US3042116A

US3042116A - Expendable sealing plug

Info

Publication number: US3042116A
Application number: US843551A
Authority: US
Inventors: Frank W Sharp; Jr Erskin L Medford
Original assignee: Otis Engineering Corp
Current assignee: Otis Engineering Corp
Priority date: 1959-09-30
Filing date: 1959-09-30
Publication date: 1962-07-03
Anticipated expiration: 1979-07-03

Description

July 3, 1962 F. W. SHARP I'AL EXFENDABLE SEALING PLUG Filed Sept. 3

im "im Ammann 3 IN V EN T ORS.

Erskm Lynn Medford, Jr. Fronk Wayne Sharp ATTORNEY United States Patent 3,042,116 EXPENDABLE SEALING PLUG Frank W. Sharp and Erskin L. Medford, Jr., Duncan,

Okla., assignors, by mesne assignments, to Otis Engineering Corporation, Dallas, Tex., a corporation of Delaware Filed Sept. 30, 1959, Ser. No. 843,551 9 Claims. (Cl. 166-179) This invention relates to expendable plugs for use with well tools. More particularly, it relates to sealing plugs of the expendable type useful in temporarily closing oli the bore of well packers.

After a lower producing zone in an oil and gas well or the like has been completed, it is oftentimes desirable to treat another zone thereabove. To treat the upper zone, it is common practice to set a packer between the two zones isolating one from the other. It is desirable to iso late the lower producing zone to prevent possible contamination thereof while treating the upper zone. Two metlb ods that have been used to isolate the lower zone are: first, run a bridge plug, treat the upper zone, and then drill through the bridge plug to produce the lower Zone; and second, to insert an expendable sealing plug in the packer bore, treat the upper zone, and then either pump the plug ont or force it out with production tubing. Expendable type sealing plugs used in the past were retained in the well tool by shear pins and were expended into the well by applying a predetermined pressure thereto. Consequently, they were subject to being inadvertently pumped out during the treatment of the upper zone or being blown upwardly by sudden increases in pressure in the well therebelow.

It is therefore one object of this invention to provide an improved sealing plug of the expendable type for use in closing oif the bore of well tools or conduits.

Another object of this invention is` to provide an improved expendable sealing plug that will withstand a pressure differential equivalent to the tool or conduit in which it is located and yet may be easily discharged into the well below by a mechanical force applied thereto.

A `sealing plug, constructed in accordance with this invention, is adapted to be inserted in `a flow conductor in a well or in a conventional well tool, such as a packer, to prevent the flow of fluid through the bore of the Well tool. Such an expendable sealing plug includes an adapter member whereby the plug is attached to the well tool, a tubular body member having its lower end closed slidably located in the adapter member, releasable latching means adapted to hold the tubular body member in the adapter member, and a plunger member mounted for movement in the tubular body and adapted to prevent releasing of the latching means when in its upper position and to release the latching means when in its lower position. When the plunger member is moved to its lower position and the releasable latching means becomes disengaged from the adapter member, the plunger member, holding means and tubular body are free to drop into the well therebelow providing a fully open ybore in the packer.

The' foregoing and additional objects and advantages of the invention will become more apparent when the fo1- lowing description is read in conjunction with the accompanying drawing wherein similar parts are designated by similar characters in all views and wherein:

FIGURE l is an elevation view showing a well having a schematic conventional packer set in a well casing and an expendable sealing plug, in accordance with the invention located in the packer.

FIGURE 2 is similar to FIGURE 1 but shows the expendable sealing plug after the holding means has been disengaged by the lower end or stinger of a section of production tubing.

ice

, FIGURE l is illustrative of a typical installation -involving `the use of an expendable sealing plug 10. In addition to the sealing plug 10, there is also shown a schematical conventional well packer 12 set in a well casing 14 located in a well bore 1S. The packer 12 is set or expanded so that it isolates a lower zone 20 from the well thereabove. It is :apparent that with the packer 12 and expandable sealing plug 10 arranged as shown, various treating operations Imay be performed in the well bore 18 thereabove without affecting the lower Zone 20.

The expendable sealing plug 10 includes a hollow substantially tubular receiving and supporting member or adapter 22, a tubular body 24 located in the adapter 22, a plunger 26 slidable in the tubular body 24 but initially fixed thereto by a shear pin or screw 28, and releasable latching means, such as the balls 30, adapted initially to hold the tubular body 24 in a fixed position relative to the adapter 22.

The adapter 22 -is attached as by threads 32 to the lower end 16 of the packer 12. Other well apparatus may be attached to the lower end portion of the adapter 22 by the threads 34. A groove 36 in the interior of the adapter 22 provides upwardly and downwardly facing

abutments

38 and 39, respectively.

The tubular body 24 has its lower end closed as at 40 and is provided with sealing means, such as O-type seals 42, which encircle lthe upper exterior thereof. The O- type seals 42 are adapted to form a fluid-tight seal, in the embodiment shown, with the interior of the packer 12. A plurality of openings 44 extend through and are radially spaced about the side wall 46 of the tubular body 24. The openings 44 are of suicient size that the balls 30 may be inserted therein.

The plunger 26 has on its exterior an upper, an interf mediate, and a

lower flange

48, 50', and 52 respectively.

The upper ilange 48 is adapted to engage the lower end 54 of a tubular operating member or stinger 56 connected to the lower end of a well tubing as shown in FIGURE 2. A plurality of fluid ports 58 extend through the upper flange 48. The intermediate flange 50 carries in grooves in its outer periphery O-type seals 62 which are adapted to form a slidable yet Huid-tight seal with the interior at the tubular body 24. The lower ange 52. also car-ries in grooves in its outer periphery O-type seals 66 which likewise form a slidable fluid-tight seal with the interior of the tubular body 24. An upper portion 70 of the lower flange 52 extends upwardly past the openings 44 retaining the balls 3% therein. The plunger 26 has a passageway 68 that extends axially therethrough.

In the operation of an expendable sealing plug 10, constructed in accordance with Ithe invention, the adapter 22 is attached to the packer 12 by means of the threads 32. The packer 12 and sealing plug 10 are then lowered into the well bore 18 by conventional means and after reaching the proper location in the well bore 18, the packer 12 is set or anchored in the well bore in the usual manner by conventional apparatus (not shown), isolating the lower zone 20 from the well thereabove. The apparatus used to lower and set the packer 12 is then removed and the packer 12 and sealing plug 10 are located as shown in FIGURE 1.

As illustrated in FIGURE 1, the tubular body 24 is positioned in the adapter 22` by the balls 30. The balls 3i) located in the openings 44 are of a suitable diameter so that they contact the upwardly and/or downwardly facing

abutments

38 and 39 of lthe adapter 22 and thus provide `the support for locking the plug in place in said adapter against movement in either direction therein. The uppor portion 7l) of the lower flange 52 of the plunger 26 is initially positioned adjacent to the openings 44 by the shear screw 28 preventing the balls 30 from moving inwardly and releasing the tubular body 24 from the adapter 22. The passageway 68 is provided in the plunger 26 so that, while treating the well above the packer 12 the treating lluid will llow through the passageway 68 lling the space d ened by the O-type seals 66 and the interior :of the `closed lower end 40 of the tubular body 24. The pressure of the treating fluid in this space will be equal to the pressure of the -treating fluid above the plungerr26. Upper and lower surfaces of `the plunger 26 subject'to the treating iiuid pressure are of equal area and, consequently, the forces due to pressure are balanced, placing the plunger 26 in a state of equilibrium with respect to the treating pressure. The ports 58 in the upper ange 48 are provided to prevent sudden surges in pressure or shock waves caused by treating operations, such as perforating, from mechanically driving the plunger 26 down shearing the screw 2.8 and releasing the sealing plug 10.

After the treating operation has been performed, it is necessary to provide a means for removing the sealing plug 10 and yet prevent contamination of the lower or producing zone 20'. FIGURE 2 illustrates one means of releasing the sealing plug 10. As shown therein, the lower end 4 of the stinger 56 contacts the upper ange 4S driving the plunger 26 downwardly shearing the screw 28. sealing relationship with the interior of the packer 12 prior to the releasing of the sealing plug 10, thereby preventing treating fluid from above the packer 12 `flowing into and contaminating the lower zone 20.

As has been previously stated, the plunger 26 is pressure-balanced so that the only force required to, cause it to move downwardly is that required to sever the shear screw 28. A-fter the screw 28 has been severed, further downward movement of the stinger 56 moves the upper portion 70 of the lower flange 52 of the plunger 26 downwardly until it is below the openings 44 inthe tubular body, 2,4. The balls 30 are then free to move into the space between the intermediate and lower anges Si) and 520i the plunger 26. In this position, the balls 30 are out of engagement with the upwardly and downwardly facing

surfaces

38 and 39 and the balls no longer lock the plug in place inthe adapter 22 against movement ineither direction. The sealing plug lil is thus released from the adapter 22. If the sealing plug l() does not `fall from the packer` 1 2, subsequent or continued downward movement of the stinger 5.6 wil-l force it into the well therebelow.

Oneofthe important advantages of the sealing plug is that the pressure of the treating iluidV exerts a force only on Ithe tubular body :24 which is retained by the balls 30. Thus, it canbe seen that the sealing plug 10 is adapted to hold pressures which exert a force from either above or below. Also, it can be seen that, since those portions of the sealing plug 10 responsive to lluid pressure are not retainedY by shear pins or screws, the

sealing plug 10 will not be inadvertently released by unexpectedly high pressures, either from above or below.

It should be noted that therspecic embodiment herein presented is by way of, example only and many variations may be made thereto without departing from the spirit of the invention or the scope of the annexed claims.

We claim: Y

l. A sealing plugof the expendable type` for use in closing-off the bore of`a well tool or other conduit comprising, in combination, a hollow receiving and supporting member having interior upwardly and downwardly facing abutments, said hollow member being adapted for connection to said well-tool or other conduit; and a plug including, a tubularI body member having a closed lower end, saidtubular body member slidably'located in said `hollow member, a plunger member mounted for movement in saidtubular body member, and releasable latching. means in theforrn ofat leastonespherical ball carried by said tubularr bodyfmember, saidplunger member engaging said latching means and-holding said latching means in posi- It should be noted that the seal '72 is in a slidable tion projecting beyond the surface of said body member to engage said abutments to -hold said tubular body member in said hollow member when said plunger member is in an upper position, said plunger member having relief means thereon for receiving said latching means to permit said latching means to move relatively inwardly of said body member away from said abutments and out of projecting engaging position to release said tubular body from said hollow member for movement in either longitudinal direction relative to said hollow member upon movement of said plunger member to a lower position.

2. The invention as claimed in claim 1 wherein sealing means encircles the exterior of said tubular body member for preventing the ow of fluid between said tubular body member and said hollow member and well tool and sealing means encircles said plunger and engages said tubular body member for preventing flow of fluid between said body member and said plunger through said hollow member.

3. The invention as claimed in claim 2 wherein said plunger member has an axial passageway extending therethrough whereby upper and lower surfaces thereon are subject to the pressure of fluid in said passageway, said sealing means on said plunger and engaging said body member being of a size providing equal opposed upper and lower surface areas, subjected to the pressure of fluid in the passageway for balancing the pressure applied to said plunger to prevent movement of the plunger yby fluid pressure acting thereon.

4. A sealing plug of the expendable type suitable for use in closing off the bore of a well tool or other conduit comprising, in combination, a hollow adapter member having an interior groove providing upwardly and downwardly facing abutments therein, said adapter member being adapted lfor connection to said well tool or other conduit; and a plug member including, a tubular body member having a closed lower end and having anopening in the side wall thereof, said tubular member being located in said adapter member, sealing means on said tubular member for preventing the flow of fluid between said tubular member and said adapter member, a plunger member mounted for movement longitudinally in said tubular member, yieldable means holding said plunger member in an initial upper position, said yieldable means beingadapted upon application of a predetermined force to `said plunger to permit said plunger to move to a lower position relative `to s aid tubular body, said plunger member having a passageway extending therethrough whereby equal opposed upper and lower surfaces thereon are subjectptothe pressureofY fluid in said passageway so that fluid pressure in said` passageway does not exert a force acting o n said plunger member tending to move theV plunger member relative to said body member, and releasable latching means comprising a spherical ball movahly located in said opening and movable therein to a projecting position by said plunger member when said plunger member-is in an upper position in said tubular member, said plunger member being movable longitudinally downwardly in said tubular member from position engaging said ball to permit said ball to move inwardly of said opening, saidball when held in projecting position by said plunger member contacting the abutments of the interior groove of the adapter member tovprovide the sole means for limitingv the longitudinal movement of the plug relativeto the. adapter member, whereby the plug is held in placednthe adapter member by-saidball when said ball is held in such projecting position, said plunger member having relief -means thereon for `receiving said ball uponmovement of said plunger downwardlyin said tubular member to permit inward movement of said ball in the lateral` opening of said tubular membertoV arretracted position wherein said ball no longer engagessaid abutmentsl of` said adapter member to free Y said plug from engagement with said abutments and. per.-

mit said plug to be moved longitudinally in either direction relative to said adapter member.

5. A sealing plug of the expendable type suitable for use in closing olf the bore of a well tool or other conduit comprising, in combination, a hollow adapter member having about its interior upwardly and downwardly facing spaced-apart abutments, said adapter member being adapted for connection to said well tool, a tubular body member having a closed lower end and having `an opening in the side wall thereof, said tubular member being located in said adapter member and well tool, sealing means encircling said tubular member above said opening for preventing uid flow between said tubular member and well tool, a plunger member mounted for movement in said tubular member, said plunger member having upper, intermediate, and lower spaced-apart flanges provided thereon and having an axial passageway extending therethrough, sealing means encircling each or said lower and intermediate anges forming a fluid-tight seal with the interior of said tubular member, upper and lower surfaces on said plunger member, each said upper and lower surfaces subject to the pressure of liuid in said passageway, yieldable means holding said plunger in an initial position in said tubular member wherein said sealing means on said plunger member prevents fluid low through said opening and wherein an upper portion of said lower `flange is `adjacent said opening, said yieldable means being adapted to permit movement of said plunger member to a lower position in said tubular member upon the application of a predetermined force to said plunger member, and releasable latching means located in -said opening cooperable with said tubular and plunger members to contact -the abutments in said adapter member to limit the relative movement between said tubular and adapter members when said plunger member is in its initial position, said late-hing means being adapted upon movement of said plunger member to its lower position to release said plunger and tubular members from said adapter member.

6. A sealing plug of the character set forth in claim 4 and including means on the upper end of said plunger projecting above said tubular body member and providing means for engagement of an operating device with said plunger to move said plunger downwardly relative to said body member to release said ball.

7. A sealing plug of the expendable type suitable for use in closing off the bore of a well tool or other conduit comprising, in combination, a hollow adapter member having an interior groove providing upwardly and downwardly Afacing abutments therein, said adapter member being adapted for connection in said well tool or other conduit; and a plug member including a tubular body member having a closed lower end and having an opening in the side wall thereof and a plurality of radially spaced lateral openings, said tubular member being located in said adapter member; sealing means on said tubular member for preventing flow of uid between said tubular member and said adapter member; a plunger member mounted for movement longitudinally in said tubular member; yieldable means holding said plunger member in an initial upper position in said tubular member, said yieldable means being adapted upon application of a predetermined force to said plunger to permit said plunger to move to a lower position relative to said tubular member, said plunger member having a passageway extending therethrough whereby equal opposed upper `and lower surfaces thereon are subject to the pressure of fluid in said passageway so that fluid pressure in said passageway does not exert a force acting on said plunger member tending to move the plunger member relative to said body member, and releasable latching means comprising a plurality of balls, one located in each of said openings, and movable therein to projecting positions to engage the abutments of said adapter member to limit relative movement between said tubular member and said adapter member when said plunger is in the initial upper position, said balls being the sole support for the locking of -the plug member in the hollow adapter member, said plunger member having release means to permit the balls to retract inwardly of the openings and the body member upon movement of said plunger member to its lower position to permit the balls to withdraw `from engagement with the abutments of said groove so that the plug is no longer locked against movement in either longitudinal direction in said hollow adapter member.

8. A sealing plug of the expendable type for use in closing oil the bore of a tubular receiving and supporting member having means for connecting the receiving and supporting member to a well tool or well conduit, said plug including a tubular body closed at its lower end and having a longitudinal central bore and a plurality of radially spaced lateral openings; -a ball movably mounted in each of the lateral openings; a plunger longitudinally movable in the central bore of the tubular body and having a surface engageable with the balls to hold the balls in a projecting position, ythe balls when in a projecting position projecting beyond the outer surface of the tubular body and engaging in a recess in the receiving and supporting member and providing the sole means of support of the plug in the receiving and supporting member, said plunger having opposed areas within the central bore of the body sealed between the plunger and the body so that fluid pressure in the central bore of the body acting on said opposed sealed areas is balanced so that the force of tluid pressure present and acting on the plunger does not cause said plunger to move relative to said tubular body, said plunger having a passageway communicating between opposite ends of said plunger; and shear means for holding the plunger in an upper position in said tubular body -with the plunger holding the balls in projecting position, said plunger having a reduced `area providing a relief means permitting the balls to retract inwardly of the lateral openings in the body and out of engagement in the recess of the receiving and supporting member, the upper end of the plunger projecting above the body member, the upper end of the plunger being exposed to the application of force from above the body member whereby upon the application of a predetermined force `shears the shear means to position the relief means of the plunger adjacent the balls to permit the balls to move `from projecting position and ffree the plug from its locked position in the receiving and supporting member for longitudinal movement in either direction through said receiving and supporting member.

9. The device of claim 8 wherein said receiving and supporting member has seal means for sealing between the receiving and supporting member and a well conduit in which said receiving and supporting member is positionable and means lowerable on a flow conductor for engaging the upper end of the plunger to apply force thereto to move the plunger downwardly in said tubular body, said lowerable means including seal means for sealing with the well cond-uit to which the tubular receiving and supporting member is connected to prevent escape of duid between the lowerable means and the well conduit.

References Cited in the file of this patent UNITED STATES PATENTS 1,715,504 Johnston et al. June 4, 1929 2,370,476 Lynd Feb. 27, 1945 2,565,731 Johnston Aug. 28, 1951 2,655,217 Bagnell Oct. 13, 1953 2,737,245 Knox Mar. 6, 1956 2,776,015 Bielstein Ian. l, 1957 2,928,469 Crowe Mar. 15, 1960