Bypass valve for a flow through gas lift plunger

Abstract

A bypass valve for a gas lift plunger includes a cylindrical valve having opposed ends, a circumferential sidewall and a first flow through aperture which extends through the circumferential sidewall. A body is provided with a cylindrical valve seat and a second flow through aperture. The cylindrical valve is rotatable relative to the valve seat. When the cylindrical valve is rotated to a first position the first flow through aperture and the second flow through aperture are in register thereby permitting gas to flow through. When the cylindrical valve is rotated to a second position, the first flow through aperture and the second flow through aperture are out of register and the flow of gas is restricted. An activation sleeve which overlies the body is used to move the cylindrical valve between the first position and the second position.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a bypass valve for a flow through gas lift plunger

BACKGROUND OF THE INVENTION

[0002] A gas lift plunger that does not have a flow through port takes approximately 30 minutes to descend to the bottom of the well. All during this time of the gas lift plunger is descending, the gas well is not producing. With a flow through gas lift plunger, gas flows through the gas lift plunger allowing it to fall more rapidly. This allows for more rapid “cycling” of the plunger, which reduces fluid build up and results in better production from the well.

[0003] The key to the operation of the flow through gas lift plunger is the operation of the bypass valve. The bypass valve must close when the gas lift plunger reaches the bottom of the well, so that pressure can build up below the gas lift plunger. The valve must open when the gas lift plunger reaches the top of the well, to allow the gas lift plunger to fall with gas flowing through the port as the gas lift plunger descends. U.S. Pat. No. 2,661,024 (Knox 1953) illustrates a conical valve and seat arrangement, which is widely used today in flow through gas lift plungers. A more recent example of a bypass valve for a gas lift plunger is described in U.S. Pat. No. 6,179,309 (Bender 2001).

SUMMARY OF THE INVENTION

[0004] The present invention relates to an alternative configuration of bypass valve for a gas lift plunger.

[0005] According to the present invention there is provided a bypass valve for a gas lift plunger which includes a cylindrical valve having opposed ends, a circumferential sidewall and a first flow through aperture which extends through the circumferential sidewall. A body is provided with a cylindrical valve seat and a second flow through aperture. The cylindrical valve is rotatable relative to the valve seat. When the cylindrical valve is rotated to a first position the first flow through aperture and the second flow through aperture are in register thereby permitting gas to flow through. When the cylindrical valve is rotated to a second position, the first flow through aperture and the second flow through aperture are out of register and the flow of gas is restricted. A pin extends from at least one of the opposed ends of the cylindrical valve. An activation sleeve overlies the body. The activation sleeve has at least one guide slot which is adapted to engage the pin. When the activation sleeve moves in a first direction, the pin moves along the guide slot to rotate the cylindrical valve to the first position. When the activation sleeve moves in a second direction, the pin moves along the guide slot to rotate the cylindrical valve to the second position.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to in any way limit the scope of the invention to the particular embodiment or embodiments shown, wherein:

[0007] FIG. 1 is a side elevation view of a gas lift plunger constructed in accordance with the teachings of the present invention.

[0008] FIG. 2 is a side elevation view, in section of the gas lift plunger illustrated in FIG. 1.

[0009] FIG. 3 is an exploded side elevation view of the gas lift plunger illustrated in FIG. 1.

[0010] FIG. 4 is a detail side elevation view, in section, of the valve of the gas lift plunger illustrated in FIG. 1, with the valve in a fully open position.

[0011] FIG. 5 is a detail side elevation view, in section, of the valve of the gas lift plunger illustrated in FIG. 1, with the valve in an intermediate position.

[0012] FIG. 6 is a detail side elevation view, in section, of the valve of the gas lift plunger illustrated in FIG. 1, with the valve in a fully closed position.

[0013] FIGS. 7 a , 7b and 7c are detailed side elevation views partially in section of a bypass valve with activation sleeve illustrated in FIGS. 4 through 6 in first, intermediate and second positions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0014] The preferred embodiment, a bypass valve for a flow through gas lift plunger, generally identified by reference numeral 10, will now be described with reference to FIGS. 1 through 7c.

[0015] Structure and Relationship of Parts:

[0016] Referring to FIG. 1, gas lift plunger, generally indicated by reference numeral 100 is illustrated. Gas lift plunger 100 has a main housing 12 and a valve housing 14 which is coupled to main housing 12. Referring to FIG. 3, the components of bypass valve 10 are shown in an exploded view. Those components include: a cylindrical valve 16, a valve seat body 18, pins 20 which secure valve seat body 18 to valve housing 14, an activation pin 22, an activation sleeve 24 having a first end 25, a second end 27 and which slides in close tolerance within valve housing 14 overlying valve seat body 18, and an end cap 26 which is used to prevent activation sleeve 24 from being withdrawn from valve housing 14. Cylindrical valve 16 is further has opposed ends 28, a circumferential sidewall 30 and a first flow through aperture 32 that extends through sidewall 30. Referring to FIG. 2, valve seat body 18 has a cylindrical valve seat 34 and a second flow through aperture 36. Cylindrical valve 16 is nested within and rotatable relative to valve seat 34. Referring to FIG. 4, when cylindrical valve 16 is in a first position, first flow through aperture 32 and second flow through aperture 36 are in register thereby permitting gas to flow through. Referring to FIGS. 2 and 6, when cylindrical valve 16 is in a second position, first flow through aperture 32 and second flow through aperture 36 are out of register and the flow of gas is restricted. Referring to FIG. 5, an intermediate position is shown where first flow through aperture 32 and second flow through aperture 36 are partially in register. Referring to FIGS. 7a, 7b and 7c, activation sleeve 24 has at least one guide slot 38 adapted to engage activation pin 22. Where activation sleeve 24 moves in a first direction 40 relative to valve seat body 18 (FIGS. 7a through 7c), activation pin 22 follows guide slot 38 causing cylindrical valve 16 to rotate from the first position to the second position, closing bypass valve 10. Where activation sleeve 24 moves in a second direction 42 relative to valve seat body 18 (FIGS. 7c through 7a), activation pin 22 follows guide slot 38 causing cylindrical valve 16 to rotate from the second position to the first position, opening bypass valve 10.

[0017] Operation:

[0018] The use and operation of a bypass valve for a flow through gas lift plunger 10 will now be described with reference to FIGS. 1 through 7c. Referring to FIG. 1, gas lift plunger 100 is inserted into a well, destined for the bottom. Referring to FIG. 4, travel time will be substantially reduced where cylindrical valve 16 is in a first position where first flow through aperture 32 and second flow through aperture 36 are in register. When both apertures are in register, bypass valve 10 is open, allowing the constant cycling of fluids through gas lift plunger 100. At the bottom of the well, gas lift plunger 100 must now block the well and build up pressure below. Referring to FIGS. 4 through 6, at the bottom of the well, contact is made with second end 27 of sleeve 24. Referring to FIGS. 7a through 7c, activation sleeve 24 is now moved in a first direction 40 relative to valve seat body 18, exerting force on activation pin 22 and moving cylindrical valve 16 such that first flow through aperture 32 and second flow through aperture 36 are no longer in register. Referring to FIGS. 2 and 6, where the apertures are not in register, bypass valve 10 is closed, restricting the cycling of fluids through gas lift plunger 100. Gas lift plunger rises up the well to surface with the flow of gas and fluid. In the wells in which gas lift plunger 100 operates, an activation rod depends from a lubricator spring(not shown) at surface. The activation rod has a diameter which is small enough to extend up into main housing 12 and long enough to reach first end 25 of activation sleeve 24. However, the activation rod diameter is too large to pass through activation sleeve 24. Referring to FIGS. 6 through 4, when gas lift plunger 100 reaches surface, activation rod extends into main housing 12 until it strikes first end 25 of activation sleeve 24. This impact causes bypass valve 10 to be opened again, as sleeve 24 is moved in direction 42, where it again extends from housing 14. Referring to FIGS. 7c through 7a, activation sleeve 24 is now moved in a second direction 42 relative to valve seat body 18, exerting force on activation pin 22 and moving cylindrical valve 16 such that first flow through aperture 32 and second flow through aperture 36 are again in register allowing the flow of fluids.

[0019] It should be noted that the use of bypass valve 10 for a flow through gas lift plunger results in many benefits to a well operation including (but not restricted to): reduced non-production time, simplicity and ease of maintenance and a reduced danger of leaving parts in the well due to malfunction. As compared to other valve configurations, bypass valve 10 provides relatively little flow through restriction. The teachings of the present invention can be scaled up or scaled down, to suit different dimensions of tubing or casing.

[0020] In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.

[0021] It will be apparent to one skilled in the art that modifications may be made to the illustrated embodiment without departing from the spirit and scope of the invention as hereinafter defined in the claims.

Claims

1. A bypass valve for a gas lift plunger, comprising: a cylindrical valve having opposed ends, a circumferential sidewall and a first flow through aperture which extends through the circumferential sidewall; a body with a cylindrical valve seat and a second flow through aperture, the cylindrical valve being rotatable relative to the valve seat, when the cylindrical valve is rotated to a first position the first flow through aperture and the second flow through aperture are in register thereby permitting gas to flow through, when the cylindrical valve is rotated to a second position, the first flow through aperture and the second flow through aperture are out of register and the flow of gas is restricted; a pin extending from at least one of the opposed ends of the cylindrical valve; an activation sleeve overlying the body, the activation sleeve having at least one guide slot which is adapted to engage the pin, such that when the activation sleeve moves in a first direction that pin moves along the guide slot to rotate the cylindrical valve to the first position and when the activation sleeve moves in a second direction the pin moves along the guide slot to rotate the cylindrical valve to the second position.