US3311169A - Retrievable and hydraulically actuated well packer - Google Patents

Description

March 28, 1967 P. R. HEFLEY ETAL 3,311,169

RETRIEVABLE AND HYDRAULICALLY ACTUATED WELL PACKER g Sheets-Sheet 1 Filed Aug. 10, 1964 United States Patent O RETRIEVABLE AND HYDRAULICALLY ACTUATED WELL PACKER Phillip R. Hefley and Gilbert H. Tausch, Houston, Tex.,

assignors to Cameo, Incorporated, Houston, Tex., a corporation of Texas Filed Aug. 10, 1964, Ser. No. 388,443 8 Claims. (Cl. 166-120) This invention relates to subsurface well tools and more particularly to an improved packer assembly to be lowered to selected depth in a well bore and controlled for pressure fluid actuation to an annulus pack-off setting.

An object of the invention is to provide a packer which is free of complex and costly components for economical production and which is easy to install and reliable in use and re-use over a long life.

Another object is to provide controllable hydraulically actuated devices to stress and deform a packing element into pack-off relation and to securely anchor the assembly against displacement from its set position within the well bore and also to provide for ready relief at any subsequent time of a previously set packer assembly.

A further object of the invention is toprovide a bypass tube projected through a deformable packing collar and communicating pressure fluid from below the expanded packing collar to an upper dead-ended and piston sealed chamber for the outward projection of the piston into hold-down gripping engagement with the wall of the well bore and thus utilize pressure fluid of a higher value beneath the packer than that above the packer for resisting upper packer displacement under the pressure differential.

A still further object of the invention is to provide a packer assembly in which a packer setting cylinder is slidably sleeved on and co-operates with a mandrel to enclose a piston subdivided chamber for cylinder movement in a packer setting direction and in response to pressure differentials on opposite sides of the piston; there being a one-way ratchet connection between the piston and the cylinder for holding the cylinder against movement in reverse or packer release direction together with a detachable connection between the piston and a packer traversing production tubing section to hold down the tubing section at a lower limit of a lost motion connection with a tube abutment for the packing element; such detachable connection being releasable b-y manipulation from the surface of the tubing section, whereupon tubing section elevation relative to the ratcheted together piston and cylinder first takes up lost motion relative to and then raises the top abutment to relieve packer setting stress.

Other objects and advantages will become apparent from the accompanying drawings wherein FIG. 1 is a side elevation of the packer assembly; FIGS. 2A and 2B are companion views on a larger scale showing portions of the packer assembly in vertical section and to one side of the longitudinal center line of the packer assembly, and FIGS. 3A and 3B are also vertical sections at substantially a right angle to the views shown in FIGS. 2A and The packer assembly as illustrated is for placement above an upper fluid production zone of a dual completion oil and/or gas well. As is usual, one production tubing string extends to the well head from a lower fluid production zone and through a pair of vertically spaced apart packers set one above and the other below the upper production Zone and a second production tubing string leads to the well head from the upper zone and passes through the uppermost packer. Each string is made ward travel of the assembly 18 3 ,31 1,169 Patented Mar. 28, 1967 up of tube sections joined in end to end succession. One section of the longer or lower fluid production string, as at 1, is a component of the packer assembly illustrated. A tubular mandrel 2 is a section of the fluid production tubing string for the upper zone and the top end of the mandrel 2 is screw threaded into a bore or passage extending axially and in laterally ofiset relation to the center line of a hold-down slip carrier ring or body 3, as seen in FIG. 3A.

The lower end of the tubing string which is above and in alignment with the mandrel 2 is shown as comprising a magnetic steel nipple or collet 4 to be stabbed into the passage. For a given distance upwardly from its lower end, the collar has circumferentially spaced apart slits to provide deflectilble fingers 5 having peripheral latching bosses 6 to snap into a keeper groove internally of the passage. Above the spring fingers 5, the collet carries an annular seal 7 to bear on a co-operating sealing surface in the passage. Located within a counterbore of the collet 4 is a stack of rings, such as a nonmagnetic-ring 8, a magnetic ring 9 and a nonmagnetic'ring 10!.

Each nonmagnetic ring 8 and 10 carries two axially spaced apart rows of permanent bar magnets 11 arranged so that the inner faces of the magnets in one row are of opposite polarity to the inner faces of the magnets in the companion row of the mounting ring, whereby there will be inwardly protruding magnetic signaling fields vertically spaced apart a distance determined by the selected height of the intervening spacer ring 9'. These fields will be later referred to.

Laterally oflset in the upper body 3 on the side of its longitudinal center line opposite to the bore in which the collet 4 is socketed is an axial bore within which a portion of the production tube section 1 is housed and has bearing for both rotative and slide movements at a time after an interconnecting shear pin 12 has been previously broken. This bore is counterbored at upper and lower ends of the body 3. The upper counter-bore provides an upwardly facing shoulder 13 for stop engagement with a downwardly facing shoulder 14 on the tube section 1 and the lower counterbore provides a downwardly facing shoulder 15 as a limit stop for a snap ring 16 carried by the tube section below its shoulder 14 at a distance greater to a predetermined extent than the vertical spacing between the shoulders 13 and 15 on the 'body 3, so that a relative lost motion longitudinally of the tube section and the body can occur in the absence of the shear pin 12.

Below the upper body 3 and as best seen in FIG. 1, there are successively sleeved on both production tubing sections 1 and 2, a deformable packing element or collar 17 of rubber or other like elastic material, a slip carrier and piston enclosing barrel assembly 18 and a gauge ring 19. The bottom edge of the body 3 and the top edge of the assembly 18 provide abutment members for opposite ends of the packing collar 17 whereby upon uprelative to the body 3, an axial squeeze force will be applied to radially deform or expand the collar outwardly into contact with the wall of a well bore and thereby close off and separate the annulus space above and below the packer assembly. Opposite end faces of the packing collar 17 preferably are covered by pressure distributing expander rings 20.

The cylinder barrel assembly 18 includes a slip expander collar 21 having downwardly tapered conical portions for engagement behind a set of radially movable slips 22 which are carried in the upper head portion 23 of a slide cylinder 24 having a bottom head portion 25. The two head portions 23 and 25 are closures for opposite ends of the cylinder 24 and have slide bearing on the tube 1 and mandrel 2 and which slide surfaces are preferably sealed by O-rings, as seen in FIG. 3B. The

pass tube '37 is threaded at its upper end into space internally of the cylinder 24 and surrounding tube sections 1 and 2 provides a chamber which is subdivided or partitioned by a piston 26 into an upper chamber space 27 and a lower chamber space 28. The periphery of the piston is for slide bearing thereon by the cylinder 24 and these bearing surfaces are preferably sealed by an O-ring carried by the piston. Similarly, O-rings sealthe bearing portions between the piston and the peripheral surfaces of the tube sections 1 and 2. Initially, the piston is secured to the tubing section 1 by interengageable screw threads29 and the barrel assembly 13 is secured to the mandrel 2 by shear pins 30 and 31 and in this position of the parts the lower chamber 28 communicates with the interior of the mandrel 2 through one or more lateral ports 32 in the mandrel while the upper chamber space 27 communicates with the interior of the mandrel through clearance surrounding the mandrel and one or more lateral ports 33 through the mandrel wall.

7 Referring to FIG. 2B, it will be seen that the piston 26 carries ndepending pin 34 which extends through an aperture in the lower closure head 30. A set of segmental ratchets 35 are fitted Within an upwardly tapered portion of the pin receiving aperture and are retained within the aperture by a gland 36. The ratchets cooperate with the head 30 and pin 34 to provide a oneway gripping action accommodating free upward movement of the head relative to the pin while resisting downward travel of the head and barrel assembly.

.A ay-pass tube, as seen in FIG. 2A, is indicated at 37 as projecting through the packing collar 17 and in open communication at its lower end with the exterior of the packer assembly below the packing element. This byan axial bore 38 drilled upwardly in the upper body 3 to communicate with a pair of piston chambers each of which is formed by drilling a cylindrical hole radially inwardly from the periphery ofthe body and is closed or deadended by a piston or slip button 39. Each piston has a vertical slot in its outer face to straddle a retaining strap 40 and the outer face of the piston has upwardly extending wickers or clutch teeth which when the pistons are projected outwardly can engage the wall of the well bore to resist upward movement of the body 3. A coil spring 41 interposed between the retainer strap 40 and the piston 39 acts to bias the piston to retracted position. Projected position of the piston can occur when fluid acting against the rear face of the piston is of higher pressure than the pressure of fluid acting against the front face of the piston. Preferably, two diametrically opposite sets of two hold-down slips will be provided in the body 3.

The packer assembly minus the collet 4 and tubing string thereabove but otherwise in the relationship illustrated in the drawing, will be lowered with the tubing string 1 into a well bore to a selected depth at which it is desired to set the packer. Pressure of well fluid in which the packer may be submerged will be balanced on opposite sides of the hold-down slips 39 and will also be balanced within the chambers 27 and 28 on opposite sides of the piston 26. An unbalance of pressure on opposite sides of the piston 26 so that higher pressure obtains within the upper chamber 27 will, after a given spread, cause the shear pin 30 to break and slide the barrel assembly 18 upwardly on the piston 26. The force will be transmitted through the slips 22 and expander 21, causing the shear pin 31 to break for both deforming the packing collar 17 and moving the slips 22 outwardly into clutching engagement with the wall of the well bore and the parts will be anchored securely in place by reason of the slips 22 and by reason of the action of the one-way ratchet 35 so that the expanded acking element 17 will seal off the annulus space surrounding the packer assembly above and below the packer element. Should annulus pressure below the packer exceed the pressure above the packer, the'higher pressure acting across the packer by way of the by-pass 37 will project the holddown slips 39 and resist upward displacement.

For such packer setting purpose and after the tubing string collet 4 has been stabbed into position and locked, a retrievable tool may be lowered through the tubing string 2 and arranged to seal the tube bore intermediate the ports 32 and 33. Fluid pressure above the seal can then be increased by pumping downwardly into the tubing string 2 for entry of the fluid pressure through the port 33 and into the chamber 27.

A preferred setting tool of a known type is illustrated in FIGS. 3a and 3b in operative relationship within the mandrel and in the instant just prior to its actuation. This tool includes a body 50 which can be lowered on a wire line and which contains a pair of magnetic field responsive switches 51 axially spaced apart to correspond with the spacing of the fields provided by the two sets of magnets 11-11 so that two switches are concurrently closed as they come into the two signaling fields. This completes an electric circuit for firing an explosive charge housed within the body 51) for affording actuating pressure on a slide plunger which both projects latching dogs 52 into a keeper groove. of the mandrel 2 and opens a chamber 53 at either atmospheric or a reduced pressure level for communication through side ports in the tool body 50 with the mandrel port 32 and lower chamber 28 to thereby evacuate fluid from and reduce pressure within the chamber 28. Spaced apart peripheral seals 54 carried on the body bear on the mandrel above and below the port 32 and seal well fluid from the path of communication between the depression chamber 53 and the piston chamber 28. A by-pass contained within the tool body and around the seals 54 enables well pressure fluid from below to reach the port 33 and the upper chamber 27. In the event well pressure is insuflicient to fully set the packer, fluid under pressure can be pumped from the surface downwardly for the purpose of completing the setting of the packer. After the packer has been set, the wire line tool can be retrieved and the packer will be held in the set relation of the parts.

Removal of the packer can be effected by applying rotative force on the tubing string 1, first, to break the shearable pin 12 and then to rotate the screw threads 29 out of engagement for detachment of the tubing and piston connection. Thereupon, elevation of the tubing string 1 will take up the lost motion between the snap ring 16 and the pickup shoulder 15 on the body 3, and with continued elevation the body 3 will rise and remove the axial stress on the expanded packer 17 for its contraction. Additional upward travel of the tubing string 1 will bring its upwardly facing shoulder 43 into engagement with the downwardly facing shoulder 45 on the slip expander 21 for allowing slip contraction and thereafter the barrel 18 will be picked up by the gauge ring 19 and brought back to the surface with the rest of the assembly.

A deformable collar which has been under stress for a considerable period of time may tend to stick and resist relative .movement of a tubing string on which it is sleeved, and to overcome this problem the opposing surfaces of the packer 17 and tubing string 1 are lined with a relatively thin layer 60 of tough, waxy solid plastic compound. The fluorocarbon compounds are excellent for this purpose, and particularly polytetrafluoroethylene.

What is claimed is:

1. In a well bore packer assembly, a mandrel having an upper packing collar abutment body, a deformable packing collar surrounding the mandrel below said body, a lower collar abutment and cylinder barrel slidably sleeved on the mandrel and co-operating therewith in forming a piston enclosing chamber, a piston positioned within the chamber and partitioning the same int-o upper and lower sections so that a higher fluid pressure within the upper section will push the lower abutment barrel toward the upper packing collar abutment body and a production tubing section extending from said body and having connection with the piston by which the position of the piston is fixed relative to said abutment body.

2. In a well bore packer assembly as in claim 1, said mandrel having axially spaced apart ports communicating with the piston chamber on opposite sides of the piston and means in the mandrel to receive a seal for closing said ports from one another and accommodating diflerential pressure action within the chamber sections.

3. In a well bore packer assembly as in claim 1, a one-way ratchet connection between the piston and the slidable barrel active against relative barrel movement in the direction away from said abutment body.

4. In a well bore packer assembly as in claim 3, said one-way ratchet connection including a dependent pin carried by the piston and projected slidably through an aperture in the barrel, said aperture having an upwardly tapered portion and ratchet segments housed in the tapered portion and formed interiorly thereof with ratchet teeth engageable with the pin and exteriorly thereof with upwardly tapered surfaces in slide bearing wedging engagement on said tapered portion.

5. In a well packer assembly as in claim 1, the production tubing section connection with the piston comprising interengaging screw threads on the tubing section and the piston which upon relative rotation of the tubing section enables disconnection with the piston, said tubing section and the mandrel having co-operating pick up shoulders which come into engagement upon elevation of the tubing section following such piston disconnection and upon further elevation of the tubing section raise the upper packing collar abutment away from the lower collar abutment and cylinder barrel for relief of setting force on the packing collar.

6. Ina well bore packer assembly as in claim 1, the production tubing section connection with the piston being disconnectable in response to predetermined movement manipulation of the tubing section, and co-operating pickup abutments on the tubing section and the body which are interengageable to raise the mandrel and its upper packing abutment body upon elevation of the tubing section relative to the lower collar abutment and cylinder barrel.

7. In a well bore packer assembly, a subassembly unit comprising a mandrel and an upper packing collar abutment fixed on the mandrel, a production tubing section extended into said unit and having lost motion connection therewith, a packing collar surrounding the mandrel and the tubing section, a liner of fluorocarbon compound between the collar and the tubing section, hydraulically actuated slip means carried by said abutment, pressure fluid by-pass means across the packing collar leading from the bottom thereof to said slip means, a lower abutment and slip assembly sleeved on and co-operating With the mandrel to aiford a piston chamber therebetween, a piston within the chamber having a one-way ratchet connection with said abutment and slip assembly, pressure fluid ports communicating the chamber on opposite sides of the piston with the interior of the mandrel and a detachable interconnection initially joining the tubing section with the piston and detachable to render the lost motion connection effective.

8. In a well bore packer assembly, a mandrel, a deformable packing collar surrounding the mandrel, upper and lower packing collar abutments of which one is fixed to the mandrel as a unit therewith and the other is slidable on the mandrel to deform the packing collar under stress, a production tubing section projected through the packing collar, a lost motion connection between the tubing section and said unit, a detachable connection between the tubing section and said unit to render the lost motion connection inelfective until said packing collar is to be released and means facilitating relative travel of the tubing section through a stressed packing collar after the detachable connection has been detached and comprising a layer of tough, waxy solid plastic compound interposed between adjoining surfaces of the packing collar and the tubing section.

References Cited by the Examiner UNITED STATES PATENTS 2,467,801 4/1949 Baker 166-120 2,878,877 3/1959 Baker 166-120 3,166,127 1/1965 Broun et al. 166-120 3,211,226 10/1965 Myers et al. 166-120 CHARLES E. OCONNELL, Primary Examiner, JAMES A. LEPPINK, Examiner

Claims (1)

1. IN A WELL BORE PACKER ASSEMBLY, A MANDREL HAVING AN UPPER PACKING COLLAR ABUTMENT BODY, A DEFORMABLE PACKING COLLAR SURROUNDING THE MANDREL BELOW SAID BODY, A LOWER COLLAR ABUTMENT AND CYLINDER BARREL SLIDABLY SLEEVED ON THE MANDREL AND CO-OPERATING THEREWITH IN FORMING A PISTON ENCLOSING CHAMBER, A PISTON POSITIONED WITHIN THE CHAMBER AND PARTITIONING THE SAME INTO UPPER AND LOWER SECTIONS SO THAT A HIGHER FLUID PRESSURE WITHIN THE UPPER SECTION WILL PUSH THE LOWER ABUTMENT BARREL

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