US2713909A - Multiple plug feeding and ejecting conduit head - Google Patents

Description

July 26, 1955 R. c. BAKER 2,713,909

MULTIPLE PLUG FEEDING AND EJECTING CONDUIT HEAD Filed Dec. 15, 1952 24 45 ezusz/v c. amaze INVENTOR.

BY /4 M Ma AWTQENEFS United States Patent MULTIPLE PLUG FEEDING AND EJECTIN G CGNDUIT HEAD Reuben C. Baker, Coaliuga, Calif., assignor to Baker Oil Tools, Ine., Los Angelcs, Califi, a corporation of California Application December 13, 1952, Serial Na. 325,868

15 Claims. (Cl. 166-70) The present invention relates to well apparatus, and more particularly to tubing or conduit heads for introducing cementing plugs, and the like, into a conduit string disposed in a Well bore.

In the pumping of cementitious material, such as cement slurry and synthetic resins, into a well bore, contamination of the charge of cementitious material by the fluid in the well conduit preceding and following it can be prevented by the use of one or more separating plugs disposed at the upper or lower ends of the cementitious material, or at both ends. In introducing the plug or plugs in the conduit string, the inlet of the head at the upper end of the latter has been disconnected, the plug introduced, and the inlet reconnected, to enable the plug to be pumped down the conduit str'mg. This unsatisfactory procedure is magnified when a plurality of plugs are to be inserted in the conduit string at difierent times.

Accordingly, it is an object of the present invention to provide an improved apparatus for introducing a plug into a conduit string, when desired, without disconnecting the hydraulic connections to the apparatus.

Another object of the invention is to provide an apparatus capable of effecting individual introduction of a plurality of plugs into a conduit string, when desired, without disconnecting the hydraulic connections to the apparatus.

A further object of the invention is to provide an apparatus that enables an unlimited number of plugs to be introduced individually into a conduit string, without disconnection of the hydraulic lines leading to and from the apparatus.

Yet another object of the invention is to provide an apparatus capable of efiecting introduction of a plurality of plugs into a conduit string, which is compact, positive in its operation, and in which hydraulic forces in the apparatus do not eflect its operation, since they balance or neutralize themselves.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a longitudinal section through an apparatus embodying the invention, taken along the line 1-1 in Fig. 2, and on an enlarged scale with respect to Fig. 2;

Fig. 2 is a top plan view, on a reduced scale, of the apparatus disclosed in Fig. l;

Fig. 3 is a cross-section, on a reduced scale, taken along the line 33 on Fig. 1;

Fig. 4 is a fragmentary longitudinal section, on an enlarged scale, taken along the line 44 on Fig. 2.

The apparatus disclosed in the drawings is capable of vented by a suitable side seal 28 in the upper and lower trunnions 22,

effecting introduction of one or a plurality of plugs into a conduit string, such as a tubing string, disposed in a well bore, and connected with a mechanism (not shown) in the well bore. The apparatus actually constitutes a conduit or tubing head H having a pressure inlet pipe or sub 10 secured to its upper portion, and a discharge pipe or sub 11 secured in its lower portion. These two pipes are in alignment, so that fiuid under pressure introduced into the inlet pipe 10 can pass through the apparatus and out through the discharge pipe 11. The fluid under pressure is also effective to pump plugs that may be disposed in alignment with the pipes out of the tubing head H and on through the discharge pipe 11, in a manner described hereinafter.

The conduit or tubing head H includes a housing 12 that may include a generally cylindrical wall 13 having a lower closure member 13a threaded into its lower end and an upper closure member 14 threaded into its upper end. These two closure members may be secured in place by suitable lock screws 15 extending through the housing wall 13 and into the closure members 13a, 14. In addition, fluid leakage from the interior of the housing 12 and through the threaded connections between the wall and the closure members can be prevented by suitable side seals 16 on the closure members engaging the inner wall 13 of the housing.

The pressure inlet pipe or sub 10 is threaded into the upper closure member 14 at one side of the axis of the apparatus, whereas the discharge pipe or sub 11 is threaded into a depending extension 17 of the lower closure member 130, and in alignment or coaxial relation to the inlet pipe 10. As described below, a plug can be placed in alignment with the inlet and discharge pipes 10, 11 whenever it is to be ejected into the discharge pipe 11.

The wall 13 and closure member 13a, 14 together provide a space or chamber 18 in which a barrel or cylinder 19 is disposed. This barrel or cylinder is rotatable about the axis of the apparatus by piloting its lower trunnion 20 into a companion socket 21 in the lower closure 13a, its upper trunnion 22 extending through a hole 23 in the upper closure member 14 and projecting above the latter, for reception of a suitable operating handle 24 that may be removably secured to the upper trunnion by a key 25 fitting in the upper trunnion and received in a keyway 26 in the hub portion 27 of the handle member 24. Leakage of fluid outwardly along the lower trunnion 20 is prethis trunnion engaging the wall of the socket 21, whereas leakage of fluid in the opposite direction along the upper trunnion 22 is prevented by a side seal 29 carried on the latter and engaging the closure wall defining the hole or bore 23 through which the trunnion passes.

The lower trunnion 20 rests upon a bearing disc or plate 30, for the purpose of reducing frictional resistance to rotation of the cylinder 19 in the housing 12. This bearing disc is supported by the lower end 31 of the socket 21, and has a hole 32 therewithin in alignment with a hole 33 extending through the lower closure member 13a to its exterior. The holes 32, 33 are provided, so that 20 are acted upon by atmospheric pressure acting over the cross-sectional areas of the trunnions, which are made of the same diameter, to balance the efliect of atmospheric pressure on the trunnions. Fluid under pressure entering the apparatus through the pressure inlet pipe 10 will have no efliect on forcing the cylinder or barrel 19 in an upward or downward direction, since it is acting against the upper end of the barrel over the same cross-sectional area as against the lower end of the barrel. Accordingly, the hydraulic force tending to shift the barrel or cylinder 19 downwardly is counterbalanced by the hydraulic force tending to shift the barrel or cylinder in an upward direction.

The chambers 35 themselves are also equi-angularly disposed with respect to one another. As disclosed, a liner 36 defines each chamber, the liner having an upper flange 37 seating within a counterbore 38 in the cylinder and engaging a shoulder 39 forming the lower end of the counterbore. The liner is provided for a particular size of tubing plug P, to be used in the apparatus. However, if a large tubing plug is to be used, then the liners 36 will be removed and the effective diameter of each plug chamber 35 will be increased accordingly. As an example, with a liner 36 in place, the effective diameter of the chamber 35 can be approximately two inches, to receive a two-inch diameter tubing plug P. Upon removal of the liner, each chamber 35 will then have an eifective diameter of about two and one-half inches for the reception of a two and one-half inch diameter tubing plug P.

As mentioned above, the aligned inlet and discharge pipes 10, 11 are disposed to one side of the axis of the cylinder 19. The discharge pipe communicates with a pressure inlet opening 40 in the upper closure member 14, the discharge pipe 11 communicating with an outlet opening 41 in the lower closure member 13a, which is in alignment with the inlet opening 40. The common axis of the inlet and outlet openings 40, 41 is spaced the same radial distance from the axis of rotation of the cylinder or barrel 19, as the axes of the plug chambers in the barrel. Accordingly, the barrel can be rotated to place each of its chambers 35 in alignment with the pressure inlet and outlet openings 40, 41.

The chambers may be so located and held in such location by a locking or a retaining device. Thus, the upper closure member 14 may have a plurality of recesses or holes 42 opening upwardly through its upper end that are equi-angularly spaced from each other. The lever arm or handle member 24 may have a hole 43 the same radial distance from the rotational axis of the cylinder 19 as the other holes 42. A lock or retainer pin 44 is inserted through the lever arm hole 43 and can be received within any one of the holes 42 in the upper closure member 14.

When the handle member 24 has been turned to rotate the cylinder 19, and when the handle hole 43 and one of the other holes 42 are in alignment, a plug chamber 35 will then be in alignment with the inlet and the outlet openings 46, 41 through the upper and lower closure members 14, 13a. In this way, the lever arm 24 may turn the cylinder 19, upon removing the lock or retainer pin 44 from an upper closure hole 42, and the pin inserted in one of the other holes 42. Upon insertion of the pin in each hole, the operator is assured that a plug chamber 35 is in alignment with the inlet and outlet openings 40, 41. Of course, the lock or retainer holes 42 in the closure member 14 conform in number and spacing to the number of chambers 35 in the cylinder or barrel 19, so that the lever arm 24 may be turned and its lock pin 44 inserted progressively into each hole, with assurance that the plug chambers 35 will be rotated progressively into alignment with the inlet and outlet openings 40, 41.

In order to clear the pressure inlet pipe 19, the handle or lever arm member 24 is made of L shape, as disclosed in full lines in Fig. 2. With such shape, it is not possible to rotate the cylinder 19 through 360 degrees, since the lever arm 24 will engage the opposite side of the pressure inlet pipe 10 before that extent of rotation has been achieved. However, by providing the angular or L shape of the lever arm, it can first be used in the full line position disclosed in Fig. 2, until the cylinder 19 has been rotated a partial revolution, whereupon it can he slipped endwise off the key 25 and upper trunnion 22, and then turned over so that its initial upper face is then disposed in a downward direction, whereupon the handle member 24 can again be replaced on the upper trunnion 22 with the key 25 disposed within the handle keyway 26. When this is done, the handle 24 will occupy the broken line position disclosed in Fig. 2, which will then allow it to turn the barrel or cylinder 19 to the extent required, the L shape of the handle member avoiding interference by the pressure inlet pipe 10.

When one of the plug chambers 35 is aligned with the pressure inlet and outlet openings 40, 41, another plug chamber is aligned with an entrance opening in the upper closure member 14, through which the plugs P can be inserted in each chamber 35. This entrance opening can be closed by threading a plug 51 thereinto, the upper end of the plug preferably being flush with the upper end of the closure member 14, to avoid interference with movement of the lever arm or handle 24. The plug 51 can be rotated for the purpose of threading it into the entrance opening 50, or removing it therefrom, by the provision of a suitable tool (not shown) in the noncircular recess 52, which may be of hexagonal shape, in the upper end of the plug. In addition, leakage of fluid through the threaded connection between the plug 51 and the upper closure member 14 may be prevented by a suitable side seal 53 on the plug engaging the closure wall defining the entrance opening 50.

In using the apparatus, all of the plug chambers 35, with the exception of one, may have tubing plugs P of any desired type inserted therewithin by removing the entrance plug 51 and rotating the cylinder 19 to dispose various chambers 35 in alignment with the entrance opening 50. In the specific device disclosed in the drawings, there are five plug chambers, so that four of such plug chambers will have rubber or other types of plugs P inserted therein, by successively rotating the cylinder to place the chambers 35 in alignment with the entrance opening 59.

After the cylinder 19 has been loaded with the rubber plugs l, the entrance plug 51 is replaced, to close the entrance opening 50. The discharge pipe 11 can be connected to the upper end of the tubing, or other conduit string, disposed in the well bore, and the necessary connections made to the pressure inlet pipe from the pumping mechanism disposed at the top of the well bore. The cylinder 19 is rotated so that the particular chamber 35 that is devoid of a plug P is in alignment with the inlet and outlet openings 46, 41, which chamber may correspond with the zero lock hole position disclosed in Fig. 2. The lock pin 44- can then be inserted through the lever arm hole 43 and this lock hole 42, to assure the alignment of the empty chamber 35 with the inlet and outlet openings 40, 41. Loss of the lock pin, when removed from the holes 42, 43, may be prevented by attaching a chain to an eye 61 of the pin 44 and securing its other end to the outer portion of the handle or arm 24.

Fluid may now be pumped down through the inlet pipe 10, empty plug chamber 35 and discharge pipe 11. As an example, the fluid may be circulated down through the parts just referred to for a continued passage down through the tubing string in the well bore, for the purpose of conditioning the latter. If it is desired to introduce a charge of cement slurry, or synthetic resin, into the tubing string in the well bore, the charge can be pumped toward the pressure inlet pipe 10, and, when it reaches such pipe, the lock pin 44 is removed from a companion lock hole 42 and the handle 24 and cylinder 19 rotated a partial revolution until the lock pin is disposed in alignment with another lock hole 42, such as the number 1 hole 42, shown in Fig. 2, into which the lock pin 44 is then inserted. Such partial rotation positions a tubing plug P in another chamber 35 in alignment with the pressure inlet and outlet openings 40, 41, whereupon the pressure of the fluid in the inlet pipe will force the plug P out of such chamber in which it is contained, and into the discharge pipe or sub 11, this plug then proceeding downwardly through the tubing string ahead of the cementitious material thereabove, in order to prevent contamination of the cementitious material by the preceding liquid in the tubing string.

When the upper end of the charge of cementitious material is at or near the pressure inlet opening 40, the lock pin 44 can be removed from the number 1 lock hole 42 and the handle member 24 rotated again toward the number 2 lock hole position, the lock pin then being inserted in this number 2 hole 42, which insures the alignment of the next chamber 35 in the barrel 19 with the inlet and outlet openings 40, 41. When such alignment occurs, the pressure in the inlet pipe 10 will force the plug P out of its chamber 35 and ejects it into the discharge pipe 11, for continued passage down through the tubing string on top of the charge of cementitious material. This plug prevents contamination of the cementitious material by the displacement fluid in the conduit string and apparatus above it.

Whenever desired, succeeding plugs P in the cylinder chambers 35 can be brought into alignment with the inlet and outlet openings 40, 41, by rotating the cylinder or barrel 19, the aligned position being assured upon inserting of the lock pin 44 in the respective lock holes 42 in the upper closure member 14, until all of the plugs have been ejected. Of course, during rotation of the barrel 19 in the same direction, the position of the handle 24 will eventually have to be reversed to that shown in broken lines in Fig. 2.

As plugs P are ejected from each chamber 35 and out through the outlet opening 41 and discharge pipe 11, additional plugs P can be loaded into empty cylinder chambers. All that need be done is to relieve the pressure in the pressure inlet pipe 10 and remove the entrance plug 51, which then allows additional tubing plugs to be inserted through the entrance opening 50 and into the empty barrel chambers 35. When the chambers have been reloaded or refilled with plugs, the entrance plug 51 can again be threaded into the closure member 14, to close the entrance opening. In this manner, an unlimited number of plugs may be disposed in the apparatus for ejection from the head H and into the conduit string, without disconnecting any of the hydraulic lines leading to and from the apparatus.

It is, accordingly, apparent that an apparatus has been provided which enables one or a number of plugs P to be introduced into a conduit string, whenever desired, without disconnecting the hydraulic lines leading to the apparatus. A plurality of plugs can be introduced individually whenever desired, and the number of plugs is unlimited, in view of the ability to reload the apparatus. The apparatus is compact and positive in its operation, since the chambers 35 can be placed in exact alignment with the inlet and outlet openings 40, 41. In addition, the cylinder 19 can be rotated freely, since the pressure within the apparatus is balanced at all times, thereby precluding the presence of any unbalanced hydraulic pressures that might tend to shift the cylinder 19 axially in one longitudinal direction or the other.

The inventor claims:

1. In apparatus of the character described: a housing structure having a fluid inlet and a fluid outlet spaced from each other; a holder movable in said housing structure and having a chamber adapted to receive a plug; and means for shifting said holder in said housing structure to place said chamber in one position into alignment with said inlet and outlet and in another position out of alignment with said inlet and outlet.

2. In apparatus of the character described: a housing structure having a fluid inlet and a fluid outlet; a holder movable in said housing structure and having a chamber adapted to receive a plug; said housing structure having an entrance opening through which a plug can be inserted in said chamber; removable means closing said opening; and means for shifting said holder in said housing structure to place said chamber selectively in alignment with said entrance opening or in alignment with said outlet and between said inlet and outlet.

3. In apparatus of the character described: a housing structure having a fluid inlet and a fluid outlet spaced from each other; a holder movable in said housing structure and having a chamber adapted to receive a plug; means for shifting said holder in said housing structure to place said chamber in one position into alignment with said inlet and outlet and in another position out of alignment with said inlet and outlet; and means for selectively retaining said holder with its chamber in or out of alignment with said outlet.

4. In apparatus of the character described: a housing structure having a fluid inlet and a fluid outlet spaced from each other; a holder movable in said housing structure and having a plurality of spaced chambers adapted to receive plugs; and means for shifting said holder in said housing structure to selectively place each chamber in one position in alignment with said inlet and outlet and in another position out of alignment with said inlet and outlet.

5. In apparatus of the character described: a housing structure having a fluid inlet and a fluid outlet; a holder movable in said housing structure and having a plurality of spaced chambers adapted to receive plugs; said housing structure having an entrance opening through which plugs can pass; removable means closing said opening; and means for shifting said holder in said housing structure to selectively place each chamber in alignment with said opening or in alignment with said outlet and between said inlet and outlet.

6. In apparatus as defined in claim 5, wherein said entrance opening and outlet are spaced from each other such that alignment of one chamber with said entrance opening locates another chamber in alignment with said outlet.

7. In apparatus of the character described: a housing structure having a fluid inlet and a fluid outlet spaced from each other; a holder rotatably mounted in said housing structure and having a chamber adapted to receive a plug; and means for rotating said holder in said housing structure to locate said chamber in one position into alignment with said inlet and outlet and in another position out of alignment with said inlet and outlet.

8. In apparatus of the character described: a housing structure having a fluid inlet and a fluid outlet; a holder rotatably mounted in said housing structure and having a chamber adapted to receive a plug; said housing structure having an entrance opening through which a plug can be inserted in said chamber; removable means closing said opening; and means for rotating said holder in said housing structure to place said chamber selectively in alignment with said entrance opening or in alignment with said outlet and between said inlet and outlet.

9. In apparatus of the character described: a housing structure having a fluid inlet and a fluid outlet spaced from each other; a holder rotatably mounted in said housing structure and having a plurality of circumferentially spaced chambers adapted to receive plugs; and means for rotating said holder in said housing structure to selectively locate each chamber in one position in alignment with said inlet and outlet and in another position out of alignment with said inlet and outlet.

10. In apparatus of the character described: a housing structure having a fluid inlet and a fluid outlet; a holder rotatably mounted in said housing structure and having a plurality of circumferentially spaced chambers adapted to receive plugs; said housing structure having an entrance opening through which plugs can pass; removable means closing said opening; and means for rotating said holder in said housing structure to selectively locate each rotatably mounted in said housing structure and having a plurality of eircumferentially spaced chambers adapted to receive plugs, said holder having oppositely directed trunnions rotatably supported in said housing structure, said trunnions being substantially equal in cross-sectional area and being exposed to atmospheric pressure; and means for rotating said holder in said housing structure to selectively locate each chamber in alignment with said outlet and between said inlet and outlet.

13. In apparatus of the character described: a housing structure having a fluid inlet and a fluid outlet; a holder rotatably mounted in said housing structure and having a plurality of circumferentially spaced chambers adapted to receive plugs, said holder having oppositely directed trunnions rotatably supported in said housing structure,

and means attached to one of said trunnions for rotating said holder in said housing structure to locate each chamber in alignment with said outlet and between said inlet and outlet.

14. In apparatus of the character described: a housing structure having a fluid inlet and a fluid outlet; a holder rotatably mounted in said housing structure and having n I.) a plurality of circumferentially spaced chambers adapted to receive plugs; said housing structure having an entrance opening through which plugs can pass; removable means closing said opening; said holder having oppositely directed trunnions rotatably supported in said housing structure; and means attached to one of said trunnions for rotating said holder in said housing structure to selectively locate each chamber in alignment with said opening or in alignment with said outlet and between said inlet and outlet.

15. in apparatus of the character described: a housing structure having a fluid inlet and a fluid outlet; a holder rotatably mounted in said housing structure and having a plurality of circumferentially spaced chambers adapted to receive plugs; said housing structure having an entrance opening through which plugs can pass; removable means closing said opening; said holder having oppositely directed trunnions rotatably supported in said housing structure; means attached to one of said trunnions for rotating said holder in said housing structure to selectively locate each chamber in alignment with said opening or in alignment with said outlet and between said inlet and outlet; and means for selectively retaining said holder in various positions to which it is rotated in alignment with said outlet and entrance opening.

References Cited in the file of this patent UNITED STATES PATENTS

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