US2589506A - Drillable packer - Google Patents

Description

March 18, 1952 o. MoRRlsx-:TT

DRILLABLE PACKER Filed April l5, 1947 INVENTOR. ol L MoRRlsETT Ww IME TTO/YNEY Patented Mar. 18, 1952 DRILLABLE PACKER 0. L. Morrisett, Duncan, Okla., assigner to Halliburton Oil Well Cementing Company, Duncan,

Okla.

Application April 15, 194i', SerialfNo. 741,630

n '2 Claims.

This invention relates to apparatus adapted for use in voil wells, and more particularly to a packer adapted to seal the lower end of a conduit such as a' tubing within the casing of an oil well.

In the drilling or reworking of oil wells, it is often desirable to seal tubing or other pipe in the c asing of the well. For example, when it is desired topump cement or other slurry down tubing and force the slurry out into a formation, it becomes necessary to seal the tubing to the well casing and to prevent the fluid pressure of the cement slurry from lifting the tubing out of the Well.r

Packers, bridge plugs, and cement retainers, suitable for the general purposes outlined, are well known and the art is well developed. How- Vever, the devices heretofore designed have sometimes set prematurely while they were being lowered into the wells, or they have failed to hold properly -against movement lin the casing. Occasionally the packers of such tools have leaked `or the back-pressure valves, with which they are usually provided, fail to seal properly. Even more serious than these dinculties, however, is the damage sometimes caused by inability to disconnect the tubing from the packer after the cementing operation is performed.

The apparatus of the present invention is designed to overcome these diiculties by providing a drillable packer which is set automaticallly by rotation of the tubing upon which it is run into the well and which is capable of being completely disconnected from the tubing before any cementing operation is performed. Provision is also made for holding a back-pressure valve open until the packer is set, so that the tubing lls with fluid while it is being run into the Well.

the packer are disconnected.

It is another object of the invention to devise a novel means for controlling the setting of slips while simultaneously controlling the operation of a. back-pressure valve associated with a drilli able packer in a well.

Other objects and advantages reside in certain novel features of the arrangement and construction of parts as will be more -apparent from the following description taken in connection with the accompanying drawing, in which:

Fig. 1 is a vertical cross-sectional View of a packer constructed in accordance with the principles of the present invention. The View shows the apparatus inside a casing but before it has been set in its operation position Fig. 2 is a vertical cross-sectional view of the packer shown in Fig. l. This view shows the packer secured in position inside the casing, but before the packer 'has been disconnected from the tubing;

Fig. 3 is a vertical cross-sectional View of the apparatus of Fig. 2 but with the tubing disconnected from the packer;

Fig. 4 is aV transverse cross-sectional view of the valve-holding means of the packer in Fig. 1, the section being taken along line 4-4 in Fig. l;

Fig. 5 is a cross-sectional view of the latching means of the packer of Fig. l, the section being taken along the line 5-5 of Fig. l.

Referring to the drawing in detail, it will be seen that an oil well casing is illustrated at II. Within this casing is a string of tubing, the lower end of which is shown at I2. To this tubing is attached a packer for temporarily sealing the tubing to casing I I.

The lower end of tubing I2 is attached by threads I3 to an upper mandrel I4. The mandrel Iii is provided with a dizzy thread I5, upon which is mounted a setting sleeve i6, which is provided with drag springs Il. The drag springs press against the casing I I so that when the tubing I2 and mandrel I4 are rotated, the sleeve I6 is held against rotation but is forced to travel in a downward direction on the mandrel Iii.

At the lower end of the sleeve Iii, a trip ring It is mounted. With the parts in the running-in position shown in Fig. l, the trip ring I3 is spaced some distance above the latohing means which secures the packer to the mandrel latching means consists of anannular housing 20 which contains a release trigger 2l in the form of a split ring of spring steel. (See Fig. 5.) The lower end of this trigger ring 2| fits into a slot ZIa in the lower mandrel IB while the upper periphery is disposed beneath a shoulder at the upper rim of thehousing 20. Thus thehousing 20 cannot move either upwardly or downwardly on the mandrel I9 until the trip ring I8 on the sleeve IB entersk thehousing 20 and expands the I. The

Itrigger ring 2|. After the trigger ring 2| is expanded, thehousing 20 is free to slide on the lower mandrel I9.

A swivel or tube and ring coupling withshear pins is provided to rotatably connect the lower mandrel to the upper one. To this end, the lower mandrel I9 is provided at its upper end with a supportingring 25 to which it is connectedby means ofshear pins 26. The supportingring 25 and theshear pins 26 constitute the only means for connecting the lower mandrel I9 and the parts carried by it to the upper mandrelV I4 and hence to the string of tubing I2. Thus the mandrels I4 and I9 may part upon the exertion of a predetermined stress on the` shear pins. Threaded to the lower end of the upper mandrel I4 is atube 22 which extends down into the lower mandrel I9. Thetube 22 is provided with ashoulder 23 carryinghammer rings 24;. Thering 25 is mounted on thetube 22 above theshoulder 23. Thetube 22 can rotate inside the ring25 and also can move longitudinally a limited distance inside said ring so as to impart a jar between thehammer rings 24 and thering 25. Thus, thetube 22 may be used to hammer against the supportingring 25 toshear pins 26 when the mandrel I4 is pulled upwardly after the, slips are set.

The lower end of thetube 22 abuts against aY seat 21 inside the mandrel I 9, and the tube passes through packing 50 which is held in position inside the mandrel I9 by a nut 5I. Thus until the mandrels I 4 and I9 are separated following theshearingof pins 26, a seal is maintained between thetube 22 and the mandrel I9 and a leakproof fluid conduit is provided from the tubing I2 to the bottom of mandrel I9.

The mandrel I9 carries a set ofupper slips 28 on anupper wedge member 29, and this wedge member carries a locking ring orpawl 30. A ratchet 3I is provided on the outside ofV the mandrel I9, and co-operates with thepawl 38 to prevent theupper wedge 29 from moving in an upward direction once it has moved down on the mandrel I9. Also carried on the outside of mandrel I9 is apacker 32, alower wedge member 33, and a lower set ofslips 34. Thelower slips 34 are held in position by an interlockingbead 35 on mandrel I9 and by a clampingshear band 36. Thelower wedge 33 abuts` theshoe 32a of the packerv which in turn is held againstashoulder 31 on the mandrel I9 and theupper wedge 29 abuts against thepawl 38 which in turn is held against ashoulder 38 on the mandrel I9. Thus, with the parts in the position shown in Fig. l, the wedges and slips are prevented from moving upwardly on mandrel I9 when the apparatus is being lowered in a well.

Therupper slips 28 are held in position by a clampingshear band 39 and by an interlockingbead 48 on thehousing 20. Thus until theband 39 bursts, theupper slips 28 are secured to thehousing 20.

Theshear band 36 on the lower end of the mandrel I9 performs a double function. It holds thelower slips 34 locked in position on abead 35 ofcoupling 44 secured to the mandrel I9 bythreads 45 until thewedge 33 moves downwardly, and it holds a back-pressure valve open while the assembly is being lowered into the well. The back-pressure valve is shown at 4I. It is of the conical type and is guided by astem 42 which is carried by a spider section 43 (see Fig. 4)l of thecoupling 44. The valve 4I is urged upwardly byaspring 46 and is adapted to seat at 41. I-Iorizontally-slidable pins 48 (see Fig. 4). are. pro- 4 K y. vided for holding the valve open. The pins extend throughslips 34, thespider section 43 and into agroove 49 provided in thevalve stem 42. Thepins 48 are held tightly in thegroove 49 by theband 36 which presses against the heads of the pins. The holes 53 (see Fig. 4) in theslips 34, through which thepins 48 extend, are made smaller than the head of the pins but large enough to enable the pins 4.8 to be inserted easily. When theslips 34 are forced out to contact the casing, theband 36 bursts and thepins 48 are pulled out ofgroove 49 due to the outward radial movement ofslips 34. This releases the back-pressure valve 4I and allows it to seat at 41.

The operation of the present invention in carrying out a cementing operation is as follows: The apparatus is lowered into the casing II, with the parts in the position as illustrated in Fig. l. Upon reaching the desired depth the packer is set.

In order to set the` packer, the tubing I2. is rotated in a clockwise direction. Since the drag springs I1 keep the sleeve I6 andthe trip ring; I8 from rotating, this causes the drag springs'sleeve, and trip ring assembly to be forced downwardly by the dizzy thread I5, on the mandrel I4.. Only the tubing I2, the mandrel I4 and thetube 22 rotate. The mandrel I9 does no t rotate since thetube 22 turns in thering 25. TheV tubing must be rotated at least fifteen revolutions beOre the trip ring I8 contacts the trigger 2l. This extra rotation is provided so that there will be no danger of the packer being set accidentally while it is going into the hole. With continued rotation the lower end of the trigger 2| is forced out of contact with the 'slot 2Ia releasing thehousing 20. When thehousing 20 is released, it, together with the upper slips 28is forced downfwardly on the mandrel I9 until theslips 28 contact the casing II. With continued rotation of the tubing I2, theslips 23 will continue to move downwardly in the casing and thus moveL thelower wedge 33 downwardly and set` the lower slips 34 and force thepacker 32 out into sealing contact with casing I I. On the other hand, if theslips 28 do not slide, down in the casing, the mandrel I4 is lifted, due to the jacking action of the dizzy threads I5 so that the mandrel I9 and al1 the parts carried by it are lifted up. In either case, the parts then assume the position shown in Fig. 2. It will be observed that, as the lower slips 34 are forced out by thewedge 33, the slips pull thepins 48 out of thegroove 49 of thevalve stem 42, thus releasing the backrpressure valve 4I and allowing ity to seat, at 4,1.y

After the packer has beenl set the tubing .may be released from the packer assembly by further rotation or by pulling up on the tubing withl suffi,- cient force to shear pins 26. These pins are made strong enough so that there will bey no danger of them shearing until after the packer ,and slips have been set inthe manner described above. Rather rugged shear pins must be, emploved because, the forces employed, in. setting 4the-slips and packing sleeve set up` reactive f QIces which are transmitted through the shear` pins. 26. When the tubing has been released, it. can,Y then be lifted up until thetube 22 is clear of the packer assembly, as illustrated in Fig. 3. With ther tubing released, circulation or reverse circulation of mud or other fluid can be carried out.. Ifv desired the tubing I2 can beset down again. Thetube '2.2 will be, guided by the tapern. the, top of. nut

5I down through packing 50 and, assume the posithe mandrel I9.

tion inside the mandrel I9 like that shown in Fig. 2.

With the apparatus and its parts in the position shown in Fig. 2, either before or after the shearing ofpins 26, a cementing operation can be performed. The cement slurry may be pumped down through the tubing, through the` pre-set packer and out into the formation below. Theslips 28 and 34 will prevent the packer from moving in either direction. Thepacker 32 will prevent slurry passing between thetube 22 and To insure thattube 22 will not be forced upwardly when a high fluid pressure is exerted, it is good practice to set part of the tubing weight down on the packer assembly.

After the cement has been pumped past the back-pressure valve 4I and the cementing operation has been completed, the pressure may be released and the tubing removed from the Well. When the pressure is released the back-pressure valve Il! will close and the cement slurry will be held in place under pressure. There is no necessity for manipulation of the tubing as is usually required to disconnect it from the packer assembly. The shearing ofpin 26, if this occurs before the cementing operation is started, (as preferable) disconnects the tubing from the packer, so"

that all that is required to 'remove the tubing from the well is merely to pull it in an upward direction. When the tubing I2 is brought out of the hole, the drag spring I'I and tripping ring I8 are brought out with it.

The present apparatus can be used as a bridge by dropping a bridging ball down through the tubing, with the ball seating at 21.

After the packer has performed its services and it is desired to remove it from the well bore, it may be drilled up. Thewedge members 29 and 33, the mandrel I9, thetrigger housing 20, and thecoupling 44 may be made of some soft drillable material such as a magnesium alloy. Theslips may be made of a more rugged drillable material such as cast iron.-

Only one embodiment of the present invention has been shown and described herein, but it will be obvious to those skilled in the art that various other arrangements may be adopted Without departing from the spirit of the invention and the scope of the annexed claims.

I claim:

l. A packer and setting assembly adapted to be connected to the lower end of tubing for sealing the same to casing in an oil well, said assembly consisting of an upper mandrel and a lower mandrel rotatably connected to each other through a tube and ring swivel coupling, and shear pins securing one of said coupling members to one of said mandrels, a packer slidably mounted on the outside of said lower mandrel adapted, when expanded, to engage the casing in the well to maintain a seal between said lower mandrel and the casing, two sets of slips and slip setting wedge members slidably mounted on the outside of said lower mandrel, one above and one below said packer, latching means on said lower mandrel for holding said slips and said packer in retracted position while the assembly is being lowered into the well, said latching means including a release trigger latching the upper wedge member in inoperative position, a sleeve threaded to said upper mandrel, said sleeve having drag springs frictionally engaging a surrounding well casing to hold the sleeve against rotation as the upper mandrel is rotated, said sleeve having a trip ring adapted upon rotation of said upper mandrel to move in a longitudinal direction to engage and actuate said release trigger to release and expand the slips and packer and thereafter set said slips and packer, whereupon said upper mandrel may be disconnected from the lower mandrel merely by pulling upwardly en the tubing to shear said shear pins.

2. A packer and setting assembly adapted to be connected to the lower end of tubing for sealing the same to casing in an oil well, said assembly including an upper mandrel and a lower mandrel, a swivel connecting the two mandrels together, a shear device connecting an element of said swivel with one of said mandrels for permitting the same to part upon the exertion of a predetermined stress thereon, said lower mandrel having a packer, upper and lower slips and slip setting wedge members slidably mounted thereon together with latching mechanism for holding the same in inoperative position while the assembly is being lowered into the easing, said latching mechanism having la trigger initially locking said upper wedge member on said lower mandrel in an inoperative position and said upper mandrel having a tripping mechanism thereon for engaging and releasing said trigger to cause said latching mechanism to release said upper wedge member and packer and said slips and move the same downwardly on said lower mandrel until they are set in the casing, said tripping mechanism including a sleeve threaded to said upper mandrel and having drag springs for engaging the casing to hold the sleeve against rotation thereby causing movement of the sleeve longitudinally of the upper mandrel upon rotation of the upper mandrel, whereby the packer and slips may be set simply by rotation of the upper mandrel with respect to the lower mandrel after which the upper mandrel may be removed from the well simply by pulling upwardly thereon to shear said shear device or simply by further rotation yof said upper mandrel to cause said tripping mechanism to exert a predetermined stress on said shear device by lifting the upper mandrel away from the set slips.

O. L. MORRISETT.

' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,121,051 Ragan et al June 2l, 1938 2,300,438 Spang- Nov. 3, 1942 2,327,092 Botkin Aug. 17, 1943

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