Cement retainer and bridge plug for well casings

June 21, 1938. R. c. baker 2,121,002

CEMENT RETAINER AND BRIDGE PLUG FOR WELL CASINGS Filed Oct. 10, 1936 .2 Sheets-Sheet 1

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June 21, 1938. r. c. baker 2,121,002

CEMENT RETAINER AND BRIDGE PLUG FOR WELL· CASINGS Filed Oct. 10, 1936 2 Sheets-Sheet 2

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Patented June Σ1. 1938

2,121,002

UNITED STATES PATENT OFFICE

2,121,002 mmrr RETAINER AND BRIDGE PLUG FOB WELL CASINGS

Reuben C. Baker, Coalinga, Calif., assignorto Baker OR Tools, Inc., Huntington Park, Caln., a corporation of California

Application October 10, 1936, Serial No. 105,041

Claims. (CL 166—13) centric circulating port 12 surrounded by a valve

This invention relates to devices commonly termed “cement retainers” and “bridge plugs which are utilized in packing off, cementing and other analogous operations in deep oil wells.

It is the principal object of my present invention to provide an improved and simplified apparatus of the character referred to which may be expeditiously run in the casing of a deep oil well bore and set at a desired point therein, and 10 efficiently employed in bridging, cementing and analogous operations.

In practicing my invention, I provide a packer body which may be detachably connected to the lower end of a string of tubing and run in the 15 well bore. This packer body is fitted with operative slips for firmly anchoring it to the surrounding casing so that it will resist dislodgement either from pressures above or pressure below it in the casing. The packer body is also fitted with ο» an expansible packing or sealing element for sealing off the space between the exterior orthe body and the casing wall. The slips or anchoring means and the packing element are operated by fluid pressure and by manipulating the run05 ning in tubing at the derrick floor. The tool may be utilized in bridging the casing and in cementing through the casing at any level above the bottom of the bore. The tool may also be used in various other operations, such as repressuring, 30 if so desired.

One form which the invention may assume is exemplified in the following description and illustrated by way of example in the accompanying drawings, in which:

Fig. 1 is a longitudinal sectional view through a portion of a well casing and disclosing my improved apparatus positioned therein with the parts in the position they assume when the device is being run into the casing.

. Fig. 2 is a view similar to Fig. 1 with the exception that the up-pressure slips are shown as tripped and ready for flrm setting.

Fig. 3 is a, view similar to Fig. 2 but showing the parts in the position that they assume when ₄₅ the device has been completely set in the casing.

Referring more particularly to the accompanying drawings, i 0 indicates a packer or what is commonly known as a cement retainer and bridge plug. This device is cylindrical in cross section -,0 and of an overall external diameter slightly less, ’’ when its parts are in unset position, than the internal diameter of the well casing into which it is to be run and set. The packer or cement retainer 10 includes an elongated hollow cylindrical body ₆₆ II, the lower end of which is formed with a conCooperating with this valve seat to control the flow of fluid upwardly into the body 11 from below the same is a downwardly opening back pressure 0 valve 15 of the poppet type. This valve is fitted with a valve stem 16 which extends vertically upward into the body 11 and is reciprocably mounted in a guide Π formed centrally of a spider 18 formed integrally with or secured within the body II . An expansion spring 19 is arranged between the guide IT and an enlarged head 16α formed on the upper extremity of the valve stem 16. The spring 19 constantly tends to maintain the valve 15 seated on the seat 14, thereby closing the main circulating port 12. It is obvious, however, that the valve 15 may be opened by fluid pressure from within the body when the same exceeds the pressure in the casing below the packer 10. .

For the purpose of running the body 11 into the casing, the upper end of the body is interiorly threaded with a left-hand female thread to receive a left-hand male thread formed on the lower end of a tubular sub 11 a, which may be threadedly connected to the lower end of running in 25 tubing 49. The purpose of the left-hand thread is to enable the sub I la and the tubing 49 to be unscrewed from the body 11 after the tool has been tripped and set in the casing.

It will be noticed that the body 11 is hollow and 30 cylindrical and is formed with a lower bore 28 and an upper bore 21. These two are connected by an intermediate bore 22 which is reduced in diameter with respect to the upper and lower bores 21 and 20. A bridging valve seat 23 is 35 formed at the junction between the upper bore 21 and the intermediate bore 22, the purpose of this seat being hereinafter described.

Slidably fitting the intermediate bore 22 is a trip sleeve 24 which has a passageway 25 formed 40 coaxially therethrough. At its upper end the sleeve 24 is formed with a trip valve seat 26 to receive a ball trip valve 27 as shown in Fig. 2. Depending from the lower end of the sleeve 24 are spaced legs 28 which connect the sleeve 24 45 to a circular trunnion 29. This trunnion 29 is connected to the head 16α by means of a shear Din 30.

When the packer is assembled for running-in, it is desirable to hold the valve 15 open so that 50 fluid may pass freely upwardly through the body II. To maintain the valve in this open position, I secure the sleeve 24 to the body 11 by a shear pin 32 which is sheared as will be described to release the sleeve and render it ineffective to hold M

2,121,002 the valve 15 open after the packer has been set’ in the casing.

A packer sleeve 33 formed of rubber or any other suitable pliable material is arranged ex5 teriorly on the body 11 and is anchored at its lower end to a fixed ring 34 which is bolted or otherwise secured to an annular flange 35 circumscribing the lower end of the body I I. The upper end of the packer sleeve 33 is anchored to a 10 sliding ring 36 slidably fitting the exterior of the body 11. This sliding ring 36 is formed with an annular groove 36α into which is fitted a spring latch ring 37. When the packing sleeve 33 is compressed into sealing position as shown in Mg. 15 3, this latch ring engages annular latching grooves 36b on the body 11 to latch the sleeve 33 against longitudinal expansion.

Referring particularly to Mgs. 1 to 3, inclusive, it will be seen that above the packer sleeve 33 20 the body II is provided with a lower cone 36. This lower cone is bored so that it is capable of reciprocation on the exterior surface of the body 11. The exterior of the lower cone 36 is formed with a frusto-conical face with its smaller diam25 eter lowermost.

Arranged about the exterior of the conical surface of the lower cone is a set of down-pressure slips A which are segmental in form and the interior faces of which are frusto-conical to coin30 cide with and be complementary to the conical face of the lower cone member 38. Obviously, any relative longitudinal movement of the cone 38 and slips A will be accompanied by radial movement of the slips relative to the body II.

Referring to Mg. 1, where the parts are shown in the position which they assume when the device is run into the casing, it will be noticed that the slips A are arranged in their innermost position and that each is secured to the lower cone 40 38 by a shear pin 42.

When the lower cone 38 is assembled on the body 11 prior to running the tool into the casing, it is secured to the body 11 by a shear pin 44. It will also be noticed that within its lower end the 45 lower cone 38 is formed with an annular groove 46 which receives a spring latch ring 45. This latch ring is adapted to engage the annular latch grooves 36b formed about the exterior surface of the body II to latch the lower cone 38 in posi50 tion on the body 11 when the tool has been runin the casing and set as will be described.

Reciprocably mounted on the body above the lower cone 38 is an upper cone member 58 which has a frusto-conical face 51 arranged with its 55 smaller diameter uppermost. Arranged about the conical face 51 of the upper cone 58 Is a set of up-pressure slips B which are likewise segmental and which are formed with an interior conical face coinciding with and complemental to the conical face 51 of the upper cone member 58. The up-pressure slips B are each connected to the cone member 56 by a shear pin 53.

I desire to point out here that when the device ₆₅ is assembled for lowering into the well casing, the down-pressure set of slips A and the uppressure sets of slips B are so connected by the shear pins 42 and 53 to the lower and upper cones that they will be in contracted position, and 70 will not interfere with the lowering of the device into the well casing.

Secured on the sub Ila and positioned just above the upper end of the body 11 is an annular flange I lb of a diameter sufficient so that it will 75 be engaged by the slips B in any attempt of the latter to move longitudinally upward relative to the body II.

Referring more particularly to Mg. 1, it will be noticed that the lower cone member is formed „~..^{ap upwardJ}y extending annular cylinder M within which an annular piston 55, depending from the upper cone member 50, extends and is reciprocable. These telescoping parts of the lower and upper cones form an annular pressure chamber 56 between them and suitable packing rings 57 are provided and fitted to both the cylinder and the piston to prevent fluid leakage This pressure chamber 56 communicates with the interior of the packer body II through suitable ports 58. It is intended that when fluid pressure be built up within the packer body 11, that this pressure be exerted in the pressure chamber 56, tending to move the cones 38 and 50 in opposite directions longitudinally of the packer body. ,

To produce this Internal pressure in the packer body I I the ball valve 27 is permitted to seat on the seat 26 of the sleeve 24, shutting off further circulation downwardly through the body II Fluid pressure may then be built up within the ί body II, and which pressure will build up in the pressure chamber 66 through the ports 50 Dils pressure will be insufficient to shear the pin 44 connecting the lower cone to the body, but is sufficient to move the upper cone 50 upwardly 3 relative to the body and to the lower cone. This movement will be resisted by engagement of the slips B with the flange lib, but the pressure will be sufficient to shear the pins 53, detaching the slips B from the upper cone 50. Obviously, con- 3 tlnued upward movement of the upper cone 50 on the body 11 and relative to the slips B will be accompanied by radial outward movement of the slips B until they tightly engage the casing as shown in Mg. 2.

The pump pressure in the body 11 is then relieved and an upward strain is taken on the running-in tubing 49. The moment that the body 11 commences to move upwardly, it will do so relative to the upper cone 50 due to the 4 fact that the latter will be held stationary relative to the casing due to the contact of the slips B with the casing. This upward movement of the body II will continue until the upper end of the cylinder 54 engages the annular abutment on the upper cone 50 at the junction between the conical face and the piston 55. Thereafter continued upward movement will move the upper cone 50 sufficiently upward to tightly jam the slips B into the wall of the casing, at which time _vfurther upward movement of the upper cone 50 will be prevented. ,

As the body II continues to move upwardly, the strain will be sufficient to shear the pin 44, releasing the lower cone from the body II As «r this upward movement of the body 11 continues, the ring 36 at the upper end of the packing element 33 will engage the lower ends of the segmental slips A, moving them upwardly relative to the lower cone and shearing the pins 42. Obviously, further upward movement of the body 11 will move the slips into contact with the casing due to the complementary conical faces of the lower cone and the slips. ' . As the body II continues to move upwardly, the 70 ring 36 will remain stationary because of being blocked from further upward movement by the slips, but the lower ring 34 of the packing element will continue to move upwardly with the body 11. This will shorten the distance between the sliding 75

2,121,002 ring 18 and the fixed ring 34, and consequently compress the packer sleeve 33 irito tight contact with the casing and effect a seal between the exterior of the body 1I and the casing. The packer 5 sleeve 33 will maintain this position thereafter due to the engagement of the latch ring 37 with the annular grooves 36b, as Illustrated in Fig. 3.

The device is then set and ready for further operation. Pump pressure is again built up with10 in the body 11 to a value sufficient to shear the pin 32. This pressure Is considerably greater than the first fluid pressure created to trip the uppressure slips. When the pin 32 is sheared, the sleeve 24 will move downwardly, which downward 15 movement will be accompanied by shearing of the pin 30 connecting the sleeve 24 to the valve stem 16. This will release the valve stem and enable the valve 15 to seat on the seat 14. The sleeve 24 will drop to an ineffective position within the 20 lower chamber 20 as illustrated in Fig. 3.

If the device is to be used in cementing, cement slurry may then be pumped downwardly through the running-in tubing 49, thenc.e longitudinally through the body II, opening the valve 15 and 25 discharging through the port 12. In most instances the casing is perforated below the device so that the cement may discharge outwardly through the casing.

After the cementing operation has been com30 pleted, the back pressure of the cement and the spring 19 will close the back pressure valve 15 and prevent the cement from passing upwardly through the body II. The seal effected by the sleeve 33 will prevent the cement from passing 35 upwardly around the body between it and the casing.

Upon completion of the cementing operation, the running-in tubing 49 may be disconnected from the body 11 due to the left-hand screw con40 nection between the sub I la and the body II. I may prefer to use in connection with this device a suitable circulating jar of any preferred type or design.

If it is desired to use the apparatus here dis45 closed as a bridge plug, a ball 60 shown in dotted lines in Fig. 3 is dropped through the tubing after the device is set as previously described. This bridging ball 60 will seat on the seat 23 and prevent fluid from being pumped downwardly -_n through the body II. The back pressure valve 15 will prevent fluid from passing upwardly through the body so consequently an effective bridge will be provided.

All of the major parts of the device here shown 55 are constructed preferably of cast iron or other material which can be readily drilled out so that after the device’s usefulness has ended, it may be drilled up so as to leave the casing unobstructed.

Although the device Has been described for use _eo in bridging a casing and for cementing operations, it is obvious that it has various other uses and that it may be put to these uses without departing from the present invention.

While I have shown the preferred form of my 65 invention, it is to be understood that various changes may be made in its construction by those skilled in the art without departing from the spirit of the invention as defined in the appended claims.