US3374838A

US3374838A - Fluid expansible packer and anchor apparatus

Info

Publication number: US3374838A
Application number: US506626A
Authority: US
Inventors: James H Current
Original assignee: Schlumberger Well Surveying Corp
Current assignee: Schlumberger Well Surveying Corp
Priority date: 1965-11-08
Filing date: 1965-11-08
Publication date: 1968-03-26
Anticipated expiration: 1985-03-26

Description

March 26, 1968 J. H. CURRENT FLUID EXPANSIBLE PACKER AND ANCHOR APPARATUS 3 Sheets-Sheet 1 Filed Nov. 8, 1965 INVENTOR.

Jwre: Current ATTORNEY March 26, 1968 J. H. CURRENT 3,

FLUID EXPANSIBLE PACKER AND ANCHOR APPARATUS Filed Nov. 8. 1965 s Sheets-Sheet 2 a'fames IV; Cur/en! INVENTOR.

ATTORNEY March 26, 1968 J, H. CURRENT 3,374,838

FLUID EXPANSIBLE PACKER AND ANCHOR APPARATUS I Filed Nov. 8, 1965 (Ewe: fi. Curve/7f INVEN'IOR.

ATTORNEY United States Patent 3,374,838 FLUID EXPANSIBLE PACKER AND ANCHOR APPARATUS James H. Current, Houston, Tex., assignor to Schlumberger Well Surveying Corporation, Houston, Tex., a corporation of Texas Filed Nov. 8, 1965, Ser. No. 506,626 8 Claims. (Cl. 166-123) ABSTRACT OF THE DISCLOSURE fy the force applied to the body member and abutments.

The oppositely movable members can be alternatively comprised of normally retracted expansible elastomeric means which can be expanded into engagement with the well casing wall and then elongated under pressure to apply force to the body member and abutments. Moreover, the present invention can include a releasing mechanism which is hydraulically operated to release the pressure generating means and oppositely movable members from the well tool after the slips and packing are expanded.

The present invention relates to well equipment and, more particularly, to an apparatus for operating well tools in a well bore.

Setting tools for use with bridge plugs, packers or other well tools are very often complicated in their operation and, therefore, more subject to malfunction. Additionally, the cost of the apparatus is usually proportional to the complexity of the mechanism.

It is, therefore, an object of the present invention to provide a new and improved setting tool which is simple in operation and low in cost. 1

With this and other objects in view, the present invention includes a setting tool for operating bridge plugs, packers, cement retainers or other well tools in a well bore. The apparatus utilizes a simple fluid crossover system to impart oppositely directed forces to members on the packer or other apparatus being operated in the well bore.

In one embodiment, a rubber member is expanded into engagement with the casing with its ends being subsequently stretched in opposite directions to impart oppositely directed forces to portions of a well tool. The expanded and stretched rubber member serves as oppositely moving pistons or cups which are normally retracted out of engagement with the well conduit as the tool is being lowered into the well.

In another embodiment, the conventional releasing mechanism between the setting tool and the operated tool is replaced by a hydraulic releasing mechanism.

The novel features of the present invention are set forth with particularity in the appended claims. The present in.- vention both as to its organization and manner of operation together with further objects and advantages thereof, may best be understood by wayof illustration and example of certain embodiments when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a cross-sectional view of a setting tool em- I 3,374,838 Patented Mar. 26, 1968 ice bodying features of the present invention and shown coupled to a bridge plug;

FIG. 2 is a sectional view of an alternative embodiment of the setting tool shown in FIG. 1;

FIG. 2A is a cross-sectional view taken along lines 2A2A of FIG. 2;

FIGS. 3 and 4 show still other embodiments of a setting tool;

FIG. 5 shows a hydraulic release mechanism for a setting tool; and

FIGS. 6 and 7 show an alternative embodiment of an expandable piston element for use with a setting tool.

Referringfirst to FIGURE 1', a setting tool generally indicated by the reference numeral 1-8 is suspended in a well bore on a cable 17 and is shown coupled to a bridge plug 20. Bridge plug 20 has an elongated cylindrical mandrel 21 having an enlarged diameter frusto-conical portion at its lower end which provides an upwardly facing shoulder or abutment 22 and a converging nose 23. The lower end of nose 23 defines the outer opening of a blind axial bore 24 which extends upwardly along the axis of the mandrel 21 for a substantial distance toward the opposite or upper end 25 of the mandrel. A series of slots or gaps 26 provided in the frusto-conical nose 23 form a plurality of equally spaced lugs 27 thereon each of which are rounded at their outermost end. At the opposite or upper end 25' of mandrel 21 a second blind axial bore 28 is provided which extends downwardly along the axis of the mandrel but is terminated short of the upper end of axial bore 24 so as to form a solid bridge 29 between the two bores. Internal threads 30 within axial bore 28 provide a means for attaching the mandrel to the setting tool 18.

A plurality of lower expansible slip members 31 are slidably disposed around the mandrel with their lower ends in engagement with the upwardly facing shoulder 22 of nose 23. Teeth 33 around the outer surface of the slips are directed downwardly and the internal tapered surface 34 of the slips diverges outwardly and upwardly.

A lower slip expanding member 35 is slidably disposed around mandrel 21 with itsouter surface 36 complementarily tapered and engaged with the inner tapered surface 34 of the lower expansible slip 31. The engaging surfaces of' the slip and expander can be dove-tailed together (not shown) in a well known manner to provide relative sliding movement therebetween.

'An elastomeric packing element 37 which has its ends bonded to oppositely directed lower and

upper antiextrusion rings

38, 39, respectively, is slidably disposed around the mandrel 21 with the base portion 42 of lower anti-extrusion ring 38 resting on the upwardly facing end 43 of lower expander 35. An upper expander 44, identical to but oppositely directed from the lower expander 35, is slidably disposed around mandrel 21 with the downwardly facing end 45 of the expander 44 resting on the base portion 46 of the upper anti-extrusion ring 39. Upper slips 47, identical to but oppositely directed from lower slips 31, are slidably disposed around mandrel 21 and can have their inner tapered surface 48 dove-tailed to the complementarily tapered inwardly and upwardly inverging surface 49 of upper expander 44. An actuating and locking assembly 50, slidably disposed around the upper end 25 of mandrel 21, is arranged to engage upper slip member 47 as the mandrel moves upwardly therethrough and includes a ratchet-lock arrangement which prevents the mandrel from being forced downwardly after the bridge plug is set. The

assembly 50 includes a tubular mandrel locking sleeve or abutment 51 engaging the upper end of upper slip member 47. The inner member of the locking assembly 50 is a slidable annular ratchet cone or body lock 54 received within and cooperatively engaged with a complementarily tapered inner recess 55 of mandrel locking sleeve 51.

Mandrel locking sleeve 51 is a tubular member having a cylindrical outer surface and an axial bore which is uniformly tapered, as shown at 55, for at least a portion of its length so as to diverge outwardly and upwardly toward the upper end of the locking sleeve to receive body lock 54. The lower end of the mandrel locking sleeve 51 is engaged with the upper end of the upper slip member 47.

The body lock 54 is an annular split cone nut received within mandrel locking sleeve 51 and having an internal bore of a uniform diameter and a downwardly converging tapered outer surface 65 complementary to the inner tapered surface 55 of mandrel locking sleeve 51. The inner bore 64 of body lock 54 is provided with a plurality of upwardly facing ratchet teeth 66 complementarily engaged with a plurality of downwardly facing ratchet teeth 67 around the upper end of mandrel 21. This construction permits the body lock to alternately expand and contract as it ratchets downwardly over ratchet teeth 67 until

ratchet teeth

66, 67 finally engage in the set position of the bridge plug.

The setting tool 18 is threadedly connected to the upper end of the bridge plug mandrel 21. The setting tool is comprised of an upper end portion 68 which is connected to cable 17 having electrical conductors therein. The upper end portion 68 is threadedly connected to a main housing 69. An annular sleeve 71 is positioned about the main housing. The upper end of sleeve 71 has an enlarged annular shoulder member 72 which is connected by means of shear pin 73 to the main housing 69. The lower end of the sleeve 71 is threaded for connection to the upper end of the bridge plug mandrel 21. A plurality of longitudinal openings or ports 74 are formed in the wall of the sleeve. An annular rubber element 84 is positioned about the annular sleeve 71. The rubber element is fitted between the upper end of locking assembly 50 on the bridge plug and the lower face of shoulder member 72 on sleeve 71. An annular cavity 86 is formed in the rubber element which cavity is arranged to be longitudinally positioned over the openings 74 in sleeve 71.

Ports

88 and 89 are provided in shoulder portion 72 and are aligned with openings in the upper end of the rubber element to permit filling of the tool with a fluid.

The main housing has a recessed portion 76 on its outer surface between upper and lower shouldered

portions

77 and 78, respectively. O-ring seals are positioned in annular grooves in the outer surface of the upper and lower shouldered portions. The upper shouldered portion 77 has a larger diameter than the lower shouldered portion 78 to provide differential areas for purposes to be hereinafter described. A plurality of passageways or chokes 79 connect the recessed portion 76 on the housing with a bore 81 in the upper end of the main housing. Check valves 87 in the chokes permit fluid to pass-from bore 81 to recess 76 but not in the opposite direction. The upper end portion 68 of the setting tool, whichis threadedly received within bore 81, has an upper bore 82 therein which is enlarged at its lower end to form a chamber 83. An igniter 80 is positioned in the upper bore 82 while a powder charge fills the chamber 83.

In the operation of the apparatus described in FIG. 1, an assembled setting tool 18 and bridge plug 20 are lowered by means of cable 17 into a well bore to a position where it is desired to expand the bridge plug into engagement with the well conduit. At this point, an electrical circuit (not shown) is activated to energize the igniter 80 which, in turn, detonates the powder charge in chamber 83 and thereby generate-s pressure in the bore 81 in the upper end of the main housing. The expanding gases in bore 81 flow through choke 79 into the recessed portion 76. The recessed portion 76 and cavity 86 of element 84 are filled with oil. Therefore, as the gases further expand, the oil transmits the increase in pressure to the rubber element 84. This causes the rubber element to expand outwardly into engagement with the well bore as shown by the dotted lines in FIG. 1. Subsequently, further expansion of element 84, due to increasing pressure, is directed to the upper and lower ends of the rubber element to "move the ends of the rubber element upwardly and downwardly, respectively.

As a result of downward movement of the lower end of rubber element 84, the locking sleeve or abutment 51 is forced downwardly against the upper slip 47. Downward motion of the slip 47 is transmitted through the expander 44 to the upper end of packing element 37 to compress and expand the packing element. Further downward movement of slip 47 causes the slip to ride downwardly and outwardly on the expander 44 until the slip is in locking engagement with the wall of the well bore. At the same time, upward movement of the upper end of the rubber element 84 causes the shoulder 72 and sleeve 74 to move upwardly. This upward movement of the Sleeve 74 is transmitted to the attached mandrel 21 of the bridge plug whereu on the lower upwardly facing shoulder or abutment 21 on the lower end of the bridge plug pushes slip member 31 upwardly.

Upward motion of the setting tool mandrel causes the lower expander to push against the lower end of the packer element 37 which together with the downward compression of the upper end of the packer element expands the packer outwardly into engagement with the well bore. When the packer element has become fully expanded in the well bore, the upper and lower slips will then fully set into engagement with the well bore thereby anchoring the bridge plug in the well bore. Locking assembly 50 maintains the anchored position of the various parts comprising the bridge plug. Upon such anchoring of the plug, the mandrel 21 will cease to move upwardly and, therefore, the sleeve 74 attached thereto will be restrained from further upward movement.

As noted previously, the upper shouldered end 77 of the recess 76 in the main housing provides a greater work ing area to the expanding gases within the recess than shoulder 78 and, therefore, a net upward force is applied to the main housing. Thus, after setting of the bridge plug, continued expansion of gases Within the setting tool will apply a greater force upwardly upon the housing 69 than is applied downwardly on the housing thereby tending to move the housing upwardly. The sleeve 71 which is threadedly connected to the anchored bridge plug is restrained frorn movement. The shear pin 73 holding the housing to the sleeve 71 is designed so that it will be sheared by this net upward force on the housing after the bridge plug is set. Shearing of the pin then permits the housing portion of the setting tool to be retrieved from the well leaving the sleeve 71 and rubber element 84 in the hole with the bridge plug. The retrieved portion of the tool may then be used again.

An alternative arrangement of the fluid crossover system of FIG. 1 can be affected by providing a piston in the bore 81 of FIG. 1 similar to the arrangement in FIG. 3 to be described later. In such an alternative system, the check valve 87 is omitted and oil is provided in bore 81 between the piston and the lower end of the bore. The piston provides a solid interface between the expanding gas, generated by the detonation of the powder charge, and the hydraulic fluid thereby providing a more direct transfer of force between the two mediums.

In embodiments of the apparatus where oil or other liquid is used to fill a portion .of the apparatus, at least two plugged

outlets

88 and 89 are provided in the ap paratus, one to fill the apparatus with oil and the other to permit the escape of air during the filling operation.

FIG. 2 shows another embodiment of the setting tool apparatus which is constructed for use without a hydraulic oil or the like. In this device, no check valve is positioned in the choke 79 and the detonation of the explosive charge causes gases to expand within the bore 81 in the main housing 69 which gases flow through the choke into the recessed portion 76 of the housing and the cavity 86 within the rubber element 84.

Also shown in FIG. 2 is an alternative arrangement of the rubber element structure. A shell 91 is formed of a structural material such as steel in the shape of the cavity 86 and is positioned within the cavity of element 84 to support its walls. Such a steel support will prevent the rubber element from collapsing inwardly into the cavity and opening 74 due to hydrostatic pressures within the well bore. As shown in FIG. 2A, the steel support is in the form of an annular hollow shell with radial ribs 92 spaced about the shell to support the outer surface 93 of the shell. Slots 94 are formed in the inner and outer walls of the shell to permit the transmission of an expanding fluid such as gas or oil therethrough to expand the rubber element outwardly. I

Referring now to FIG. 3, another embodiment of the setting tool is shown for use with a well tool. The apparatus is illustrated as being connected to the upper end of a bridge plug such as the bridge plug of FIG. 1. The setting tool is comprised of a housing member 101 having an interior bore 102 in its upper end. The open upper end of the bore 102 is threaded to receive an end closure 103. Bore portions are formed in the end closure for receiving an igniter 104 and a powder charge 106. The end closure is arranged to receive a cable or wireline 107 therein for providing means for lowering the apparatus into a well bore and for supplying electrical energy to the igniter 104. The bore 102 in the housing has an annular shoulder 108 projecting inwardly therein to act as a stop or limiting means for the travel of a piston 109 slidably received between the blind end of bore 102 and the annular shoulder 108.

The outer surface of housing 101 has a recess 111 below the blind end of the bore 102 which forms an annular chamber or cylinder 112 about the housing. A passageway or choke 113 is provided in the wall of the housing and interconnects the annular chamber 112 with the bore 102 in the housing. An annular sleeve 114 is slidably positioned about the exterior of the housing, the sleeve having an inwardly projecting shoulder 116 which serves as a piston and is received within the annular chamber 112. A shallow recess 117 is formed on the exterior of the housing for receiving the sleeve thereon. Seal means are provided in the outer surface of the housing between the housing and the sleeve to seal off chamber 112. Seal means are also provided between the piston 116 on the sleeve and the surface of recessed portion 111 of the housing.

A collar 118 is connected to the lower end of housing 101 by means of a shear stud or pin 119. The lower end of the collar is externally threaded for connection with the threaded upper end of mandrel 2-1 on the bridge plug. An annular ring 121 having a notch 122 in its upper surface is positioned about the collar 118 and rests on top of locking assembly 50 on the bridge plug. The notch 122 is sized to receive the lower end of sleeve 114.

In the operation of the apparatus shown in FIG. 3, the too is lowered to the desired position within the well bore whereupon electrical energy is supplied to the igniter 104. This, in turn, ignites the powder charge which produces an expansion of gases in the upper end of the bore 102 and forces the piston 109 to move downwardly in the bore. The portion of the bore 102 below the piston is filled with a fluid or hydraulic oil which upon downward movement of the piston is forced through the choke into the upper end of chamber '112. The introduction of hydraulic oil under pressure into the chamber causes the annular piston 116 on sleeve 114 to move downwardly thereby carrying the sleeve downwardly against the annular ring 121 and portions of the bridge plug therebelow.

The portion of the chamber 112 below the annular piston 116 is at atmospheric pressure, therefore the down- 'ward movement of the piston and sleeve is unrestricted except for the resistance of the bridge plug and com- 6 pression of the air. In setting the bridge plug, the setting tool is so constructed that the annular piston 116 will not engage the lower end of the chamber 112 in the housing. Therefore, as the bridge plug becomes anchored in the well bore, pressure in the chamber 112 above the piston 116 will be directed upwardly against the housing wall at the upper end of the chamber thereby tending to move the housing upwardly. The housing is held from such upward movement by means of the shear pin 119 which is designed to break at a pressure which will be developed in the chamber 112 after the bridge plug is set. Upon breaking of the shear pin 119, the housing 101 and annular sleeve '114 are retrieved from the well bore by means of the cable 107 attached to the upper end of the housing, leaving the set bridge plug, ring 121 and collar 118 in the well bore. It is noted that piston 109 is larger than piston 116 thus providing a force multiplier in the system.

Next, referring to FIG. 4 of the drawings, another embodiment of the setting tool apparatus is shown connected to the upper end of the bridge plug as in FIG. 3. The apparatus of FIG. 4 is operated in much the same manner as that shown in FIG. 3 and also includes a hydraulic multiplying device in the hydraulic crossover section of the tool. In particular, a bore 126- in the upper end of the housing 127 has large and small diameter portions '128, 129, respectively. A piston 131 is slidably mounted in bore 126, the piston also having large and

small diameter portions

132, 133 for reception respectively in the large and small diameter portions of the bore. Seal means are provided on the piston to prevent communication between the large and small diameter portions of the bore when the piston is positioned therein.

A difference from the setting tool of FIG. .3 is the provision of a passageway 134 in the housing which connects a recessed chamber 136 on the housing with the large diameter portion 128 of bore 126 in the interior of the housing. A sleeve and piston are mounted about the housing with the piston received in chamber 136. A port 137 is provided in the piston 131 to connect the large diameter portion 128 of the bore with a chamber 138 in the interior of the piston 131. p In the assembly of the setting tool of FIG. 4, the recessed chamber 136 below piston 135, the large portion 128 of bore 126, and chamber 138 within the piston are placed at atmospheric pressure and sealed off at such pressure before entry of the tool into the well bore. Additionally, a plugged port (not shown) is provided in the setting tool for filling the small diameter portion 129 of the bore with a fluid such as hydraulic oil. A passageway or choke 141 connects the small diameter portion 129 of the bore with the upper portion of recessed chamber 136 above the annular piston 135 and is filled with hydraulic fluid as is the space in chamber 136 above the annular piston.

-In the operation of the apparatus set forth in FIG. 4, the tool is lowered to a desired position in the well bore whereupon an energizing current is applied to an igniter which detonates a powder charge. This generates pressure within the upper end of bore 126 above the piston 131 to force the piston downwardly and pressurize the hydraulic oil in the small diameter portion 129" of the bore. The pressurized oil flows through choke 141 into the upper end of chamber 136. This in turn forces the annular piston and sleeve 135 downwardly against the upper end of the bridge plug to set the bridge plug in the well bore.

It is noted that the force transmitting piston 131 has a large upper end 132 subjected to expanding gases and a small lower end 133 acting against the hydraulic oil. This configuration of the piston provides a force multiplying means which generates a larger pressure in the hydraulic oil system than is generated by the expanding gases in the bore above the piston. The large portion 128 of the bore below piston 131, being at atmospheric pressure, provides a minimum of resistance to movement of the piston. This is also true of piston 135 moving in chamber 136. The addition of the passageway 134 between the chambers provides an additional volume of air at atmospheric pressure and also permits communication of the chambers with the chamber 138 in the interior of the piston which is also at atmospheric pressure. The inner connection of these chambers further minimizes resistance to the movement of the pistons therein since the chamber 138 within the interior of the piston provides a reservoir or volume of normally uncompressed air which reduces the pressure of the air in the chambers. After the bridge plug is set, the continued pressurization of the hydraulic fluid in the upper portion of chamber 136 above the annular piston 135 tends to force the housing upwardly against the shear pin 119 which breaks under the application of such force to permit retrieval of the setting tool from the well bore.

Referring now to FIG. 5, another embodiment of a setting tool is shown for operating a bridge plug or the like in a well bore. The apparatus is similar in operation to that shown in FIG. 3 of the drawings in that a powder charge 151 is detonated to provide expanding gases for driving an annular sleeve and piston member 152 downwardly to operate the bridge plug 153 in the well bore.

The apparatus shown in FIG. also incorporates a novel releasing mechanism for releasing the setting tool from the operated tool such as a bridge plug. In this embodiment of the apparatus, the sleeve member 152 has one or more ports 150 which permit well fluids to enter recessed chamber 155 below the annular piston. A lower housing member 154 is positioned about the main housing member 156 between the annular sleeve and the main housing and is threaded at its lower end 157 for attachment to the mandrel 21 on the bridge plug. An annular closure member 158 is connected by shear means 159 to the upper end of the lower housing 154. The lower housing and attached annular closure member form a chamber 161 between the lower housing and the main housing. The interior wall of the lower housing is stepped at 162 to provide large and small

interior bore portions

163, 164 in the chamber 161. The main housing has an inwardly extending shoulder 166 at its lower end which is movable within the chamber 161. The annular closure member 158 on the upper end of the lower housing is ar ranged to slidably seal against the outer surface of the main housing. However, the shoulder 166 at the lower end of the main housing is arranged to provide a restricted opening or bypass 167 between the shoulder 166 and the small bore 164 of chamber 161.

In the operation of the apparatus of FIG. 5, the chamber 161 formed between the housings is filled with oil or other suitable fluid. The tool is lowered into the well and operated therein as described heretofore with respect to the other setting tools. Upon detonation of the power charge in the tool, the expanding gases move the sleeve and annular piston 1'52 downwardly against the hydrostatic pressure of well fluids in the lower portion of the recessed chamber 155. The downward movement of sleeve 152 acts on the bridge plug to set and anchor the bridge plug within the well bore. The apparatus is so arranged that when'the bridge plug is fully set, the annular piston does not engage closure member 158, there still being a space in the lower portion of chamber 155. Therefore, when the bridge plug has become anchored in the well bore, further expansion of gases in the upper portion of the chamber 155 above the annular piston continues to push upwardly on the upper end of the chamber to move the main housing 156 in an upward direction. Such upward movement of the main housing is restricted by the capacity of the bypass 167 at the lower end of the housing to pass fluids from one side of shoulder 166 to the other. Continued upward force on the main housing moves the shoulder 166 into the large bore portion 163 of the chamber 161 whereupon the restrictive force is released and the main housing 156 is permitted to accelerate rapidly in an upward direction. The accelerated upward movement of the shoulder 166 causes the shoulder to impact the closure member 158 with force. This impact is sufiicient to shear the pin 159 and move the annular closure member 158 out of the end of chamber 161 to release the main housing 156 from the lower housing 154 and the bridge plug 153. Well fluid in the recessed chamber above the annular closure member 158 is permitted to escape through the ports 150 in the sleeve 152 and thereby permit unrestricted upward movement of the annular closure member during the operation of the release mechanism. Piston 166 moves within chamber 161 throughout the setting operation and is timed to move into the large bore 163 just after setting of the bridge plug.

Referring to FIGS. 6 and 7, alternative arrangements of an inflatable piston are shown for use with the apparatus of FIG. 1. FIG. 6 shows an annular rubber element 171 with an interior cavity and having upper and lower anti-extrusion rings 172 and 173, respectively, positioned over its ends. The anti-extrusion rings are comprised of integrally formed cup-shaped, expansible members having an annular base portion 174 and a circumferentially expansible skirt portion 176. The skirt portion is readily expansible by virtue of the imbricated fingerlike segments 177 which are each twisted slightly about their central axis and symmetrically arranged with one another so that the One edge of each segment slightly overlaps the outer face of the segment adjacent that edge and the opposite edge of each segment slightly overlaps the inner face of the segment adjacent that opposite edge. The details of this anti-extrusion ring are better shown in applicants co-pending application Ser. No. 356,152, filed Mar. 31, 1964.

In the expansible rubber element 171, it is noted that an interior groove 178 is formed in the element at the narrowest point in its peripheral wall. This groove provides a weak point in the wall of the element which facilitates the breaking or rupturing of the element into upper and lower cups.

The rubber element is positioned about a housing 181 which is shown as an integral cast member. The setting tool has pressure generating means similar to the devices of FIGS. 1 and 2. The rubber element is positioned over an opening 182 which communicates with the pressure generating means. The setting tool housing 181 is connected to the bridge plug by means of a shear stud 183 which is threadedly interposed between the housing and the bridge plug.

As shown in FIG. 7, upon application of pressure to the interior of cavity 170 in the element, the element is expanded outwardly into engagement with a well conduit 179. In addition, the segmental skirts 176 of the

antiextrusion members

172, 173 expand outwardly with the rubber element.As the pressure within cavity 170 increases, the weak point 178 ruptures and the rubber element separates into upper and lower cup-

type pistons

175, 180 which move up and down respectively, transmitting force within the cavity to portions of the well tool adjacent the cups. These cups seal with the pipe to hold the differential pressure or force created by the internal pressure in the cavity. The subsequent transfer of force by means of the cups is utilized as a work generating means to operate the bridge plug or other tool to which the setting tool is connected. In FIGS. 6 and 7, the downward moving cup 180 operates the bridge plug. Upon anchoring of the bridge plug in pipe 179, the pressure in cavity 170 is efie'ctive to move cup upwardly against housing 181 and thereby shear the stud 183 to release the setting tool from the bridge plug.

By use of the arrangement of cups or expanding rubber elements, it is possible to form one or more pistons on the setting tool which utilize the maximum working 9 area possible, that is, the diameter of the well bore. Pistons or piston areas which are manufactured as part of the tool may not utilize this area because of the dif ficulty in running the tool into a well bore. By utilizing the greatest working area available, less pressure or force is required to operate the setting tool.

In the embodiments of the tool which utilize the rubber element to form one or more pistons in the tool, it is pointed out that the moving or working parts of the setting tool are expendable in construction and arranged on the tool to be left in the well bore upon retrieval of the setting tool to the surface.

Although the apparatus disclosed herein has been set forth for use primarily with a bridge plug, it is readily seen that such apparatus may be used to perform any number of work operations in -a well bore and therefore it is intended that the scope of the invention be extended to cover all such uses. Additionally, while particular embodiments of the present invention have been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

1. Apparatus for use in a well bore comprising: a body member having a first abutment; a second abutment which is movable on said body member whereby said abutments can be moved relatively toward each other; normally retracted anchors and packing between said abutments which can be expanded into engagement with a well conduit wall in response to movement of said abutments relatively toward each other; means for moving said abutments relatively toward each other including expansible means having opposed piston portions which can be expanded by fluid under pressure against a well conduit wall to form, together with the well conduit wall, a power device capable of exerting oppositely directed forces on said body member and said second abutment in order to move said abutments relatively toward each other; and means releasably coupled to said body member for applying fluid under pressure to said expansible means.

2. The well tool of claim 1 further including a means for locking said second abutment against movement relatively away from said first abutment.

3. In an apparatus for use with a well tool having elements requiring oppositely directed forces for its operation, a body having a bore portion separated from a chamber portion by a metering orifice, said body and chamber portions being adapted to receive a fluid, pressure generating means in said bore portion for generating pressure and transferring fluid under pressure to said chamber portion, the fluid under pressure imposing force at opposite ends of said chamber portion, means for transmitting said force at opposite ends of said chamber portion to the elements of the well tool, said force transmitting means including an expandable resilient means on said body, a cavity within said resilient means, and means for conducting the fluid under pressure to said cavity to expand said resilient means outwardly as well as longitudinally in one direction, said body having diiferential areas exposed to move said body in a direction opposite to the longitudinal movement of said resilient means, and support means in said cavity to prevent the inward collapse of said resilient means, said support means being arranged to permit the transfer of fluid under pressure therethrough.

4. In an apparatus for use with a well tool, a body having first and second chamber portions separated by a metering orifice, said portions being adapted to receive a fluid, first and second piston means respectively in said chamber portions, pressure generating means in said first chamber portion above said first piston means for moving said first piston means to increase the fluid pressure in said first chamber portion, the increased fluid pressure communicating with said second chamber portion by means of said orifice, said second piston means being movable in response to the increase in fluid pressure in said second chamber portion, said second chamber portion below said second piston means being at a relatively low pressure, means for transmitting force applied to said second piston means and said body to said well tool, said first piston means and said first chamber portion being arranged to provide force multiplying means for generating an increase in fluid pressure in said second chamber portion and further including passageway means connecting said second chamber portion below said second piston means with a reservoir of fluid at an equally low pressure.

5. The apparatus of claim 4 wherein said force multiplier is provided by arranging said first chamber to have a portion thereof at said relatively low pressure, said portion being interconnected with said passageway means.

6. The apparatus of claim 5 and further including expandable anti-extrusion means positioned about the opposite ends of said resilient means and movable away from one another with said end portions.

7. In an apparatus for use with a well tool having elements requiring oppositely directed forces for its operation, a body, force generating means on said body, relatively movable elements on said body and responsive to said force generating means for movement of one of said elements relative to the other to operate said well tool, a member connected to said well tool, one of said elements being movable relative to said member during the operation of said well tool, hydraulic means for controlling the rate of relative movement between said member and said one of said elements, and releasable stop means for limiting the relative movement between said member and said one of said elements, said hydraulic means including means for rapidly increasing the rate of relative movement between said member and said one of said elements to release said stop means.

8. The apparatus of claim 7 wherein said hydraulic means includes a fluid chamber with restricted bypass means limiting the rate of movement of said one of said members therein, said stop means is an annular member closing one end of said fluid chamber, and said stop means is connected by shear means to said member connected to said well tool in such a manner that the rapid movement of said one of said members is arranged to impact and shear said annular member and thereby release said body from the well tool.

References Cited UNITED STATES PATENTS 2,196,653 4/1940 Baker et al. 166-122 2,315,931 4/1943 Burt et 'al 166-122 2,618,344 11/1952 Turecher et al. 166-1212 2,681,114 6/ 1954 Conrad 166-6 3 2,764,243 9/1956 Page 166-187 2,799,343 7/1957 Conrad 166-63 2,943,684- 7/1960 Smith 166-187 2,966,946 1/1961 McCulloch et al. 166-1 87 2,987,129 6/1961 Webb -297 JAMES A. LEPPINK, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,374,838 March 26, 1968 James H. Current In the heading to the printed specification,

lines

4 and 5, "assignor to Schlumberger Well Surveying Corporation" should Column 5, line 58, "too" should read tool Column 7, line 56, "power" should read powder line 54, "segmental" should read segmented line 61, force" should read Signed and sealed this 5th day of August 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr. WILLIAM E. SCHUYLER, JR.

Attesting Officer Commissioner of Patents