US2221204A - Cementing plug - Google Patents

Description

Nv.12,194o.* SANTIAGO 2,221,204 CEMENTING PLUG Filed April 25, 1938 2 Sheets-Sheet l ffyz ggf

5/ l 48 v Izzi/wier c/alliez; anfing@ ihr/ley Nov. l2, 1940. 1 J. J. SANTIAGO 2,221,204

` CEMENTING PLUG Filed April 25, 1958 2 sheets-sheet 2 prise gripping means and Patented Nev. i2, 194o James J. Santiago, Los

Angeles, Calif., assignor vtoJohn Grant, Los Angeles, v (ialii'.' Application Apm'zs, 193s, serial No. 204,096

9 Claims.

v This invention has to do generally `with well -cementing plugs (also variously `referred to as cement retainers, barriers and bridge forming devices), and relates particularly to an improved type of cementing plug adapted to be set within the casing and controlled in different stages of the cementing process, by operation ofthe pipe string connected to-the plug and extending to the ground surface.

Plugs of the present form may be used in perstring connected to the plug and deposited at a predetermined location either vwithin or outside For example, the plug'may be Vused in performing a bottom cementing job, i; e.

Iin depositing cement around the lower` end of the casing to shut 0E a water region above; orl

in discharging cement into an intermediate section of the casing, to be deposited as a plug within the casing or to be forced through an openingin the casing to form a barrier around its '4 outside. The various situations in which cementing plugs'may be usedare known to those familiar with the art. I f Y Structurally, plugs of the present type compacker adapted to be expanded into tight enga ement with the well Vcasing at the depth at whiih the .plug is set, and

a normally or initially opel; valve forcontrolling passage or num tnrougn//tne plug. Means also is provided for mainta g circulation from the pipe string connected to the plug, into the casing above the packer, and for selectively directing the circulation above or through the plug. My major object is to provide'a cementing plug in which the gripping means and packer may be set (expandedi/mechanically and the valve released for closing, by operation of the pipestring, and in which the circulation controlling means is embodied as a. part of the plug itself, as distinguished from connected butl otherwise independent devices such as have been used heretofore. Another object of the intention is te provide a closure means for the circulating fluid passage within the plug, that will obstruct the passage against downward ilow during circulation into the casing above the plug, and which may thereafter be opened to permit fluid flow through 'theplug For this purpose I may use a normally open disc type closure thatA will seat under the .iluid pressure maintained during upward circulation, and which thereafter can be broken simply by increasing the uid pressure -tioned above,

v which:

(Cl. 16B-12) Fig. 1 is a longitudinal section showing the positions of the parts as the plugis being lowered within the well; v V

Fig. 2 is a similar view showing the slips and 15 packer expanded, and the valve holding means released Fig.`3 is a view showing the section of the plug remaining in the well after the lowering pipe is disconnected; go

Fig. 4 is a section on line 4 4 of Fig. 2;

. Figs. 5, 6, 7 and 8 are cross sections on linesy 5 5, 8 8, 1 1 and 8 8 of Fig. 1; and i Fig. 9 is a view showing a variational form of the invention. l

Referring rst to Figs. 1 and 2, the plug, generally indicated'at I0, is shown to be lowered within the well casing il on the pipe I2 that extends to the ground surface. The plug I0' may be describedA generally as comprising upper and 30 lower, or body and mandrel sections I3 and I4, respectively,'these sections being relatively rotatable and relatively vertically movable by way of the pipe I2, to expand'the pipe engaging means I5 and packer I6, and to control the' valve, gen- 35 erally indicated at Il, all in the manner to be later explained. The body section I3 comprises a tubular member I8 attached by sub I9 to the pipe I2, and having intermediate its ends a. thickened section 20 through which extends a reduced o threaded joint at 24, so that right-handed rotation of the upper section relative to the lower section will unscrew the joint at 24, enabling the bodyand upper mandrel section to be disconected from the lower portion of the plug remaining in the casing (see Fig. 3). The lower mandrel section 23 carries the pipe engaging 50' means I5 and packer I6 which are adapted to be radially expanded into engagement with the casing by upward relative movement of the mandrel. While in the broadaspects ofthe invention, any suitable form of pipei gripping means -may be used, I preferably employ double-faced wedge slips 25 having toothed gripping surfaces 26 and 2l capable of holding the plug, when set, against upward or downward movement.` Wedge surfaces 28 and 29 of the slips bear against correspondingly tapered wedge sleeves 30 and 3| surrounding the mandrel and movable longitudinally thereon. When the plug is assembled the slips 25 are positively held in radially con- .tracted positions by wires 33 encircling the intermediate reduced diameter portions 25a of the slips (see Fig. 6), the ends of each wire being tied or otherwise held together in a suitable mannenas indicated at 3d.

The packer sleeve i6, made of rubber or other suitable material, is placed about the lower portion of the mandrel between the wedge shaped end 35 of sleeve 3l and an oppositely tapered shoulder 36 on the mandrel. Below the packer, the mandrel carries a plurality of bowed spring elements 3l which frictionally engage the casing ll with suillcient tightness to support the mandrel Vand to hold the mandrelagainst rotation relative to the body during the later described operation of the plug parts. As a further means for holding the mandrel against rotation within the casing, I provide e. plurality of gripping elements 38 retained within vertically extending recesses 39 in the outer surface of the mandrel by screws 4G. These gripping elements 38 have limited rotation within recesses 3S and are shaped to provide sharply tapered edges-4I projecting beyond the surface of the mandrel. Edges 4l of the gripping elements normally are in engagement with the casing,.and due to the shape of the elements, as illustrated, they are caused to bite into the casing as th'e mandrel tends to rotate right-handedly or in a clockwise direction. While going into the hole, the gripping elements 38 may engage and perhaps lightly score the casing, and later will be forced to resist right-handed rotation of the lower mandrel section. j

The slips and packer are expanded by virtue of relative,y rotation between the body `I3 and mandrel- Iii through a releasable rotative driving connection between the body and nut 43 threaded on'the upper end of the lower mandrel ken as the slips expand so that the lower por-- tion of theA plug thereafter remains permanentlyy fixed withinQ the casing. -At the same time, up- A ward movement of the mandrel shoulder 36 rela- VVVmandrel.

section 23.' Formed integrally with nut 43 are a plurality of upstanding lugs or teeth 43a interntting," in the position of the parts shown in Fig. l, with correspondingly spaced teeth 44 on the lower end of the body. By right-handed rotation of the suspension pipe and body, nut 4 3 is rotated on the', mandrel (with the latter being held against-rtation by springs 3l and gripping elements 38), causing the mandrel to become elevated within the nut to a position as illustrated in Fig. 2.. 'I'his upward movement of the mandr'el brings wedge sleeves 30 and 3|- `relatively together to expand the slips 25 into gripping engagement with the casing, Wires 33 being brotive to the lower end 35 of sleeve 3l expands the'packer I6 into fluid tight engagement with the casing. Obviously, the slips and packer are retained in their expanded positions by the Ithreaded connection between nut I3 and lthe- The valveY mbly, lgenerally indicated at I1, comprises a valve 43 carried on the lower end y of a stem I3 extending-through 'a spider or guide 5 3 inserted within bore 5l, and a pair of. steel balls and 55, the latter of which projects within an annular groove 5l. in the valve stem, to hold the valve open. Detentsl 52 are released from holding engagement with the valve stem v during the operation oiV setting the slips and packer, as previously described, by upward movement of the mandrel section' to the point at which the detents are brought opposite an annular recess 58 within the wedge ring 3l, at

which point they are moved out of the valve stem groove 5l by the upward thrust of spring 53.

The bore 6i). of lower mandrel section 23 contains a tubular insert or bushing 5l, press-tted within the bore, and having a downwardly tapering ball seat '62. The lower end of the bushing projects downwardly within an annular recess 63 and provides a seat for an upwardly concaved disc 6d at the upper end of the valve stem d8. 'Ihe bottom projecting end of the bushing is notched at 65 to form openings through which circulating iluid discharged through the mandrel bore 60 may pass around the/disc 65 and thence ow downwardly through :the spaces 59e Fig. 7) between lugs 59 and u h passage 36 into the casing below the plug. "i, It willbe observed that when detents y52 release the valve rod, the valve` is prevented from closing due to rod with disc 5t. The particular functions of the disc will be best understood at a later point in considering the operation of the plug.

Provision is made wherebyy uid pumped down through the pipe string l2 may be selectively discharged downwardly through the mandrel bore into the casing or well below the packer, or through body openings 61 into the casing above the packer. For this purpose I form on the upper end of mandrel section 22 a head 68, essentially a valve, adapted to engage or seat against body shoulder l2 and annularly spaced at 69 from the'body so that with the parts, posi.- tioned as in Fig. 1, fluid discharged into the body chamber. 10 ows downwardly past the head 68 and thence through vertically extending ways 'll to the outlets 6l. on the head prevent the upper mandrel section from at any time closing oil the discharge of v-uidinto the body at times when circulation ings 6'1 and causing the nuid to be discharged Circularly spaced lugs 63a/ downwardly through the mandrel bore. In this same operation, the engagement of ways Il with splines .14 vprovides a connection between the l. body and upper mandrel section whereby the latter may be disconnected from the lower mandrel section by right-handed rotation of the pipe string' lz.

As previously indicated, the present form of plug is adaptable for use in a variety o! cementing operations; either in cementing around the cement. isA to be deposited within or around an in rodiate' section of casing. In carryinlout a` cementing operation with anyqiarticular 'ob-4 lower end of the casing, or in operations where l it is tube set, the

jectlve, the plug is loweredv or forced downwardly through the casing to the proper depth on the .pipe string I2. the slips-Ii and packer I6 of course being radially retracted and the valve 46 5 held open as illustrated in Fig. l. While the plug is being lowered, circulation may be maintained at any depth'withln the casing above the plug through openings 61. as previously explained. Also, if for any reason itis desired to klo circulate through the plug into the casing below,

the body I8 may be` elevated to seat shoulder I2 against mandrel head 68, to requirevthe circulation to pass through the plug. When the plug hasbeen lowered to the position at which body is rotated ina righthanded direction to setthe slips 275 and packer I6, and to release the valve holding detent 52,

all in the manner previously explained.

With the plug now in set position, a cementing operation may be performed to deposit cement within the casing or well either below or above the plug. Assume for example that it is desired to place a cement bridge within the casing below the plug and on top of a previouslyset bar-l rier (not shown); My plus lsrst lowered to a position in contact with or close to the lower set barrier. With the body and mandrel in the reiative positions shown in Fig. 1, cement is pumped down through the pipe string I 2 and the circulating mud being displaced ahead of the cement. is discharged outwardly into the casing through openings 8l above the packer. During this time,

the fluid pressure within the mandrel bore acts to seat disc Si ag shoulder 53a as shown in Fig. 2,l to close .oi circulation through the plug and require all the huid to iow out through the openngs'l. When the downwardly moving cement column reaches the plug, as may be determined by calculationsxbased on the length-of 40 the 'pipe string in volume of cement pumped into u, the body le is raised to` the position or Fig. 2, bringing seatV 'l2 against the head B8 to close oil circulation above the packer. 'Ihe full pump pressure then becomes applied to the disc B5. and this pressure breaks the disc, permitting the cement to be discharged down through the Amandrel past the valve 45, the latter being held operi by the uid pressure to pass the cement. It is only when circulationthrough openingse'l is cut oli that suiicient pressure is Vapplied to the disk to break it; at al1 other times the' disk will re' main unbroken and will. function vas a check against ud flow down through the plug. After the disk is broken and while the cement is discharged from the bottom of the plug, the plug is raised until all or substantially all thecement' has been dischargedto form acement bridge resting on the lower barrier. The plug is then in a position at the top/ofthe discharged bridge of cement. :The partsxoi'v the plug are then operated to expand the packer and set the slips. v

A suitable object, such as ball 8B, has been the pipe string through the plug tothe deposited cement below.

""At thesameltimegglve le seats (disc 84 having been broken) to preventpwarddisplacement of .7x5 the cement throughtheplug `and to maintain v essary that either the disk 64,

' Y openings 6'I.`

stated above. The body I8 and upper mandrelv section V22 now may be disconnected from the llower mandrel section by right-handed rotation Il of the pipe string to unscrew 'the threaded joint at 2l, leaving-thc lower section of the plug set within the casing as shown inria-3. i

If it is desired to discharge cement above tlfe plug, that may be done, and done either before 10 or after cement has been discharged below. For discharge of cement above the lug it is only neche ball 8U, or the' valvel. close the lower; part/ of the plug passage, and that. the mandrel and body be in the 15 relative positions shown inl Fig. 1.

Fig. 9 illustrates a `variational form of the inentlon similar in all respects to the previously described form excepting that the pressure breakable disc is not used.. The form of apparatus 20 shown in Fig. 9 may be used for depositing cement either above or below the plug proper. Assume, for example, that it is desired to place a cement bridge within the casing directly above the plug. :The plug is lowered and set at prede- -95 termined depth as previously described. Circulation through ports 61 may be maintained at any time before or after the slips or packer are expanded to seat the plug, while the body is' lowered to disengage seat l2 from the mandrebhead 30 6B; or circulation may be maintaineifi'through the plug by elevating the body into e gagement with the mandrel head and forcing t egcirculation past the valve. In the abs ce of the disc, the valve rod is released from the detents 52, but suiicient ,pressure may be maintained to force the duid past the valve. With the parts vpositioned as in Fig. 9, the ball 8U' may be inserted within .the pipe string I2 directly ahead of the cement idc charge. As the cement is pumped into and through the pipe string, the fluid column below the cement is displaced .outwardly through openings E'I into the casing above the plug, the valve seating spring 5I! preferably being suiciently 45 strong to keep the valved Aseated .and thus require the uid to dischargednto the casing above the plug. When forced down into themandrel,

and the cement charge :is

around and above the plus lhi'ough openings 6i. s'

Before the cement takes its initial set, the body and upper mandrel sectionmay be disconnected from the lower mandrelsection, as-previously for placing cement below the plug, the cement may be pumped into the pipe string and the uid 60 column below the cement discharged through- When the lower end of the cement column reaches the plug, shoulder I2 may be seated against the mandrel head 68 and the cethrough the mandrel bore 65 ment forced' down pe-St valve I6 into the casing below. In this instance, ball may be inserted into the pipe strlngfollowing the cement and, 4together. with the cement, is forced down throughthe pipe string by iluid pressure until the ball seats on 7o themandrel bushingIiI. Valve 46 then seats tp prevent lrpwarddisplacement of theA deposited cement within the' casing. -As vin the Aiirst described operation, after removal of the body and -upper mandrel section, tbeslower sectionv of the of course seats when the valve ,35/

plug remains set cement bridge.

I claim: 1. A cementing plug device adapted to be lowered ona suspension pipe within well pipe and adapted to 'deliver iiuid from the suspension pipe selectively into the well either below or within the casing above the above the plug device, said plug device comprising into the wen at .a point above the weu pipe engaging means,.and cooperating valvular means operated by relative movement of the mandrel assembly andthe tubular connecting member and adapted in one relative position of said connecting member to open said last mentioned passage and in another relative position to close said last mentionedpassage.

2. A cementing plug device adapted to be low- 'ered on a suspension pipe within well pipe and adapted to deliver uid from the suspension pipe selectively into the well either below or above the plug device, said plug device comprising a longitudinally passaged mandrel assembly, a movable well pipe engager carried by the mandrel assembly, operating means for the engager operable by virtue of rotation relative to said mandrel assembly, a tubular connecting lmember connected to the-suspension pipe and the manl I drel assembly, said tubular connecting `member being operably connectible with said engager operating means, means selectively operable for closing the mandrel passage against downward passage` of iluid therethrough, said tubular connecting member being longitudinally rand rotationally movable relative to the mandrel assembly-and having a passage therethrough leading A adapted to deliver fluid from the suspension pipe from its interior and discharging into the well at a point above the well pipe engager, and cooperating valvular means on the mandrel assembly and onlsaid tubular connecting member 5 adapted upon, relative longitudinal `movement in `one direction to open (said last mentioned passage and upon relative longitudinal movement in the other-direction to close said last mentioned passage.

3. A cementing plug device adapted to be lowered on a suspension pipe within well pipe and selectively into the well either below or above the plug de vfce, said plug device comprising a 60 longitudinally passaged mandrel assembly, said mandrel assembly including an upper tubular mandrel extension disengageable from the mandrel by rotation relative'thereto, a movable well pipe engager carried bythe mandrel, operating 65 means for the engager operable by virtue of rotation relative to said mandrel, a tubular connecting member connected to the suspension pipe and the mandrel extension, means selectively operabllefor closing vthe mandrel passage against downward passage of fluid therethrough, said tubular connecting member being longitudinally and rotationally movable relative to the mandrel assembly and voperatively connectible 75 and disconnectible with the Well' pipe engager ing into the well at a point above the well pipe' engager, and cooperating valvular means on the mandrel extensionYV and on said tubular connecting member adapted upon relative longitudinal movement in one direction vto open said last mentioned passage and upon relative longitudinal movement in the other direction to close said last mentioned passage.

4. In a cementing plugl adapted to be lowered within well pipe on a suspension pipe and including a mandrel having a longitudinal duid passage therethrough in communication with the suspension pipe, an upwardly seating back pressure valve adapted to close said passage against fluidn ilow vupwardly through said passage, a pair of vertically spaced seats in' the mandrel, the upper seat facing downwardly and the lower seat facing upwardly, and a irangible closure adapted to be moved between upper and lower positions and to seat on either of vsaid pair of seats, said trangible closure engaging the valve tb hold it open when seated on the upper ,seat and adapted to be moved onto the lower seat by iluid pressure applied from above, and

adapted to close the passage through the lowersion pipe, an upwardly seating back pressurevalve adapted to close said passage against fluid flow upwardly through said passage, a pair of vertically spaced seats in the mandrel, the upper seatiacing downwardly and the lower seat facing upwardly, an'd a frangible closure adapted to be moved `between upper and lower positions and to seat on either of said pair of seats, said fran- I gible closure engaging the valve to hold it open when seated on the upper seat and adapted to be moved onto the-lower seat by fluid pressure applied from above, and adaptedto close the passage through the lower seat when seated thereon so that said closure may be brokenby` application of a predetermined iluid pressure to permit closing of the valve, and means in the body forming a iiuid by-pass around the upper seat.

6. A cementing plug device adapted to be lowered on a suspension pipe within well pipe and -adapted to deliver uid from the suspension pipe plug adapted to be lowered .I

selectively into the well either below or abovethe plug device, said plug device comprising a longitudinally passaged mandrel assembly, well pipe engaging means carried by the mandrel assembly, a tubular connecting member connected to the suspension pipe and the mandrel assembly,- said tubular connecting member being movabley relative to the mandrel assembly and having a passage therethrough leading from its interior and discharging into the well-at a point above the well pipe engaging means, and cooperating valvular means operatedrby relative movement of the mandrel assembly J and the tubular connecting member and adapted in one relative position of said connecting member to lopen said` last mentioned passage and in another relative position to close said last mentioned passage.

7*. A cementing plug device adapted to be low- :ered on a suspension pipe within Well pipe and adaptedlto deliver fluid from the suspension pipe selectively into the well either below or above the plug device, said plug device comprising a longitudinally passaged mandrel assembly, said mandrel assembly including an upper tubular mandrel extension disengageablefrom the mandrel by' rotation relative thereto, a movable well pipe engager carriedV by the mandrel,l operating means for the engager operable by virtue of rotation relative to said mandrel, a tubular connecting member connected to the suspension pipe and. the mandrel extension, said tubular connecting member being longitudinally and rotationally movable relative to the mandrel assembly and operatively connectible and disconnectiblev with the well pipe engager operating means by relative longitudinal movements in opposite directions, means-establishing rotational engagement of said connecting member with said mandrel extension by virtue of the relative longitudinal movement that disengages the well pipe engager operating means, said tubular connecting member having a passage therethrough leading from its interior and discharging into the well at a point above the well pipe engager, and cooperating valvular means on the mandrel extension and on said tubular connecting member adapted upon relative longitudinal ymovementin one direction to open said last mentioned passage and upon relative* longitudinal' movement in theother direction to close said last mentioned passage.

8. A cementing plug device adapted to be lowered on a suspension pipe within well pipe and adapted to deliver fiuid from the suspension pipe into the well either below or above the plug device, said plug device comprising a longitudinally valve open and releasable by\ virtue lof pipe engager expansion to allow the valve to close, a tubular connecting member connected tothe suspension pipe and the mandrel assembly, said tubular connecting member being movable relative to the mandrel assembly and being, in association with the mandrel assembly, provided with passage and valvulanmeans for discharging cement at a point above the well pipe engager when the tbular connecting member is in a predetermined position relative to the mandrel assembly, said valvular means being closed when the tubular connecting member is in another predetermined position relative to the mandrel assembly tod-ischarge cement through the mandrel assembly below the plug device.

9. A cementing plug device adapted to be lowered on a suspension pipe within well pipe and adapted to deliver fluid from the suspension pipe into the well either below or above the plug device, said plug device comprising a longitudinally passaged mandrel' assembly, an expansible well pipe engager carried by the mandrel assembly,

rotary operating means for saidlengager, an upwardly closing valve controlling the longitudinal mandrel passage, means holding said valve open and releasable by virtue of pipe engager expan- 'semblyand drivingly connectible with the engager operating means by longitudinal movementy in one direction,l and the mandrel assembly and tubular connector having passage and valvular means for discharging cement at a point above the well pipe engager, said valvular means controlledv by relative longitudinal movement of the connector to open the connector passage to discharge cement above the engager or-to close the connector passage to direct cement downwardly through the mandrel assembly to dschargebelow l the plug device.,

Y JAMES J. SANTIAGO.

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