US2875837A - Packer - Google Patents

Description

M. A. GARRISON PACKER March 3, 1959 Filed Oct. 25, 1954 I 2 Sheets-Sheet 1 INVENTOR. MAR/0N A. CARR/SON ATTORNEYS March 3, 1959 M. A. GARRISON PACKER 2 Sheets-Sheet 2 Filed 001:. 25, 1954 INVENTOR. MAR/0N 14. CARR/SON BY ATTORNEYS United States Patent O This invent ion' relates to a deep well packer construcnoi ib'le assembly'for" preventing the plastic end'fiow or." extrusion ofithe packer rubber when the". packer is subjected to high diiferential 'pressure's.

It is the principal object of this-invention toprovide a mechanism for preventing plasticend' flow, or extrusion,

More particularly,the*invention1 is directed to an of a packer element, which device may be expanded from a retracted condition of relatively less diameter than a" -well bore orcasing to an expanded position engagingthetperiphery of the well bore or pipe'in which the packer is tobe set. i

Anotherobject' of this-invention isto' provide an anticxtr usion'devi'ce according to the preceding object, wherein theanti-extrusion' assembly isrne'chanically actuated independentlyof the packing 'element, whereby the anti-- extrusion assembly may beucompletely' expanded prior (other setting of the packing element.

Afurtheriobjectof. this invention is to provide a packer construction as set forth in either ofi the preceding ob jects; whereinmeans are provided to permit reciprocating theitools topound through abridge in the borehole'=with.- out inadvertentexpansion ofthe packing element'or the extrusiontpreventiondevice;

A preferredform ofrny inventionisrdeseribed in the following: detailed specification, and illustrated by way of examplewin the accompanying drawings, wherein:

Fig; 1 shows asectional view of the upper portion of afpacker constructed' in accordancewith my invention.-

Fig. 2" is'acontinuation of- Fig. 1 and shows a sectional view ofthe lower portion of the packer.

, Fig. 3 is a sectional view taken online 3"3 of- Fig. 2.

Figs; 4 and 5:'areviews of the upper and'lowei' portions, respectively,- of the packer showing the packer in an intermediate: position, wherein the extrusion prevention device has been expanded with the packing element remainin g contracted.

Figkdis a sectional view taken on line 6-6 of Fig. 5.

Fig. 7 is aperspective view of oneof the leaves of theanti-end flow assembly.

Referring now to the drawings, wherein like reference numerals are used to denote like elements throughout'the various views'shown, the packer comprises a central supporting mandrellfl. An upper housing, generally indicated at 11,- -;comprising upper and lower portions 12 and" 13, respectively, is telescopically mounted aboutthe upper end of 'the mandrel 10'. The upper po'rtion12 ofsthe housing 11 is adapted to be threaded onto the lower end of a well string (not shown) by the threaded connection indicated at I4.- The internal diameter of the-upper portion 12 of the housing 11 is slightly larger thantheiinternal diameter of the lower portion 13 thereof. A tubular. cap 15 is threaded ontothe upper end of the mandrel 10 and is adapted to abut the upper end of the lower portion 13 of the housing 11 to limit the upward movement of the housing 11 relative to the mandrel 10. The lowerportion 13 of the housing 11 is provided with a plurality of longitudinally extending grooves 16. Each of the grooves 16 is. adapted. to slidably receive a key 17 fastened to the mandrel 10;, whereby the housing 11 is' permitted, to. move longitudinally relative to the mandrel 10 but is locked against rotation relative thereto; A- pair of shear pins 18 initially lock the housing 11 and mandrel 10 against relative longitudinal movement.

An elastomer packing element 19 is mounted on the mandrel 10' below the housing 11. The upper end of the packing element. 19 is bondedlto a metallic ring 20, which is connected" to the. lowerend-of the housing 11 by a split sleeve. 21 held together by bolts v22. Bolts 22 extend through thesplit'ring on cords preferably parallel to adiameter. Each bolt is inserted. into a threaded aperture in. the other segment. Consequently, Fig. 4 shows a side elevation of-onesleeve in which the bolts do not extend through. to the outside surface. An annular metal ring 23'; having substantially the same diameter as the packing-element 19, iskeyed to the mandrel 10 adjacent the lower. end of the packing element 19 by a pair of snap rings24 and 25 fitting into suitable grooves provided in the: mandrel 10. above and below the ring 23.

A second-"housing, generally indicated at. 26, is slidably mounted on the lower end of the mandrel 10. The housing 26 is. formed of two sectionsl27 and 28, respectively. The upper section 27"is. provided with longitudinal. grooves.29'containing keys 30 fixed to the mandrel.10,"whereby'thehousing 26; is permitted to move longitudinally relative to: the mandrel 10 but is. prevented from rotating relative thereto. A plurality of shear-pins 31 are fixed to the housing section 27 and extend inwardlythe'refrom into sliding blocks 32, which are slidably mounted in grooves 33 formed in the mandrel10.

The lowersection28 of the housing- 26 has an internal dianreteri'slightly larger than the upper section 27 and slidably receives therewithin a piston head 34'- threaded onto the mandrel 10; The piston head 34 is provided with the usual packing rings 35 to seal against the inner wall of thehousing section 2 8. A mandrel extension 36, of substantially smaller diameter than the piston 34, extendsdownwardly therefrom and is slidably received within a central bore through a partition 37 in the housing section 28 below the piston 34. A restricted orifice 38 provides restricted fluidcommunication between the space 48 inside the housing 28, between the piston head 34 and the partition 37, and the well bore outside of the housing section-28. The orifice 38 is located immediately above the partition 37. As will subsequently be more fully explained, the pistonhead 34, fluid chamber 48 and orifice 38 provide a dash-pot assembly for retarding downward: movement of the mandrel 10 relative to the housing 26.

1 Referring nowto Fig. 2, a' plurality of grooves 39 are formed in the outer surface of the mandrel 10 between the ring 23 and the upper end of the housing 26. The lower portions. 39a of the grooves'39 are straight and extend parallel to the axis of the mandrel 10, and the upper :portions '39bare wound around the mandrel 10 in the form of a spiral. for purposes which will be hereinafter setJforth. A plurality of overlapping leaves, generally indicated at 40, each having a depending pivot pin 41, are spaced-circumferentially around the mandrel 10,

with the pivotpins 41 of each rotatably mounted in suitable sockets 42 provided in the upper end of the upper section 27 of the housing 26. Each of the leaves 40 is provided with an inwardly extending spherical dog 43, which'is slidably received in one of the grooves 39.

As can best be seen in Fig.7, each of the leaves 40 has an inner .or rear portion 44, to which the pin 41 and spherical dog 43 are attached. This portion of the leaf 40 is adapted to lie: closely adjacent the upper surface of the housing section 27. An intermediate portion 45 is formed integrally with the rear portion 44 and is stepped upwardly with respect thereto, so that its undersurface is in a plane slightly above the plane of the upper surface of the rear portion 44. Similarly, the front or outermost portion 46. is "stepped upwardly. from the intermediate portion 45, so. that the plane of its undersurface is slightly above the plane of the upper surface of the intermediate portion 45.

Referring now to Fig. 3, it can be seen that when the leaves 40 are in their retracted positions, the intermediate portion 45. of each leaf overlies the rear portion 44 of the next adjacent leaf, and the front or outer portion 46 overlies the intermediate portion 45 thereof. When the leaves are in extended position, as shown in Fig. 6, the'end portions 46 and intermediate portions:45 form a continuous unbroken annular ring adapted to receive therewithin the annular ring 23 and form a solid abutment: completely filling the bore hole to prevent end flow, or extrusion, of the packing element 19.

In the useof the device, a tail pipe (not shown) is fastened to the lower end of the lower housing 26 by means of the thread 47. The tail pipe is either long enough to reach the bottom of the well, or is provided with any one of. many well-known anchoring devices. The upper housing 11 isconnected by thread 14 to the lower end of a well string (not shown) and the device is lowered into the well. Well fluid flows into the chamber 48 through the orifice 38. If the tool strikes an obstruction in the bore, it may be spudded, i. e., reciprocated to pound through the obstruction, without shearing the pins 31 and 18, since the fluid in the chamber 48 will act as a shock absorber to absorb the shock of the spudding action. The mandrel 10 is permitted some vertical movement with respect to the housing 26 without actuating the leaves 40 because of the straight portions 3% of the grooves 39. The amount of this vertical movement is limited by the length of the slots 33 in which the blocks 32, connected to the shear pins 31, ride...

When the desired location is reached, weight is set down slowly on the upper end of the tool and the mandrel 10 moves downwardly relative to the housing 26 which is supported by the tail pipe. The fluid in the chamber 48 passes outwardly through the orifice 38 into the well bore. When the top ends of the slots 33 reach the blocks 32, the pins 31 will shear. At this time, the spherical dogs 43 on the leaves 40 are just leaving the straight portions 39a of the grooves 39 and entering the spiral portions 39b thereof. Continued downward movement of the mandrel 10 relative to the lower housing 26 moves the spherical dogs 43 relative to the pivot pins 41,to pivot the leaves 40 outwardly from their retracted positions shown in Figs. 2 and 3 to their extented positions shown in Figs. 5 and 6. The ring 23 moves downwardly and seats within the ring formed by the overlapped outer and intermediate portions 46 and 45, respectively, of the leaves 40. This is the relationship shown in Figs. 4 and 5, wherein the anti-extrusion assembly is extended but the packing element has not yet been expanded. Further downward pressure causes the pins 18 to shear and permit the upper housing 11 to move downwardly relative to the mandrel to expand the packing element 19.

From the foregoing description, it may be seen that I have provided a packer construction incorporating an anti-extrusion assembly adapted when expanded, to completely fill the well bore to prevent end flow of the elastomer packing element, and wherein the anti-extrusion assembly is mechanically actuated entirely independent of the setting of the packing element, whereby the antiextrusion assembly is completely expanded prior to the setting of the packing element. It is further evident that I have provided a structure which is capable of spudding to get by obstructions in the well bore without inadvertently expanding either the anti-extrusion assembly or the packing element. a

While I have shown and described the preferred form of my invention, it is to be understood that various changes may be made in its construction by those skilled in the art, without departing from the spirit ofthe invention as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In a packer construction, .the combination comprsiing a support, an elastomer packing element mounted on said support and adapted to becompressed longitudinally into engagement with a borehole wall, said support including a tubular housing, a mandrel telescopically re ceived in said housing and arranged for relative movement thereto, an anti-extrusion device mounted on said support opposite an end portion of said packingelement, said anti-extrusion device including a plurality of ele ments arranged circumferentially about said mandrel, each of said elements being conformed to overlap its adjacent elements and including an outer portion and an inner dog portion, means pivotally mounting each. of said elements on said support at' a point spaced from the. dog portion thereof for movement substantially normal to'the axis of said housing and mandrel between an inwardly retracted position and an extended position wherein the maximum diameter of said elements is greater than the uncompressed diameter of said packing element, and

means carried by said support for engaging said dog portions a'ndresponsive to relative movement between said housing and said mandrel to move'said elements from said retracted position to said extended position prior to compression of said packing element.

' 2. In a packer construction, the combination comprising a tubular housing, a mandrel slidably received within said housing for limited longitudinal movement relative thereto, an elastomer packing element. carried by'said mandrel, said packing element being adapted to be compressed longitudinally to effect expansion thereof into engagement with a borehole wall, and an anti-extrusion device received between opposing portions of said packing element and said housing, said anti-extrusion device including a plurality of equally spaced elements arranged circumferentially about said mandrel, each of said elements including an arcuate outer portion conformed to overlap its adjacent elements and an inner dog portion for engaging said mandrel, means pivotally mounting each of said elements on said housing at a point spaced from said dog portion for movement substantially normal to the axis of said housing and mandrel between an .inwardly retracted position and an extended position wherein the maximum diameter of said elements is greater than the uncompressed. diameter of said packing element, said mandrel including means engaged with said dog portions for pivoting said elements between said positions in response to said longitudinal movement of said mandrel relative to said housing.

3. In a packer construction, a tubular housing, a mandrel, means for slidably but non-rotatably receiving one end of said mandrel within said housing and permitting limited longitudinal movement relative thereto in either direction, said mandrel carrying at its other end an elastomer packing element adapted to be compressed longitudinally into engagement with a borehole wall, and an anti-extrusion device received between opposing ends of said housing and packing element and initially spaced from said packing element, said anti-extrusion device comprising a plurality of relatively flat leaves arranged circumferentially about said mandrel and each conformed to overlap its adjacent leaves, each of said leaves including an arcuate outer portion and an inner dog portion for engaging said mandrel, means pivotally mountwherein the maximum diameter of said leaves isgreater :than the uncompressed diameter of said packingclement, said mandrel having a plurality of spiral grooves each slidably receiving one of said dog portions to pivot said leaves between said positions in response to said longitudinal movement of said mandrel relative to said housing.

4. In a packer construction, a tubular housing, a mandrel, means for slidably but non-rotatably receiving one end of said mandrelwithin said housing and permitting limited longitudinal movement relative thereto in either direction, said mandrel carrying at its other end an annular elastomer packing element adapted to be compressed longitudinally into engagement with a borehole wall and a rigid annular ring, and an anti-extrusion de vice received between opposing ends of said housing and ring and initially spaced from said ring, said antiextrusion device including a plurality of equally spaced relatively flat leaves arranged circumferentially about said mandrel and each conformed to overlap its adjacent leaves and to receive said ring, each of said leaves including an arcuate outer portion and an inner dog portion for engaging said mandrel, means pivotally mounting each of said leaves on said housing between the outer and dog portions thereof for movement substantially normal to the axis of said housing and mandrel between an inwardly retracted position and an extended position wherein the maximum diameter of said leaves is greater than the uncompressed diameter of said packing element, said mandrel having a plurality of parallel spiral grooves each slidably receiving one of said dog portions to pivot said leaves between said positions in response to said longitudinal movement of said mandrel relative to said housing.

5. In a packer construction, the combination comprising a support including a tubular housing and a mandrel, said housing having an enlarged bore portion and a lateral orifice in fluid communication therewith, said mandrel including an enlarged end portion slidably received in said enlarged bore portion, an elastomer packing element mounted on said support and adapted to be compressed longitudinally into engagement with a borehole wall, and an anti-extrusion device mounted on said support opposite an end portion of said packing element, said anti-extrusion device including a plurality of elements arranged circumferentially about said mandrel, each of said elements being conformed to overlap its adjacent elements and including an outer portion and an inner dog portion, means pivotally mounting each of said elements on said support at a point spaced from the dog portion thereof for movement substantially normal to the axis of said housing and mandrel between an inwardly retracted position and an outwardly extended position wherein the maximum diameter of said elements is greater than the uncompressed diameter of said packing element,

lost motion means allowing longitudinal movement of said mandrel relative to said housing without actuating said elements, and means carried by said support for engaging said dog portions and responsive to relative movement between said housing and mandrel to move said elements from said retracted position to said extended position prior to the compression of said packing element.

6. In a packer construction, a tubular housing having an enlarged bore portion and a lateral orifice in fluid communication therewith, a mandrel extending out of said housing and having an enlarged end slidably received in said enlarged bore portion, means for slidably but nonrotatably keying said housing and mandrel together, said mandrel carrying at its other end an annular elastomer packing element adapted to be compressed longitudinally into and a rigid annular ring, engagement with a borehole wall and an anti-extrusion device received between opposing ends of said housing and packing element and initially spaced from said ring, said anti-extrusion device comprising a plurality of equally spaced relatively fiat leaves arranged circumferentially about said mandrel and each conformed to overlap its adjacent leaves and to receive said ring, each of said leaves including an arcuate outer portion and an inner dog portion for engaging said mandrel, means pivotally mounting each of said leaves on said housing between the outer and dog portions thereof for movement substantially normal to the axis of said housing and mandrel between an inwardly retracted position and an extended position wherein the maximum diameter of said leaves is greater than the uncompressed diameter of said packing element, said mandrel having a plurality of parallel grooves each slidably receiving one of said dog portions, each groove including a longitudinal portion and a spiral portion, said longitudinal portions permitting longitudinal movement of said mandrel relative to said housing without actuating said leaves and said spiral portions pivoting said leaves between said positions in response to further longitudinal movement of said mandrel relative to said housing.

References Cited in the file of this patent UNITED STATES PATENTS 2,171,049 Simmons Aug. 29, 1939 2,546,377 Turechek Mar. 27, 1951 2,555,647 King June 5, 1951 2,704,581 Potts Mar. 22, 1955

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