that, if desired, additional fluid may be supplied to further set or expand thepacker 14 after the sliding sleeve valve has closed. It is primarily for this purpose that thecentral opening 41 is preferably provided in thepartition 24.

In the arrangement shown the flow of fluid through thecentral opening 41 is controlled by a one-way check valve which includes an upwardly closingvalve member 61 disposed within the lower chamber B and normally urged by aspring 62 or the like toward a seating surface provided therefor on the upper portion of thepartition 24 around theopening 41. Thespring 62 is shown with its upper end fitted to thevalve member 61 and with its lower end resting on atransverse support 63, which is secured to thepartition 24 and has one ormore perforations 64 extending therethrough. It will be noted that theperforations 64 provide iiuid communication between the portions of the chamber B above and below thesupport 63.

The one-way check valve is adapted to open upon the force applied downwardly against thevalve member 61 by uid pressure in the upper chamber A becoming sufficiently greater'than the force exerted upwardly thereagainst by lluid pressure in the lower chamber B to overcome thespring 62. In operation thevalve member 61 will ordinarily remain in its upward or closed position until after the sliding sleeve valve initially providing fluid communication between the chambers A and B has been closed and additional Huid has been thereafter supplied through thepassageway 22 to increase the uid pressure in the chamber A.

An important feature of the invention resides in the construction and arrangement whereby thelower packer 14 is coupled in theassembly 10 by a releasable connection for which there is provided supporting means which prevents the connection from being broken or separated prior to thepacker 14 being at least partially set or expanded and fluid being confined or entrapped, as aforesaid, so as to hold thepacker 14 in such set or expanded position.

In the arrangement shown the releasable connection is provided between thehollow coupling member 17 and the upper end portion of themandrel 21 and is employed for coupling together thepackers 13 and 14. Thus, thecoupling member 17 is shown with its upper end threadedly connected to the lower end portion of thetubing 16 which extends downwardly from theupper packer 13. It is understood, however, that in certain applications, such as when thelower packer 14 is to be used as a retrievable bridge plug or the like, the assembly 1i) may not include an upper packer, such as thepacker 13. ln such event thecoupling member 17 may be threadedly or otherwise connected to or, if desired, may be made integral with other apparatus, such as the lower end of thedrill pipe 12, of the type which is adapted to be lowered into a well bore.

The releasable connection includes yieldable means which initially interconnects thecoupling member 17 and themandrel 21 and must be overcome in order to either break or form the connection. In the typeof releasable connection shown best in Figures 2 and 2A the yieldable means is ayieldable snap ring 65 which upon the supporting means provided therefor being removed or rendered inoperative, as will appear more fully hereinafter, is adapted to be overcome by causing relative longitudinal movement between the couplingmember 17 andmandrel 21.

As illustrated, themandrel 21 initially has its upper end portion closely fitted within thehollow coupling member 17, which is shown in Figure 2 in its lowermost position thereon, with an upwardly facingshoulder 66 on themandrel 21 engaging a downwardly facingshoulder 67 provided within themember 17.

Theyieldable snap ring 65 may be a split-type ring made of metal or the like which is adapted to be overcome by radial compression thereof resulting from relative longitudinal movement occurring between the couplingmember 17 and themandrel 21. Thus, as shown best in Figure 2A, thering 65 is mounted at rest in its uncompressed position within a groove 65a extending peripherally about themandrel 21. The groove 65a is preferably of sufficient depth to receive theentire ring 65 upon radial compression thereof.

It will be noted that when thering 65 is at rest, its outer portion protrudes to some extent from the groove 65a. Also, it will be noted that when thecoupling member 17 is in its lowermost position on the mandrel 2l, the protruding portion of thering 65 registers with an innerannular recess 65b provided in the wall of thecoupling member 17, thus resisting relative upward movement of themember 17 thereon.

The connection supporting means in the arrangement of Figures l to 6, inclusive, comprises means for initially supporting thesnap ring 65 against being radially compressed to a position within the groove 65a in which the outer portion of thering 65 no longer extends into therecess 65b. This support is shown provided in part by one ormore pins 68, each of which is slidably positioned within aslot 69 extending radially inward from the groove 65a to thecentral bore 52 of themandrel 21.

Thepins 68 are in turn initially supported in their outermost positions within theslots 69 and when in such Y positions preferably engage thering 65. The support for thepins 68 is shown provided by the operatingmember 47, which has itsupper end portion 70 normally disposed in thebore 52 opposite theslots 69, preferably preventing thepins 68 from moving inwardly out of supporting relation to thering 65.

Thus, the connection supporting means includues both theupper end portion 70 of the operatingmember 47 and thepins 68 mounted within theslots 69.

It will be noted that theannular recess 56 provided on theelongated portion 51 of the operatingmember 47 is initially disposed within the bore 52 a suitable distance below theslots 69 but is adapted to move into alignment therewith (see Figure 4) upon the operatingmember 47 being moved, as hereinbefore described, to its upward position within thecase 18. Upon therecess 56 being thus moved into alignment with theslots 69, thepins 68 are no longer prevented from moving inwardly alongsuch slots 69 and, as a result, thering 65 is no longer supported against radial compression.

Thering 65 is preferably selected so that upon the support therefor being removed, as aforesaid, a predetermined force tending to move thecoupling member 17 upwardly with respect to themandrel 21 is required to be applied, such as by raising thedrill pipe 12, in order to compress thering 65 radially inward within the groove 65a suiciently to permit themember 17 to be moved upwardly to a position (see Figure in which the releasable connection istbroken. Similarly, a predeter- 'mined force may thereafter be required to be applied in 8 order to overcome thering 65 and permit the` couplingmember 17 to be returned to its lowermost position (see Figure 4) on themandrel 21, thus reforming or remaking the releasable connection.

To facilitate radial compression of thering 65 due to relative longitudinal movement between the couplingmember 17 and themandrel 18, as aforesaid, the upper and lower surfaces of the outer portion of thering 65 and the surfaces of themember 17 engageable thereby are preferably suitably tapered or inclined, as shown best in Figure 2A. i

Thus, it will be noted that the releasable connectio may be selectively broken and formed, as desired, while the operatingmember 47 is in its upward position within thecase 18, the connection supporting means being then removed or rendered inoperative. Also, it will be 4noted that at all times when the releasable connection'is thus adapted to be selectively broken and formed, thepacker 14 is in at least a partially set or expanded position and the sliding sleeve valve is closed, with the result that thelower packer 14 then supports itself against longitudinal displacement within thecasing 11.

In order that thepacker 14 may be returned to its relaxed or unexpanded position and ythe connection supporting means replaced or again rendered operative, it 1s desirable for means to be provided whereby the operating member i7 may be returned to its initial or downward position with respect to both thecase 18 and themandrel 21. It is primarily for this purpose that themandrel 2,1 is, as hereinbefore indicated, mounted for relative longitudinal movement within thecase 18.

The mandrel 2l is shown in Figure 2 in its initial or uppermost position within thecase 18, with an intermediate raised portion '71 of themandrel 21 engaging an upper abutment 'l2 provided within thecase 18. lThemandrel 21 when in its uppermost position is preferably normally supported `in such position by yieldable means, such as ayieldable snap ring 73, which must be overcome in order to move themandrelV 21 downwardly within thecase 18.

Theyieldable snap ring 75 may be a split-type ring made of metal or the like and may be adapted to be overcome by radial compression thereof resulting from relative longitudinal movement occurring between themandrel 21 and the case 18'. Thering 75 is shown mounted at rest in its uncompressed position within agroove 74, which extends peripherally about the in-termedlate raisedportion 71 and is preferably of sufficient depth to receive theentire ring 73 upon radial compression thereof.

It will be noted that when thering 73 is at rest, its outer portion `protrudes to some extent from thegroove 74. Also, it will be noted that when themandrel 21 is in its u pward position within thecase 18, lthe protruding portion of the ring '73 registers with an innerannular recess 75 provided in the wall of the case -18 below itsupper abutment 72, thus resisting relative downward movement of themandrel 21 within the ease .18.

Thering 73 is preferably selected so that a predetermined force tending to move themandrel 21 downwardly within thecase 13 is required to be applied, such as by further lowering thedrill pipe 12 when the coupling member 17 -is in its lowermost position on themandrel 21, in order to compress the ring '73 radially inward Within thegroove 74 sufliciently to permit themandrel 21 to be moved to its lowermost position within thecase 18, as shown in Figure 6. In order to facilitate radial cornpression of the ring '73 due to such relative downward movement of themandrel 21, the lower surface of the outer portion of thering 73 and the surfaces of thecase 18 engageable thereby are preferably suitably inclined or tapered, as shown. Similarly, the upper surface of the outer portion of thering 73` and the surfaces of theca'se 18 engageable thereby may be suitably inclined or tapered to facilitate thereafter returning the mandrel21v to its uppermost position within thecase 18.

, It will be noted in Figure 2. that when themandrel 21 is in its uppermost position and the operatingmember 47 is in its initial or downward position, the lower end of the mandrel 2.1 is disposed a suitable distance above the transverse wall 4S, which is thus permitted to move upwardly within the chamber A as themember 47 is moved to its upward position (see Figure 4). -Upon themandrel 21 being thereafter moved downwardly within thecase 18, its lower end engages thetransverse wall 48 and thereby carries or returns the operatingmember 47 to its initial or downward position within the case 1S (see Figure 6). As a result, the sliding sleeve valve controlling the flow of fluid through thelateral port 39 in thepartition 22 is opened and the uid previously confined or entrapped in the lower chamber B is permitted -to escape therefrom through the alignedports 39 and 44, whereupon the inherent resiliency of the packingsleeve 19 causes relaxation thereof and returns the slidingshoe 26 to its uppermost position on thecase 18 and thesprings 35 return the slips 2i) to their innermost or unexpanded positions within therecesses 31.

Upon the packer 14- being thus returnedto its unexpanded position, the weight thereof may be suiiicient to cause themandrel 21 to move relatively upward within thecase 18 and resume its uppermost position therein, as shown in Figure 2. In order to facilitate the return of themandrel 21 to such position, a spring 7'7 or the like may, if desired, be mounted so as to normally urge the mandrel Z1 upwardly. Thespring 77 is shown encircling themandrel 21 and with its upper end engaging the intermediate raisedportion 71 thereof. The lower end of thespring 77 is shown supported by alower abutment 78 provided within thecase 18.

Referring now to Figures 7, 8 and 9, the arrangement there illustrated is substantially identical to that heretofore described, with the exception that another type of releasable connection is employed. ln particular, the modified releasable connection is adapted to be bro-ken or separated in response to relative rotation, rather than relative longitudinal movement, between the parts interconnected thereby.

In Figure 7 the .parts of the modified arrangement are shown in the respective positions occupied by them during the lowering thereof into Ithe well casing 11. There is shown alower Well packer 14 which includes acase 18 having a mandrel 21' extending upwardly therefrom. Aspline 79 is shown secured to themandrel 21 and extends lengthwise thereof through a groove Si) provided in the wall of thecase 18 near the upper end thereof. The arrangement is such that the mandrel 21' is at time movable longitudinally within the case 18', as has been hereinbefore described with reference to the arrangement of Figures l to 6, inclusive, but thespline 79 prevents substantial relative rotation of the mandrel Z1 therein. As a result, themandrel 21 is supported against relative rotation within thecasing 11 upon thepacker 14 being set or expanded (see Figure 9).

The upper end portion of themandrel 21 is shown in Figure 7 closely fitted within a hollow coupling member 17', which is threadedly or otherwise connected at its upper end to thetubing 16 extending downwardly from the upper packer 13 (see Figure l). Sealing rings 23 or the like are preferably provided between the mandrel 211' and thecoupling member 17 to prevent the escape of iiuid from the interior of the member 17'.

The modified type of releasable connection includes a split-type collar orring 81 which may be made of metal or the like and has provided on its outer surface a plurality of buttress or ratchetthreads 82. Thering 81 1s shown mounted at rest in an uncompressed position within agroove 83 which extends peripherally about the upper pontion of themandrel 21 and is preferably of sufficent depth to receive theentire ring 81 upon radial compression thereof.

As shown best in Figure 8, the ring $1 is supported, such as by a pin orbolt 84, against substantial relative v10 rotation with respect to .themandrel 21"'. To this end thebolt 84 may be screwed into or otherwise secured to the mandrel Z1 and is shown extending radially outward therefrom into the space between the split ends of the ring S1.

lt will be noted in Figure 7 that when the ring S1 is at rest, itsthreads 82 protrudes 4to `some extent from thegroove 83 so as to engagecompanion threads 85 which are provided within thecoupling member 17. Thethreads 82 and 85 are downwardly inclined or tapered or are otherwise suitably arranged so as to permit the connection to be formed by moving thecoupling member 17 downwardly with respect to thering 81 and mandrel 2-1. Upon the connection being thus formed, thethreads 82 and 85 resist relative upward movement of thecoupling member 17 and must be overcome by rotational movement in order to break or Separate the connection.

However, the modified type of releasable connection when formed initially supported against being broken or separated due to relative rotation between the parts interconnected thereby. This support is shown provided by connection supporting means which in part includes one or more pins d6, each of which is slidably positioned within aslot 87 extending radially inward from the periphery of themandrel 21 to acentral bore 52 provided therein.

Thepins 86 are initially supported in their outermost position within theslots 87 by theupper end portion 70 of an operating member 47', which may be identical to themember 47 heretofore described. When in such position the pins S6 extend into aninner recess 88 provided in the wall of thecoupling member 17. The recess S8 may be annular so that the walls thereof engage each of thepins 36 and thereby limit relative longitudinal movement between the mandrel Z1 and thecoupling member 17. As an alternative, arecess 88 may be provid-ed for eachpin 86 and eachrecess 88 may be in the form of an inwardly extending bore the walls of which engage thepin 86 therein on all sides and thereby limit both relative longitudinal movement and relative rotation between themandrel 21 and thecoupling member 17.

In order to limit relative outward movement of thepins 86 along theslots 87, eachpin 86 preferably has provided near its innermost end a flange 89 or the like which is adapted to engage anabutment 90 provided within the slotted portion of the mandrel 21'.

It will be noted that while, as hereinbefore described, thering 81 is initially connected to thecoupling member 17 by the threads `82 and 85 and is supported by thebolt 84 against substantial rotation with respect to the mandrel 21', it is initially not possible to screw the coupling membere 17' oti of thering 81. This is partly because themandrel 21 does not become supported against relative rotation within thecasing 11 until thepacker 14,V has been at least partially set or expanded and partly because thepins 86 in cooperation with therecess 88 prevent relative upward movement of thecoupling member 17 ou themandrel 21 during such time the operatingmember 47 is in its initial or downward position within thecase 18.

r[The connection supporting means in the arrangement of Figures 7 and 8 may be considered as including both theupper end portion 70' of the operating member 47' and the pins S6 mounted within theslots 87. Some additional protection against operation of the releasa-ble connection means before thepacker 14 has been at least partially set or expanded may be considered as resulting from the requirement of relative rotation to separate the interconnected parts.

As in the case of the arrangement of Figures l to 6, inclusive, the operatingmember 47 is adapted to move to its upward position within thecase 18 upon sulii- 'cient force being applied thereto by the iiuiid supplied to set or expand the packer 14'. U-pon the operating member 4T' being so moved, an annular recess 56' provided thereon moves into alignment with theslots 87, permitting thepins 86 to move inwardly into thebore 52 of the mandrel 21' sufficiently so that their outermost ends no longer extend into therecess 88, as shown in Figure 9, thus removing or rendering inoperative the supp-ort initially provided for the releasable connection. At the same time, huid is confined or entrapped in the case 1'8 so as to hold thepacker 14 in at least a partially set or expanded position, as herein'before described with reference to thepacker 14.

Upon the support for the releasable connection being removed, as aforesaid, the connection may then be broken or separated by applying rotational force, such as by rotating thedrill pipe 12, in a direction (for example, in a clockwise direction) such as to screw the coupling member i17 off of the ring S1. In Figure 9 thecoupling member 17 is shown after having been screwed otf of the4ring 81 suiciently to partially break or separate the connection.

After the releasable connection has been broken or separated, it may be formed again at any time by applying suicient force, such as by lowering or setting down thedrill pipe 12 so as to overcome theyieldable ring 81 by radial compression thereof and return themember 17 to its initial or lowerm'ost position on themandrel 21. As in the case of the arrangement shown in Figures 1 to 6, inclusive, thepacker 14 may then be returned to its relaxed or unexpanded position by applying additional force, such as by further lowering thedrill pipe 12, so as to move the mandrel 21' to its lowermost position within the case 18'. Thereafter the connection supporting means becomes replaced or is rendered operative again as the mandrel 21' returns to its uppermost position within the case 18', thus returning the parts to the respective positions shown in Figures 7 and 8.

VIt will be appreciated by those skilled in the art that the invention as herein disclosed provides particular advantages when applied in connection with a well operation wherein it is desired to employ upper and lower well packers in a straddle packer arrangement. the performance of such a well operation using, for example, the arrangement of Figures l to 6, inclusive, theassembly 10 is lowered on thedrill pipe 12 to a position within the casing 1'1 in which, as show-n, thelower packer 14 has its packingsleeve 19 disposed below the series ofpertorations 15.

During the lowering thereof, the parts of theassembly 10 are in the respective positions shown in Figures l, 2 and 2A. That is, thepackers 13 and 14 are in their relaxed or unexpanded positions and are securely coupled or locked together due to the releasa-ble connection being then supported, as hereinbefore described.

Upon reaching the desired location in thecasing 11,

the packer .14 is set or expanded by supplying iluid to the lower chamber B in thecase 18, such as by pumping the fluid into the upper end of thedrill pipe 12 at the surface of the ground and downwardly along thepassageway 22 into the upper chamber A and thence into the lower chamber B through theports 44 and 39, which are then in alignment due to the sliding sleeve valve being initially open, as hereinbefore described.

Upon thepacker 14 being at least partially set or expanded, the slidingY sleeve valve closes automatically and at the same time the support for the releasable connection is removed or rendered inoperative, due to .the iiuid pressure in the chamber A applying suthcient force, as hereinbefore described, to move the operatingmember 47 to its upward position within thecase 18, as shown in Figure 4.

`Up to this point the procedure is substantially the same using either of the arrangements shown in the drawing. Thereafter the releasable connection is broken or separated by the application of longitudinal or rotational force, depending on the type of connection used, and the upper part of theassembly 10 is moved upwardly within thecasing 11 to a position in which theupper packer 13 upon being set or expanded will effect a fluid-tight seal above the series ofperforations 15. Since there is then no pipe or tubing interconnecting thepackers 13 and 14, it is apparent that seals may be thus eiected at or near the upper and lower limits of zones or formations of any thickness, whereupon the Well operation may be carried out in accordance lwith well known practices.

Upon completion of the well operation the releasable connect-ion is formed again and the parts of theassembly 10 returned to their initial positions, as hereinbefore described, whereupon theentire assembly 10 may be withdrawn from the well or moved to another location therein.

It will also be appreciated by those skilled in the art that while a releasable connection or safety joint constructed in accordance with the disclosure herein provides particular advantages when used for coupling into an assembly or string a packer or other apparatus which is hydraulically operable, such a connection or joint may also be used to advantage for coupling into an assembly or string a packer or other apparatus which is not hydraulically operable, in which event fluid pressure may still be employed for removing the support initially preventing the connection from being broken or separated.

lWhile the invention has been herein described with particular reference to its application in certain arrangements, it is understood that the invention may be applied elsewhere. It is apparent that various changes and modifications within the spirit of the invention will now present themselves to persons skilled in the art. Accordingly, the invention is best delined by the scope of the appended claims.

I claim:

l. A well packer comprising an elongated hollow case having an upper and a lower chamber therein, means within said case forming a passageway for supplying fluid under pressure to said upper chamber, an operating member mounted for relative longitudinal movement within said upper chamber, said operating member having a lower surface exposed to the fluid pressure in said upper chamber and an upper surface exposed to the space outside said case, whereby the building up of fluid pressure within said upper chamber tends to move said operating member upwardly therein, valve means including the lower portion of said operating member for controlling the passage of fluid between said chambers, said valve means being open and permitting uid to pass in either direction between said chambers when said operating member is in its downward position and being adapted to close and thereby confine uid in said lower chamber upon said member being moved upwardly from its downward position, at least one resilient and cxpansible packing member on said case adapted to be hydraulically set or expanded, means responsive to the lluid pressure in said lower chamber -for expanding said packing member, and means for yieldably supporting said operating member in its downward position and thereby holding said valve means open until the fluid pressure in said 'chambers becomes suicient to at least partially expand said packing member, whereupon said operating member moves upwardly and said valve means `closes automatically to confine fluid in said lower chamber and hold said packing member in an expanded position.

' 2. A well packer as claimed in claim l including a mandrel mounted -for limited relative longitudinal movement within said upper chamber and adapted upon being moved downwardly therein to engage said operating member, and connection means on said mandrel for securing said packer to other apparatus of the type lowered into a well bore, the arrangement being such that said operating member may be moved downwardly to open .said

. 13 valve means Aand permit the escape of fluid confined in said lower chamber by moving said mandrel downwardly at a time when said packing member is held in expanded supporting engagement with the wall of a well bore into which said packer has been lowered, whereupon said packing member is permitted to return to its unexpanded position.

3. A well packer as claimed in claim 1 including an upwardly closing one-way check valve between said chambers for permitting additional fluid under pressure to be supplied to said lower chamber to further expand said packing member while said operating member is in its upward position.

4. In an assembly including upper and lower parts adapted to be releasably coupled together and lowered into an oil or gas well or the like, the combination of means within said lower part forming a chamber adapted to be supplied with iluid under pressure, a mandrel extending into said chamber and mounted for limited relative longitudinal movement therein with respect to said lower part, said mandrel having a bore extending upwardly from the lower end thereof and having a lateral slot connecting Vthe upper portion of said bore with the space outside said mandrel, a pin mounted for movement within said slot into and out of said bore, said pin being adapted when in its outward position to prevent and when in its inward position to permit relative movement between said mandrel and said upper part in a direction such as to cause separation of said parts when coupled together, an operating member mounted for relative upward and downward movement within said bore, said operating member having a lower surface exposed to the fluid pressure in said :chamber whereby the building up of iluid pressure therein tends to move said operating member to its upward position within Said bore, said operating member having its upper portion disposed within said bore opposite said slot and having on said upper portion a recess alignable with ,said pin, said recess being adapted to move into alignment with said pin upon the lluid pressure in said chamber moving said operating member to its upward position whereby said pin is permitted to move inwardly to a position permitting separation of said parts, and said operating member having a surface engageable by said mandrel whereby said member may be returned to its downward position within said bore by moving said mandrel downwardly and then upwardly within said chamber.

5. The invention as claimed in claim 4 including means for yieldably connecting said operating member to said Vlower part when in its downward position within said 'bore and means for yieldably connecting said mandrel to said lower part when in its uppermost position within said chamber.

y 6. In an assembly including upper and lower parts adapted to be lowered together into a well bore or the like, the combination of releasable connection means responsive to relative movement between said parts for selectively coupling together and separating said parts, means within one of said parts forming upper and lower chambers, means within said chamber-containing part forming a passageway for supplying iluid under pressure to said `upper chamber, an operating member mounted for upward and downward movement within said upper chamber, said operating member having a lower surface exposed to the fluid pressure in said upper chamber and having an upper surface exposed to fluid pressure in the well outside said assembly, whereby said operating member tends to move upwardly upon fluid under pressure being supplied to said upper chamber, connection supporting means responsive to movement of said operating member for selectively preventing and permitting operation of said releasable connection means to separate said parts when coupled together, said connection supporting means being adapted to prevent separation of said parts when said operating member is in its downward position within said upper chamber and to permit separation thereof upon said operating member being moved to its upward position therein, valve means responsive to movement of said operating member for selectively permitting and preventing fluid dow between said chambers, said valve means being adapted to move from its open to its closed position as said operating member moves from its downward to its upward position, packing means including at least one resilient and expansible member mounted on lsaid chamber-containing part, means responsive to the fluid pressure in said lower chamber for expanding said packing means into tight engagement with the wall of said well bore and yieldable means for supporting said operating member in its downward position within said upper chamber until the fluid pressure in said chambers becomes suflicient to -at least partially expand said packing means.

7. The invention as claimed in claim 6 including a mandrel mounted for limited relative longitudinal movement within said upper chamber upon relative movement occurring between said parts when coupled together, said mandrel upon moving downwardly within said upper chamber being adapted to engage said operating member and return said member to its downward position therein, and yieldable means for supporting said mandrel in its uppermost position within said upper chamber whereby a predetermined force is required to move said mandrel downwardly therein.

8. A well packer comprising a body having a chamber therein and a iiuid passageway adapted to conduct fluid under pressure to said chamber, initially open valve means in said body communicating said passageway with said chamber and closable for confining fluid therein, packing means on the exterior of said body, duid pressure-actuatable means actuatable by the pressure of uid in said vchamber for expanding said packing means, said initially open valve means including a duid pressure-actuatable member movably mounted in said body, movable for closing said valve means, releasable means initially maintaining said pressure-actuatable member in open position, said member having two opposed surfaces, one of said surfaces being exposed to pressure of the fluid in said passageway being supplied to said chamber to urge said member toward valve closing position and the other of said surfaces being exposed to the pressure of iluid in the welloutside said body urging said member toward open valve position, whereby said member tends to close said valve means when the pressure of fluid being supplied to said chamber exceeds the pressure of fluid in the well outside said body.

9. A well packer comprising a body having a chamber therein, means including a fluid passageway and initially open valve means forming a passageway for supplying uid under pressure to said chamber, packing means on the exterior of said body, means actuatable by the pressure of fluid in said chamber for expanding said packing means, said initially open valve means including a iluid pressure-actuatable operating member mounted in said body, movable for closing said valve means to conne fluid in said chamber, releasable means initially maintaining said valve means open, said member having two opposed surfaces, one of said surfaces being exposed to the fluid pressure in said passageway and the other of said surfaces being exposed to the fluid pressure n Ithe well outside said body, said releasable means releasing said member for movement to close said initially open valve means when the force applied to said member due to the pressure of fluid in said passageway reaches a predetermined value` greater than the force applied to said member dueto the pressure of fluid in the well outside lsaid body, whereupon the iluid confined in said chamber tends to hold said packing means in an expanded position.

10. A well packer as claimed in claim 9 including additional valve means in said bodyadapted to communicate said passageway with said chamber and operable to permit additional fluid under pressure to be supplied to 'further expand said packing means after said initially open valve means has closed.

1I. A well packer comprising an elongated body having therein an upper chamber and a lower chamber and a passageway for supplying uid under pressure to said upper chamber, initially open valve means between and communicating said chambers, at least one resilient and expansible packing member on the exterior of said body adapted to be hydraulically set or expanded, means actuatable by the uid pressure in said lower chamber for expanding said packing member, said initially open valve means including an operating member mounted for movement in one direction in said upper chamber to close said valve means and confine iluid in said lower chamber, said operating 'member having two opposed surfaces, one of said surfaces being exposed to the lluid pressure in said upper chamber and the other of said surfaces being exposed to the uid pressure in the well outside said body, said operating member being adapted to move in said one direction when the force applied thereto due to the pressure of fluid in said upper chamber reaches a predetermined value greater than the force applied to such member due to the pressure of fluid in the well outside said body, whereupon the iluid confined in said lower chamber tends to hold said packing member in an expanded position;

12. A well packer as claimed in claim 1l including normally closed, fluid pressure-actuatable one-way valve means between and communicating said upper and lower chambers for permitting additional uid under pressure to be supplied to said lower 'chamber to further expand said packing member after said initially open valve means has closed.

13. A well packer as claimed inclaim 11 wherein there is means movably mounted in said body actuatable to engage and move said operating member in a reverse direction within said upper chamber to return said initially open valve means to its open position after closure thereof and thereby permit the escape of fluid confined in said lower chamber, whereupon said packing member is permitted to return to its unexpanded position. y

14. In an assembly including two parts adapted to be telescoped and lowered together into a well bore or the like, the combination of releasable connection means initially coupling together said parts and responsive to relative movement therebetween to effect separation of said parts, means in one of said parts forming a body having a chamber therein and a duid passageway for conducting fluid under pressure to said chamber, an operating member mounted for movement in said body Yfrom an initial position therein, said operating member having two opposed surfaces, one of said surfaces being exposed to the pressure of fluid being supplied to said chamber and the other of said surfaces being exposed to the pressure of fluid in the well outside said body, whereby said operating member tends to move away from its initial position in said body when fluid under pressure is supplied to said chamber, connection locking means including a portion of said operating member and an element movably mounted in one of said parts and engageable by said operating member for initially preventing release of said releasable connection means, said connection locking means being in locking position when said operating member is in its initial position in said body and being adapted to unlock and thereby permit operation of said releasable connection means to separate said parts upon said operating member being moved away from its initial position in said body, and means for yieldably supporting said operating member in its initial position in said body and thereby maintaining said conandasse Y Y 16 nection locking means in its locking position until the force applied to said operating member due to the pressure of fluid being supplied to said chamber reaches a predetermined value greater than the force applied to said operating member due to the pressure of fluid in the well outside said body.

15. The invention as claimed inclaim 14 wherein there is means movably mounted in said body actuatable to engage and return said operating member to its initial position in said body and thereby return said connection locking means to its locking position to prevent operation of said releasable connection means.

116. In an assembly including two parts adapted to be telescoped and lowered together into a well bore or the like, the combination of releasable connection means initially coupling together said parts and responsive to relative movement therebetween to effect separation of said parts, means within one of said parts forming a body having a chamber therein and a fluid passageway for conducting fluid under pressure to said chamber, at least one packing member on said body adapted to be hydraulically set or expanded, means responsive to the fluid pressure in said chamber for expanding said packing member, an operating member mounted for movement in said body from an initial position therein, initially open valve means including a portion of said operating member for controlling the passage of fluid from said passageway into said chamber, said valve means being open and permitting fluid to pass from said passageway into said chamber to expand said packing member when said operating member is in its initial position in said body and being adapted to close and thereby confine fluid in said chamber to hold said packing member in an expanded position upon said operating member being moved away from its initial position in said body, connection locking means also including a portion of said operating member and an element movably mounted in one of said parts and engageable by said operating memberv for controlling operation of said releasable connection means, said locking means being in locking position to prevent operation of said releasable connection means when said operating member is in its initial position in said body and being adapted to unlock and thereby permit operation of said releasable connection means to separate said parts upon said operating member being moved away from its initial position in said body, said operating member having two opposed surfaces, one of said surfaces being exposed to the pressure of fluid in said passagewaybeing supplied to said chamber and the other of said surfaces being exposed to the pressure of fluid in the well outside said body, whereby said operating member tends to move away from its initial position in said body when uid under pressure is supplied to said chamber, and means for yieldably supporting said operating member in its initial position in said body and thereby maintaining said valve means in its open position and said connection locking means in its locking position until the pressure of fluid being supplied to said chamber becomes suiiicient to at least partiallyexpand said packing member.

References Cited in the iile of this patent UNITED STATES PATENTS 2,150,310 Baker Mar. 14, 1939 `2,187,635 Stamps Jan. 16, 1940 2,227,730 Lynes `Tan. 7, 1941 2,227,751 Lynes Jan. 7, 1941 2,315,921 Baker Apr. 6, 1943 2,799,346 Baker et al. July 16, 1957 2,806,532 Baker et al Sept. 17, 1957

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