US3011555A - Well packers - Google Patents

Description

Dec. 5, 1961 E. H. CLARK, JR 3,011,555

WELL PACKERS Filed April 14, 1958 2 Sheets-Sheet 1 II a .14 E00 2a lNV ENT OR.

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Dec. 5, 1961 E. H. CLARK, JR 3,011,555

WELL PACKERS Filed April 14, 1958 Y 2 Sheets-Sheet 2 I100 30 I E00 6:

-44 it -45 11/ 2 -Ak INVENTOR.

3,011,555 WELL PACKERS Earnest H. Clark, Jr., Downey, Caiifi, assignor to Baker Oil Tools, Inc., Los Angeles, Calif., a corporation of California Filed Apr. 14, 1558, Ser. No. 728,147 19 Claims. (Cl. 166122) The present invention relates to subsurface well bore apparatus, and more particularly to well packers and bridge plugs adapted to be set in well bores.

An object of the invention is to provide subsurface well bore apparatus capable of being set hydraulically in a well bore on a tubular string to form a bridge plug in the well bore, in which fluid in the tubular string can be placed under pressure without setting the apparatus until setting is purposely desired.

Another object of the invention is to provide an improved well packer or bridge plug capable of being set hydraulically in the well bore. r

A further object of the invention is to provide a sub surface well packer or bridge plug capable of being set hydraulically in the well bore, which is short and com- I pact, rendering it economical to manufacture.

Yet another object of the invention is to provide a well packer or bridge plug that is easy to drill out or remove after it has served its purpose in the well bore. In' fact,

only the upper few inches of the packer or plug need be disintegrated by a drill bit, the tool then being in condition to be pushed out of the way to the bottom of the hole.

Still a further object of the invention is to provide a hydraulically set well packer or bridge plug, in which the maximum pressure that can be imparted to the tool during the setting operation is limited automatically.

An added object of the invention is to provide a hydraulically set well packer or bridge plug, which is automatically released from a tubular running-in string, through which the setting pressure is applied, when the setting pressure reaches a predetermined maximum value.

Another object of the invention is to provide a well packer or bridge plug set hydraulically in a well bore by pressure applied through a tubular running-in string, in which the fluid pressure in the running-in string is multiplied for application to the tool in effecting its setting. This, a relatively low unit pressure in the tubular running in string is multiplied to a high pressure imposed on the tool. a

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of several forms in which it may be embodied. Such forms are shown in the drawings accompanying and forming part of thepresent specification. These forms will now be described in-tdetail, 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. t 7

Referring to the drawings:

FIGURE 1 is a combined side elevational and 1ongitudinal sectional view through an apparatus embodying the invention disposed in a well casing, or similar well conduit, with its parts in retracted position;

FIG. 2 is a longitudinal section through the apparatus shown in FIG. 1 with the well packer anchored in packedolf condition in the well casing;

FIG. 3 is a view similar to FIG. 2 showing the tubular string and portion of the setting mechanism released from the set packer for elevation in the well casing;

FIG. 4 is an enlarged cross-section taken along the line 4-4 on FIG. 1;

' ite tates Patent '0 FIG. 5 is a quarter longitudinal section through a portion of a modified form of well packer;

FIG. 6 is an enlarged cross-section taken along the line 6-6 of FIG. 5.

The apparatus specifically illustrated in the drawings is a well packer A adapted to be anchored in packed-01f condition in a well casing B, or similar well conduit, and preferably against movement therewithin in both an upward and a downward direction. The well packer is lowered in the well casing on a tubular string C, such as drill pipe or tubing, which may include, at any desired point above the well packer or bridge plug A, another well packer (not shown) through which fluid under pressure can be pumped for action upon the present well packer A, and also for the purpose of circulating fluid through the present tool.

The well packer A includes a main body 10 which has a central passage or chamber 11 therein, the lower end of which is closed, as by means of a plug 12 threaded into the lower end of the body. The upper end of the chamber or cylinder 11 is closed by a slidable piston or plunger 13which has a smaller outside diameter than the inside diameter of the body chamber 11. A slidable seal is pro- 1 vided between-the plunger and the upper portion of the body, as by havinga rubber or rubber-like O ring 14 disposed in an internal groove 15 in the body, and sealingly engaging the plunger or piston 13. This plunger or piston initially occupies an upper position within an outer cylinder or coupling sleeve *16, the upper end of which is threadedly secured to the lower portion of the tubular string C. This cylinder or coupling sleeve is releasably secured to the upper portion of the body 10, as by means of a coupling element or pin 17 consisting of an outer enlarged head 18 disposed in a radial bore 19 in the lower portion of the sleeve 16, and also received within a counterbore 20 in the exterior of the body 10. This coupling element or pin 17 also includes an inner piston portion 21 integral with the head 18 and disposed within a radial or lateral cylinder 22 formed completely through the body 10- of the tool and opening into the central passage 11 of the latter. The coupling pin 17 is maintained inv its coupling position, such as disclosed in FIGS. 1, 2 and 4, by means of a shear pin 23 located in a transverse 'hole 24 in the sleeve 16 and received within a companion aligned hole in the coupling ele'ments head 18. Leakage of fluid through the radial cylinder 22 is prevented by a piston ring 25, such as a rubber or rubber-like'O ring, sealingly engaging the wall of the cylinder 22.

The upper portion of the plunger or piston 13 is suitably secured to the central hub 26 of a spider 27, the arms 28 of which diverge from one another'and are integral with a valve seat or upper piston member 29 having a passage 30 therethrough, and which is slidable along the cylinder wall 31. This upper piston member or valve seat 29 has a piston ring 32, such as' a rubber or rubber-like 0 ring, mounted in its periphery and adapted to slidably seal against the wall 31'of the cylinder sleeve 16. The upper piston or valve seat 29 is adapted to be engaged by a companion valve element 33, such as a ball valve member, adapted to be dropped, at the proper time, from the top of the well bore into the tubular string C, moving downwardly through the fluid in the tubular string and coming to rest upon the valve seat 29, to close the central passage 30 through the latter. In the absence of the valve element 33, fluid can pass from the exterior of the cylinder 16 through bleeder or circulation ports 34 in its lower portion into the annular space'35 between the plunger 13 and the cylinder 16, flowing up wardly through this space, between the arms 28 and through the central passage 30 in the upper piston 29 into the tubular string C. Conversely, fluid can also flow or be pumped downwardly from the tubular string C through the upper piston 29, between the arms 28 into the annular space 35 between the plunger and cylinder, passing out through the bleeder or circulation ports 34 into the annulus 36 around the apparatus.

The well packer or bridge plug A has a plurality of segmental slips 37 disposed around the body 10. These slips have upper sets of wickers 38 facing in a downward direction and adapted to dig into the Wall of the well casing B to prevent downward movement of the well packer therewithin, as well as lower wickers 39 facing in an upward direction and adapted to dig into the wall of the well casing to prevent upward movement of the well packer or bridge plug therewithin. The upper and lower portions of these wickered slip members 37 may be integral with one another and are initially retained in a retracted position by an encompassing split retracting ring 40 that inherently tends to contract, and which is received within an external groove 41 in the slips, urging them inwardly and holding their wickers 38, 39 spaced from the wall of the well casing B.

The upper portions of the slips 37 have inner surfaces 42 tapering in a downward and inward direction, being adapted to coact with a companion tapered surface 43 on an upper expander 44 secured to the body 10, as by being threaded thereon, its unthreading being prevented by a set screw 45. The slips 37 also have lower inner inclined surfaces 46 tapering in an upward and inward direction and coacting with a companion tapered surface 47 on a lower expander 48 initially secured to the body of the tool by one or more shear screws 49. Disposed around the body It) of the tool is a packing sleeve 56, of rubber or rubber-like material, the upper end of which bears against or which may be coupled to the lower portion of the lower expander 48, the lower end of the packing sleeve being adapted to bear against or be coupled to a thrust ring 51 which is initially secured to the body of the packer by one or more shear screws 52. This thrust ring 51 is adjacent an annular cylinder 53, the lower portion 54 of which is threadedly secured on the lower end of the body 10, and which may have an external taper or nose 55 to act as a guide for the well packer as it is lowered in the well casing.

The lower portion 54 actually constitutes a cylinder head, leakage between the head and the body of the tool being prevented by a seal ring 56. A cylinder sleeve or skirt 57 extends upwardly from the head and is spaced from the body 10 to define an annular cylinder space 58 in which an annular piston 59 is disposed. Initially, the lower end of the piston may rest upon the cylinder head 54, its upper end being adjacent the thrust ring 51. Immediately above the cylinder head 54, the body 10 is provided with one or a plurality of radial ports 60 therethrough establishing communication between the central passage or inner cylinder 11 of the body 14} and the annular cylinder space 58.

Leakage of fluid in an upward direction from the annular cylinder 53 is prevented by an inner seal ring 61 mounted on the piston 59 and engaging the body 16 above the ports. Leakage of fluid between the piston 59 and the cylinder skirt 57 in an upward direction is prevented by a seal ring 62 on the piston sealingly engaging the inner wall of the cylinder 53.

A seal ring 63 may also be provided in the end of the piston 59 which seals against the lower surface of the thrust ring 51, and another seal ring 64 may be provided in the lower expander 48 for sealing engagement against the periphery of the body 10.

After the packer has been anchored in packed-off condition in the well casing, in the manner described hereinbelow, the parts are retained in such condition by a split lock or ratchet ring 65 disposed between the body 10 and the upper portion of the piston 59. This split ratchet ring has internal ratchet teeth 66 facing in a downward direction adapted to coact with companion upwardly facing ratchet teeth 67 on the body. The ratchet ring 65 also has external cam surfaces 68 adapted to coact with companion cam surfaces 69 in the piston 59. Thus, the piston 59 can move upwardly relative to the body 10 of the tool, the ratchet ring 65 merely ratcheting past the body teeth 67, but any tendency for the piston to move downwardly is resisted by the camming action of the inclined cam surfaces 68, 69 urging the ratchet sleeve inwardly to maintain the locking engagement of the downwardly facing ratchet teeth 66 with the upwardly facing body teeth 67. On the other hand, should the body 10 tend to move upwardly with respect to the piston 59, such action is prevented by the locking action of the ratchet teeth 66, 67 against one another and by the cam surfaces 68, 69 on the ratchet ring and the piston holding the ratchet ring 65 inwardly.

The well packer A is anchored in packedoflf condition Whenever the plunger or piston 13 is moved downwardly within the upper cylinder or coupling sleeve 16 and the body 10 of the tool. The downward force is transmitted through a liquid 70 filling the body of the tool and its ports 60. Thus, the downward force on the plunger or piston 13 is transmitted through the liquid 70 into the annular cylinder, being exerted in an upward direction on the annular piston 59. Such downward force on the plunger 13 is imposed hydraulically as a result of the valve element 33 being moved down through the tubular string C into engagement with the valve seat 29, closing the passage 30 through the latter. Pressure can be built up in the fluid in the tubular string C which acts downwardly on the ball 33 and the valve element 30 in order to shift the plunger 13 downwardly. The force of the plunger acts upon the fluid 70 in the packer body It}, forcing it outwardly into the annular cylinder 53 and urg ing the piston 29 in an upward direction. When the upward force on the piston 29 exceeds the shear strength of the screws 52 holding the thrust ring 51 to the body, such screws are sheared or disrupted, the thrust ring 51 then moving upwardly toward the lower expander 48 and foreshortening the packing sleeve 50, compressing the latter and expanding it in an outward. direction against the well casing B.

A continuation of the upward force on the piston 59, thrust ring 51, packing sleeve 50 and lower expander 48 will disrupt Or shear the screws 4a holding the lower expander to the body 10, the lower expander then moving upwardly with the thrust ring and the packing sleeve under and behind the slips 37, shifting the latter outwardly against the wall of the well casing. Actually, the upward movement of the lower expander 48 will be accompanied by a downward movement of the body 10 of the tool and of the upper expander 44, the latter moving down within the upper portion of the slips 37 and also urging them outwardly against the wall of the casing.

The hydraulic force can be increased by increasing the pressure on the fluid in the tubular string C, such pressure and increased force being transmitted through the plunger 13, which is moving down into the body 10, to shift the piston 59 upwardly and the body It) relatively downwardly to wedge the upper and lower expanders 44, 48 more firmly behind the slips 37 to embed their upper urging them outward against the wall of the well casing. B, and to further compress the packing sleeve 50 against the wall of the well casing and also against the body 10 of the tool. Such upward movement of the piston 59 and relative downward movement of the body 10 is permitted by the ratcheting action of the ratchet ring teeth 66 and the body teeth 67 upon one another. However, such teeth will coengage and prevent relative downward movement of the piston 59 or upward movement of the body 10 with respect to one another, holding the well packer or bridge plug A anchored in packed-off condition against the well casing.

It is to be noted that there is an annular space 71 between the plunger 13 and the inner wall 72 of the central passage or cylinder 11 in the body 10. The liquid under pressure in the body is also being exerted on the radial piston portion 21 of the coupling element or pin 17, tending to force it outwardly. The shear pin 23 holding this coupling pin in its coupling position to secure the coupling sleeve 16 to the body of the tool has a shear strength such that it will only be disrupted by the hydraulic pressure tending to force the piston 21 outwardly when such pressure reaches a predetermined maximum value. When such pressure is imposed on the liquid, the pin 23 is disrupted and the coupling pin 17 blown out of the aligned radial holes 19, 22, allowing the fluid pressure in the tubular string to shift the plunger 13 downwardly to its fullest extent, the liquid merely being forced to squirting out of the aligned radial holes 22, 19, thus relieving the pressure in the tool. At this time the coupling sleeve or cylinder 16 is released from the body 10 of the tool, allowing the tubular string C to be elevated, raising the coupling sleeve upwardly with it away from the well packer or bridge plug A, which remains anchored in packed-off condition in the well casing (FIG. 3). The

plunger 13 will remain within the body 10 of the tool and the valve ball element 33 may remain on its valve seat 29. However, the coupling sleeve 16 is elevated above the valve seat 29 and the valve ball element 33, there then being a full opening through the cylinder or coupling sleeve 16 through which fluid can be discharged.

It it to be noted that the cross-sectional area of the upper piston or valve seat 29 is substantially greater than the cross-sectional area of the plunger or piston 13. Accordingly, the unit pressure applied to the ball valve ele ment 33 and the valve seat 29 is multiplied several times by the plunger or piston 13 upon the liquid 70 within the body of the tool, this higher unit pressure then being exerted over the cross-sectional area of the annular piston 59 for the purpose of anchoring the well packer or bridge plug in packed-off condition in the well casing. By way of example, the area acrossthe valve seat 29 can be four to six times the area of the plunger or piston 13. Thus, if the shear pin 23 is designed to shear when a unit pressure of 8000 pounds is imposed upon the piston 59, the maximum pressure that can be imparted to the liquid is 8000 p.s.i., which is the maximum setting force imposed on the well packer. If the maximum unit liquid pressure is 8000 p.s.i. and if the ratio of the areas of the upper piston 29 and plunger 13 is 4 to 1, then only a fluid pressure of 2000 p.s.i; would be imposed upon the fluid in the tubular string C. If such ratio is 6 to 1, then only a unit pressure of about 1350 pounds need be imposed on the fluid in the tubular string C above the upper piston or valve seat 29 and the valve ball element 33.

The well packer or bridge plug A disclosed can be used in conjunction with an upper retrievable packer (not shown) to which it is connected. The tubular string C shown in the drawings may actually be the lower portion of such a retrievable packer. Normally, fluid can pass through the bleeder ports 34, the annulus 35 between the plunger 13 and coupling sleeve 16 and the spider 27 into the tubular string C, the latter automatically filling with the ,well bore fluid as the apparatus A is lowered through the liquid in the well casing B. Similarly, fluid can be pumped in a downward direction through the tubular string C and the retrievable packer (not shown), passing through the spider 27, the annulus 35 between the plunger 13 and setting sleeve 16, and out through the bleeder and circulation ports 34. Such circulation of fluid in either direction can occur without setting the well packer A, its slips 37 and packing sleeve 50, and other parts, remaining in their initial or retracted positions.

Assuming that the well packer or bridge plug A is to be set below a hole in the well casing, the location of which is unknown, the bridge plug A can be attached to a retrievable packer and the latter run in the well bore by means of a tubular string C. The retrievable packer is set against the well casing at intervals and pressure applied to the fluid in the annulus 36 between the tubular string and the well casing above the packer until the hole in the casing is located. When the hole is thus located the valve ball member 33 is dropped in the tubular string C and will gravitate to its seat 29, whereupon pressure is applied to the plunger 13 to anchor the packer A in packed-oif condition within the well casing B, until the maximum pressure is reached, whereupon the coupling element 17 is blown out of the aligned radial holes 22, 19, disconnecting the coupling sleeve 16 from the body 10 of the well packer. The upper packer (not shown) and tubular string C are then elevated until the upper packer is above the casing hole, whereupon it can be anchored in packed-oflcondition to the well casing at its upper location and cement slurry, or the like, pumped down the tubular string C and through the upper retrievable packer, passing out through the casing hole to seal the wall of the formation and plug the hole. The set packer A will prevent any of the pressure from being imposed on the fluid below its setting location. After the cement plugging operation has been completed, the tubular string C and the upper packer can be removed from the well casing in a known manner, leaving the well packer or bridge plug A anchored in packed-off condition in the well casing.

The application of pressure upon the anchored plug from above cannot release the packer A since its downward movement is resisted by the wedging of the upper expander 44 behind the slips 37 and the'digging of the downwardly facing teeth 38 into the wall of the well casing. The packing element 50 remains sealed against the well casing B and the packer body 10. If the bridge plug is anchored in. the well casing under a condition in which pressure is applied to it 'from below, tending to raise it, then such upward movement is resisted by the upward wedging of the lower expander 48 behind the slips 37 and the digging of the upwardly facing teeth 39 into the wall of the well casing, the packing sleeve 50 also remaining anchored in packed-off condition against the well casing and the body of the tool.

If it is desired to remove the well packer A from the well casing B, or at least to remove it from its set location in the well casing, it can be disintegrated readily by a drill bit. The entire well packer is comparatively short and has a relatively small quantity of metal in it. It is made primarily of readily drillable materials, such as cast iron or magnesium. As a matter of fact, it is only necessary to drill away a relatively small upper portion of the well packer. Thus, drilling need occur of only the upper part of the body 10', the upper expander 44 and the upper portion of the slips 37, whereupon the entire well packer can be pushed'down the casing to the bottom of the hole. If a milling tool, such as a washover shoe, is run in the well casing, it will only be necessary to mill away a few inches, such as three or four inches, of the upper expander 44 and the upper portion of the slips 37 for the well packer to be released from the well casing, enabling it to be pushed downwardly to the bottom of the hole, where it is out of the way. Thus, the bridge plug A can be removed from its anchored location in the well casing in a very simple and expeditious manner. Even if it has tobe drilled out completely, its short length will enable its complete disintegration and flushing from the well bore to take place in a comparatively short time.

In the form of the invention disclosed in FIGS. 1w 4, inclusive, the plunger 13 remainsin the body 10 of the tool after it has been set in the well casing. In the modified form illustrated in FIGS. 5 and 6, the plunger 13a can be retrieved. Thus, a longitudinal groove is provided in the plunger and aretracting pin 81 is threaded into the cylinder sleeve 16 and fits within such longitudinal groove 80, initially in its lower end.

The well packer embodying the retrieving feature shown in FIGS. 5 and 6 is operated in the same manner as in the other form of the invenion. However, after the coupling pin 17 has been blown out of the radial holes 22, 19 by the liquid 70 reaching its predetermined maximum pressure, the elevation of the tubular string C and the coupling sleeve 16 will move the retracting pin 31 upwardly with it until the pin engages the plunger 13 at the upper end of the longitudinal groove 80, then lifting the plunger 13 upwardly with it. With the plunger 13 removed, there is less material to be drilled out in the event it is necessary to disintegrate the entire bridge plug A.

The inventor claims:

1. In a well apparatus adapted to be lowered in a well bore on a tubular running-in string: a body; normally retracted means on said body adapted to be expanded outwardly of said body; means releasably connecting said body to the running-in string; fluid operated means on said body coacting with said normally retracted means to expand said normally retracted means outwardly of said body; mechanical means movable in said body for forcing a fluid under pressure into said fluid operated means to expand said normally retracted means outwardly of said body; and means connected to said releasable means and adapted to be subjected to said fluid under pressure when it reaches a predetermined value for releasing said releasable means.

2. In well apparatus adapted to be lowered in a Well bore on a tubular running-in string: a body; normally retracted means on said body adapted to be expanded outwardly of said body; means for connecting said body to a running-in string; fluid operated means on said body coacting with said normally retracted means to expand said normally retracted means outwardly of said body; mechanical means movable in said body for applying pressure to fluid in said fluid operated means to expand said normally retracted means outwardly of said body; and means adapted to be subjected to said fluid under pressure when it reaches a predetermined value for relieving said fluid under pressure.

3. In well apparatus adapted to be lowered in a well bore on a tubular running-in string: a body; normally retracted means on said body adapted to be expanded outwardly of said body; means releasably connecting said body to the running-in string; fluid operated means on said body coacting with said normally retracted means to expand said normally retracted means outwardly of said body; mechanical means movable in said body for applying pressure to fluid in said fluid operated means to expand said normally retracted means outwardly of said body; and means connected to said releasable means and adapted to be subjected to said fluid under pressure when it reaches a predetermined value for releasing said releasable means and for relieving said fluid under pressure.

4. In well apparatus adapted to be lowered in a well bore on a tubular running-in string; a body having a chamber therein containing a liquid; normally retracted means on said body adapted to be expanded outwardly of said body; fluid operated means on said body communicating with said chamber and coacting with said normally retracted means to expand said normally retracted means outwardly of said body, said fluid operated means being operable by the pressure of the liquid; a cylinder in communication with the tubular string and connected to said body; plunger means slidable in said cylinder and also slidable in said chamber and initially spaced from one end of said chamber, whereby fluid under pressure in the running-in string and cylinder shifts said plunger means in said cylinder and toward said end of said chamber to impose a pressure on said liquid which is operable on said fluid operated means to expand said normally retracted means outwardly of said body.

5. In well apparatus adapted to be lowered in a well bore on a tubular running-in string: a body having a chamber therein containing a liquid; normally retracted means on said body adapted to be expanded outwardly of said body; fluid operated means on said body communicating with said chamber and coacting with, said normally retracted means to expand said normally retracted means outwardly of said body, said fluid operated means being operable by the pressure of the liquid; a cylinder in communication with the tubular string; means subject to the pressure of the liquid in said chamber releasably connecting said cylinder to said body; plunger means slidable in said cylinder and chamber, whereby fluid under pressure in the tubular string and cylinder shifts said plunger means in said cylinder and chamber to cause said plunger means to impose a pressure on said liquid which is operable on said fluid operated means to expand said normally retracted means outwardly of said body and which is operable on said releasable means to release the same.

6. In well apparatus adapted to be lowered in a Well bore on a tubular running-in string: a body having a chamber therein containing a liquid; normally retracted means on said body adapted to be expanded outwardly of said body; fluid operated means on said body communicating with said chamber and coacting with said normally retracted means to expand said normally retracted means outwardly of said body, said fluid operated means being operable by the pressure of the liquid; a cylinder in communication with the tubular string and connected to said body; plunger means slidable in said cylinder and also slidable in said chamber and initially spaced from one end of said chamber, whereby fluid under pressure in the running-in string and cylinder shifts said plunger means in said cylinder and toward said end of said chamber to impose a pressure on said liquid which is operable on said fluid operated means to expand said normally retracted means outwardly of said body; said plunger means having a first portion subject to the fluid pressure in said cylinder and a second portion in said chamber for imposing pressure on the liquid in said chamber, said first portion being substantially greater in cross-sectional area than said second portion.

7. In well apparatus adapted to be lowered in a well bore on a tubular running-in string: a body having a chamber therein containing a liquid; normally retracted means on said body adapted to be expanded outwardly of said body; fluid operated means on said body communicating with said chamber and coacting with said normally retracted means to expand said normally retracted means outwardly of said body, said fluid operated means being operable by the pressure of the liquid; a cylinder in communication with the tubular string; means subject to the pressure of the liquid in said chamber releasably connecting said cylinder to said body; plunger means slidable in said cylinder and chamber, whereby fluid under pressure in the tubular string and cylinder shifts said plunger means in said cylinder and chamber to impose a pressure on said liquid which is operable on said fluid operated means to expand said normally retracted means outwardly of said body and which is operable on said releasable means to release the same; said plunger means having a first portion subject to the fluid pressure in said cylinder and a second portion in said chamber for imposing pressure on the liquid in said chamber, said first portion being substantially greater in cross-sectional area than said second portion.

8. In well apparatus adapted to be lowered in a well bore on a tubular running-in string: a body having a chamber therein containing a liquid; normally retracted means on said body adapted to be expanded outwardly of said body; fluid operated means on said body communicating with said chamber and coacting with said normally retracted means to expand said normally retracted means outwardly of said body, said fluid operated means being operable by the pressure of the liquid; a cylinder in communication with the tubular string and connected to said body; plunger means including an upper piston portion slidable in said cylinder and a solid plunger connected to said piston portion and shiftable in said chamber, whereby fluid under pressure in tl 1e tubular string and cylinder shifts said piston portion in said cylinder and said plunger in said chamber to cause said plunger to impose a pressure on said liquid which is operable on said fluid operated means to expand said normally retracted means outwardly of said body.

9. In Well apparatus adapted to be lowered in a well bore on a tubular running-in string; a tubular body having a closed lower end to provide a chamber containing a liquid, said body having an upper opening into said chamber; normally retracted means on said body adapted to be expanded outwardly of said body; fluid operated means on said body communicating with said chamber and coacting with said normally retracted means and being operable by the pressure of the liquid to expand said normally reracted means outwardly of said body; plunger means extending through said opening into said chamber and responsive to the pressure of fluid in substantially the entire length of the running-in string to be shifted downwardly in said chamber to impose pressure on the liquid which operates on said fluid operated means to expand said normally retracted means outwardly of said body.

10. In well apparatus adapted to be lowered in a well bore on a tubular running-in string extending to the top of the well bore? a tubular body having a closed lower end to provide a chamber containing a liquid, said body having an upper opening into said chamber; normally retracted means on said body adapted to be expanded out wardly of said body; fluid operated means on said body communicating with said chamber and coacting with said normally retracted means and being operable by the pressure of the liquid to expand said normally retracted means outwardly of said body; a cylinder in communication with the tubular string and connected to said body; plunger means slidable in saidcylinder and extending through said opening into said chamber, whereby fluid under pressure in substantially the entire length of the tubular string and in the cylinder shifts said plunger means downwardly in sm'd cylinder and chamber to impose pressure on the liquid which operates on said fluid operated means to expand said normally retracted means outwardly of said body.

11. In well apparatus adapted to be lowered in a well bore on a tubular running-in string; a tubular body having a closed lower end to provide a chamber containing a liquid, said body having an upper opening into said chamber; normally retracted means on said body adapted to be expanded outwardly of said body; fluid operated means on said body communicating with said chamber and coacting with said normally retracted means and being operable by the pressure of the liquid to expand said normally retracted means outwardly of said body; a cylinder in communication with the tubular string; means subject to the pressure of the liquid in said chamber releasably connecting said cylinder to said body; plunger means slidable in said cylinder and extending through said opening into said chamber, whereby fluid under pressure in the tubular string and cylinder shifts said plunger means downwardly in said cylinder and chamber to impose pressure on said liquid which is operable on said fluid operated means to expand said normally re-' tracted means outwardly of said body and which is operable on said releasable means to release the same.

12. In well apparatus adapted to be lowered in a well bore on a tubular running-in string; a tubular body having a closed lower end to provide a chamber containing a liquid, said body having an upper opening into said chamber; normally retracted means on said body adapted to be expanded outwardly of said body; fluid operated means on said body communicating with said chamber and coacting with said normally retracted means and being operable by the pressure of the liquid to expand said normally retracted means outwardly of said body; a cylinder in communication with the tubular string and connected to said body; plunger means slidable in said cylinder and extending through said opening into said chamber, whereby fluid under pressure in the tubular string and cylinder shifts said plunger means downwardly in said cylinder and chamber to impose pressure on the liquid which operates on said fluid operated means to expand said normally retracted means outwardly of said body; and means responsive to the liquid pressure in said chamber for relieving such pressure when it reaches a predetermined value.

13. In well apparatus adapted to be lowered in a well bore on a tubular running-in string; a tubular body having a closed lower end to provide a chamber containing a liquid, said body having an upper opening into said chamber; normally retracted means on said body adapted to be expanded outwardly of said body; fluid operated means on said body communicating with said chamber and coacting with said normally retracted means and being operable by the pressure of the liquid to expand said normally retracted means outwardly of said body; a cylinder in communication with the tubular string and connected to said body; plunger means slidable in said cylinder and extending through said opening into said chamber, whereby fluid under pressure in the tubular string and cylinder shifts said plunger means downwardly in said cylinder and chamber to impose pressure on the liquid which operates on said fluid operated means to expand said normally retracted means outwardly of said body; said plunger means vhaving a bypass to permit fluid to flow between the interior of said cylinder above said plunger means and the exterior of said cylinder above said normally retracted means; and means for closing said by-pass to enable fluid pressure to be built up in the tubular string for action on the plunger means.

14. In well apparatus adapted to be lowered in a well bore on a tubular running-in string; a tubular body having a closed lower end to provide a chamber containing a liquid, said body having an upper opening into said chamber; normally retracted means on said body adapted to be expanded outwardly of said body; fluid operated means on said body communicating with said chamber and coacting with said normally retracted means and being operable by the pressure of the liquid to expand said normally retracted means outwardly of said body; plunger means extending through said opening into said chamber and responsive to the pressure of fluid in the running-in string to be shifted downwardly in said chamber to impose pressure on the liquid which operates n said fluid operated means to expand said normally retracted means outwardly of said body; said plunger means having a by-pass to permit fluid to flow between the tubular string above the plunger means and a region externally of the body above the normally retracted means; and means for closing said by-pass to enable fluid pressure to be built up in the tubular string for action on said tubular means.

15. In Well apparatus adapted to be lowered in a well bore on a tubular running-in string: a body having a chamber therein containing a liquid; normally retracted means on said body adapted to be expanded outwardly of said body; fluid operated means on said body communicating with said chamber and coacting with said normally retracted means to expand said normally retracted means outwardly of said body, said fluid operated means being operable by the pressure of the liquid; a cylinder in communication with the tubular string; means subject to the pressure of the liquid in said chamber releasably connecting said cylinder to said body; plunger means slidable in said cylinder and chamber, whereby fluid under pressure in the tubular string and cylinder shifts said plunger means in said cylinder and chamber to impose a pressure on said liquid which is operable on said fluid operated means to expand said normally retracted means outwardly of said body and which is operable on said releasable means to release the same; and coengageable means on said cylinder and plunger means for withdrawing said plunger means from said chamber following release of said releasable means.

16. In well apparatus adapted to be lowered in a well bore on a tubular runningin string: a body having a chamber therein containing a liquid; normally retracted means on said body adapted to be expanded outwardly of said body; fluid operated means on said body communicating with said chamber and coacting with said normally retracted means to expand said normally retracted means outwardly of said body, said fluid operated means being operable by the pressure of the liquid; a cylinder in communication with the tubular string; means releasably connecting said cylinder to said body; plunger means slidable in said cylinder and chamber, whereby fluid under pressure in the tubular string and cylinder shifts said plunger means in said cylinder and chamber to impose a pressure on said liquid which is operable on said fluid operated means to expand said normally retracted means outwardly of said body; and coengageable means on said cylinder and plunger means for Withdrawing said plunger means from said chamber following release of said releasable means.

17. In well apparatus adapted to be lowered in a well bore on a tubular running-in string: a hollow body containing a fluid; normally retracted means on said body adapted to be expanded outwardly of said body; means releasably connecting said body to the running-in string; fluid operated means on said body communicating with the interior of said body and coacting with said normally retracted means to expand said normally retracted means outwardly of said body; mechanical means movable in said body for forcing the fluid in said body under pressure into said fluid operated means to expand said normally retracted means outwardly of said body; and means connected to said releasable means and adapted to be subjected to said fluid under pressure when it reaches a predetermined value for releasing said releasable means.

18. In well apparatus adapted to be lowered in a well bore on a tubular running-in string: a hollow body containing a fluid; normally retracted means on said body adapted to be expanded outwardly of said body; means for connecting said body to a running-in string; fluid op erated means on said body communicating with the interior of said body and coacting with said normally retracted means to expand said normally retracted means outwardly of said body; mechanical means movable in said body for forcing the fluid in said body under pressure into said fluid operated means to expand said normally retracted means outwardly of said body; and means adapted to be subjected to said fluid under pressure when it reaches a predetermined value for relieving said fluid under pressure.

19. In well apparatus adapted to be lowered in a well bore on a tubular running-in string: a hollow body containing a fluid; normally retracted means on said body adapted to be expanded outwardly of said body; means releasably connecting said body to the running-in string; fluid operated means on said body communicating with the interior of said body and coacting with said normally retracted means to expand said normally retracted means outwardly of said body; mechanical means movable in said body for forcing the fluid in said body under pressure into said fluid operated means to expand said normally retracted means outwardly of said body; and means connected to said releasable means and adapted to be subjected to said fluid under pressure when it reaches a predetermined value for releasing said releasable means and for relieving said fluid under pressure.

References Cited in the file of this patent UNITED STATES PATENTS 2,133,383 Erwin et al Oct. 18, 1938 2,566,323 Forsyth et a1 Sept. 4, 1951 2,671,640 Baker Mar. 9, 1954 2,703,623 Baker Mar. 8, 1955 2,741,313 Bagnell Apr. 10, 1956 2,807,325 Webb Sept. 24, 1957

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