US3374839A

US3374839A - Well packer apparatus

Info

Publication number: US3374839A
Application number: US539794A
Authority: US
Inventors: Maurice P Lebourg
Original assignee: Schlumberger Technology Corp
Current assignee: Schlumberger Technology Corp
Priority date: 1966-04-04
Filing date: 1966-04-04
Publication date: 1968-03-26
Anticipated expiration: 1985-03-26

Description

' March 26, 1968 M. P. LEBOURG WELL PACKER APPARATUS 3 Sheets-Sheet 1 Filed April 4, 1966 .INVENTOR.

March 26, 1968 M. P. LEBOURG WELL PACKER APPARATUS Filed April 4, 1966 3 Sheets-Sheet 2 Meow/re I? Zeoury I N VEN TOR.

3 Sheets-Sheet 5 M. P. LEBOURG WELL PACKER APPARATUS March 26, 1968 Filed April 4, 1966 United States Patent ()filice 3,374,839 WELL PACKER APPARATUS Maurice P. Lehourg, Houston, Tex., assignor, -by mesne assignments, to Schlumberger Technology Corporation, Houston, Tex., a corporation of Texas Filed Apr. 4, 1966, Ser. No. 539,794

4 Claims. (.Cl. 166-131) ABSTRACT OF THE DISCLOSURE A well packer apparatus including a body member having a fluid passageway, slip and expander means for anchoring against movement in a well conduit, packing means for packing off a well conduit, port means in the body member extending between the passageway and the exterior of the body member, the packing .means being normally disposed on the body member above the port means, and releasable means which couples the packing means to the body member and which is responsive to a predetermined force to permit movement of the packing means relative to the body member ,to position below the port means. a

This invention relates generally to subsurface well tools, and more particularly to a retrievable well packer usable in well bore pressuring operations.

Retrievable well packers which are run on a tubing string and set in tension for performing well pressuring operations such as squeeze cementing may include an upper slip and drag block assembly in combination with a lower packer element. The packer'is set by first manipulating a control mechanism to permit relative movement between parts of .the packer and then applying tension to the tubing string to set slips in engagement with the well conduit and expand the packing element to pack oifthe annulus between the wellconduit and the body of the packer. Pressuring operations .can then be performed by displacing fluid under pressure down through the t ibing string and into the formation through cqnduit perforations.

The load required to set the packer and maintain an effective annulus seal is maintained primarily by an upward strain taken on the tubing string at the earthssurface. In the not uncommon circumstance wherein the formation zone at whichthe pressuring operation is being performed will take large amounts of fluid, for example where the formation fluid level is low, the fluid pressure elow the packer and :within the tubing string candrop to relatively low values once the formation starts to take fluid so that the packer will be supporting a substantial amount of weight of the fluid in the'aniiulus thereabove. This additional weight in combination with the normal tension load imposedon the tubing string for maintaining the packer seat can overload the' tubing string and cause failure thereof.

The general object of the present invention is to provide anew and improved tension-type wellI packer apparatus which incorporates certain safety features which prevent overloading thetubing string underthe abovementioned or similar conditions v' Apparatus in accordance with the present invention comprises a tubular body adapted :to he suspendedin a well conduit on a running-in'string and to be anchored therein by slip and expander rneans. Thebo'dy carries a packer element which is disposed intermediate :the'slip and expander means and an abutment and is rnountedf'or movement on the bodybetween first and secondpositions. The abutment is normally rigidly sec lrjedtothenbody and is adapted to transmit compressive forces tothe'packe'r element but a securing means responsive to a predetermined force can release the ,packer' element for' rnovement Patented Mar. 26, 1968 relative to the body. A plurality of lateral passageways in the body are located between said first and second relative positions and communicate with the bore in the body. When the packer element is in one of the positions and the securing means unreleased, fluid communication between the bore of the body and the well annulus above the packer element is .blocked; when the securing means is released and the packer element is moved to the other position, fluid communicationbetween the bore of the body and the well annulus above .the packing element is established.

The present invention has other objects and advantages which will become moreclear in connection with the'following specification. The novel features of the present invention being set forthwith particularity in the appended claims, the present invention both as to its structural organization and operation'may be best understood by way of illustration and example of one embodiment thereof When'taken in conjunction with the accompanying drawings in which:

FIG. "1 illustrates a well packer apparatus incorporating the present invention in position with a cased well bore;

FIG. 2 is a partial longitudinal cross-section view with parts of the well packer apparatus of the present invention being shown in the relative positions they will occupy when loweredinto a well conduit; 7

FIG. 3 is a view similar to FIG. 2 but showing the parts of the well packer apparatus in the relative positions they will occupy when the packer is in a set conditionin the well conduit; 7

FIG. 4 is a layout of the J-slot arrangement used in the packer apparatus; i

FIG. 5 is an enlarged view of an expander cone shown partially in section with a support ring'insert ed;

FIG. 6 is an enlarged fragmentary view showing the expander cone in a collapsed condition for disengaging the slips from the well conduit;

FIG. '7 is an enlarged fragmentary view of the lower abutment and body of the well packer which embodies the principles of the present invention; and

FIG. 8 is alongitudinal cross-sectional view illustrating an opera-tion of'the present invention.

@Referring .to FIG. 1 of the drawings a tension-type packer 10 'is shown suspended within a well conduit 11 on a running-in string 12 which expands upwardly to the earths surfacejlf desired, a safety joint, bypass and other accessories can be connected in the running-in string 12 above the packer. The well packer 10 includes a longitudinally extending tubular body or mandrel 13 threaded or otherwise provided with a coupling at its upper end for connection to the runningein string 12. The lower end of the body 13 is likewise connected to a tubing string L4 as by a threaded coupling 15. Slidablymounted on an upper portion of the body 13 isa slip and drag block assembly 16 which includes a plurality of normally retracted slip elements generallyindicated as 17, each having an enlarged head portion 18 provided with'a plurality of wickers or teeth 19 on the periphery thereof. A stopcollar 210 is connected to the body 13 to limit upward movement of the assembly 16 relative thereto.

Below the slip and drag block assembly 16 is an expander'assembly 21 having an inclined surface 22 thereon which is co'opera'ble with the slip elements 17 for shifting them outwardly of the b'ody'13 upon relative movements between the expander assembly and the slip elements.

An elastornericpacking sleeve 23 encircles thebody13 and' is received between an upper gauge ring 24 and a lower annular abutment orsupport 25. The upper gauge ring 24is adapted f or slidingimovement over the body .13 and the abutment 25 is releasabiy secured to the body J so as to be normally movable therewith. Sliding movement of the upper gauge ring 24 toward the lower abutment 25 will compress the packing element 23 and radially expand it into engagement with the well conduit for packing off the annular space between the well conduit and the packer body 13.

The lower abutment 25 generally includes a ring member 26 which is connected to a sleeve 27 which sealabiy closes a plurality of lateral ports through the wall of the packer body 13. A frangible member cooperates between the sleeve 27 and the body 13 to releasably secure the lower abutment to the body.

Referring particularly to FIG. 2, the slip and drag block assembly 16 includes a carrier body 28 which is provided at angularly spaced points thereabout with longitudinally extending slots 29 in which a plurality of drag blocks 30 are radially shiftable and urged outwardly into frictional engagement with the well conduit 11 by means of a plurality of coiled compression springs 31 which seat at the base of the slots 29 and extend into spring seat recesses 32 in the respective drag blocks 30. The stem 33 of the respective slip elements 17 project into a slot 34 formed in the lower end of a respective drag block 30', the slip elements being pivotally connected to the drag blocks by pi-vot pins 35 extending through the side walls of the drag blocks and through the stems 33 of the slip elements.

Means are provided for normally biasing the head portions 18 of the slip elements 17 away from the wall of the well conduit 11 and in this connection it will be noted that there is an extension 36 formed on the upper end of each slip element and extending from the slots 34 in the respective drag blocks 30 into a bore 37 extending through the body of each drag block, there being a coiled compression spring 38 seating in the base of the slot 34 of each drag block and extending through the bore 37 so as to engage the extension 36, thus tending to pivot the slip elements 17 about their pivotal mountings 35 in a direction to move the slip head portions 18 away from the well conduit. Such movement of the slip head portions is limited upon engagement of the slip stems 33 with the webs 39 extending between the side walls of the slots 34 in the drag blocks 30, whereby the slip extension 36 may not be urged by coil spring 38 into contact with the well casing 11.

Outward movement of the drag blocks is of course limited by engagement with the well conduit when the tool is being run into a well. But otherwise, ejection of the drag blocks 30 from the carrier body slots 29 is precluded by an axially extending annular flange 40 formed at the outer periphery of the drag block carrier body 28 adjacent its upper end.

Inasmuch as the drag blocks 30 frictionally engage the well conduit 11 it is necessary to provide control means for releasably connecting the drag block carrier housing 28 to the mandrel or body 13 of the well packer. The control means includes an inwardly projecting lug 41 connected to the upper end of the carrier body 28 and a J-slot 42 in the wall of the body 13. As shown in FIG. 4, the J-slot 42 has a relatively long lengthwise extending portion 43, a short length vertical portion 44 and an intermediate length vertical portion 45. An upwardly inclined slot portion 46 connects the intermediate and

short length portions

45, 44 and a downwardly inclined slot portion 47 connects the short and

long portions

44, 43. When the parts of the packer are in the position shown in FIGS. 1 and 2, that is, in condition for being run into a well, the lug 4-1 is disposed at point A at the upper end of the inter mediate length vertically extending portion 45 of the J- slot. The resistance caused by frictional engagement of the drag blocks with the well conduit allows the body 13 to be moved relative to the slip and drag block assembly 16. Appropriate manipulation of the running-instring 12 by imparting up and down movement thereto while holding right-hand torque will position the lug 41 Within the 4 long vertically extending slot 43 and permit setting of the packer 10 within the well conduit.

Below the J-slot 42 in the mandrel 13 is a downwardly facing shoulder or stop means 48. Spaced downwardly from the shoulder 48'on the mandrel is a member 49. Member 49, for example, may be a rectangularly shaped snap ring received in a groove 50 in the mandrel. Slidably mounted on the mandrel 13 between the stop means 48 and the ring member 49 is an annular support ring 51. An annular recess portion 52 (FIG. 6) is formed on the lower end of the carriage body 28 and is sized to receive therein the upper end of the support ring 51. The support ring 51 on the mandrel 13 is coextensive with and normally supports the expander cone 53 in an expanded position.

The structural details of the expander assembly 21 are shown in FIG. 5. In general terms, it may be stated that the expander assembly includes an outer, radially expandable and contractable cone member 53 in combination with the cone support ring 51 on the body 13. The cone 53 has an outer surface 54 which is inclined downwardly and outwardly from an upper end surface 55 to a cylindrical outer surface 56 of large diameter. The bore 57 through the cone is formed of a plurality of

counterbores

58, 59 which provide upwardly facing shoulders 60, 61 respectively. Thus constructed, the bore 57 has a plurality of stepped surfaces which normally receive complementary outer surfaces of the support ring 51.

The cone is made radially expansible and contractabfe by providing alternating series of radially cut

slots

62, 63 through the wall thereof, each series of slots extending from one end of the cone to points 64 near respective opposite end thereof. In the cones expanded condition shown in FIG. 5, the support ring 51 is received wi.hin the bore 57 of the cone to normally maintain the ex panded condition. However, should the support ring be removed from the bore, the cone 53 will collapse radially inwardly to a contracted condition.

The expander cone 53 has an outer relieved portion 65 at its lower end which provides a seat for a complementarily shaped portion on the upper end of the gauge ring 24. An annular recess 66 is formed within the bore of the upper gauge ring 24 to permit movement of the ring member 49 relative to the gauge ring. Upward travel of the support 51, the cone 53 and the upper gauge ring 24 is limited by the downwardly facing shoulder 48 on the mandrel or body 13.

In operation of the apparatus thus far described, the well packer 10 is positioned within the Well conduit 11 at the desired setting point. Then the operator, while holding right-hand torque on the running-in string, will sequentially pick up, slack off and again pick up on the runningin string so as to align the lug 41 on the carrier body 28 with the long longitudinally extending portion 43 of the J-slot 42. It may be readily appreciated that the direction of torquing may be reversed by reversing the J-slot arrangement. As the mandrel 13 moves upwardly relative to the drag block assembly 17 (which is frictionally held relative to the well conduit) the lower abutment 25, packing element 23, upper gauge ring 24 and the expander assembly 21 move upwardly relative to the drag block as-' sembly. The outer tapered surface 54 of the expander cone 53 engages the tapered sloping surfaces 67 on the slip head portions 18 so as to pivot the heads outwardly into gripping engagement with the well conduit. When the upwardly holding teeth 19 on the slips grip the casing, further upward movement of the expander cone is not possible so that further upward travel of the mandrel and the lower abutment 25 will compress and expand the resilient packing element 23 into sealing engagement with the wall of the Well conduit. The packing element 23, when expanded, provides an effective seal between the mandrel and the well conduit so long as the tension is maintained on the running-in string 12. The lug 41, for example, can be'in a position B as shown in FIG. 4.

Normally, torecover the packer from the well it is only necessary to relieve the upward tension on the running-in string 12 and lower the running-in string so that the lower abutment 25 releases the compression on the packing element 23. Subsequently, the shoulder 48 engages the support ring 51 to move the expander assembly 21 and the upper gauge ring 24 downwardly. The expander cone 53, when moved from below the slips, permits the slips to retract inwardly.

As was previously mentioned, the elastomeric packing element 23 is received between the upper gauge ring 24 and the lower abutment 25. The lower abutment includes a' ring member 26 having an annular recess 68 therein which receives the upper end portion of the sleeve 27 as shown in FIG. 7. A plurality of screws 69 or other suitable fastening means connect the ring and the sleeve as an integral unit. The sleeve 27 is releasably connected to the mandrel or body 13 by a ring-like shear member 70 disposed in complementary annular grooves in the sleeve 27 and the mandrel or body 13. The shear member 70 can be inserted intothe annular grooves through a tangential passageway 71 in the sleeve (FIG. 2).

A plurality of laterally extending ports 72 are provided in the body or mandrel 13 and are positioned adjacent to sleeve 27.

Sealing elements

73, 74 above and below the ports prevent fluid flow through the ports when the ports are thus positioned. That portion of the packer body 13 below the lower end of the sleeve 27 and the upper end of the lower coupling member has a suificient length whereby upon shear release. of the member 70 which releasably secures the lower abutment and the body 13 to one another, relative'movement of the body with respect to the abutment 25 and the elastomeric packer element 23 will place the lateral ports 72 above the packer element and provide fluid communication between the body passageway and the annular space exteriorly of the body 13 above the packer element.

The operation of the lower abutment shear member 70 and the body ports 72 occurs when the fluid pressure below the packer drops to a sufficient extent that there is a danger of running-in string failure due to tensile overloading. This can occur, for example, when a formation being treated or squeezed begins to take fluid rapidly and the hydrostatic pressure below the packer drops to such an extent that a substantial portion of the weight of the fluid column in the annulus above the packer is being imposed upon the packer and tends to move the packer downwardly within the well conduit. The annular shear member 70 which releasably secures the abutment 25 to the body in the position shown in FIGS. 2 and 3 is designed to shear release in response to forces less than the forces required to stress the running-string 12 beyond its yield point in tension.

When the shear member 70 is thus released, the lower abutment 25 and the packing element 23 can slide downwardly with respect to the body 13 to the position shown in FIG. 8 where the body ports 72 are disposed above the packing element 23. Thus positioned, fluid communication is established between the bore of the body 13 and the annular space between the well conduit 11 and the body above the packing element, thereby permitting fluid pressures in the well annulus and in the running-in string 12 to equalize before the running-in string 12 can become overloaded and fail. The abutment and packing element slide downwardly over the body 13 and are caught by the collar 15 so that no parts of the packer are left as debris in the well conduit.

The expander assembly 21 can be operated to contract the cone and release the slips when the packer does not release in a normal manner when the running-in string 12 is lowered. Failure to release can be due to such factors as jamming of the slips, bonding of the packing element to the well casing, debris in the J-slot, etc. In any event, it will be immediately apparent to the operator that the packer has failed to release. In that event, the operator can apply tension to the running-in string 12 in an amount suflicient to overcome the shear strength. of the shear ring Upon release of the ring 70, the body moves quickly in an upward direction and the member 49 will move within the annular space 66 and deliver a jarring blow to the lower end of the support ring 51, thereby disabling the support ring by displacing it upwardly relative to the cone 53. It will be noted that due to the stepped longitudinal surfaces on the cone and support ring, the support ring will provide support up to a point when both stepped portions thereof simultaneously move from the

counterbores

58, 59 in the cone 53. At this point, the cone 53 contracts and collapses inwardly due to its natural tendency to return to its original shape.

When the cone 53 moves radially inwardly, the slip elements 17 are no longer supported thereby and the compression springs 38 act to pivot the slips away from their conduit gripping positions. Furthermore, continued upward movement of the support ring 51 will cause the upper end of the ring to engage in the recessed end portion 52 of the carriage body 28 and transmit upward movement of the body 13 to the carriage body. The consequent lifting forces applied thereto are applied to the slip elements 17 and due to the inclination of the upper surfaces of the wickers or teeth 19 will effect inward camrning of the slips away from the conduit wall. With the slip element 17 released, the entire packer can be withdrawn from the well.

It will be appreciated that the present invention offers numerous other advantages in addition to those already disclosed. For example, should a swabbing action occur when withdrawing the packer from the well conduit, the packer can be set and the shear member 70 operated to permit relative movement of the packer element 23 and the body 13 to expose the ports 72 above the packing element 23, thereby providing additional bypass for well fluids around the packing element. Also, should the packer accidentally set while withdrawing it from the well conduit, the shear member 70 will operate automatically to release the set condition before damage can be done to the running-in string.

It will be readily apparent that a tension-type well packer has been disclosed incorporating safety features which prevent overloading and failure of the running-in string. Since certain changes and modifications may be made in the apparatus as disclosed without departing from the scope of the inventive concept involved, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Apparatus for use in a well conduit comprising: a body having a bore therethrough and adapted for connection to a running-in string extending upwardly to the earth surface; slip and expander means on said body for anchoring in the well conduit, said slip means being shiftable outwardly of the body and supported in an anchoring position by said expander means; means responsive to an upward force on said body for releasing sai-d anchoring means; packing means disposed on said body below said slip and expander means and movable longitudinally relative to said body between first and second positions; a port in said body communicating with said bore and located between said first and second positions; and abutment means releasably holding said packing means in said first position, said abutment means being responsive to the upward force to release said anchoring means to release said packing means for relative movement to said second position.

2. Apparatus for use in a well conduit comprising: a body having a bore therethrough; a control assembly on said body including means for frictionally engaging the well conduit; anchor means on said control means for gripping the well conduit; expander means on said body cooperable with said slip means for shifting said slip means into gripping engagement with the well conduit; a pliant packer element disposed about said body below said expander means, said packer element being movable on said body between first and second positions; an abutment on said body normally holding said packer element in one of said positions; releasable means for securing said abutment to said body so that said abutment is effective to hold said packer element in said one of said positions but can be released to permit movement of said packer element to the other of said positions; and a lateral passageway in said body located between said positions, said passageway communicating said bore with the well annulus when said packer element is moved to the other of said positions upon release of said securing means.

3. A well tool for use in a well bore, the combination comprising: a body having a passageway therethrough; anchor means on said body for gripping a well conduit; packer means on said body for packing off the well bore; port means in said body extending between said passageway and the exterior of said body, said packer means normally disposed on said body above said port means; and releasable means coupling said packer means to said body, said releasable means being responsive to a predetermined force to permit movement of said packer means relative to said body to a position below said port means.

4. A well tool comprising: a body member having a fluid passage; expansible and contractable expander means and normally retracted slip means movable relative to said expander means to expanded positions for anchoring against movement in a well conduit; releasable support means between said expander means and said body member for suporting said expander means in expanded condition and said slip means in anchoring condition;

packing means for packing off the annulus between said body member and a surrounding well conduit wall; port means in said body member extending between said fluid passage and the exterior of said body member, said packing means being normally disposed on said body member above said port means to prevent communication between said port means and the well annulus above said packing means; and releasable means for coupling said packing means to said body member, said releasable coupling means being operative in response to a predetermined force on said body member to permit movement of said packing means relative to said body member to a position where said port means communicates said fluid passage with the well annulus above said packing means, release of said coupling means enabling movement of said support means from between said expander means and said body member so that said expander means can contract and said slip means can move from expanded toward retracted positions.

References Cited UNITED STATES PATENTS 2,338,326 1/1944 Green 166140 X 2,389,985 11/1945 Justice et al. 166-131 X 2,796,938 6/1957 Lynes et al. 166-226 X 2,841,224 7/1958 Baker et al. 166129 X 2,951,539 9/1960 Malone et al 166226 X 3,035,639 5/1962 Brown et al. 166226 X 3,211,229 10/1965 Bramlett 166128 CHARLES E. OCONNELL, Primary Examiner.

DAVID H. BROWN, Examiner.