US2785758A

US2785758A - Apparatus for anchoring tubing strings in well bore conduits

Info

Publication number: US2785758A
Application number: US420527A
Authority: US
Inventors: Rcubon C Baker
Original assignee: Baker Oil Tools Inc
Current assignee: Baker Hughes Oilfield Operations LLC
Priority date: 1954-04-02
Filing date: 1954-04-02
Publication date: 1957-03-19
Anticipated expiration: 1974-03-19

Description

March 19, 1957 R. c. BAKER 2,785,758

APPARATUS FOR ANCHORING TUBING STRINGS IN WELL BORE CONDUITS- Filed April 2, 1954 2 Sheets-Sheet 1 C j?? 1. C

ATTORNEYS.

' March 19, 1957 R. C. BAKER APPARATUS FOR ANCHORING TUBING STRINGS IN WELL BORE CONDUITS Filed April 2, 1954 j if, 25

2 Sheets-Sheet 2 HIM! 4f mmm- 45 INVENTR.

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TTOQNEYS,

iinited States APPARATUS FOR AN CHGRING TUBlNG STRINGS EN WELL BRE. CONDUIT S Reuben C. Baker, Coalinga, Calif., assgnor to Baker Gil Tools, Inc., Los Angeles, Calif., a corporation of California Application April 2, 1954, Serial No. 420,527

Claims. (Cl. 166-212) proved subsurface well tool capable of anchoring a string of tubing in a well casing against longitudinal displacement, the tool being capable of safely withstanding comparatively high pressures.

Another object of the invention is to provide a hydraulically actuatable tubing anchor operable by pressure diderentials internally of the tool to move and hold the anchoring members against the well casing, in which the tubing anchor embodies devices for equalizing internal and external pressures, if necessary, in order to obtain reiease or" the tool from the well casing, in the event such pressures are not otherwise equalized.

A further object of the invention is to provide a tubing anchor having gripping members that are expanded outwardly into engagement with a well casing by hydraulic pressure within the tool, in which any pressures below the tool and tending to elevate it are utilized to engage the gripping members more securely against the well casing.

Yet a further object of the invention vis to provide a tubing anchor having gripping members expanded outwardly into engagement with a well casing by hydraulic pressure within the tool, in which release of the gripping members can be assisted by imposing a downward force on the tool in the well casing.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration'of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. lt will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure l is a combined longitudinal sectional and side elevational view of an embodiment of the invention, with its gripping members in retracted position, to enable the tool to be moved longitudinally in a well casing;

Fig. 2 is a view similar to Fig. 1, disclosing the equalizer valve in open position;

Fig. 3 is a view similar to Fig. 1, disclosing the tubing anchor anchored against the well casing;

Eig. 4 is a fragmentary enlarged longitudinal section or" a portion of the equalizer valve.

As disclosed in the drawings, a -tubing anchor A is to be lowered through a string of well casing B by means ot` a string of tubing or drill pipe C to a point in the casing at which it is to be anchored therewithin. The tubing anchor may be connected with another tool (not shown) secured to its lower end.A As an example, this undisarent ice gage the well casing in packed-oir condition and resist downward movement therewithin.

The tubing anchor A includes an upper tubular mandrelor inner member 11i adapted to be threadedly attached to the lower end of the tubing string C. This tubular mandrel is telescopically arranged within a tubular body 11 formed of several sections. Thus, the main intermediate portion 12 of the tubular body has its lower end threaded onto a lower body member 13, which may have a lower threaded box 14 for attachment to tubing or a tool (not shown) therebelow. The upper portion of `the body 12 is threaded onto a cap or lock ring 15 slidably engageable with the exterior of the tubular mandrel 16. To prevent foreign matter from passing between the body 11 and mandrel 1li, a suitable rubber wiper ring 16 may be secured to the cap 15 for slidable sealing engagement with the mandrel 10.

Disposed around the body 11 in circumferentially spaced relation are a plurality of longitudinal slots 17 in which gripping members 18 are slidable. The sides of the gripping members slidably engage the sides of the;

slots 17, the gripping members encompassing a rubber, or rubber-like, expansion sleeve 19, whose upper and lower ends engage the interior of the intermediate body member 12 on opposite sides of the slots. The lower portion oi the expansion sleeve 19 is disposed within an annular space between the upper portion 20 of the lower body member 13 and the intermediate body member 12 below the slots 17. The upper end of the rubber sleeve 19 is disposed within a companion annular space formed between the intermediate body member 12 and an outwardly directed ilange portion 21 of an inner protective nipple 22, which depends from the ilange portion along the inner surface of the rubber sleeve 19, and whose lower end engages a shoulder 23 on the lower body member 13. This nipple or protective member 22 has a plurality of side ports 24 establishing communication between the interior of the nipple 22 and the interior of the rubber expanding sleeve 19. The inner nipple 22 is held in a downward position in snug engagement with the shoulder 23 by a clamp nut 25 threaded into a threaded box portion 4b in the upper end of the intermediate body member 12 and engaging the upper end of the nipple. This nut 25 is prevented from loosening by a suitable set or lock screw 26 threaded through the body wall and engaging the clamp nut.

closed tool may consist of a well packer adapted to en- Leakage of fluid around the upper end 19a of the expansion sleeve is prevented by forming it as a lip or edge adapted to engage the inner wall of the intermediate body member 12. Similarly, leakage of Huid around the lower end 19h of the expansion sleeve is prevented by forming it as a lower lip seal engaging the inner wall of the intermediate body member 12. Fluid under pressure between the expansion sleeve 19 and the nipple 22 will press these upper and lower lip seals 19a, 1% securely against the inner wall of the intermediate body member 12', and prevent such uid from passing around the sleeve to its exterior. Leakage of uid endwise from the expansion sleeve 19 is further prevented by a suitable upper side seal ring 27, such as an O ring made of rubber or rubberlike material, contained within a groove 28 in the upper portion of the nipple and engaging the inner wall of the intermediate body member 12. Similarly, leakage of iiuid through the threaded joint between the intermediate body member 12 and lower body member 13 is prevented by a rubber or rubber-like O ring 29, or corresponding side seal, contained within a groove 315 in the lower body member 13 and engaging the inner wall or the intermediate body member 12 below the lower lip 19b.v It is evident that the lip seals 19a, 19]) and the

side seals

27, 29 prevent fluid frompassing out of the interior of the'rubber expansion sleeve 19 except through the nippleV ports 24.

Fluid under pressure within' the tubular mandrel 10 and the nipple 22 exerts an outward expanding force on the rubber expansion sleeve 19, carrying the gripping members 18. outwardly toembed their external portions 18u; which may be provided 'with suitable wickers or teeth, outwardly into anchoring4 lengagement withV the wall of the well casing Bf When theA internal pressure is relieved or' substantially equalized with respect to the external pressure, the gripping members are released and may be fully retracted by means of upper and lower springs 31 contained within upper and lower sockets 32 provided in the upper and lower terminal portionsi33, 34 of each gripping memberyand bearingv against upper and lower stop or retainer rings 35 secured to the' exterior of the intermediate body memberlZ on opposite sides of the longitudinal slots 17 Vintany suitable manner, as through use ofA the upper and l'wer screws 36. Thus, it is apparent that the helical compression springs 31 are constantly urging the gripping members 18 to a retracted position out of engagement from the wall of the Well casing, to correspondingly shift the rubber expansion sleeve 19 inwardly. However, this sleeve inherently tends to assume the `inward position shown in Figs. l and 2. When a pressure diierential of a suicient magnitude to overcome the inherent elasticity of the rubber sleeve 19 and the force of the springs 31 is imposed within the tool, then the rubber sleeve 19 is expanded outwardly to correspondingly expandthe gripping members 18 outwardly into anchoring engagement with the 'casing B. VThe higher the pressure dierential within the tool, the greater will be the force holding the gripping members anchoredto the Well casing. Y

As described above, the grippingrmembers 18 are released upon the relieving of the pressurel internally of the tubing string C and tool A, or its substantially equalizing with respect to therexternal pressure. In the event that a. mere relievingrof the pressure internally of the tool cannot occur, then an egualizing valve 37 is `embodied in the tubing anchor A, to make it possible Yfor such pressures tribe-substantially equalized. s

A'Jhe tubular mandrel o r inner member 10 has an outwardly directed flange 3Sv provided with externalleft-'hand threads 39 meshing with companion internal left-hand threads 40 in the intermediate body member 12. The internal left-handrthreads 40 may be the same .set of threads as are threadedly engaged by the clamp nut `25 and the upper cap or lock ring 15. The mandrel flange 38 is of a much shorter length than the distance :between the upper end of the clamp nut 25 and the .lower .end of the cap 15, permittingthe mandrel 10gto move longitudinally in both directions upon its rotation within the body 11 to the extent ylimited by engagement of the upper angeshoulder 41 with the .lower end of the cap YI5, for of the lower ange shoulder 42 with the'upperend kof the clampnut 25.

yWhen the mandrel 10 is threaded downwardly of the bodyll and occupies the position shown inFigs. 1 and 3, its lower cylindrical valve head vportion `43 is moved Within-a. cylindrical seat 46in the clamp nut 25 and nipple 22 into Vsealing engagement with a suitable seal Vring 47 contained within a groove 43 formed collectively in the upper end of the nipple 22 and thelower/end ofthe'clamp nut 25. This Yseal 47 will sealingly engage theperiphery ofthe valve head and prevent iluidfrom'passing around 'the exterior'of the'latter in "both directions. It.' is molded ohja-'metallic Vring 6G and has upper and lower outer lip portions 61 engagingthe 'base 48a of the grooveiS to prevent fluid leakage around the seal ringl "47 in vboth directions. When the mandrel is inthe lower vposition Vdisclosed in Fig. l, with the valve head 45 engagingthe Yseal 47,l'luid cannot pass between the interior and exterior of the tool througholne or more side'openings -or parts-49 .provided inthe intermediate bodyl member 12 above-the `clampnut 25. However, upon 'rotating the Vtubular-imanto they body, the tubular mandrel iselevated, by virtue of the threaded

connection

39, 49, to the extent limited by engagement of the upper angeshoulder i1 with the cap 15, which displaces the cylindrical valve head 45 above its companion seal 47, as disclosed in Fig. 2, which then opens the side ports 49 and allows the rluid to pass through these ports to equalize the pressure internally and externally of the tubing anchor.

It is to be noted that the lower ends 50 of the slots 17 are inclined to some extent' ina downward and outward direction to engage companion inclinedV surfaces 51 on the lower ends of the gripping members 1S. The upper ends 52 of the slotsv 17 are also inclined in an outward and downward direction, to engage correspondingly inclined surfacesr on the upper ends of the gripping members. The inclined surfaces 50, 51 at the lower ends of the slots 17 and gripping members 18 are utilized to assist in holding the gripping members in their outward anchored position against the well casing B, whereas the

upper surfaces

52, 53 are of'a retracting character, to facilitate release and retraction of the gripping members 18 with respect to the well casing B.

ln the event the gripping members 1S have been expan-dedV outwardly by the expansion sleeve 19 and an internal pressure differential is maintained within the tool, then the hydraulic forces may be acting on the body member 11 from below, or on some other equipment (not shown) Ysecured to the body and tending to elevate the latter. Should this action tend to occur, then the lower expander surfaces 50 are brought upwardly into engagement with the companion surfaces 51 at the lower end of the gripping members 18 and exert a laterally outward component of orce't'ending to hold the gripping members 18 yanchored against the well casing B.

Conversely, should the pressure within the tool be released, or equalized with respect to the pressure externally of the tool, and the gripping members 18'stil1 fail to retract, then a downward force can be imposed on the tubing I'string C andi'nandiel 1.0, which will b e 'transmitted through `the intermediate 'body member 12 and. cause the upperretracting surfaces V52 to engage the companion surfaces Y 51% on the upper ends of the gripping members -18 to urge the 'latter in .an inward direction.

Normally, theplarts of @the tool `.occupy the relative positions shown in Fig. l, in which theequaliziug valvef37 is closed and thegripping members 18 and expansion sleeve 19 Yare retracted. 'The tool A, usually connected to another ltool .or well 'packer therebelow, is lowered in the well casing -B `tothe point at which it is to be anchored to the Well casing. The lluid in lthe Vtubing string C and within the toolA may then Vbe subjected to pressure, the tool therebelow (not shown) usually effecting a seal with the well casing enabling a .pressure t0 be built up within the tubing string C and the tubing anchor A. This uid under pressure will pass through the nipple ports 24 and expand the expansion sleeve .19 outwardly, Vforcing theanchoring members 18 laterally outward in their slots 1-7 intoY anchoring engagement with the Wall ofthe well casing B (Fig. 3). -As the pressure diierential increases, the greater Vis the anchoring force exerted in an outward .direction upon the'ianchon'ng members 18. The wickers or teeth 18a on the fanchoringmembers are designed to resistlongitudinal.displacementofe tool A in both an upward and -a downward-:direction Whenever. itl-isdesired :ton'elease the .tubing anchor A, it is merely necessary toerelievethepressure therewithin, which will allow --the expansion .-Sleeve 19 to retract inherently, andY whichfwill enableithe retractor spring 31 to'shift Athe'grippingzmembers 18 back Yto their retracted positions, such 'asshown in Fig. ,1, which will then allow the :tubing string C. and the :tool 'A ato .be `VVmoved longitudnallyin .theme11 casing-fin either'anupward orzdownwardfdirection. VWith thefparts inithecondition just ref erred to, the tool A can be elevated in the well casing B and removedcompletely from the well bore.

dhould a pressure differential remain in the tubing string C and the tool A, the gripping members 1S will be held in their anchored position against the well casing, in the manner disclosed in Fig. 3. Under these conditions, the gripping members i8 will prevent rotation of the body 11 of the tool, w ereupon the tubing string C and the tubular mandrel 10 may be rotated in a clockwise or right-hand direction, to thread the mandrel upwardly within the body 11 and lift the valve head 45 above its companion seal 47, such as shown in Fig. 2, opening the side ports 49 and allowing the pressure internally and externally of the tool to equalize, thereby eilecting retraction of the packing sleeve 19 and the gripping members 18 from the well casing. The tubing anchor A may now be elevated or lowered in the well casing B.

In the event it is desired to again expand the gripping members 1S into anchoring engagement with the well casing, the mandrel 10 must be relowered, to place its valve head 45 in sealing engagement with the companion seal 47` Such relowering action will occur by suitably holding the body ,ll against rotation to permit the tubing string C and mandrel 10 to be rotated in a couuterclockwise direction, or to the left. Usually, the tool (not shown). connected to and disposed below the tubing anchor A has provisions for preventing its rotation, which will also forestall rotation of the body 11 of the tubing anchor, to which it is connected. Following the relowering of the mandrel l@ and closing of the side ports 49, a pressure differentim can again be imparted to the uid in the tubing string C and tool A to again expand the anchoring members i8 outwardly into rm gripping engagement with the wall of the well casing B.

The inventor claims:

l. In an apparatus to be anchored in a Well casing disposed in a well bore: a body having circumferentially spaced slots therein; casing gripping members slidable laterally in said slots; a pliant, elastic sleeve within said body and gripping members sealingly engaging said body on opposite sides of said slots and expandible outwardly by uid under pressure therewithin to shift said gripping members outwardly into engagement with the well casing; and a sleeve within said elastic sleeve xedly and immovably secured to said body 'and having a port for directing uid under pressure into the interior of said elastic sleeve, said sleeve secured to said body having means thereon engaging said elastic sleeve to prevent an end portion of said elastic sleeve from moving yaway from sealing engagement with said body.

2. 1n an apparatus to be anchored in a well casing disposed in a well bore: a body having circumferentially spaced slots therein; casing gripping members shdable laterally in said slots; a pliant, elastic sleeve within said body and gripping members sealingly engaging said body on opposite sides of said slots and expandible outwardly by uid under pressure therewithin to shift said gripping members outwardly into engagement with the well casing, the lower ends of said slots and the lower ends of said gripping members being inclined in a downward and outward direction and engageable with each other upon upward movement of said body relative to said gripping members to urge the latter laterally outward.

3. In an apparatus to be 'anchored in a well casing disposed in a well bore: a body having circumferentially spaced slots therein; casing gripping members slidable laterally in said slots; a pliant, elastic sleeve within said body `and gripping members sealingly engaging said body on opposite sides of said slots and expandible outwardly by tluid under pressure therewithin to shift said gripping members outv ardly into engagement with the well casing, the lower ends of said slots and the lower ends of said gripping members being inclined in a Vdownward and outward direction and engageable with each other upon upward movement of said body relative to said gripping sleeve within said elastic sleeve secured to said body and having a port for directing fluid under pressure into the interior of said elastic sleeve.

4. ln an apparatus to be anchored in a well casing disposed in a well bore: a body having circumferentially spaced slots therein; casing gripping members slidable laterally in said slots; a pliant, elastic sleeve within said body and gripping members sealingly engaging said body on opposite sides of said slots and expandible outwardly by iluid under pressure therewithin to shift said gripping members outwardly into engagement with the well casing, the lower ends of said slots and the lower ends of said gripping members being inclined in a downward and outward direction and engageable with each other upon upward movement of said body relative to said gripping members to urge the latter laterally outward; the upper ends of said slots and the upper ends of said gripping members being inclined in a downward and outward direction and engageable with each other upon downward movement of said body relative to said gripping members to urge the latter laterally inward.

5 ln an apparatus to be anchored in ya well casing disposed in a well bore: a body having circumferentially spaced slots therein; casing gripping members slidable laterally in said slots; a pliant, elastic sleeve within said body and gripping members sealingly engaging said body on opposite sides of said slots and expandible outwardly by fluid under pressure therewithin to shift said gripping members outwardly into engagement with the well casing; the upper ends oi said slots and the upper ends of said gripping members being inclined in a downward and outward direction and engageable with each other upon downward movement of said body relative to said gripping members to urge the latter laterally inward.

6. in apparatus to be anchored in a well casing disposed in a well bore: a body having circumferentially spaced slots therein; casing gripping members slidable laterally in said slots; a pliant, elastic sleeve within said body and gripping members sealingly engaging said body on opposite sides of said slots and expandible outwardly by fluid under pressure therewithin to shift said gripping members outwardly into engagement with the well casing; a tubular mandrel connectible to a tubing string and telescoped within said body vand movable longitudinally relative thereto, said body having a side port above said elastic sleeve; and valve means operable by said mandrel in response to manipulation of the tubing string and moving longitudinally of said body to selectively open or close said body side port.

7. In an apparatus to be anchored in a Well casing disposed in a well bore: a body having circumierentially spaced slots thereing. casing gripping members slidable laterally in said slots; a pliant, elastic sleeve within said body and gripping members sealingly engaging said body on opposite sides of said slots and expandible outwardly by iluid under pressure therewithin to shift said gripping members outwardly into engagement with the well casing; a tubular mandrel connectible to a tubing string and threaded within said body for movement longitudinally relative thereto; said body having a side port above said elastic sleeve; and valve means operable by said mandrel in response to rotation and longitudinal movement of said mandrel with respect to said body for selectively opening or closing said body side port.

8. ln an apparatus to be anchored in a well casing disposed in a well bore: a body having circumferentially spaced slots therein; casing gripping members slidable laterally in said slots; a pliant, elastic sleeve within said body and gripping members sealingly engaging said body on opposite sides of said slots and expandible outwardly by iluid under pressure therewithin to shift said gripping members outwardly into engagement with the well casing; a tubular mandrel connectible to a tubing string and threaded within said body for movement longitudinally relative, theres; Sad. bedr having a Sid@ am; valve means: @perale by Sad mandrel' in responser 10. ,rQfafQtl and Qgsitudivral @vement 0f Said, mandrel Withfespegt to s'aidbody for selectively opening or closing said body sidepert; and a sleeve within said elastic sleeve secured to said body and having a port for directing fluid under pressnre into theA interior of said elastic sleeve.

9, In an apparatus'to be anchored in a Well casing disposed in a Well bore: a body having circumferentially spaCCd Slots therein; casing gripping members slidable laterally insaid slots; a pliant, elastic sleeve Within said body and gripping members sealingly engaging said body on opposite sidesY of said slots and expandible outwardly by fluid under pressure therewithin to shift said gripping members Qlltwardly into engagement with the well casing; a tubular. mandrel connectible to a tubing string and threaded within said body for movement longitudinally relative thereto; said body having a side port; valverneans operable by said mandrel in response to rotation and longitudinal movement of said mandrel with respect to said body for selectively opening or closing saidvbody side port; the lower ends of said slots and the lewer ends of said gripping members being inclined in a downwarl and outward direction and engageable with each other upon upward movement of said body relative to said gripping members to urge the latter laterally outward; and a sleeve within said elastic sleeve casing; a sleeve Within said elastic sleeve irredly and movably secured to said body and'having a poi-ttor recting uid under pressure into the interior of said elastie sleeve; a tubular mandrel connectible to a tubing .s t g and. telescope@- wfhia 'Sad batir and. mprablezsl w dinally relative thereto; said body having a side port; and valve means operableby said mandrel and rfrioya longitudinally of said body'to selectively open Yar'iclfcese said body side port.

References. Cited the 519 Qf, this parent UNTED- STA-fili??v PATENTS,

2,352,700 Ferris July 4, 1944 V.7.,3,7(),8-3` 2 Baker. Mar. 6,Y 19.45 2,584,448 Hern Feb. 5, 1952 2,603,163 Nixon Iuly- 15', 1.952 2,638,168 Parks Mayl 12,1953